Kaleidoscope: Extending the Language: Control Flow

+ + + + Chris Lattner + The LLVM Compiler Infrastructure + Last modified: $Date: 2007-10-17 11:05:13 -0700 (Wed, 17 Oct 2007) $ + · not

__main()
main()
llvm.global_ctors
_GLOBAL__I__tmp_webcompile...
__main()
main()
__main
__main
llvm/runtime/GCCLibraries/crtend/
llvm.global_ctors
+def fib(x)
+  if x < 3 then
+    1
+  else
+    fib(x-1)+fib(x-2);
+
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+
+    ...
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    return tok_identifier;
+
+/// IfExprAST - Expression class for if/then/else.
+class IfExprAST : public ExprAST {
+  ExprAST *Cond, *Then, *Else;
+public:
+  IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
+    : Cond(cond), Then(then), Else(_else) {}
+  virtual Value *Codegen();
+};
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static ExprAST *ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  ExprAST *Cond = ParseExpression();
+  if (!Cond) return 0;
+  
+  if (CurTok != tok_then)
+    return Error("expected then");
+  getNextToken();  // eat the then
+  
+  ExprAST *Then = ParseExpression();
+  if (Then == 0) return 0;
+  
+  if (CurTok != tok_else)
+    return Error("expected else");
+  
+  getNextToken();
+  
+  ExprAST *Else = ParseExpression();
+  if (!Else) return 0;
+  
+  return new IfExprAST(Cond, Then, Else);
+}
+
+static ExprAST *ParsePrimary() {
+  switch (CurTok) {
+  default: return Error("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  }
+}
+
+extern foo();
+extern bar();
+def baz(x) if x then foo() else bar();
+
+declare double @foo()
+
+declare double @bar()
+
+define double @baz(double %x) {
+entry:
+	%ifcond = fcmp one double %x, 0.000000e+00
+	br i1 %ifcond, label %then, label %else
+
+then:		; preds = %entry
+	%calltmp = call double @foo()
+	br label %ifcont
+
+else:		; preds = %entry
+	%calltmp1 = call double @bar()
+	br label %ifcont
+
+ifcont:		; preds = %else, %then
+	%iftmp = phi double [ %calltmp, %then ], [ %calltmp1, %else ]
+	ret double %iftmp
+}
+
llvm-as < t.ll | opt -analyze -view-cfg
F->viewCFG()
F->viewCFGOnly()
Function*
fcmp one
x = 1; x = x + 1; 
Codegen
IfExprAST
+Value *IfExprAST::Codegen() {
+  Value *CondV = Cond->Codegen();
+  if (CondV == 0) return 0;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  CondV = Builder.CreateFCmpONE(CondV, 
+                                ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
+                                "ifcond");
+
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = new BasicBlock("then", TheFunction);
+  BasicBlock *ElseBB = new BasicBlock("else");
+  BasicBlock *MergeBB = new BasicBlock("ifcont");
+
+  Builder.CreateCondBr(CondV, ThenBB, ElseBB);
+
+  // Emit then value.
+  Builder.SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->Codegen();
+  if (ThenV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = Builder.GetInsertBlock();
+
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  Builder.SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->Codegen();
+  if (ElseV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = Builder.GetInsertBlock();
+
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  Builder.SetInsertPoint(MergeBB);
+  PHINode *PN = Builder.CreatePHI(Type::DoubleTy, "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+   # Compile
+   g++ -g toy.cpp `llvm-config --cppflags --ldflags --libs core jit native` -O3 -o toy
+   # Run
+   ./toy
+
+...
+
+ # print 100 '*' (ascii 42) characters
+ extern putchard(char)
+ for x = 1, x < 100, 1.0 in putchard(42);
+
+  ... in enum Token ...
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10
+
+  ... in gettok ...
+  if (IdentifierStr == "def") return tok_def;
+  if (IdentifierStr == "extern") return tok_extern;
+  if (IdentifierStr == "if") return tok_if;
+  if (IdentifierStr == "then") return tok_then;
+  if (IdentifierStr == "else") return tok_else;
+  if (IdentifierStr == "for") return tok_for;
+  if (IdentifierStr == "in") return tok_in;
+  return tok_identifier;
+
+/// ForExprAST - Expression class for for/in.
+class ForExprAST : public ExprAST {
+  std::string VarName;
+  ExprAST *Start, *End, *Step, *Body;
+public:
+  ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
+             ExprAST *step, ExprAST *body)
+    : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+  virtual Value *Codegen();
+};
+
+/// forexpr ::= 'for' identifer '=' expr ',' expr (',' expr)? 'in' expression
+static ExprAST *ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifer.
+  
+  if (CurTok != '=')
+    return Error("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  ExprAST *Start = ParseExpression();
+  if (Start == 0) return 0;
+  if (CurTok != ',')
+    return Error("expected ',' after for start value");
+  getNextToken();
+  
+  ExprAST *End = ParseExpression();
+  if (End == 0) return 0;
+  
+  // The step value is optional.
+  ExprAST *Step = 0;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (Step == 0) return 0;
+  }
+  
+  if (CurTok != tok_in)
+    return Error("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  ExprAST *Body = ParseExpression();
+  if (Body == 0) return 0;
+
+  return new ForExprAST(IdName, Start, End, Step, Body);
+}
+
+Value *ForExprAST::Codegen() {
+  // Output this as:
+  //   ...
+  //   start = startexpr
+  //   goto loop
+  // loop: 
+  //   variable = phi [start, loopheader], [nextvariable, loopend]
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   nextvariable = variable + step
+  //   endcond = endexpr
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->Codegen();
+  if (StartVal == 0) return 0;
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+  BasicBlock *PreheaderBB = Builder.GetInsertBlock();
+  BasicBlock *LoopBB = new BasicBlock("loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  // Start insertion in LoopBB.
+  Builder.CreateBr(LoopBB);
+  Builder.SetInsertPoint(LoopBB);
+  
+  // Start the PHI node with an entry for Start.
+  PHINode *Variable = Builder.CreatePHI(Type::DoubleTy, VarName.c_str());
+  Variable->addIncoming(StartVal, PreheaderBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  Value *OldVal = NamedValues[VarName];
+  NamedValues[VarName] = Variable;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (Body->Codegen() == 0)
+    return 0;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->Codegen();
+    if (StepVal == 0) return 0;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(Type::DoubleTy, APFloat(1.0));
+  }
+  
+  Value *NextVar = Builder.CreateAdd(Variable, StepVal, "nextvar");
+
+  // When evaluating the end condition, the value of the variable is the
+  // incremented value.
+  NamedValues[VarName] = Variable;
+  
+  
+  // Compute the end condition.
+  Value *EndCond = End->Codegen();
+  if (EndCond == 0) return EndCond;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = Builder.CreateFCmpONE(EndCond, 
+                                  ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *LoopEndBB = Builder.GetInsertBlock();
+  BasicBlock *AfterBB = new BasicBlock("afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  Builder.SetInsertPoint(AfterBB);
+  
+  // Add a new entry to the PHI node for the backedge.
+  Variable->addIncoming(NextVar, LoopEndBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    NamedValues[VarName] = OldVal;
+  else
+    NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::DoubleTy);
+}
+
- # print 100 '*' (ascii 42) characters
  extern putchard(char)
- for x = 1, x < 100, 1.0 in putchard(42);
+ def printstar(n)
+   for i = 1, i < n, 1.0 in
+     putchard(42);  # ascii 42 = '*'
+     
+ # print 100 '*' characters
+ printstar(100);
 
+declare double @putchard(double)
+
+define double @printstar(double %n) {
+entry:
+        ; initial value = 1.0 (inlined into phi)
+	br label %loop
+
+loop:		; preds = %loop, %entry
+	%i = phi double [ 1.000000e+00, %entry ], [ %nextvar, %loop ]
+        ; body
+	%calltmp = call double @putchard( double 4.200000e+01 )
+        ; increment
+	%nextvar = add double %i, 1.000000e+00
+
+        ; termination test
+	%multmp = fcmp ult double %i, %n
+	%booltmp = uitofp i1 %multmp to double
+	%loopcond = fcmp one double %booltmp, 0.000000e+00
+	br i1 %loopcond, label %loop, label %afterloop
+
+afterloop:		; preds = %loop
+        ; loop always returns 0.0
+	ret double 0.000000e+00
+}
+
 Value *ForExprAST::Codegen() {
-  // Output this as:
-  //   ...
-  //   start = startexpr
-  //   goto loop
-  // loop: 
-  //   variable = phi [start, loopheader], [nextvariable, loopend]
-  //   ...
-  //   bodyexpr
-  //   ...
-  // loopend:
-  //   step = stepexpr
-  //   nextvariable = variable + step
-  //   endcond = endexpr
-  //   br endcond, loop, endloop
-  // outloop:
-  
   // Emit the start code first, without 'variable' in scope.
   Value *StartVal = Start->Codegen();
   if (StartVal == 0) return 0;
-  
+
   // Make the new basic block for the loop header, inserting after current
   // block.
   Function *TheFunction = Builder.GetInsertBlock()->getParent();
@@ -667,14 +698,35 @@
   BasicBlock *LoopBB = new BasicBlock("loop", TheFunction);
   
   // Insert an explicit fall through from the current block to the LoopBB.
-  // Start insertion in LoopBB.
   Builder.CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
   Builder.SetInsertPoint(LoopBB);
   
   // Start the PHI node with an entry for Start.
   PHINode *Variable = Builder.CreatePHI(Type::DoubleTy, VarName.c_str());
   Variable->addIncoming(StartVal, PreheaderBB);
-  
+
   // Within the loop, the variable is defined equal to the PHI node.  If it
   // shadows an existing variable, we have to restore it, so save it now.
   Value *OldVal = NamedValues[VarName];
@@ -685,7 +737,26 @@
   // allow an error.
   if (Body->Codegen() == 0)
     return 0;
-  
+
OldVal
   // Emit the step value.
   Value *StepVal;
   if (Step) {
@@ -697,12 +768,15 @@
   }
   
   Value *NextVar = Builder.CreateAdd(Variable, StepVal, "nextvar");
+
NextVar
   // Compute the end condition.
   Value *EndCond = End->Codegen();
   if (EndCond == 0) return EndCond;
@@ -711,7 +785,15 @@
   EndCond = Builder.CreateFCmpONE(EndCond, 
                                   ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
                                   "loopcond");
-  
+
   // Create the "after loop" block and insert it.
   BasicBlock *LoopEndBB = Builder.GetInsertBlock();
   BasicBlock *AfterBB = new BasicBlock("afterloop", TheFunction);
@@ -721,7 +803,18 @@
   
   // Any new code will be inserted in AfterBB.
   Builder.SetInsertPoint(AfterBB);
+
   // Add a new entry to the PHI node for the backedge.
   Variable->addIncoming(NextVar, LoopEndBB);
   
@@ -730,7 +823,6 @@
     NamedValues[VarName] = OldVal;
   else
     NamedValues.erase(VarName);
-
   
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::DoubleTy);
@@ -738,6 +830,17 @@
 
ForExprAST::Codegen
-...
+#include "llvm/DerivedTypes.h"
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/Module.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/PassManager.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Support/LLVMBuilder.h"
+#include <cstdio>
+#include <string>
+#include <map>
+#include <vector>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2, tok_extern = -3,
+
+  // primary
+  tok_identifier = -4, tok_number = -5,
+  
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10
+};
+
+static std::string IdentifierStr;  // Filled in if tok_identifier
+static double NumVal;              // Filled in if tok_number
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = getchar();
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = getchar())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = getchar();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do LastChar = getchar();
+    while (LastChar != EOF && LastChar != '\n' & LastChar != '\r');
+    
+    if (LastChar != EOF)
+      return gettok();
+  }
+  
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = getchar();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+
+/// ExprAST - Base class for all expression nodes.
+class ExprAST {
+public:
+  virtual ~ExprAST() {}
+  virtual Value *Codegen() = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+class NumberExprAST : public ExprAST {
+  double Val;
+public:
+  NumberExprAST(double val) : Val(val) {}
+  virtual Value *Codegen();
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+class VariableExprAST : public ExprAST {
+  std::string Name;
+public:
+  VariableExprAST(const std::string &name) : Name(name) {}
+  virtual Value *Codegen();
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+class BinaryExprAST : public ExprAST {
+  char Op;
+  ExprAST *LHS, *RHS;
+public:
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
+    : Op(op), LHS(lhs), RHS(rhs) {}
+  virtual Value *Codegen();
+};
+
+/// CallExprAST - Expression class for function calls.
+class CallExprAST : public ExprAST {
+  std::string Callee;
+  std::vector<ExprAST*> Args;
+public:
+  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
+    : Callee(callee), Args(args) {}
+  virtual Value *Codegen();
+};
+
+/// IfExprAST - Expression class for if/then/else.
+class IfExprAST : public ExprAST {
+  ExprAST *Cond, *Then, *Else;
+public:
+  IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
+  : Cond(cond), Then(then), Else(_else) {}
+  virtual Value *Codegen();
+};
+
+/// ForExprAST - Expression class for for/in.
+class ForExprAST : public ExprAST {
+  std::string VarName;
+  ExprAST *Start, *End, *Step, *Body;
+public:
+  ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
+             ExprAST *step, ExprAST *body)
+    : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+  virtual Value *Codegen();
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+class PrototypeAST {
+  std::string Name;
+  std::vector<std::string> Args;
+public:
+  PrototypeAST(const std::string &name, const std::vector<std::string> &args)
+    : Name(name), Args(args) {}
+  
+  Function *Codegen();
+};
+
+/// FunctionAST - This class represents a function definition itself.
+class FunctionAST {
+  PrototypeAST *Proto;
+  ExprAST *Body;
+public:
+  FunctionAST(PrototypeAST *proto, ExprAST *body)
+    : Proto(proto), Body(body) {}
+  
+  Function *Codegen();
+};
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser it looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() {
+  return CurTok = gettok();
+}
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+  
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0) return -1;
+  return TokPrec;
+}
+
+/// Error* - These are little helper functions for error handling.
+ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
+PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
+FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
+
+static ExprAST *ParseExpression();
+
+/// identifierexpr
+///   ::= identifer
+///   ::= identifer '(' expression* ')'
+static ExprAST *ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+  
+  getNextToken();  // eat identifer.
+  
+  if (CurTok != '(') // Simple variable ref.
+    return new VariableExprAST(IdName);
+  
+  // Call.
+  getNextToken();  // eat (
+  std::vector<ExprAST*> Args;
+  if (CurTok != ')') {
+    while (1) {
+      ExprAST *Arg = ParseExpression();
+      if (!Arg) return 0;
+      Args.push_back(Arg);
+      
+      if (CurTok == ')') break;
+      
+      if (CurTok != ',')
+        return Error("Expected ')'");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+  
+  return new CallExprAST(IdName, Args);
+}
+
+/// numberexpr ::= number
+static ExprAST *ParseNumberExpr() {
+  ExprAST *Result = new NumberExprAST(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static ExprAST *ParseParenExpr() {
+  getNextToken();  // eat (.
+  ExprAST *V = ParseExpression();
+  if (!V) return 0;
+  
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken();  // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static ExprAST *ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  ExprAST *Cond = ParseExpression();
+  if (!Cond) return 0;
+  
+  if (CurTok != tok_then)
+    return Error("expected then");
+  getNextToken();  // eat the then
+  
+  ExprAST *Then = ParseExpression();
+  if (Then == 0) return 0;
+  
+  if (CurTok != tok_else)
+    return Error("expected else");
+  
+  getNextToken();
+  
+  ExprAST *Else = ParseExpression();
+  if (!Else) return 0;
+  
+  return new IfExprAST(Cond, Then, Else);
+}
+
+/// forexpr ::= 'for' identifer '=' expr ',' expr (',' expr)? 'in' expression
+static ExprAST *ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifer.
+  
+  if (CurTok != '=')
+    return Error("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  ExprAST *Start = ParseExpression();
+  if (Start == 0) return 0;
+  if (CurTok != ',')
+    return Error("expected ',' after for start value");
+  getNextToken();
+  
+  ExprAST *End = ParseExpression();
+  if (End == 0) return 0;
+  
+  // The step value is optional.
+  ExprAST *Step = 0;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (Step == 0) return 0;
+  }
+  
+  if (CurTok != tok_in)
+    return Error("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  ExprAST *Body = ParseExpression();
+  if (Body == 0) return 0;
+
+  return new ForExprAST(IdName, Start, End, Step, Body);
+}
+
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+static ExprAST *ParsePrimary() {
+  switch (CurTok) {
+  default: return Error("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  }
+}
+
+/// binoprhs
+///   ::= ('+' primary)*
+static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+    
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+    
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    getNextToken();  // eat binop
+    
+    // Parse the primary expression after the binary operator.
+    ExprAST *RHS = ParsePrimary();
+    if (!RHS) return 0;
+    
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec+1, RHS);
+      if (RHS == 0) return 0;
+    }
+    
+    // Merge LHS/RHS.
+    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+  }
+}
+
+/// expression
+///   ::= primary binoprhs
+///
+static ExprAST *ParseExpression() {
+  ExprAST *LHS = ParsePrimary();
+  if (!LHS) return 0;
+  
+  return ParseBinOpRHS(0, LHS);
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+static PrototypeAST *ParsePrototype() {
+  if (CurTok != tok_identifier)
+    return ErrorP("Expected function name in prototype");
+
+  std::string FnName = IdentifierStr;
+  getNextToken();
+  
+  if (CurTok != '(')
+    return ErrorP("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorP("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  return new PrototypeAST(FnName, ArgNames);
+}
+
+/// definition ::= 'def' prototype expression
+static FunctionAST *ParseDefinition() {
+  getNextToken();  // eat def.
+  PrototypeAST *Proto = ParsePrototype();
+  if (Proto == 0) return 0;
+
+  if (ExprAST *E = ParseExpression())
+    return new FunctionAST(Proto, E);
+  return 0;
+}
+
+/// toplevelexpr ::= expression
+static FunctionAST *ParseTopLevelExpr() {
+  if (ExprAST *E = ParseExpression()) {
+    // Make an anonymous proto.
+    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
+    return new FunctionAST(Proto, E);
+  }
+  return 0;
+}
+
+/// external ::= 'extern' prototype
+static PrototypeAST *ParseExtern() {
+  getNextToken();  // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+static Module *TheModule;
+static LLVMFoldingBuilder Builder;
+static std::map<std::string, Value*> NamedValues;
+static FunctionPassManager *TheFPM;
+
+Value *ErrorV(const char *Str) { Error(Str); return 0; }
+
+Value *NumberExprAST::Codegen() {
+  return ConstantFP::get(Type::DoubleTy, APFloat(Val));
+}
+
+Value *VariableExprAST::Codegen() {
+  // Look this variable up in the function.
+  Value *V = NamedValues[Name];
+  return V ? V : ErrorV("Unknown variable name");
+}
+
+Value *BinaryExprAST::Codegen() {
+  Value *L = LHS->Codegen();
+  Value *R = RHS->Codegen();
+  if (L == 0 || R == 0) return 0;
+  
+  switch (Op) {
+  case '+': return Builder.CreateAdd(L, R, "addtmp");
+  case '-': return Builder.CreateSub(L, R, "subtmp");
+  case '*': return Builder.CreateMul(L, R, "multmp");
+  case '<':
+    L = Builder.CreateFCmpULT(L, R, "multmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return Builder.CreateUIToFP(L, Type::DoubleTy, "booltmp");
+  default: return ErrorV("invalid binary operator");
+  }
+}
+
+Value *CallExprAST::Codegen() {
+  // Look up the name in the global module table.
+  Function *CalleeF = TheModule->getFunction(Callee);
+  if (CalleeF == 0)
+    return ErrorV("Unknown function referenced");
+  
+  // If argument mismatch error.
+  if (CalleeF->arg_size() != Args.size())
+    return ErrorV("Incorrect # arguments passed");
+
+  std::vector<Value*> ArgsV;
+  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+    ArgsV.push_back(Args[i]->Codegen());
+    if (ArgsV.back() == 0) return 0;
+  }
+  
+  return Builder.CreateCall(CalleeF, ArgsV.begin(), ArgsV.end(), "calltmp");
+}
+
+Value *IfExprAST::Codegen() {
+  Value *CondV = Cond->Codegen();
+  if (CondV == 0) return 0;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  CondV = Builder.CreateFCmpONE(CondV, 
+                                ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
+                                "ifcond");
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = new BasicBlock("then", TheFunction);
+  BasicBlock *ElseBB = new BasicBlock("else");
+  BasicBlock *MergeBB = new BasicBlock("ifcont");
+  
+  Builder.CreateCondBr(CondV, ThenBB, ElseBB);
+  
+  // Emit then value.
+  Builder.SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->Codegen();
+  if (ThenV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = Builder.GetInsertBlock();
+  
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  Builder.SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->Codegen();
+  if (ElseV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = Builder.GetInsertBlock();
+  
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  Builder.SetInsertPoint(MergeBB);
+  PHINode *PN = Builder.CreatePHI(Type::DoubleTy, "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::Codegen() {
+  // Output this as:
+  //   ...
+  //   start = startexpr
+  //   goto loop
+  // loop: 
+  //   variable = phi [start, loopheader], [nextvariable, loopend]
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   nextvariable = variable + step
+  //   endcond = endexpr
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->Codegen();
+  if (StartVal == 0) return 0;
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+  BasicBlock *PreheaderBB = Builder.GetInsertBlock();
+  BasicBlock *LoopBB = new BasicBlock("loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  Builder.CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  Builder.SetInsertPoint(LoopBB);
+  
+  // Start the PHI node with an entry for Start.
+  PHINode *Variable = Builder.CreatePHI(Type::DoubleTy, VarName.c_str());
+  Variable->addIncoming(StartVal, PreheaderBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  Value *OldVal = NamedValues[VarName];
+  NamedValues[VarName] = Variable;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (Body->Codegen() == 0)
+    return 0;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->Codegen();
+    if (StepVal == 0) return 0;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(Type::DoubleTy, APFloat(1.0));
+  }
+  
+  Value *NextVar = Builder.CreateAdd(Variable, StepVal, "nextvar");
+
+  // Compute the end condition.
+  Value *EndCond = End->Codegen();
+  if (EndCond == 0) return EndCond;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = Builder.CreateFCmpONE(EndCond, 
+                                  ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *LoopEndBB = Builder.GetInsertBlock();
+  BasicBlock *AfterBB = new BasicBlock("afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  Builder.SetInsertPoint(AfterBB);
+  
+  // Add a new entry to the PHI node for the backedge.
+  Variable->addIncoming(NextVar, LoopEndBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    NamedValues[VarName] = OldVal;
+  else
+    NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::DoubleTy);
+}
+
+Function *PrototypeAST::Codegen() {
+  // Make the function type:  double(double,double) etc.
+  std::vector<const Type*> Doubles(Args.size(), Type::DoubleTy);
+  FunctionType *FT = FunctionType::get(Type::DoubleTy, Doubles, false);
+  
+  Function *F = new Function(FT, Function::ExternalLinkage, Name, TheModule);
+  
+  // If F conflicted, there was already something named 'Name'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != Name) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = TheModule->getFunction(Name);
+    
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorF("redefinition of function");
+      return 0;
+    }
+    
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorF("redefinition of function with different # args");
+      return 0;
+    }
+  }
+  
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx) {
+    AI->setName(Args[Idx]);
+    
+    // Add arguments to variable symbol table.
+    NamedValues[Args[Idx]] = AI;
+  }
+  
+  return F;
+}
+
+Function *FunctionAST::Codegen() {
+  NamedValues.clear();
+  
+  Function *TheFunction = Proto->Codegen();
+  if (TheFunction == 0)
+    return 0;
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = new BasicBlock("entry", TheFunction);
+  Builder.SetInsertPoint(BB);
+  
+  if (Value *RetVal = Body->Codegen()) {
+    // Finish off the function.
+    Builder.CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    // Optimize the function.
+    TheFPM->run(*TheFunction);
+    
+    return TheFunction;
+  }
+  
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static ExecutionEngine *TheExecutionEngine;
+
+static void HandleDefinition() {
+  if (FunctionAST *F = ParseDefinition()) {
+    if (Function *LF = F->Codegen()) {
+      fprintf(stderr, "Read function definition:");
+      LF->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern() {
+  if (PrototypeAST *P = ParseExtern()) {
+    if (Function *F = P->Codegen()) {
+      fprintf(stderr, "Read extern: ");
+      F->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression() {
+  // Evaluate a top level expression into an anonymous function.
+  if (FunctionAST *F = ParseTopLevelExpr()) {
+    if (Function *LF = F->Codegen()) {
+      // JIT the function, returning a function pointer.
+      void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
+      
+      // Cast it to the right type (takes no arguments, returns a double) so we
+      // can call it as a native function.
+      double (*FP)() = (double (*)())FPtr;
+      fprintf(stderr, "Evaluated to %f\n", FP());
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  while (1) {
+    fprintf(stderr, "ready> ");
+    switch (CurTok) {
+    case tok_eof:    return;
+    case ';':        getNextToken(); break;  // ignore top level semicolons.
+    case tok_def:    HandleDefinition(); break;
+    case tok_extern: HandleExtern(); break;
+    default:         HandleTopLevelExpression(); break;
+    }
+  }
+}
+
+
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" 
+double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['*'] = 40;  // highest.
+
+  // Prime the first token.
+  fprintf(stderr, "ready> ");
+  getNextToken();
+
+  // Make the module, which holds all the code.
+  TheModule = new Module("my cool jit");
+  
+  // Create the JIT.
+  TheExecutionEngine = ExecutionEngine::create(TheModule);
+
+  {
+    ExistingModuleProvider OurModuleProvider(TheModule);
+    FunctionPassManager OurFPM(&OurModuleProvider);
+      
+    // Set up the optimizer pipeline.  Start with registering info about how the
+    // target lays out data structures.
+    OurFPM.add(new TargetData(*TheExecutionEngine->getTargetData()));
+    // Do simple "peephole" optimizations and bit-twiddling optzns.
+    OurFPM.add(createInstructionCombiningPass());
+    // Reassociate expressions.
+    OurFPM.add(createReassociatePass());
+    // Eliminate Common SubExpressions.
+    OurFPM.add(createGVNPass());
+    // Simplify the control flow graph (deleting unreachable blocks, etc).
+    OurFPM.add(createCFGSimplificationPass());
+    // Set the global so the code gen can use this.
+    TheFPM = &OurFPM;
+
+    // Run the main "interpreter loop" now.
+    MainLoop();
+    
+    TheFPM = 0;
+  }  // Free module provider and pass manager.
+                                   
+                                   
+  // Print out all of the generated code.
+  TheModule->dump();
+  return 0;
+}
 
-ready> def testfunc(x y) x + y*2;  
+ready> def testfunc(x y) x + y*2;  
 Read function definition:
 define double @testfunc(double %x, double %y) {
 entry:




From baldrick at free.fr  Wed Oct 31 03:49:25 2007
From: baldrick at free.fr (Duncan Sands)
Date: Wed, 31 Oct 2007 08:49:25 -0000
Subject: [llvm-commits] [llvm] r43550 - in /llvm/trunk:
 include/llvm/CodeGen/MachineDominators.h lib/CodeGen/MachineDominators.cpp
 lib/CodeGen/StrongPHIElimination.cpp
Message-ID: <200710310849.l9V8nPTq006029@zion.cs.uiuc.edu>

Author: baldrick
Date: Wed Oct 31 03:49:24 2007
New Revision: 43550

URL: http://llvm.org/viewvc/llvm-project?rev=43550&view=rev
Log:
Add a newline at the end of the file.

Modified:
    llvm/trunk/include/llvm/CodeGen/MachineDominators.h
    llvm/trunk/lib/CodeGen/MachineDominators.cpp
    llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp

Modified: llvm/trunk/include/llvm/CodeGen/MachineDominators.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineDominators.h?rev=43550&r1=43549&r2=43550&view=diff

==============================================================================

--- llvm/trunk/include/llvm/CodeGen/MachineDominators.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineDominators.h Wed Oct 31 03:49:24 2007
@@ -181,4 +181,4 @@
 
 }
 
-#endif
\ No newline at end of file
+#endif

Modified: llvm/trunk/lib/CodeGen/MachineDominators.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineDominators.cpp?rev=43550&r1=43549&r2=43550&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/MachineDominators.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineDominators.cpp Wed Oct 31 03:49:24 2007
@@ -21,4 +21,4 @@
 
 char MachineDominatorTree::ID = 0;
 static RegisterPass
-E("machinedomtree", "MachineDominator Tree Construction", true);
\ No newline at end of file
+E("machinedomtree", "MachineDominator Tree Construction", true);

Modified: llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp?rev=43550&r1=43549&r2=43550&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp (original)
+++ llvm/trunk/lib/CodeGen/StrongPHIElimination.cpp Wed Oct 31 03:49:24 2007
@@ -109,4 +109,4 @@
       worklist.pop_back();
     }
   }
-}
\ No newline at end of file
+}




From baldrick at free.fr  Wed Oct 31 03:57:43 2007
From: baldrick at free.fr (Duncan Sands)
Date: Wed, 31 Oct 2007 08:57:43 -0000
Subject: [llvm-commits] [llvm] r43551 -
	/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp
Message-ID: <200710310857.l9V8vhAH006802@zion.cs.uiuc.edu>

Author: baldrick
Date: Wed Oct 31 03:57:43 2007
New Revision: 43551

URL: http://llvm.org/viewvc/llvm-project?rev=43551&view=rev
Log:
Promotion of sdiv/srem/udiv/urem.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp?rev=43551&r1=43550&r2=43551&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp Wed Oct 31 03:57:43 2007
@@ -147,6 +147,8 @@
   SDOperand PromoteResult_SETCC(SDNode *N);
   SDOperand PromoteResult_LOAD(LoadSDNode *N);
   SDOperand PromoteResult_SimpleIntBinOp(SDNode *N);
+  SDOperand PromoteResult_SDIV(SDNode *N);
+  SDOperand PromoteResult_UDIV(SDNode *N);
   SDOperand PromoteResult_SHL(SDNode *N);
   SDOperand PromoteResult_SRA(SDNode *N);
   SDOperand PromoteResult_SRL(SDNode *N);
@@ -554,6 +556,12 @@
   case ISD::SUB:
   case ISD::MUL:      Result = PromoteResult_SimpleIntBinOp(N); break;
 
+  case ISD::SDIV:
+  case ISD::SREM:     Result = PromoteResult_SDIV(N); break;
+
+  case ISD::UDIV:
+  case ISD::UREM:     Result = PromoteResult_UDIV(N); break;
+
   case ISD::SHL:      Result = PromoteResult_SHL(N); break;
   case ISD::SRA:      Result = PromoteResult_SRA(N); break;
   case ISD::SRL:      Result = PromoteResult_SRL(N); break;
@@ -694,6 +702,30 @@
   return DAG.getNode(N->getOpcode(), LHS.getValueType(), LHS, RHS);
 }
 
+SDOperand DAGTypeLegalizer::PromoteResult_SDIV(SDNode *N) {
+  // Sign extend the input.
+  SDOperand LHS = GetPromotedOp(N->getOperand(0));
+  SDOperand RHS = GetPromotedOp(N->getOperand(1));
+  MVT::ValueType VT = N->getValueType(0);
+  LHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, LHS.getValueType(), LHS,
+                    DAG.getValueType(VT));
+  RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, RHS.getValueType(), RHS,
+                    DAG.getValueType(VT));
+
+  return DAG.getNode(N->getOpcode(), LHS.getValueType(), LHS, RHS);
+}
+
+SDOperand DAGTypeLegalizer::PromoteResult_UDIV(SDNode *N) {
+  // Zero extend the input.
+  SDOperand LHS = GetPromotedOp(N->getOperand(0));
+  SDOperand RHS = GetPromotedOp(N->getOperand(1));
+  MVT::ValueType VT = N->getValueType(0);
+  LHS = DAG.getZeroExtendInReg(LHS, VT);
+  RHS = DAG.getZeroExtendInReg(RHS, VT);
+
+  return DAG.getNode(N->getOpcode(), LHS.getValueType(), LHS, RHS);
+}
+
 SDOperand DAGTypeLegalizer::PromoteResult_SHL(SDNode *N) {
   return DAG.getNode(ISD::SHL, TLI.getTypeToTransformTo(N->getValueType(0)),
                      GetPromotedOp(N->getOperand(0)), N->getOperand(1));




From rafael.espindola at gmail.com  Wed Oct 31 06:52:08 2007
From: rafael.espindola at gmail.com (Rafael Espindola)
Date: Wed, 31 Oct 2007 11:52:08 -0000
Subject: [llvm-commits] [llvm] r43552 - in /llvm/trunk/lib/Target:
 ARM/ARMISelLowering.cpp ARM/ARMSubtarget.h X86/X86ISelLowering.cpp
 X86/X86Subtarget.cpp X86/X86Subtarget.h
Message-ID: <200710311152.l9VBq9no022304@zion.cs.uiuc.edu>

Author: rafael
Date: Wed Oct 31 06:52:06 2007
New Revision: 43552

URL: http://llvm.org/viewvc/llvm-project?rev=43552&view=rev
Log:
Make ARM an X86 memcpy expansion more similar to each other.
Now both subtarget define getMaxInlineSizeThreshold and the expansion uses it.

This should not change generated code.


Modified:
    llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
    llvm/trunk/lib/Target/ARM/ARMSubtarget.h
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/lib/Target/X86/X86Subtarget.cpp
    llvm/trunk/lib/Target/X86/X86Subtarget.h

Modified: llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp?rev=43552&r1=43551&r2=43552&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp Wed Oct 31 06:52:06 2007
@@ -1315,7 +1315,8 @@
   // this once Thumb ldmia / stmia support is added.
   unsigned Size = I->getValue();
   if (AlwaysInline ||
-      (!ST->isThumb() && Size < 64 && (Align & 3) == 0))
+      (!ST->isThumb() && Size <= Subtarget->getMaxInlineSizeThreshold() &&
+       (Align & 3) == 0))
     return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);
   return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
 }

Modified: llvm/trunk/lib/Target/ARM/ARMSubtarget.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMSubtarget.h?rev=43552&r1=43551&r2=43552&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMSubtarget.h (original)
+++ llvm/trunk/lib/Target/ARM/ARMSubtarget.h Wed Oct 31 06:52:06 2007
@@ -62,6 +62,7 @@
   ///
   ARMSubtarget(const Module &M, const std::string &FS, bool thumb);
 
+  unsigned getMaxInlineSizeThreshold() const { return 64; }
   /// ParseSubtargetFeatures - Parses features string setting specified 
   /// subtarget options.  Definition of function is auto generated by tblgen.
   void ParseSubtargetFeatures(const std::string &FS, const std::string &CPU);

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=43552&r1=43551&r2=43552&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Wed Oct 31 06:52:06 2007
@@ -4332,7 +4332,7 @@
   // The libc version is likely to be faster for these cases. It can use the
   // address value and run time information about the CPU.
   if ((Align & 3) != 0 ||
-      (I && I->getValue() > Subtarget->getMinRepStrSizeThreshold())) {
+      (I && I->getValue() > Subtarget->getMaxInlineSizeThreshold())) {
     MVT::ValueType IntPtr = getPointerTy();
     const Type *IntPtrTy = getTargetData()->getIntPtrType();
     TargetLowering::ArgListTy Args; 
@@ -4510,7 +4510,7 @@
     return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
 
   // If size is more than the threshold, call memcpy.
-  if (Size > Subtarget->getMinRepStrSizeThreshold())
+  if (Size > Subtarget->getMaxInlineSizeThreshold())
     return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
 
   return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);

Modified: llvm/trunk/lib/Target/X86/X86Subtarget.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86Subtarget.cpp?rev=43552&r1=43551&r2=43552&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86Subtarget.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86Subtarget.cpp Wed Oct 31 06:52:06 2007
@@ -223,7 +223,7 @@
   , HasX86_64(false)
   , stackAlignment(8)
   // FIXME: this is a known good value for Yonah. How about others?
-  , MinRepStrSizeThreshold(128)
+  , MaxInlineSizeThreshold(128)
   , Is64Bit(is64Bit)
   , HasLow4GUserAddress(true)
   , TargetType(isELF) { // Default to ELF unless otherwise specified.

Modified: llvm/trunk/lib/Target/X86/X86Subtarget.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86Subtarget.h?rev=43552&r1=43551&r2=43552&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86Subtarget.h (original)
+++ llvm/trunk/lib/Target/X86/X86Subtarget.h Wed Oct 31 06:52:06 2007
@@ -69,9 +69,9 @@
   /// entry to the function and which must be maintained by every function.
   unsigned stackAlignment;
 
-  /// Min. memset / memcpy size that is turned into rep/movs, rep/stos ops.
+  /// Max. memset / memcpy size that is turned into rep/movs, rep/stos ops.
   ///
-  unsigned MinRepStrSizeThreshold;
+  unsigned MaxInlineSizeThreshold;
 
 private:
   /// Is64Bit - True if the processor supports 64-bit instructions and module
@@ -97,11 +97,9 @@
   /// function for this subtarget.
   unsigned getStackAlignment() const { return stackAlignment; }
 
-  /// getMinRepStrSizeThreshold - Returns the minimum memset / memcpy size
-  /// required to turn the operation into a X86 rep/movs or rep/stos
-  /// instruction. This is only used if the src / dst alignment is not DWORD
-  /// aligned.
-  unsigned getMinRepStrSizeThreshold() const { return MinRepStrSizeThreshold; }
+  /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
+  /// that still makes it profitable to inline the call.
+  unsigned getMaxInlineSizeThreshold() const { return MaxInlineSizeThreshold; }
 
   /// ParseSubtargetFeatures - Parses features string setting specified
   /// subtarget options.  Definition of function is auto generated by tblgen.




From criswell at cs.uiuc.edu  Wed Oct 31 09:30:08 2007
From: criswell at cs.uiuc.edu (John Criswell)
Date: Wed, 31 Oct 2007 09:30:08 -0500
Subject: [llvm-commits] CVS: llvm-www/Users.html
Message-ID: <200710311430.JAA21770@choi.cs.uiuc.edu>



Changes in directory llvm-www:

Users.html updated: 1.23 -> 1.24
---
Log message:

Changed "Academic/Research" to "Academic Research" per Vikram's request.


---
Diffs of the changes:  (+2 -2)

 Users.html |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)


Index: llvm-www/Users.html
diff -u llvm-www/Users.html:1.23 llvm-www/Users.html:1.24
--- llvm-www/Users.html:1.23	Tue Oct 30 21:22:28 2007
+++ llvm-www/Users.html	Wed Oct 31 09:29:25 2007
@@ -76,7 +76,7 @@
 
 
 

-Academic/Research Users
+Academic Research Users
 
 
 

@@ -272,6 +272,6 @@
   src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!">
 
 
LLVM Development List

-  Last modified: $Date: 2007/10/31 02:22:28 $
+  Last modified: $Date: 2007/10/31 14:29:25 $
 
 





From djg at cray.com  Wed Oct 31 09:35:40 2007
From: djg at cray.com (Dan Gohman)
Date: Wed, 31 Oct 2007 14:35:40 -0000
Subject: [llvm-commits] [llvm] r43553 -
	/llvm/trunk/lib/Transforms/Scalar/LICM.cpp
Message-ID: <200710311435.l9VEZe3X029408@zion.cs.uiuc.edu>

Author: djg
Date: Wed Oct 31 09:35:39 2007
New Revision: 43553

URL: http://llvm.org/viewvc/llvm-project?rev=43553&view=rev
Log:
Fix a typo in a comment.

Modified:
    llvm/trunk/lib/Transforms/Scalar/LICM.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/LICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LICM.cpp?rev=43553&r1=43552&r2=43553&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LICM.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp Wed Oct 31 09:35:39 2007
@@ -802,7 +802,7 @@
 
       // If one use of value V inside the loop is safe then it is OK to promote 
       // this value. On the otherside if there is not any unsafe use inside the
-      // looop then also it is OK to  promote this value. Otherwise it is
+      // loop then also it is OK to promote this value. Otherwise it is
       // unsafe to promote this value.
       if (PointerOk) {
         bool oneSafeUse = false;




From rafael.espindola at gmail.com  Wed Oct 31 09:39:59 2007
From: rafael.espindola at gmail.com (Rafael Espindola)
Date: Wed, 31 Oct 2007 14:39:59 -0000
Subject: [llvm-commits] [llvm] r43554 - in /llvm/trunk/lib/Target:
 ARM/ARMISelLowering.cpp ARM/ARMISelLowering.h ARM/ARMSubtarget.h
 X86/X86ISelLowering.cpp
Message-ID: <200710311439.l9VEdxdu029568@zion.cs.uiuc.edu>

Author: rafael
Date: Wed Oct 31 09:39:58 2007
New Revision: 43554

URL: http://llvm.org/viewvc/llvm-project?rev=43554&view=rev
Log:
Make ARM and X86 LowerMEMCPY identical by moving the isThumb check into getMaxInlineSizeThreshold
and by restructuring the X86 version.

New I just have to move this to a common place :-)


Modified:
    llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
    llvm/trunk/lib/Target/ARM/ARMISelLowering.h
    llvm/trunk/lib/Target/ARM/ARMSubtarget.h
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp?rev=43554&r1=43553&r2=43554&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp Wed Oct 31 09:39:58 2007
@@ -1287,8 +1287,7 @@
   return DAG.getNode(ISD::BUILD_PAIR, MVT::i64, Lo, Hi);
 }
 
-SDOperand ARMTargetLowering::LowerMEMCPY(SDOperand Op, SelectionDAG &DAG,
-                                         const ARMSubtarget *ST) {
+SDOperand ARMTargetLowering::LowerMEMCPY(SDOperand Op, SelectionDAG &DAG) {
   SDOperand ChainOp = Op.getOperand(0);
   SDOperand DestOp = Op.getOperand(1);
   SDOperand SourceOp = Op.getOperand(2);
@@ -1311,11 +1310,9 @@
   // The libc version is likely to be faster for the these cases. It can
   // use the address value and run time information about the CPU.
   // With glibc 2.6.1 on a core 2, coping an array of 100M longs was 30% faster
-  // FIXME: For now, we don't lower memcpy's to loads / stores for Thumb. Change
-  // this once Thumb ldmia / stmia support is added.
   unsigned Size = I->getValue();
   if (AlwaysInline ||
-      (!ST->isThumb() && Size <= Subtarget->getMaxInlineSizeThreshold() &&
+      (Size <= Subtarget->getMaxInlineSizeThreshold() &&
        (Align & 3) == 0))
     return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);
   return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
@@ -1461,7 +1458,7 @@
   case ISD::RETURNADDR:    break;
   case ISD::FRAMEADDR:     break;
   case ISD::GLOBAL_OFFSET_TABLE: return LowerGLOBAL_OFFSET_TABLE(Op, DAG);
-  case ISD::MEMCPY:        return LowerMEMCPY(Op, DAG, Subtarget);
+  case ISD::MEMCPY:        return LowerMEMCPY(Op, DAG);
   }
   return SDOperand();
 }

Modified: llvm/trunk/lib/Target/ARM/ARMISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelLowering.h?rev=43554&r1=43553&r2=43554&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMISelLowering.h (original)
+++ llvm/trunk/lib/Target/ARM/ARMISelLowering.h Wed Oct 31 09:39:58 2007
@@ -134,8 +134,7 @@
     SDOperand LowerGLOBAL_OFFSET_TABLE(SDOperand Op, SelectionDAG &DAG);
     SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG);
     SDOperand LowerBR_JT(SDOperand Op, SelectionDAG &DAG);
-    SDOperand LowerMEMCPY(SDOperand Op, SelectionDAG &DAG,
-                          const ARMSubtarget *ST);
+    SDOperand LowerMEMCPY(SDOperand Op, SelectionDAG &DAG);
     SDOperand LowerMEMCPYCall(SDOperand Chain, SDOperand Dest,
                               SDOperand Source, SDOperand Count,
                               SelectionDAG &DAG);

Modified: llvm/trunk/lib/Target/ARM/ARMSubtarget.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMSubtarget.h?rev=43554&r1=43553&r2=43554&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMSubtarget.h (original)
+++ llvm/trunk/lib/Target/ARM/ARMSubtarget.h Wed Oct 31 09:39:58 2007
@@ -62,7 +62,11 @@
   ///
   ARMSubtarget(const Module &M, const std::string &FS, bool thumb);
 
-  unsigned getMaxInlineSizeThreshold() const { return 64; }
+  unsigned getMaxInlineSizeThreshold() const {
+    // FIXME: For now, we don't lower memcpy's to loads / stores for Thumb.
+    // Change this once Thumb ldmia / stmia support is added.
+    return isThumb() ? 0 : 64;
+  }
   /// ParseSubtargetFeatures - Parses features string setting specified 
   /// subtarget options.  Definition of function is auto generated by tblgen.
   void ParseSubtargetFeatures(const std::string &FS, const std::string &CPU);

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=43554&r1=43553&r2=43554&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Wed Oct 31 09:39:58 2007
@@ -4496,24 +4496,17 @@
     assert(!AlwaysInline && "Cannot inline copy of unknown size");
     return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
   }
-  unsigned Size = I->getValue();
-
-  if (AlwaysInline)
-    return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);
 
+  // If not DWORD aligned or if size is more than threshold, then call memcpy.
   // The libc version is likely to be faster for the following cases. It can
   // use the address value and run time information about the CPU.
   // With glibc 2.6.1 on a core 2, coping an array of 100M longs was 30% faster
-
-  // If not DWORD aligned, call memcpy.
-  if ((Align & 3) != 0)
-    return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
-
-  // If size is more than the threshold, call memcpy.
-  if (Size > Subtarget->getMaxInlineSizeThreshold())
-    return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
-
-  return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);
+  unsigned Size = I->getValue();
+  if (AlwaysInline ||
+      (Size <= Subtarget->getMaxInlineSizeThreshold() &&
+       (Align & 3) == 0))
+    return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);
+  return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
 }
 
 SDOperand X86TargetLowering::LowerMEMCPYCall(SDOperand Chain,




From kremenek at apple.com  Wed Oct 31 12:12:47 2007
From: kremenek at apple.com (Ted Kremenek)
Date: Wed, 31 Oct 2007 17:12:47 -0000
Subject: [llvm-commits] [llvm] r43559 -
	/llvm/trunk/include/llvm/ADT/FoldingSet.h
Message-ID: <200710311712.l9VHCljW005349@zion.cs.uiuc.edu>

Author: kremenek
Date: Wed Oct 31 12:12:47 2007
New Revision: 43559

URL: http://llvm.org/viewvc/llvm-project?rev=43559&view=rev
Log:
Changed access control within FoldingSet for some ivars from "private"
to "protected".  This allows iterators to work.

Modified:
    llvm/trunk/include/llvm/ADT/FoldingSet.h

Modified: llvm/trunk/include/llvm/ADT/FoldingSet.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/FoldingSet.h?rev=43559&r1=43558&r2=43559&view=diff

==============================================================================
--- llvm/trunk/include/llvm/ADT/FoldingSet.h (original)
+++ llvm/trunk/include/llvm/ADT/FoldingSet.h Wed Oct 31 12:12:47 2007
@@ -106,7 +106,7 @@
 /// back to the bucket to facilitate node removal.
 /// 
 class FoldingSetImpl {
-private:
+protected:
   /// Buckets - Array of bucket chains.
   ///
   void **Buckets;




From kremenek at apple.com  Wed Oct 31 13:23:21 2007
From: kremenek at apple.com (Ted Kremenek)
Date: Wed, 31 Oct 2007 18:23:21 -0000
Subject: [llvm-commits] [llvm] r43565 - in /llvm/trunk:
 include/llvm/Bitcode/Serialize.h lib/Bitcode/Writer/Serialize.cpp
Message-ID: <200710311823.l9VINMHR009220@zion.cs.uiuc.edu>

Author: kremenek
Date: Wed Oct 31 13:23:21 2007
New Revision: 43565

URL: http://llvm.org/viewvc/llvm-project?rev=43565&view=rev
Log:
Added Serializer::EmitRef to deal with emitting arbitrary references.
Modified Serializer::EmitPtr to handle const pointers.

Modified:
    llvm/trunk/include/llvm/Bitcode/Serialize.h
    llvm/trunk/lib/Bitcode/Writer/Serialize.cpp

Modified: llvm/trunk/include/llvm/Bitcode/Serialize.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Bitcode/Serialize.h?rev=43565&r1=43564&r2=43565&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Bitcode/Serialize.h (original)
+++ llvm/trunk/include/llvm/Bitcode/Serialize.h Wed Oct 31 13:23:21 2007
@@ -27,7 +27,7 @@
   SmallVector Record;
   bool inBlock;
   
-  typedef DenseMap MapTy;
+  typedef DenseMap MapTy;
   MapTy PtrMap;
   
 public:
@@ -42,7 +42,10 @@
   void EmitCStr(const char* beg, const char* end);
   void EmitCStr(const char* cstr);
   
-  void EmitPtr(void* ptr) { EmitInt(getPtrId(ptr)); }
+  void EmitPtr(const void* ptr) { EmitInt(getPtrId(ptr)); }
+  
+  template 
+  void EmitRef(const T& ref) { EmitPtr(&ref); }
   
   template 
   void EmitOwnedPtr(T* ptr) {
@@ -55,7 +58,7 @@
 private:
   void EmitRecord();
   inline bool inRecord() { return Record.size() > 0; }
-  unsigned getPtrId(void* ptr);
+  unsigned getPtrId(const void* ptr);
 };
 
 } // end namespace llvm

Modified: llvm/trunk/lib/Bitcode/Writer/Serialize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Writer/Serialize.cpp?rev=43565&r1=43564&r2=43565&view=diff

==============================================================================
--- llvm/trunk/lib/Bitcode/Writer/Serialize.cpp (original)
+++ llvm/trunk/lib/Bitcode/Writer/Serialize.cpp Wed Oct 31 13:23:21 2007
@@ -57,7 +57,7 @@
   EmitCStr(s,s+strlen(s));
 }
 
-unsigned Serializer::getPtrId(void* ptr) {
+unsigned Serializer::getPtrId(const void* ptr) {
   if (!ptr)
     return 0;
   




From kremenek at apple.com  Wed Oct 31 14:58:32 2007
From: kremenek at apple.com (Ted Kremenek)
Date: Wed, 31 Oct 2007 19:58:32 -0000
Subject: [llvm-commits] [llvm] r43570 - in /llvm/trunk:
 include/llvm/Bitcode/Deserialize.h lib/Bitcode/Reader/Deserialize.cpp
Message-ID: <200710311958.l9VJwXQD014203@zion.cs.uiuc.edu>

Author: kremenek
Date: Wed Oct 31 14:58:32 2007
New Revision: 43570

URL: http://llvm.org/viewvc/llvm-project?rev=43570&view=rev
Log:
Implemented deserialization of references.  References are handled
just like pointers, except that they cannot be backpatched.  This
means that references are essentially non-owning pointers where the
referred object must be deserialized prior to the reference being
deserialized.  Because of the nature of references, this ordering of
objects is always possible.

Fixed a bug in backpatching code (returning the backpatched pointer
would accidentally include a bit flag).

Modified:
    llvm/trunk/include/llvm/Bitcode/Deserialize.h
    llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp

Modified: llvm/trunk/include/llvm/Bitcode/Deserialize.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Bitcode/Deserialize.h?rev=43570&r1=43569&r2=43570&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Bitcode/Deserialize.h (original)
+++ llvm/trunk/include/llvm/Bitcode/Deserialize.h Wed Oct 31 14:58:32 2007
@@ -56,7 +56,7 @@
       
     BPatchEntry(void* P) : Ptr(reinterpret_cast(P)) {}
 
-    bool hasFinalPtr() const { return Ptr & 0x1 ? true : false; }
+    bool hasFinalPtr() const { return Ptr & 0x1 ? false : true; }
     void setFinalPtr(BPNode*& FreeList, void* P);
 
     BPNode* getBPNode() const {
@@ -69,7 +69,10 @@
       Ptr = reinterpret_cast(N) | 0x1;
     }
     
-    uintptr_t getRawPtr() const { return Ptr; }
+    uintptr_t getFinalPtr() const {
+      assert (!(Ptr & 0x1) && "Backpatch pointer not yet deserialized.");
+      return Ptr;
+    }    
 
     static inline bool isPod() { return true; }
   };
@@ -132,17 +135,30 @@
   }
   
   template 
-  void ReadPtr(T*& PtrRef) { ReadUIntPtr(reinterpret_cast(PtrRef));}
-
-  void ReadPtr(uintptr_t& PtrRef) { ReadUIntPtr(PtrRef); }
+  void ReadPtr(T*& PtrRef) {
+    ReadUIntPtr(reinterpret_cast(PtrRef));
+  }
   
+  template 
+  void ReadPtr(const T*& PtrRef) {
+    ReadPtr(const_cast(PtrRef));
+  }            
+
   void ReadUIntPtr(uintptr_t& PtrRef);
   
+  template 
+  T& ReadRef() {
+    T* p = reinterpret_cast(ReadInternalRefPtr());
+    return *p;
+  }
+
+  
   void RegisterPtr(unsigned PtrId, void* Ptr);
 
 private:
   void ReadRecord();  
   bool inRecord();
+  uintptr_t ReadInternalRefPtr();
 };
     
 } // end namespace llvm

Modified: llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp?rev=43570&r1=43569&r2=43570&view=diff

==============================================================================
--- llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp (original)
+++ llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp Wed Oct 31 14:58:32 2007
@@ -115,7 +115,7 @@
   BPatchEntry& E = BPatchMap[PtrId];
   
   if (E.hasFinalPtr())
-    PtrRef = E.getRawPtr();
+    PtrRef = E.getFinalPtr();
   else {
     // Register backpatch.  Check the freelist for a BPNode.
     BPNode* N;
@@ -132,6 +132,18 @@
   }
 }
 
+uintptr_t Deserializer::ReadInternalRefPtr() {
+  unsigned PtrId = ReadInt();
+  
+  assert (PtrId != 0 && "References cannot refer the NULL address.");
+
+  BPatchEntry& E = BPatchMap[PtrId];
+  
+  assert (E.hasFinalPtr() &&
+          "Cannot backpatch references.  Object must be already deserialized.");
+  
+  return E.getFinalPtr();
+}
 
 void Deserializer::BPatchEntry::setFinalPtr(BPNode*& FreeList, void* P) {
   assert (!hasFinalPtr());




From resistor at mac.com  Wed Oct 31 16:04:18 2007
From: resistor at mac.com (Owen Anderson)
Date: Wed, 31 Oct 2007 21:04:18 -0000
Subject: [llvm-commits] [llvm] r43578 - /llvm/trunk/lib/VMCore/Verifier.cpp
Message-ID: <200710312104.l9VL4I2M017819@zion.cs.uiuc.edu>

Author: resistor
Date: Wed Oct 31 16:04:18 2007
New Revision: 43578

URL: http://llvm.org/viewvc/llvm-project?rev=43578&view=rev
Log:
Add a preverifier pass to check that every basic block ends in a terminator, so that we don't segfault when verifying invalid code.

Modified:
    llvm/trunk/lib/VMCore/Verifier.cpp

Modified: llvm/trunk/lib/VMCore/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Verifier.cpp?rev=43578&r1=43577&r2=43578&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/Verifier.cpp (original)
+++ llvm/trunk/lib/VMCore/Verifier.cpp Wed Oct 31 16:04:18 2007
@@ -71,7 +71,25 @@
   cl::opt
   Pedantic("verify-pedantic",
            cl::desc("Reject code with undefined behaviour"));
-    
+  
+  struct VISIBILITY_HIDDEN PreVerifier : public FunctionPass {
+  	static char ID; // Pass ID, replacement for typeid
+  	
+  	PreVerifier() : FunctionPass((intptr_t)&ID) { }
+  	
+  	bool runOnFunction(Function &F) {
+      for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
+        assert(I->back().isTerminator()
+               && "Block does not end with a terminator?");
+      
+      return false;
+  	}
+  };
+  
+  char PreVerifier::ID = 0;
+  RegisterPass PreVer("preverify", "Preliminary module verification");
+  const PassInfo *PreVerifyID = PreVer.getPassInfo();
+  
   struct VISIBILITY_HIDDEN
      Verifier : public FunctionPass, InstVisitor {
     static char ID; // Pass ID, replacement for typeid
@@ -161,6 +179,7 @@
 
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
       AU.setPreservesAll();
+      AU.addRequiredID(PreVerifyID);
       if (RealPass)
         AU.addRequired();
     }




From dpatel at apple.com  Wed Oct 31 16:20:58 2007
From: dpatel at apple.com (Devang Patel)
Date: Wed, 31 Oct 2007 14:20:58 -0700
Subject: [llvm-commits] [llvm] r43578 -
	/llvm/trunk/lib/VMCore/Verifier.cpp
In-Reply-To: <200710312104.l9VL4I2M017819@zion.cs.uiuc.edu>
References: <200710312104.l9VL4I2M017819@zion.cs.uiuc.edu>
Message-ID: <149102B2-89C1-419E-8FFF-D715A12D90B3@apple.com>

Why can't you check this at the beginning of  
Verifier::visitBasicBlock() ?
-
Devang

// verifyBasicBlock - Verify that a basic block is well formed...
//
void Verifier::visitBasicBlock(BasicBlock &BB) {

On Oct 31, 2007, at 2:04 PM, Owen Anderson wrote:

> Author: resistor
> Date: Wed Oct 31 16:04:18 2007
> New Revision: 43578
>
> URL: http://llvm.org/viewvc/llvm-project?rev=43578&view=rev
> Log:
> Add a preverifier pass to check that every basic block ends in a  
> terminator, so that we don't segfault when verifying invalid code.
>
> Modified:
>    llvm/trunk/lib/VMCore/Verifier.cpp
>
> Modified: llvm/trunk/lib/VMCore/Verifier.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Verifier.cpp?rev=43578&r1=43577&r2=43578&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm/trunk/lib/VMCore/Verifier.cpp (original)
> +++ llvm/trunk/lib/VMCore/Verifier.cpp Wed Oct 31 16:04:18 2007
> @@ -71,7 +71,25 @@
>   cl::opt
>   Pedantic("verify-pedantic",
>            cl::desc("Reject code with undefined behaviour"));
> -
> +
> +  struct VISIBILITY_HIDDEN PreVerifier : public FunctionPass {
> +  	static char ID; // Pass ID, replacement for typeid
> +  	
> +  	PreVerifier() : FunctionPass((intptr_t)&ID) { }
> +  	
> +  	bool runOnFunction(Function &F) {
> +      for (Function::iterator I = F.begin(), E = F.end(); I != E; + 
> +I)
> +        assert(I->back().isTerminator()
> +               && "Block does not end with a terminator?");
> +
> +      return false;
> +  	}
> +  };
> +
> +  char PreVerifier::ID = 0;
> +  RegisterPass PreVer("preverify", "Preliminary module  
> verification");
> +  const PassInfo *PreVerifyID = PreVer.getPassInfo();
> +
>   struct VISIBILITY_HIDDEN
>      Verifier : public FunctionPass, InstVisitor {
>     static char ID; // Pass ID, replacement for typeid
> @@ -161,6 +179,7 @@
>
>     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
>       AU.setPreservesAll();
> +      AU.addRequiredID(PreVerifyID);
>       if (RealPass)
>         AU.addRequired();
>     }
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits

-
Devang





From djg at cray.com  Wed Oct 31 16:36:32 2007
From: djg at cray.com (Dan Gohman)
Date: Wed, 31 Oct 2007 21:36:32 -0000
Subject: [llvm-commits] [llvm] r43579 -
	/llvm/trunk/lib/VMCore/ConstantFold.cpp
Message-ID: <200710312136.l9VLaWUN020601@zion.cs.uiuc.edu>

Author: djg
Date: Wed Oct 31 16:36:31 2007
New Revision: 43579

URL: http://llvm.org/viewvc/llvm-project?rev=43579&view=rev
Log:
Fix a regression in test/CodeGen/X86/2007-04-24-VectorCrash.ll introduced
by r43510. Gracefully handle constants with vector type that aren't
ConstantVector or ConstantAggregateZero.

Modified:
    llvm/trunk/lib/VMCore/ConstantFold.cpp

Modified: llvm/trunk/lib/VMCore/ConstantFold.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/ConstantFold.cpp?rev=43579&r1=43578&r2=43579&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/ConstantFold.cpp (original)
+++ llvm/trunk/lib/VMCore/ConstantFold.cpp Wed Oct 31 16:36:31 2007
@@ -716,10 +716,8 @@
   } else if (const VectorType *VTy = dyn_cast(C1->getType())) {
     const ConstantVector *CP1 = dyn_cast(C1);
     const ConstantVector *CP2 = dyn_cast(C2);
-    assert((CP1 != NULL || isa(C1)) &&
-           "Unexpected kind of vector constant!");
-    assert((CP2 != NULL || isa(C2)) &&
-           "Unexpected kind of vector constant!");
+    if ((CP1 != NULL || isa(C1)) &&
+        (CP2 != NULL || isa(C2))) {
       switch (Opcode) {
         default:
           break;
@@ -747,6 +745,7 @@
         return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getOr);
         case Instruction::Xor: 
         return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getXor);
+      }
     }
   }
 




From asl at math.spbu.ru  Wed Oct 31 16:30:33 2007
From: asl at math.spbu.ru (Anton Korobeynikov)
Date: Thu, 01 Nov 2007 00:30:33 +0300
Subject: [llvm-commits] [llvm] r43578
	-	/llvm/trunk/lib/VMCore/Verifier.cpp
In-Reply-To: <149102B2-89C1-419E-8FFF-D715A12D90B3.SS2498SS@apple.com>
References: <200710312104.l9VL4I2M017819@zion.cs.uiuc.edu>
	<149102B2-89C1-419E-8FFF-D715A12D90B3.SS2498SS@apple.com>
Message-ID: <1193866233.26720.75.camel@asl.dorms.spbu.ru>


> Why can't you check this at the beginning of  
> Verifier::visitBasicBlock() ?
I think due to this:

>AU.addRequired();

DomTree crashes on invalid CFG.

-- 
With best regards, Anton Korobeynikov.

Faculty of Mathematics & Mechanics, Saint Petersburg State University.




From dpatel at apple.com  Wed Oct 31 16:42:28 2007
From: dpatel at apple.com (Devang Patel)
Date: Wed, 31 Oct 2007 14:42:28 -0700
Subject: [llvm-commits] [llvm]
	r43578	-	/llvm/trunk/lib/VMCore/Verifier.cpp
In-Reply-To: <1193866233.26720.75.camel@asl.dorms.spbu.ru>
References: <200710312104.l9VL4I2M017819@zion.cs.uiuc.edu>
	<149102B2-89C1-419E-8FFF-D715A12D90B3.SS2498SS@apple.com>
	<1193866233.26720.75.camel@asl.dorms.spbu.ru>
Message-ID: <00E474C0-6312-4479-A39C-641FF2D31841@apple.com>


On Oct 31, 2007, at 2:30 PM, Anton Korobeynikov wrote:

>
>> Why can't you check this at the beginning of
>> Verifier::visitBasicBlock() ?
> I think due to this:
>
>> AU.addRequired();
>
> DomTree crashes on invalid CFG.

aha.
ok.
-
Devang


From kremenek at apple.com  Wed Oct 31 17:42:03 2007
From: kremenek at apple.com (Ted Kremenek)
Date: Wed, 31 Oct 2007 22:42:03 -0000
Subject: [llvm-commits] [llvm] r43583 - in /llvm/trunk:
 include/llvm/Bitcode/Deserialize.h lib/Bitcode/Reader/Deserialize.cpp
Message-ID: <200710312242.l9VMg3Dt023752@zion.cs.uiuc.edu>

Author: kremenek
Date: Wed Oct 31 17:42:03 2007
New Revision: 43583

URL: http://llvm.org/viewvc/llvm-project?rev=43583&view=rev
Log:
constified several pointer arguments for methods in the Deserializer.

Modified:
    llvm/trunk/include/llvm/Bitcode/Deserialize.h
    llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp

Modified: llvm/trunk/include/llvm/Bitcode/Deserialize.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Bitcode/Deserialize.h?rev=43583&r1=43582&r2=43583&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Bitcode/Deserialize.h (original)
+++ llvm/trunk/include/llvm/Bitcode/Deserialize.h Wed Oct 31 17:42:03 2007
@@ -57,7 +57,7 @@
     BPatchEntry(void* P) : Ptr(reinterpret_cast(P)) {}
 
     bool hasFinalPtr() const { return Ptr & 0x1 ? false : true; }
-    void setFinalPtr(BPNode*& FreeList, void* P);
+    void setFinalPtr(BPNode*& FreeList, const void* P);
 
     BPNode* getBPNode() const {
       assert (!hasFinalPtr());
@@ -152,8 +152,11 @@
     return *p;
   }
 
+  void RegisterPtr(unsigned PtrId, const void* Ptr);
   
-  void RegisterPtr(unsigned PtrId, void* Ptr);
+  void RegisterPtr(const void* Ptr) {
+    RegisterPtr(ReadInt(),Ptr);
+  }
 
 private:
   void ReadRecord();  

Modified: llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp?rev=43583&r1=43582&r2=43583&view=diff

==============================================================================
--- llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp (original)
+++ llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp Wed Oct 31 17:42:03 2007
@@ -98,9 +98,9 @@
     buff.push_back('\0');
 }
 
-void Deserializer::RegisterPtr(unsigned PtrId,void* Ptr) {
+void Deserializer::RegisterPtr(unsigned PtrId, const void* Ptr) {
   BPatchEntry& E = BPatchMap[PtrId];
-  assert (E.hasFinalPtr() && "Pointer already registered.");
+  assert (!E.hasFinalPtr() && "Pointer already registered.");
   E.setFinalPtr(FreeList,Ptr);
 }
 
@@ -145,7 +145,7 @@
   return E.getFinalPtr();
 }
 
-void Deserializer::BPatchEntry::setFinalPtr(BPNode*& FreeList, void* P) {
+void Deserializer::BPatchEntry::setFinalPtr(BPNode*& FreeList, const void* P) {
   assert (!hasFinalPtr());
   
   // Perform backpatching.




From kremenek at apple.com  Wed Oct 31 19:54:57 2007
From: kremenek at apple.com (Ted Kremenek)
Date: Thu, 01 Nov 2007 00:54:57 -0000
Subject: [llvm-commits] [llvm] r43594 -
	/llvm/trunk/include/llvm/ADT/DenseMap.h
Message-ID: <200711010054.lA10sv6n000331@zion.cs.uiuc.edu>

Author: kremenek
Date: Wed Oct 31 19:54:57 2007
New Revision: 43594

URL: http://llvm.org/viewvc/llvm-project?rev=43594&view=rev
Log:
Added typedef "value_type" to DenseMap (similar typedef appears in std::map).

Added method FindAndConstruct() to DenseMap, which does the same thing as
operator[], except that it refers value_type& (a reference to both the
key and mapped data pair).  This method is useful for clients that wish
to access the stored key value, as opposed to the key used to do the
actual lookup (these need not always be the same).

Redefined operator[] to use FindAndConstruct() (same logic).

Modified:
    llvm/trunk/include/llvm/ADT/DenseMap.h

Modified: llvm/trunk/include/llvm/ADT/DenseMap.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/DenseMap.h?rev=43594&r1=43593&r2=43594&view=diff

==============================================================================
--- llvm/trunk/include/llvm/ADT/DenseMap.h (original)
+++ llvm/trunk/include/llvm/ADT/DenseMap.h Wed Oct 31 19:54:57 2007
@@ -63,6 +63,8 @@
   unsigned NumEntries;
   unsigned NumTombstones;
 public:
+  typedef BucketT value_type;
+  
   DenseMap(const DenseMap& other) {
     NumBuckets = 0;
     CopyFrom(other);
@@ -174,13 +176,17 @@
     ++NumTombstones;
     return true;
   }
-  
-  ValueT &operator[](const KeyT &Key) {
+
+  value_type& FindAndConstruct(const KeyT &Key) {
     BucketT *TheBucket;
     if (LookupBucketFor(Key, TheBucket))
-      return TheBucket->second;
-
-    return InsertIntoBucket(Key, ValueT(), TheBucket)->second;
+      return *TheBucket;
+    
+    return *InsertIntoBucket(Key, ValueT(), TheBucket);
+  }
+  
+  ValueT &operator[](const KeyT &Key) {
+    return FindAndConstruct(Key).second;
   }
   
   DenseMap& operator=(const DenseMap& other) {




From kremenek at apple.com  Wed Oct 31 19:57:37 2007
From: kremenek at apple.com (Ted Kremenek)
Date: Thu, 01 Nov 2007 00:57:37 -0000
Subject: [llvm-commits] [llvm] r43595 - in /llvm/trunk:
 include/llvm/Bitcode/Deserialize.h lib/Bitcode/Reader/Deserialize.cpp
Message-ID: <200711010057.lA10vbe8000423@zion.cs.uiuc.edu>

Author: kremenek
Date: Wed Oct 31 19:57:37 2007
New Revision: 43595

URL: http://llvm.org/viewvc/llvm-project?rev=43595&view=rev
Log:
Rewrote backpatcher.  Backpatcher now stores the "has final pointer"
flag in the **key** of the backpatch map, as opposed to the mapped
value which contains either the final pointer, or a pointer to a chain
of pointers that need to be backpatched.  The bit flag was moved to
the key because we were erroneously assuming that the backpatched
pointers would be at an alignment of >= 2 bytes, which obviously
doesn't work for character strings.  Now we just steal the bit from the key.

Modified:
    llvm/trunk/include/llvm/Bitcode/Deserialize.h
    llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp

Modified: llvm/trunk/include/llvm/Bitcode/Deserialize.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Bitcode/Deserialize.h?rev=43595&r1=43594&r2=43595&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Bitcode/Deserialize.h (original)
+++ llvm/trunk/include/llvm/Bitcode/Deserialize.h Wed Oct 31 19:57:37 2007
@@ -30,54 +30,49 @@
   //===----------------------------------------------------------===//
   // Internal type definitions.
   //===----------------------------------------------------------===//
-
-  struct PtrIdInfo {
-    static inline unsigned getEmptyKey() { return ~((unsigned) 0x0); }
-    static inline unsigned getTombstoneKey() { return getEmptyKey()-1; }
-    static inline unsigned getHashValue(unsigned X) { return X; }
-    static inline bool isEqual(unsigned X, unsigned Y) { return X == Y; }
-    static inline bool isPod() { return true; }
-  };
   
   struct BPNode {
     BPNode* Next;
     uintptr_t& PtrRef;
+    
     BPNode(BPNode* n, uintptr_t& pref) 
       : Next(n), PtrRef(pref) {
         PtrRef = 0;
       }
   };
   
-  class BPatchEntry {
-    uintptr_t Ptr;
+  struct BPEntry { 
+    union { BPNode* Head; void* Ptr; };
+    
+    BPEntry() : Head(NULL) {}
+    
+    static inline bool isPod() { return true; }
+    
+    void SetPtr(BPNode*& FreeList, void* P);    
+  };  
+  
+  class BPKey {
+    unsigned Raw;
+    
   public:
+    BPKey(unsigned PtrId) : Raw(PtrId << 1) { assert (PtrId > 0); }
     
-    BPatchEntry() : Ptr(0x1) {}
-      
-    BPatchEntry(void* P) : Ptr(reinterpret_cast(P)) {}
-
-    bool hasFinalPtr() const { return Ptr & 0x1 ? false : true; }
-    void setFinalPtr(BPNode*& FreeList, const void* P);
-
-    BPNode* getBPNode() const {
-      assert (!hasFinalPtr());
-      return reinterpret_cast(Ptr & ~0x1);
-    }
+    void MarkFinal() { Raw |= 0x1; }
+    bool hasFinalPtr() const { return Raw & 0x1 ? true : false; }
+    unsigned getID() const { return Raw >> 1; }
     
-    void setBPNode(BPNode* N) {
-      assert (!hasFinalPtr());
-      Ptr = reinterpret_cast(N) | 0x1;
+    static inline BPKey getEmptyKey() { return 0; }
+    static inline BPKey getTombstoneKey() { return 1; }
+    static inline unsigned getHashValue(const BPKey& K) { return K.Raw & ~0x1; }
+
+    static bool isEqual(const BPKey& K1, const BPKey& K2) {
+      return (K1.Raw ^ K2.Raw) & ~0x1 ? false : true;
     }
     
-    uintptr_t getFinalPtr() const {
-      assert (!(Ptr & 0x1) && "Backpatch pointer not yet deserialized.");
-      return Ptr;
-    }    
-
-    static inline bool isPod() { return true; }
+    static bool isPod() { return true; }
   };
-
-  typedef llvm::DenseMap MapTy;
+  
+  typedef llvm::DenseMap MapTy;
 
   //===----------------------------------------------------------===//
   // Internal data members.
@@ -162,6 +157,27 @@
   void ReadRecord();  
   bool inRecord();
   uintptr_t ReadInternalRefPtr();
+  
+  static inline bool HasFinalPtr(MapTy::value_type& V) {
+    return V.first.hasFinalPtr();
+  }
+  
+  static inline uintptr_t GetFinalPtr(MapTy::value_type& V) {
+    return reinterpret_cast(V.second.Ptr);
+  }
+  
+  static inline BPNode* GetBPNode(MapTy::value_type& V) {
+    return V.second.Head;
+  }
+    
+  static inline void SetBPNode(MapTy::value_type& V, BPNode* N) {
+    V.second.Head = N;
+  }
+  
+  void SetPtr(MapTy::value_type& V, const void* P) {
+    V.first.MarkFinal();
+    V.second.SetPtr(FreeList,const_cast(P));
+  }
 };
     
 } // end namespace llvm

Modified: llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp?rev=43595&r1=43594&r2=43595&view=diff

==============================================================================
--- llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp (original)
+++ llvm/trunk/lib/Bitcode/Reader/Deserialize.cpp Wed Oct 31 19:57:37 2007
@@ -25,7 +25,7 @@
  
 #ifdef NDEBUG
   for (MapTy::iterator I=BPatchMap.begin(), E=BPatchMap.end(); I!=E; ++I)
-    assert (I->second.hasFinalPtr() &&
+    assert (I->first.hasFinalPtr() &&
             "Some pointers were not backpatched.");
 #endif
 }
@@ -99,9 +99,11 @@
 }
 
 void Deserializer::RegisterPtr(unsigned PtrId, const void* Ptr) {
-  BPatchEntry& E = BPatchMap[PtrId];
-  assert (!E.hasFinalPtr() && "Pointer already registered.");
-  E.setFinalPtr(FreeList,Ptr);
+  MapTy::value_type& E = BPatchMap.FindAndConstruct(BPKey(PtrId));
+  
+  assert (!HasFinalPtr(E) && "Pointer already registered.");
+
+  SetPtr(E,Ptr);
 }
 
 void Deserializer::ReadUIntPtr(uintptr_t& PtrRef) {
@@ -111,11 +113,11 @@
     PtrRef = 0;
     return;
   }  
+
+  MapTy::value_type& E = BPatchMap.FindAndConstruct(BPKey(PtrId));
   
-  BPatchEntry& E = BPatchMap[PtrId];
-  
-  if (E.hasFinalPtr())
-    PtrRef = E.getFinalPtr();
+  if (HasFinalPtr(E))
+    PtrRef = GetFinalPtr(E);
   else {
     // Register backpatch.  Check the freelist for a BPNode.
     BPNode* N;
@@ -127,8 +129,8 @@
     else // No available BPNode.  Allocate one.
       N = (BPNode*) Allocator.Allocate();
     
-    new (N) BPNode(E.getBPNode(),PtrRef);
-    E.setBPNode(N);
+    new (N) BPNode(GetBPNode(E),PtrRef);
+    SetBPNode(E,N);
   }
 }
 
@@ -137,32 +139,28 @@
   
   assert (PtrId != 0 && "References cannot refer the NULL address.");
 
-  BPatchEntry& E = BPatchMap[PtrId];
+  MapTy::value_type& E = BPatchMap.FindAndConstruct(BPKey(PtrId));
   
-  assert (E.hasFinalPtr() &&
+  assert (!HasFinalPtr(E) &&
           "Cannot backpatch references.  Object must be already deserialized.");
   
-  return E.getFinalPtr();
+  return GetFinalPtr(E);
 }
 
-void Deserializer::BPatchEntry::setFinalPtr(BPNode*& FreeList, const void* P) {
-  assert (!hasFinalPtr());
-  
-  // Perform backpatching.
-  
+void Deserializer::BPEntry::SetPtr(BPNode*& FreeList, void* P) {
   BPNode* Last = NULL;
   
-  for (BPNode* N = getBPNode() ; N != NULL; N = N->Next) {
+  for (BPNode* N = Head; N != NULL; N=N->Next) {
     Last = N;
     N->PtrRef |= reinterpret_cast(P);
   }
   
   if (Last) {
     Last->Next = FreeList;
-    FreeList = getBPNode();    
+    FreeList = Head;
   }
   
-  Ptr = reinterpret_cast(P);
+  Ptr = const_cast(P);
 }
 
 




From sabre at nondot.org  Wed Oct 31 21:18:41 2007
From: sabre at nondot.org (Chris Lattner)
Date: Thu, 01 Nov 2007 02:18:41 -0000
Subject: [llvm-commits] [llvm] r43596 - in /llvm/trunk:
 lib/Transforms/Scalar/InstructionCombining.cpp
 test/Transforms/InstCombine/2007-10-31-RangeCrash.ll
Message-ID: <200711010218.lA12If0O004598@zion.cs.uiuc.edu>

Author: lattner
Date: Wed Oct 31 21:18:41 2007
New Revision: 43596

URL: http://llvm.org/viewvc/llvm-project?rev=43596&view=rev
Log:
Fix InstCombine/2007-10-31-RangeCrash.ll

Added:
    llvm/trunk/test/Transforms/InstCombine/2007-10-31-RangeCrash.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=43596&r1=43595&r2=43596&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Wed Oct 31 21:18:41 2007
@@ -4028,6 +4028,10 @@
             case ICmpInst::ICMP_EQ:         // (X u< 13 | X == 14) -> no change
               break;
             case ICmpInst::ICMP_UGT:        // (X u< 13 | X u> 15) ->(X-13) u> 2
+              // If RHSCst is [us]MAXINT, it is always false.  Not handling
+              // this can cause overflow.
+              if (RHSCst->isMaxValue(false))
+                return ReplaceInstUsesWith(I, LHS);
               return InsertRangeTest(LHSVal, LHSCst, AddOne(RHSCst), false, 
                                      false, I);
             case ICmpInst::ICMP_SGT:        // (X u< 13 | X s> 15) -> no change
@@ -4045,6 +4049,10 @@
             case ICmpInst::ICMP_EQ:         // (X s< 13 | X == 14) -> no change
               break;
             case ICmpInst::ICMP_SGT:        // (X s< 13 | X s> 15) ->(X-13) s> 2
+              // If RHSCst is [us]MAXINT, it is always false.  Not handling
+              // this can cause overflow.
+              if (RHSCst->isMaxValue(true))
+                return ReplaceInstUsesWith(I, LHS);
               return InsertRangeTest(LHSVal, LHSCst, AddOne(RHSCst), true, 
                                      false, I);
             case ICmpInst::ICMP_UGT:        // (X s< 13 | X u> 15) -> no change

Added: llvm/trunk/test/Transforms/InstCombine/2007-10-31-RangeCrash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2007-10-31-RangeCrash.ll?rev=43596&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2007-10-31-RangeCrash.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2007-10-31-RangeCrash.ll Wed Oct 31 21:18:41 2007
@@ -0,0 +1,35 @@
+; RUN: llvm-as < %s | opt -instcombine -disable-output
+target datalayout = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f128:64:128"
+target triple = "powerpc-apple-darwin8"
+
+define i32 @test() {
+entry:
+	%tmp50.i17 = icmp slt i32 0, 4		;  [#uses=1]
+	br i1 %tmp50.i17, label %bb.i, label %calculateColorSpecificBlackLevel.exit
+
+bb.i:		; preds = %entry
+	br label %bb51.i.i
+
+bb27.i.i:		; preds = %bb51.i.i
+	%tmp31.i.i = load i16* null, align 2		;  [#uses=2]
+	%tmp35.i.i = icmp ult i16 %tmp31.i.i, 1		;  [#uses=1]
+	%tmp41.i.i = icmp ugt i16 %tmp31.i.i, -1		;  [#uses=1]
+	%bothcond.i.i = or i1 %tmp35.i.i, %tmp41.i.i		;  [#uses=1]
+	%bothcond1.i.i = zext i1 %bothcond.i.i to i32		;  [#uses=1]
+	%tmp46.i.i = xor i32 %bothcond1.i.i, 1		;  [#uses=1]
+	%count.0.i.i = add i32 %count.1.i.i, %tmp46.i.i		;  [#uses=1]
+	%tmp50.i.i = add i32 %x.0.i.i, 2		;  [#uses=1]
+	br label %bb51.i.i
+
+bb51.i.i:		; preds = %bb27.i.i, %bb.i
+	%count.1.i.i = phi i32 [ %count.0.i.i, %bb27.i.i ], [ 0, %bb.i ]		;  [#uses=1]
+	%x.0.i.i = phi i32 [ %tmp50.i.i, %bb27.i.i ], [ 0, %bb.i ]		;  [#uses=2]
+	%tmp54.i.i = icmp slt i32 %x.0.i.i, 0		;  [#uses=1]
+	br i1 %tmp54.i.i, label %bb27.i.i, label %bb57.i.i
+
+bb57.i.i:		; preds = %bb51.i.i
+	ret i32 0
+
+calculateColorSpecificBlackLevel.exit:		; preds = %entry
+	ret i32 undef
+}




From sabre at nondot.org  Wed Oct 31 21:30:35 2007
From: sabre at nondot.org (Chris Lattner)
Date: Thu, 01 Nov 2007 02:30:35 -0000
Subject: [llvm-commits] [llvm] r43597 - in /llvm/trunk:
 lib/VMCore/Constants.cpp
 test/Transforms/InstCombine/2007-10-31-StringCrash.ll
Message-ID: <200711010230.lA12UZgp005326@zion.cs.uiuc.edu>

Author: lattner
Date: Wed Oct 31 21:30:35 2007
New Revision: 43597

URL: http://llvm.org/viewvc/llvm-project?rev=43597&view=rev
Log:
Fix InstCombine/2007-10-31-StringCrash.ll by removing an obvious
(in hindsight) infinite recursion.  Simplify the code.

Added:
    llvm/trunk/test/Transforms/InstCombine/2007-10-31-StringCrash.ll
Modified:
    llvm/trunk/lib/VMCore/Constants.cpp

Modified: llvm/trunk/lib/VMCore/Constants.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Constants.cpp?rev=43597&r1=43596&r2=43597&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/Constants.cpp (original)
+++ llvm/trunk/lib/VMCore/Constants.cpp Wed Oct 31 21:30:35 2007
@@ -2268,18 +2268,14 @@
         }
       }
     }
-  } else if (Constant *C = dyn_cast(this)) {
-    if (GlobalValue *GV = dyn_cast(C))
-      return GV->getStringValue(Chop, Offset);
-    else if (ConstantExpr *CE = dyn_cast(C)) {
-      if (CE->getOpcode() == Instruction::GetElementPtr) {
-        // Turn a gep into the specified offset.
-        if (CE->getNumOperands() == 3 &&
-            cast(CE->getOperand(1))->isNullValue() &&
-            isa(CE->getOperand(2))) {
-          Offset += cast(CE->getOperand(2))->getZExtValue();
-          return CE->getOperand(0)->getStringValue(Chop, Offset);
-        }
+  } else if (ConstantExpr *CE = dyn_cast(this)) {
+    if (CE->getOpcode() == Instruction::GetElementPtr) {
+      // Turn a gep into the specified offset.
+      if (CE->getNumOperands() == 3 &&
+          cast(CE->getOperand(1))->isNullValue() &&
+          isa(CE->getOperand(2))) {
+        Offset += cast(CE->getOperand(2))->getZExtValue();
+        return CE->getOperand(0)->getStringValue(Chop, Offset);
       }
     }
   }

Added: llvm/trunk/test/Transforms/InstCombine/2007-10-31-StringCrash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2007-10-31-StringCrash.ll?rev=43597&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2007-10-31-StringCrash.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2007-10-31-StringCrash.ll Wed Oct 31 21:30:35 2007
@@ -0,0 +1,21 @@
+; RUN: llvm-as < %s | opt -instcombine -disable-output
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i686-apple-darwin8"
+
+declare void @__darwin_gcc3_preregister_frame_info()
+
+define void @_start(i32 %argc, i8** %argv, i8** %envp) {
+entry:
+	%tmp1 = bitcast void ()* @__darwin_gcc3_preregister_frame_info to i32*		;  [#uses=1]
+	%tmp2 = load i32* %tmp1, align 4		;  [#uses=1]
+	%tmp3 = icmp ne i32 %tmp2, 0		;  [#uses=1]
+	%tmp34 = zext i1 %tmp3 to i8		;  [#uses=1]
+	%toBool = icmp ne i8 %tmp34, 0		;  [#uses=1]
+	br i1 %toBool, label %cond_true, label %return
+
+cond_true:		; preds = %entry
+	ret void
+
+return:		; preds = %entry
+	ret void
+}




From dalej at apple.com  Wed Oct 31 21:38:24 2007
From: dalej at apple.com (Dale Johannesen)
Date: Thu, 01 Nov 2007 02:38:24 -0000
Subject: [llvm-commits] [llvm] r43598 -
	/llvm/trunk/test/CodeGen/X86/2007-10-31-extractelement-i64.ll
Message-ID: <200711010238.lA12cOZd005721@zion.cs.uiuc.edu>

Author: johannes
Date: Wed Oct 31 21:38:24 2007
New Revision: 43598

URL: http://llvm.org/viewvc/llvm-project?rev=43598&view=rev
Log:
Test that expand_vector_elt(v2i64) works in 32-bit mode.


Added:
    llvm/trunk/test/CodeGen/X86/2007-10-31-extractelement-i64.ll

Added: llvm/trunk/test/CodeGen/X86/2007-10-31-extractelement-i64.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2007-10-31-extractelement-i64.ll?rev=43598&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/2007-10-31-extractelement-i64.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2007-10-31-extractelement-i64.ll Wed Oct 31 21:38:24 2007
@@ -0,0 +1,82 @@
+; RUN: llvm-as < %s | llc -march=x86 -mattr=sse2
+; ModuleID = 'yyy.c'
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i686-apple-darwin8"
+
+define <1 x i64> @a(<2 x i64> %__A) {
+entry:
+	%__A_addr = alloca <2 x i64>		; <<2 x i64>*> [#uses=2]
+	%retval = alloca <1 x i64>, align 8		; <<1 x i64>*> [#uses=3]
+	%"alloca point" = bitcast i32 0 to i32		;  [#uses=0]
+	store <2 x i64> %__A, <2 x i64>* %__A_addr
+	%tmp = load <2 x i64>* %__A_addr, align 16		; <<2 x i64>> [#uses=1]
+	%tmp1 = bitcast <2 x i64> %tmp to <2 x i64>		; <<2 x i64>> [#uses=1]
+	%tmp2 = extractelement <2 x i64> %tmp1, i32 0		;  [#uses=1]
+	%tmp3 = bitcast i64 %tmp2 to <1 x i64>		; <<1 x i64>> [#uses=1]
+	store <1 x i64> %tmp3, <1 x i64>* %retval, align 8
+	%tmp4 = load <1 x i64>* %retval, align 8		; <<1 x i64>> [#uses=0]
+	br label %return
+
+return:		; preds = %entry
+	%retval5 = load <1 x i64>* %retval		; <<1 x i64>> [#uses=1]
+	ret <1 x i64> %retval5
+}
+
+define <1 x i64> @b(<2 x i64> %__A) {
+entry:
+	%__A_addr = alloca <2 x i64>		; <<2 x i64>*> [#uses=2]
+	%retval = alloca <1 x i64>, align 8		; <<1 x i64>*> [#uses=3]
+	%"alloca point" = bitcast i32 0 to i32		;  [#uses=0]
+	store <2 x i64> %__A, <2 x i64>* %__A_addr
+	%tmp = load <2 x i64>* %__A_addr, align 16		; <<2 x i64>> [#uses=1]
+	%tmp1 = bitcast <2 x i64> %tmp to <2 x i64>		; <<2 x i64>> [#uses=1]
+	%tmp2 = extractelement <2 x i64> %tmp1, i32 1		;  [#uses=1]
+	%tmp3 = bitcast i64 %tmp2 to <1 x i64>		; <<1 x i64>> [#uses=1]
+	store <1 x i64> %tmp3, <1 x i64>* %retval, align 8
+	%tmp4 = load <1 x i64>* %retval, align 8		; <<1 x i64>> [#uses=0]
+	br label %return
+
+return:		; preds = %entry
+	%retval5 = load <1 x i64>* %retval		; <<1 x i64>> [#uses=1]
+	ret <1 x i64> %retval5
+}
+
+define i64 @c(<2 x i64> %__A) {
+entry:
+	%__A_addr = alloca <2 x i64>		; <<2 x i64>*> [#uses=2]
+	%retval = alloca i64, align 8		;  [#uses=2]
+	%tmp = alloca i64, align 8		;  [#uses=2]
+	%"alloca point" = bitcast i32 0 to i32		;  [#uses=0]
+	store <2 x i64> %__A, <2 x i64>* %__A_addr
+	%tmp1 = load <2 x i64>* %__A_addr, align 16		; <<2 x i64>> [#uses=1]
+	%tmp2 = bitcast <2 x i64> %tmp1 to <2 x i64>		; <<2 x i64>> [#uses=1]
+	%tmp3 = extractelement <2 x i64> %tmp2, i32 0		;  [#uses=1]
+	store i64 %tmp3, i64* %tmp, align 8
+	%tmp4 = load i64* %tmp, align 8		;  [#uses=1]
+	store i64 %tmp4, i64* %retval, align 8
+	br label %return
+
+return:		; preds = %entry
+	%retval5 = load i64* %retval		;  [#uses=1]
+	ret i64 %retval5
+}
+
+define i64 @d(<2 x i64> %__A) {
+entry:
+	%__A_addr = alloca <2 x i64>		; <<2 x i64>*> [#uses=2]
+	%retval = alloca i64, align 8		;  [#uses=2]
+	%tmp = alloca i64, align 8		;  [#uses=2]
+	%"alloca point" = bitcast i32 0 to i32		;  [#uses=0]
+	store <2 x i64> %__A, <2 x i64>* %__A_addr
+	%tmp1 = load <2 x i64>* %__A_addr, align 16		; <<2 x i64>> [#uses=1]
+	%tmp2 = bitcast <2 x i64> %tmp1 to <2 x i64>		; <<2 x i64>> [#uses=1]
+	%tmp3 = extractelement <2 x i64> %tmp2, i32 1		;  [#uses=1]
+	store i64 %tmp3, i64* %tmp, align 8
+	%tmp4 = load i64* %tmp, align 8		;  [#uses=1]
+	store i64 %tmp4, i64* %retval, align 8
+	br label %return
+
+return:		; preds = %entry
+	%retval5 = load i64* %retval		;  [#uses=1]
+	ret i64 %retval5
+}




From clattner at apple.com  Wed Oct 31 22:50:31 2007
From: clattner at apple.com (Chris Lattner)
Date: Wed, 31 Oct 2007 20:50:31 -0700
Subject: [llvm-commits] [llvm] r43578 -
	/llvm/trunk/lib/VMCore/Verifier.cpp
In-Reply-To: <200710312104.l9VL4I2M017819@zion.cs.uiuc.edu>
References: <200710312104.l9VL4I2M017819@zion.cs.uiuc.edu>
Message-ID: <61DC5147-BAFF-4748-9D78-169BE970A5A1@apple.com>


On Oct 31, 2007, at 2:04 PM, Owen Anderson wrote:

> Author: resistor
> Date: Wed Oct 31 16:04:18 2007
> New Revision: 43578
>
> URL: http://llvm.org/viewvc/llvm-project?rev=43578&view=rev
> Log:
> Add a preverifier pass to check that every basic block ends in a  
> terminator, so that we don't segfault when verifying invalid code.

Oh, for the love of tabs...  The tabs are stabbing by eyeballs  
out! :) :)

-Chris

>
> Modified:
>    llvm/trunk/lib/VMCore/Verifier.cpp
>
> Modified: llvm/trunk/lib/VMCore/Verifier.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Verifier.cpp?rev=43578&r1=43577&r2=43578&view=diff
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm/trunk/lib/VMCore/Verifier.cpp (original)
> +++ llvm/trunk/lib/VMCore/Verifier.cpp Wed Oct 31 16:04:18 2007
> @@ -71,7 +71,25 @@
>   cl::opt
>   Pedantic("verify-pedantic",
>            cl::desc("Reject code with undefined behaviour"));
> -
> +
> +  struct VISIBILITY_HIDDEN PreVerifier : public FunctionPass {
> +  	static char ID; // Pass ID, replacement for typeid
> +  	
> +  	PreVerifier() : FunctionPass((intptr_t)&ID) { }
> +  	
> +  	bool runOnFunction(Function &F) {
> +      for (Function::iterator I = F.begin(), E = F.end(); I != E; + 
> +I)
> +        assert(I->back().isTerminator()
> +               && "Block does not end with a terminator?");
> +
> +      return false;
> +  	}
> +  };
> +
> +  char PreVerifier::ID = 0;
> +  RegisterPass PreVer("preverify", "Preliminary module  
> verification");
> +  const PassInfo *PreVerifyID = PreVer.getPassInfo();
> +
>   struct VISIBILITY_HIDDEN
>      Verifier : public FunctionPass, InstVisitor {
>     static char ID; // Pass ID, replacement for typeid
> @@ -161,6 +179,7 @@
>
>     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
>       AU.setPreservesAll();
> +      AU.addRequiredID(PreVerifyID);
>       if (RealPass)
>         AU.addRequired();
>     }
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits



From resistor at mac.com  Wed Oct 31 22:54:24 2007
From: resistor at mac.com (Owen Anderson)
Date: Thu, 01 Nov 2007 03:54:24 -0000
Subject: [llvm-commits] [llvm] r43601 - /llvm/trunk/lib/VMCore/Verifier.cpp
Message-ID: <200711010354.lA13sOwi011032@zion.cs.uiuc.edu>

Author: resistor
Date: Wed Oct 31 22:54:23 2007
New Revision: 43601

URL: http://llvm.org/viewvc/llvm-project?rev=43601&view=rev
Log:
Now with less tabs!

Modified:
    llvm/trunk/lib/VMCore/Verifier.cpp

Modified: llvm/trunk/lib/VMCore/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Verifier.cpp?rev=43601&r1=43600&r2=43601&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/Verifier.cpp (original)
+++ llvm/trunk/lib/VMCore/Verifier.cpp Wed Oct 31 22:54:23 2007
@@ -73,17 +73,17 @@
            cl::desc("Reject code with undefined behaviour"));
   
   struct VISIBILITY_HIDDEN PreVerifier : public FunctionPass {
-  	static char ID; // Pass ID, replacement for typeid
+    static char ID; // Pass ID, replacement for typeid
   	
-  	PreVerifier() : FunctionPass((intptr_t)&ID) { }
+    PreVerifier() : FunctionPass((intptr_t)&ID) { }
   	
-  	bool runOnFunction(Function &F) {
+    bool runOnFunction(Function &F) {
       for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
         assert(I->back().isTerminator()
                && "Block does not end with a terminator?");
       
-      return false;
-  	}
+        return false;
+    }
   };
   
   char PreVerifier::ID = 0;




From sabre at nondot.org  Wed Oct 31 23:20:16 2007
From: sabre at nondot.org (Chris Lattner)
Date: Thu, 01 Nov 2007 04:20:16 -0000
Subject: [llvm-commits] [llvm] r43602 - /llvm/trunk/docs/GettingStarted.html
Message-ID: <200711010420.lA14KGRe012732@zion.cs.uiuc.edu>

Author: lattner
Date: Wed Oct 31 23:20:16 2007
New Revision: 43602

URL: http://llvm.org/viewvc/llvm-project?rev=43602&view=rev
Log:
add a broken gcc version, thanks to P. Durante for pointing this out.

Modified:
    llvm/trunk/docs/GettingStarted.html

Modified: llvm/trunk/docs/GettingStarted.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/GettingStarted.html?rev=43602&r1=43601&r2=43602&view=diff

==============================================================================
--- llvm/trunk/docs/GettingStarted.html (original)
+++ llvm/trunk/docs/GettingStarted.html Wed Oct 31 23:20:16 2007
@@ -17,37 +17,37 @@
   Getting Started Quickly (A Summary)
   
Requirements
     
-      Hardware
-      
Software
-      
Broken versions of GCC and other tools
+      
Hardware
+      Software
+      Broken versions of GCC and other tools
     
 
   Getting Started with LLVM
     
-      Terminology and Notation
-      
Setting Up Your Environment
-      
Unpacking the LLVM Archives
-      
Checkout LLVM from Subversion
-      
Install the GCC Front End
-      
Local LLVM Configuration
-      
Compiling the LLVM Suite Source Code
-      
Cross-Compiling LLVM
-      
The Location of LLVM Object Files
-      
Optional Configuration Items
+      
Terminology and Notation
+      Setting Up Your Environment
+      Unpacking the LLVM Archives
+      Checkout LLVM from Subversion
+      Install the GCC Front End
+      Local LLVM Configuration
+      Compiling the LLVM Suite Source Code
+      Cross-Compiling LLVM
+      The Location of LLVM Object Files
+      Optional Configuration Items
     
 
   Program layout
     
-      llvm/examples
-      
llvm/include
-      
llvm/lib
-      
llvm/projects
-      
llvm/runtime  
-      
llvm/test
-      
llvm-test
-      
llvm/tools  
-      
llvm/utils
-      
llvm/win32
+      
llvm/examples
+      llvm/include
+      llvm/lib
+      llvm/projects
+      llvm/runtime
+      llvm/test
+      llvm-test
+      llvm/tools
+      llvm/utils
+      llvm/win32
     
 
   An Example Using the LLVM Tool Chain
@@ -532,6 +532,10 @@
    builds with "make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2 ..."
 GCC 3.4.x on X86-64/amd64: GCC 
    miscompiles portions of LLVM.
+GCC 3.4.4 (CodeSourcery ARM 2005q3-2): this compiler miscompiles LLVM
+   when building with optimizations enabled.  It appears to work with 
+   "make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O1" or build a debug
+   build.
 IA-64 GCC 4.0.0: The IA-64 version of GCC 4.0.0 is known to
    miscompile LLVM.
 Apple Xcode 2.3: GCC crashes when compiling LLVM at -O3 (which is the




From sabre at nondot.org  Wed Oct 31 23:43:13 2007
From: sabre at nondot.org (Chris Lattner)
Date: Thu, 01 Nov 2007 04:43:13 -0000
Subject: [llvm-commits] [llvm] r43603 - /llvm/trunk/lib/VMCore/Verifier.cpp
Message-ID: <200711010443.lA14hEo5013870@zion.cs.uiuc.edu>

Author: lattner
Date: Wed Oct 31 23:43:13 2007
New Revision: 43603

URL: http://llvm.org/viewvc/llvm-project?rev=43603&view=rev
Log:
remove verifier command line option: this should be part of the API, not
a command line optn.

Modified:
    llvm/trunk/lib/VMCore/Verifier.cpp

Modified: llvm/trunk/lib/VMCore/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Verifier.cpp?rev=43603&r1=43602&r2=43603&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/Verifier.cpp (original)
+++ llvm/trunk/lib/VMCore/Verifier.cpp Wed Oct 31 23:43:13 2007
@@ -60,7 +60,6 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compiler.h"
 #include 
 #include 
@@ -68,10 +67,6 @@
 using namespace llvm;
 
 namespace {  // Anonymous namespace for class
-  cl::opt
-  Pedantic("verify-pedantic",
-           cl::desc("Reject code with undefined behaviour"));
-  
   struct VISIBILITY_HIDDEN PreVerifier : public FunctionPass {
     static char ID; // Pass ID, replacement for typeid
   	
@@ -830,12 +825,6 @@
             CI.getOperand(i+1), FTy->getParamType(i), &CI);
 
   if (Function *F = CI.getCalledFunction()) {
-    if (Pedantic) {
-      // Verify that calling convention of Function and CallInst match
-      Assert1(F->getCallingConv() == CI.getCallingConv(),
-              "Call uses different calling convention than function", &CI);
-    }
-    
     if (Intrinsic::ID ID = (Intrinsic::ID)F->getIntrinsicID())
       visitIntrinsicFunctionCall(ID, CI);
   }




From resistor at mac.com  Thu Nov  1 00:29:21 2007
From: resistor at mac.com (Owen Anderson)
Date: Thu, 01 Nov 2007 05:29:21 -0000
Subject: [llvm-commits] [llvm] r43605 - in /llvm/trunk:
 lib/Transforms/Scalar/DeadStoreElimination.cpp
 test/Transforms/DeadStoreElimination/PartialStore.ll
Message-ID: <200711010529.lA15TL35016673@zion.cs.uiuc.edu>

Author: resistor
Date: Thu Nov  1 00:29:16 2007
New Revision: 43605

URL: http://llvm.org/viewvc/llvm-project?rev=43605&view=rev
Log:
Fix test/Transforms/DeadStoreElimination/PartialStore.ll, which had been
silently failing because of an incorrect run line for some time.

Modified:
    llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp
    llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll

Modified: llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp?rev=43605&r1=43604&r2=43605&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp Thu Nov  1 00:29:16 2007
@@ -63,14 +63,18 @@
     /// from allocas, it is safe to ignore GEP indices, since
     /// either the store will be in the alloca, and thus dead,
     /// or beyond the end of the alloca, and thus undefined.
-    void TranslatePointerBitCasts(Value*& v) {
+    void TranslatePointerBitCasts(Value*& v, bool zeroGepsOnly = false) {
       assert(isa(v->getType()) &&
              "Translating a non-pointer type?");
       while (true) {
         if (BitCastInst* C = dyn_cast(v))
           v = C->getOperand(0);
         else if (GetElementPtrInst* G = dyn_cast(v))
-          v = G->getOperand(0);
+          if (!zeroGepsOnly || G->hasAllZeroIndices()) {
+            v = G->getOperand(0);
+          } else {
+            break;
+          }
         else
           break;
       }
@@ -95,7 +99,8 @@
 
 bool DSE::runOnBasicBlock(BasicBlock &BB) {
   MemoryDependenceAnalysis& MD = getAnalysis();
-  
+  TargetData &TD = getAnalysis();  
+
   // Record the last-seen store to this pointer
   DenseMap lastStore;
   // Record instructions possibly made dead by deleting a store
@@ -119,6 +124,7 @@
     } else
       pointer = cast(BBI)->getPointerOperand();
       
+    TranslatePointerBitCasts(pointer, true);
     StoreInst*& last = lastStore[pointer];
     bool deletedStore = false;
       
@@ -130,7 +136,9 @@
       while (dep != MemoryDependenceAnalysis::None &&
              dep != MemoryDependenceAnalysis::NonLocal &&
              isa(dep)) {
-        if (dep != last) {
+        if (dep != last ||
+             TD.getTypeSize(last->getOperand(0)->getType()) >
+             TD.getTypeSize(BBI->getOperand(0)->getType())) {
           dep = MD.getDependency(BBI, dep);
           continue;
         }

Modified: llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll?rev=43605&r1=43604&r2=43605&view=diff

==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll (original)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll Thu Nov  1 00:29:16 2007
@@ -1,5 +1,5 @@
 ; RUN: llvm-upgrade < %s | llvm-as | opt -dse | llvm-dis | \
-; RUN:    not grep {store sbyte}
+; RUN:    not grep {store i8}
 ; Ensure that the dead store is deleted in this case.  It is wholely
 ; overwritten by the second store.
 int %test() {




From evan.cheng at apple.com  Thu Nov  1 01:22:48 2007
From: evan.cheng at apple.com (Evan Cheng)
Date: Thu, 01 Nov 2007 06:22:48 -0000
Subject: [llvm-commits] [llvm] r43606 - in /llvm/trunk:
 include/llvm/CodeGen/SimpleRegisterCoalescing.h
 lib/CodeGen/SimpleRegisterCoalescing.cpp
Message-ID: <200711010622.lA16Mmx3020633@zion.cs.uiuc.edu>

Author: evancheng
Date: Thu Nov  1 01:22:48 2007
New Revision: 43606

URL: http://llvm.org/viewvc/llvm-project?rev=43606&view=rev
Log:
- Coalesce extract_subreg when both intervals are relatively small.
- Some code clean up.

Modified:
    llvm/trunk/include/llvm/CodeGen/SimpleRegisterCoalescing.h
    llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp

Modified: llvm/trunk/include/llvm/CodeGen/SimpleRegisterCoalescing.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/SimpleRegisterCoalescing.h?rev=43606&r1=43605&r2=43606&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/SimpleRegisterCoalescing.h (original)
+++ llvm/trunk/include/llvm/CodeGen/SimpleRegisterCoalescing.h Thu Nov  1 01:22:48 2007
@@ -109,11 +109,11 @@
 
     /// JoinCopy - Attempt to join intervals corresponding to SrcReg/DstReg,
     /// which are the src/dst of the copy instruction CopyMI.  This returns true
-    /// if the copy was successfully coalesced away, or if it is never possible
-    /// to coalesce these this copy, due to register constraints.  It returns
-    /// false if it is not currently possible to coalesce this interval, but
-    /// it may be possible if other things get coalesced.
-    bool JoinCopy(MachineInstr *CopyMI, unsigned SrcReg, unsigned DstReg);
+    /// if the copy was successfully coalesced away. If it is not currently
+    /// possible to coalesce this interval, but it may be possible if other
+    /// things get coalesced, then it returns true by reference in 'Again'.
+    bool JoinCopy(MachineInstr *CopyMI, unsigned SrcReg, unsigned DstReg,
+                  bool &Again);
     
     /// JoinIntervals - Attempt to join these two intervals.  On failure, this
     /// returns false.  Otherwise, if one of the intervals being joined is a

Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp?rev=43606&r1=43605&r2=43606&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp Thu Nov  1 01:22:48 2007
@@ -197,22 +197,24 @@
 
 /// JoinCopy - Attempt to join intervals corresponding to SrcReg/DstReg,
 /// which are the src/dst of the copy instruction CopyMI.  This returns true
-/// if the copy was successfully coalesced away, or if it is never possible
-/// to coalesce this copy, due to register constraints.  It returns
-/// false if it is not currently possible to coalesce this interval, but
-/// it may be possible if other things get coalesced.
+/// if the copy was successfully coalesced away. If it is not currently
+/// possible to coalesce this interval, but it may be possible if other
+/// things get coalesced, then it returns true by reference in 'Again'.
 bool SimpleRegisterCoalescing::JoinCopy(MachineInstr *CopyMI,
-                                        unsigned SrcReg, unsigned DstReg) {
+                                        unsigned SrcReg, unsigned DstReg,
+                                        bool &Again) {
   DOUT << li_->getInstructionIndex(CopyMI) << '\t' << *CopyMI;
 
   // Get representative registers.
   unsigned repSrcReg = rep(SrcReg);
   unsigned repDstReg = rep(DstReg);
   
+  Again = false;
+
   // If they are already joined we continue.
   if (repSrcReg == repDstReg) {
     DOUT << "\tCopy already coalesced.\n";
-    return true;  // Not coalescable.
+    return false;  // Not coalescable.
   }
   
   bool SrcIsPhys = MRegisterInfo::isPhysicalRegister(repSrcReg);
@@ -221,17 +223,17 @@
   // If they are both physical registers, we cannot join them.
   if (SrcIsPhys && DstIsPhys) {
     DOUT << "\tCan not coalesce physregs.\n";
-    return true;  // Not coalescable.
+    return false;  // Not coalescable.
   }
   
   // We only join virtual registers with allocatable physical registers.
   if (SrcIsPhys && !allocatableRegs_[repSrcReg]) {
     DOUT << "\tSrc reg is unallocatable physreg.\n";
-    return true;  // Not coalescable.
+    return false;  // Not coalescable.
   }
   if (DstIsPhys && !allocatableRegs_[repDstReg]) {
     DOUT << "\tDst reg is unallocatable physreg.\n";
-    return true;  // Not coalescable.
+    return false;  // Not coalescable.
   }
 
   bool isExtSubReg = CopyMI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG;
@@ -265,19 +267,30 @@
           RHS.overlaps(li_->getInterval(RealDstReg))) {
         DOUT << "Interfere with register ";
         DEBUG(li_->getInterval(RealDstReg).print(DOUT, mri_));
-        return true; // Not coalescable
+        return false; // Not coalescable
       }
       for (const unsigned* SR = mri_->getSubRegisters(RealDstReg); *SR; ++SR)
         if (li_->hasInterval(*SR) && RHS.overlaps(li_->getInterval(*SR))) {
           DOUT << "Interfere with sub-register ";
           DEBUG(li_->getInterval(*SR).print(DOUT, mri_));
-          return true; // Not coalescable
+          return false; // Not coalescable
         }
-    } else if (li_->getInterval(repDstReg).getSize() >
-               li_->getInterval(repSrcReg).getSize()) {
+    } else {
+      unsigned SrcSize= li_->getInterval(repSrcReg).getSize() / InstrSlots::NUM;
+      unsigned DstSize= li_->getInterval(repDstReg).getSize() / InstrSlots::NUM;
+      const TargetRegisterClass *RC=mf_->getSSARegMap()->getRegClass(repDstReg);
+      unsigned Threshold = allocatableRCRegs_[RC].count();
       // Be conservative. If both sides are virtual registers, do not coalesce
-      // if the sub-register live interval is longer.
-      return false;
+      // if this will cause a high use density interval to target a smaller set
+      // of registers.
+      if (DstSize > Threshold || SrcSize > Threshold) {
+        LiveVariables::VarInfo &svi = lv_->getVarInfo(repSrcReg);
+        LiveVariables::VarInfo &dvi = lv_->getVarInfo(repDstReg);
+        if ((float)dvi.NumUses / DstSize < (float)svi.NumUses / SrcSize) {
+          Again = true;  // May be possible to coalesce later.
+          return false;
+        }
+      }
     }
   } else if (differingRegisterClasses(repSrcReg, repDstReg)) {
     // If they are not of the same register class, we cannot join them.
@@ -286,6 +299,7 @@
     // a physical register that's compatible with the other side. e.g.
     // r1024 = MOV32to32_ r1025
     // but later r1024 is assigned EAX then r1025 may be coalesced with EAX.
+    Again = true;  // May be possible to coalesce later.
     return false;
   }
   
@@ -359,6 +373,7 @@
       JoinVInt.preference = JoinPReg;
       ++numAborts;
       DOUT << "\tMay tie down a physical register, abort!\n";
+      Again = true;  // May be possible to coalesce later.
       return false;
     }
   }
@@ -401,6 +416,7 @@
 
     // Otherwise, we are unable to join the intervals.
     DOUT << "Interference!\n";
+    Again = true;  // May be possible to coalesce later.
     return false;
   }
 
@@ -971,13 +987,17 @@
   // Try coalescing physical register + virtual register first.
   for (unsigned i = 0, e = PhysCopies.size(); i != e; ++i) {
     CopyRec &TheCopy = PhysCopies[i];
-    if (!JoinCopy(TheCopy.MI, TheCopy.SrcReg, TheCopy.DstReg))
-      TryAgain.push_back(TheCopy);
+    bool Again = false;
+    if (!JoinCopy(TheCopy.MI, TheCopy.SrcReg, TheCopy.DstReg, Again))
+      if (Again)
+        TryAgain.push_back(TheCopy);
   }
   for (unsigned i = 0, e = VirtCopies.size(); i != e; ++i) {
     CopyRec &TheCopy = VirtCopies[i];
-    if (!JoinCopy(TheCopy.MI, TheCopy.SrcReg, TheCopy.DstReg))
-      TryAgain.push_back(TheCopy);
+    bool Again = false;
+    if (!JoinCopy(TheCopy.MI, TheCopy.SrcReg, TheCopy.DstReg, Again))
+      if (Again)
+        TryAgain.push_back(TheCopy);
   }
 }
 
@@ -1021,10 +1041,13 @@
 
     for (unsigned i = 0, e = TryAgainList.size(); i != e; ++i) {
       CopyRec &TheCopy = TryAgainList[i];
-      if (TheCopy.MI &&
-          JoinCopy(TheCopy.MI, TheCopy.SrcReg, TheCopy.DstReg)) {
-        TheCopy.MI = 0;   // Mark this one as done.
-        ProgressMade = true;
+      if (TheCopy.MI) {
+        bool Again = false;
+        bool Success = JoinCopy(TheCopy.MI,TheCopy.SrcReg,TheCopy.DstReg,Again);
+        if (Success || !Again) {
+          TheCopy.MI = 0;   // Mark this one as done.
+          ProgressMade = true;
+        }
       }
     }
   }




From sabre at nondot.org  Thu Nov  1 01:49:54 2007
From: sabre at nondot.org (Chris Lattner)
Date: Thu, 01 Nov 2007 06:49:54 -0000
Subject: [llvm-commits] [llvm] r43607 - in /llvm/trunk/docs/tutorial:
	LangImpl6.html index.html
Message-ID: <200711010649.lA16ns7i022086@zion.cs.uiuc.edu>

Author: lattner
Date: Thu Nov  1 01:49:54 2007
New Revision: 43607

URL: http://llvm.org/viewvc/llvm-project?rev=43607&view=rev
Log:
Add the start of chapter 6, still much to go.

Added:
    llvm/trunk/docs/tutorial/LangImpl6.html
Modified:
    llvm/trunk/docs/tutorial/index.html

Added: llvm/trunk/docs/tutorial/LangImpl6.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl6.html?rev=43607&view=auto

==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl6.html (added)
+++ llvm/trunk/docs/tutorial/LangImpl6.html Thu Nov  1 01:49:54 2007
@@ -0,0 +1,227 @@
+
+
+
+
+  Kaleidoscope: Extending the Language: Operator Overloading
+  
+  
+  
+
+
+
+
+
Kaleidoscope: Extending the Language: Operator Overloading
+
+
+  Written by Chris Lattner
+
+
+
+Part 6 Introduction
+
+
+
+
+Welcome to Part 6 of the "Implementing a language with
+LLVM" tutorial.  At this point in our tutorial, we now have a fully
+functional language that is fairly minimal, but also useful.  One big problem
+with it though is that it doesn't have many useful operators (like division,
+logical negation, or even any comparisons other than less-than.
+
+This chapter of the tutorial takes a wild digression into adding operator
+overloading to the simple and beautiful Kaleidoscope language, giving us a 
+simple and ugly language in some ways, but also a powerful one at the same time.
+One of the great things about creating your own language is that you get to
+decide what is good or bad.  In this tutorial we'll assume that it is okay and
+use this as a way to show some interesting parsing techniques.
+
+
+
+
+Operator Overloading: the Idea
+
+
+
+
+
+The operator overloading that we will add to Kaleidoscope is more general than
+languages like C++.  In C++, you are only allowed to redefine existing
+operators: you can't programatically change the grammar, introduce new
+operators, change precedence levels, etc.  In this chapter, we will add this
+capability to Kaleidoscope, which will allow us to round out the set of
+operators that are supported, culminating in a more interesting example app.
+
+The point of going into operator overloading in a tutorial like this is to
+show the power and flexibility of using a hand-written parser.  The parser we
+are using so far is using recursive descent for most parts of the grammar, and 
+operator precedence parsing for the expressions.  See Chapter 2 for details.  Without using operator
+precedence parsing, it would be very difficult to allow the programmer to
+introduce new operators into the grammar: the grammar is dynamically extensible
+as the JIT runs.
+
+The two specific features we'll add are programmable unary operators (right
+now, Kaleidoscope has no unary operators at all) as well as binary operators.
+An example of this is:
+
+
++# Logical unary not.
+def unary!(v)
+  if v then
+    0
+  else
+    1;
+
+# Define > with the same precedence as <.
+def binary> 10 (LHS RHS)
+  !(LHS < RHS);     # alternatively, could just use "RHS < LHS"
+
+# Binary "logical or", (note that it does not "short circuit")
+def binary| 5 (LHS RHS)
+  if LHS then
+    1
+  else if RHS then
+    1
+  else
+    0;
+
+# Define = with slightly lower precedence than relationals.
+def binary= 9 (LHS RHS)
+  !(LHS < RHS | LHS > RHS);
+
+
+
+Many languages aspire to being able to implement their standard runtime
+library in the language itself.  In Kaleidoscope, we can implement significant
+parts of the language in the library!
+
+We will break down implementation of these features into two parts:
+implementing support for overloading of binary operators and adding unary
+operators.
+
+
+
+
+Overloading Binary Operators
+
+
+
+
+Adding support for overloaded binary operators is pretty simple with our
+current framework.  We'll first add support for the unary/binary keywords:
+
+
++enum Token {
+  ...
+  // operators
+  tok_binary = -11, tok_unary = -12
+};
+...
+static int gettok() {
+...
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    return tok_identifier;
+
+
+
+This just adds lexer support for the unary and binary keywords, like we
+did in previous chapters.  One nice thing
+about our current AST is that we represent binary operators fully generally
+with their ASCII code as the opcode.  For our extended operators, we'll use the
+same representation, so we don't need any new AST or parser support.
+
+On the other hand, we have to be able to represent the definitions of these
+new operators, in the "def binary| 5" part of the function definition.  In the
+grammar so far, the "name" for the function definition is parsed as the
+"prototype" production and into the PrototypeAST AST node.  To
+represent our new user-defined operators as prototypes, we have to extend
+the  PrototypeAST AST node like this:
+
+
++/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+class PrototypeAST {
+  std::string Name;
+  std::vector<std::string> Args;
+  bool isOperator;
+  unsigned Precedence;  // Precedence if a binary op.
+public:
+  PrototypeAST(const std::string &name, const std::vector<std::string> &args,
+               bool isoperator = false, unsigned prec = 0)
+  : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
+  
+  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
+  
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size()-1];
+  }
+  
+  unsigned getBinaryPrecedence() const { return Precedence; }
+  
+  Function *Codegen();
+};
+
+
+
+Basically, in addition to knowing a name for the prototype, we now keep track
+of whether it was an operator, and if it was, what precedence level the operator
+is at.  The precedence is only used for binary operators.
+
+
+...
+
+
+
+
+
+Full Code Listing
+
+
+
+
+
+Here is the complete code listing for our running example, enhanced with the
+if/then/else and for expressions..  To build this example, use:
+
+
+
++   # Compile
+   g++ -g toy.cpp `llvm-config --cppflags --ldflags --libs core jit native` -O3 -o toy
+   # Run
+   ./toy
+
+
+
+Here is the code:
+
+
++
+
+
+
+
+
+
+
+  
+  
+
+  Chris Lattner

+  The LLVM Compiler Infrastructure

+  Last modified: $Date: 2007-10-17 11:05:13 -0700 (Wed, 17 Oct 2007) $
+
+
+

Modified: llvm/trunk/docs/tutorial/index.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/index.html?rev=43607&r1=43606&r2=43607&view=diff

==============================================================================
--- llvm/trunk/docs/tutorial/index.html (original)
+++ llvm/trunk/docs/tutorial/index.html Thu Nov  1 01:49:54 2007
@@ -32,7 +32,7 @@
     
Implementing Code Generation to LLVM IR
     Adding JIT and Optimizer Support
     Extending the language: control flow
-    Extending the language: operator overloading
+    Extending the language: operator overloading
     Extending the language: mutable variables
     Thoughts and ideas for extensions
   
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+static PrototypeAST *ParsePrototype() {
+  std::string FnName;
+  
+  int Kind = 0;  // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorP("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+    
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorP("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+  
+  if (CurTok != '(')
+    return ErrorP("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorP("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorP("Invalid number of operands for operator");
+  
+  return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
+}
+
FnName
+Value *BinaryExprAST::Codegen() {
+  Value *L = LHS->Codegen();
+  Value *R = RHS->Codegen();
+  if (L == 0 || R == 0) return 0;
+  
+  switch (Op) {
+  case '+': return Builder.CreateAdd(L, R, "addtmp");
+  case '-': return Builder.CreateSub(L, R, "subtmp");
+  case '*': return Builder.CreateMul(L, R, "multmp");
+  case '<':
+    L = Builder.CreateFCmpULT(L, R, "multmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return Builder.CreateUIToFP(L, Type::DoubleTy, "booltmp");
+  default: break;
+  }
+  
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  Function *F = TheModule->getFunction(std::string("binary")+Op);
+  assert(F && "binary operator not found!");
+  
+  Value *Ops[] = { L, R };
+  return Builder.CreateCall(F, Ops, Ops+2, "binop");
+}
+
+
+Function *FunctionAST::Codegen() {
+  NamedValues.clear();
+  
+  Function *TheFunction = Proto->Codegen();
+  if (TheFunction == 0)
+    return 0;
+  
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = new BasicBlock("entry", TheFunction);
+  Builder.SetInsertPoint(BB);
+  
+  if (Value *RetVal = Body->Codegen()) {
+    ...
+
+/// UnaryExprAST - Expression class for a unary operator.
+class UnaryExprAST : public ExprAST {
+  char Opcode;
+  ExprAST *Operand;
+public:
+  UnaryExprAST(char opcode, ExprAST *operand) 
+    : Opcode(opcode), Operand(operand) {}
+  virtual Value *Codegen();
+};
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static ExprAST *ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+  
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (ExprAST *Operand = ParseUnary())
+    return new UnaryExprAST(Opc, Operand);
+  return 0;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+  ...
+    // Parse the unary expression after the binary operator.
+    ExprAST *RHS = ParseUnary();
+    if (!RHS) return 0;
+  ...
+}
+/// expression
+///   ::= unary binoprhs
+///
+static ExprAST *ParseExpression() {
+  ExprAST *LHS = ParseUnary();
+  if (!LHS) return 0;
+  
+  return ParseBinOpRHS(0, LHS);
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static PrototypeAST *ParsePrototype() {
+  std::string FnName;
+  
+  int Kind = 0;  // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorP("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    ...
+
+Value *UnaryExprAST::Codegen() {
+  Value *OperandV = Operand->Codegen();
+  if (OperandV == 0) return 0;
+  
+  Function *F = TheModule->getFunction(std::string("unary")+Opcode);
+  if (F == 0)
+    return ErrorV("Unknown unary operator");
+  
+  return Builder.CreateCall(F, OperandV, "unop");
+}
+
+ready> extern printd(x);
+Read extern: declare double @printd(double)
+ready> def binary : 1 (x y) 0;  # Low-precedence operator that ignores operands.
+..
+ready> printd(123) : printd(456) : printd(789);
+123.000000
+456.000000
+789.000000
+Evaluated to 0.000000
+
+# Logical unary not.
+def unary!(v)
+  if v then
+    0
+  else
+    1;
+    
+# Unary negate.
+def unary-(v)
+  0-v;
 
+# Define > with the same precedence as >.  We could also easily define
+# <= etc.
+def binary> 10 (LHS RHS)
+  !(LHS < RHS);
+
+# Binary logical or, which does not short circuit. 
+def binary| 5 (LHS RHS)
+  if LHS then
+    1
+  else if RHS then
+    1
+  else
+    0;
+
+# Binary logical and, which does not short circuit. 
+def binary& 6 (LHS RHS)
+  if !LHS then
+    0
+  else
+    !!RHS;
 
-...
+# Define = with slightly lower precedence than relationals.
+def binary = 9 (LHS RHS)
+  !(LHS < RHS | LHS > RHS);
+
+
+ready>
+
+extern putchard(char)
+def printdensity(d)
+  if d > 8 then
+    putchard(32)  # ' '
+  else if d > 4 then
+    putchard(46)  # '.'
+  else if d > 2 then
+    putchard(43)  # '+'
+  else
+    putchard(42); # '*'
+...
+ready> printdensity(1): printdensity(2): printdensity(3) : 
+          printdensity(4): printdensity(5): printdensity(9): putchard(10);
+*++.. 
+Evaluated to 0.000000
+
+# determine whether the specific location diverges.
+# Solve for z = z^2 + c in the complex plane.
+def mandleconverger(real imag iters creal cimag)
+  if iters > 255 | (real*real + imag*imag > 4) then
+    iters
+  else
+    mandleconverger(real*real - imag*imag + creal,
+                    2*real*imag + cimag,
+                    iters+1, creal, cimag);
+
+# return the number of iterations required for the iteration to escape
+def mandleconverge(real imag)
+  mandleconverger(real, imag, 0, real, imag);
+
mandelconverge
+# compute and plot the mandlebrot set with the specified 2 dimentional range
+# info.
+def mandelhelp(xmin xmax xstep   ymin ymax ystep)
+  for y = ymin, y < ymax, ystep in (
+    (for x = xmin, x < xmax, xstep in
+       printdensity(mandleconverge(x,y)))
+    : putchard(10)
+  )
+ 
+# mandel - This is a convenient helper function for ploting the mandelbrot set
+# from the specified position with the specified magnification.
+def mandel(realstart imagstart realmag imagmag) 
+  mandelhelp(realstart, realstart+realmag*78, realmag,
+             imagstart, imagstart+imagmag*40, imagmag);
+
+ready> mandel(-2.3, -1.3, 0.05, 0.07);
+*******************************+++++++++++*************************************
+*************************+++++++++++++++++++++++*******************************
+**********************+++++++++++++++++++++++++++++****************************
+*******************+++++++++++++++++++++.. ...++++++++*************************
+*****************++++++++++++++++++++++.... ...+++++++++***********************
+***************+++++++++++++++++++++++.....   ...+++++++++*********************
+**************+++++++++++++++++++++++....     ....+++++++++********************
+*************++++++++++++++++++++++......      .....++++++++*******************
+************+++++++++++++++++++++.......       .......+++++++******************
+***********+++++++++++++++++++....                ... .+++++++*****************
+**********+++++++++++++++++.......                     .+++++++****************
+*********++++++++++++++...........                    ...+++++++***************
+********++++++++++++............                      ...++++++++**************
+********++++++++++... ..........                        .++++++++**************
+*******+++++++++.....                                   .+++++++++*************
+*******++++++++......                                  ..+++++++++*************
+*******++++++.......                                   ..+++++++++*************
+*******+++++......                                     ..+++++++++*************
+*******.... ....                                      ...+++++++++*************
+*******.... .                                         ...+++++++++*************
+*******+++++......                                    ...+++++++++*************
+*******++++++.......                                   ..+++++++++*************
+*******++++++++......                                   .+++++++++*************
+*******+++++++++.....                                  ..+++++++++*************
+********++++++++++... ..........                        .++++++++**************
+********++++++++++++............                      ...++++++++**************
+*********++++++++++++++..........                     ...+++++++***************
+**********++++++++++++++++........                     .+++++++****************
+**********++++++++++++++++++++....                ... ..+++++++****************
+***********++++++++++++++++++++++.......       .......++++++++*****************
+************+++++++++++++++++++++++......      ......++++++++******************
+**************+++++++++++++++++++++++....      ....++++++++********************
+***************+++++++++++++++++++++++.....   ...+++++++++*********************
+*****************++++++++++++++++++++++....  ...++++++++***********************
+*******************+++++++++++++++++++++......++++++++*************************
+*********************++++++++++++++++++++++.++++++++***************************
+*************************+++++++++++++++++++++++*******************************
+******************************+++++++++++++************************************
+*******************************************************************************
+*******************************************************************************
+*******************************************************************************
+Evaluated to 0.000000
+ready> mandel(-2, -1, 0.02, 0.04);
+**************************+++++++++++++++++++++++++++++++++++++++++++++++++++++
+***********************++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+*********************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
+*******************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++...
+*****************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++.....
+***************++++++++++++++++++++++++++++++++++++++++++++++++++++++++........
+**************++++++++++++++++++++++++++++++++++++++++++++++++++++++...........
+************+++++++++++++++++++++++++++++++++++++++++++++++++++++..............
+***********++++++++++++++++++++++++++++++++++++++++++++++++++........        . 
+**********++++++++++++++++++++++++++++++++++++++++++++++.............          
+********+++++++++++++++++++++++++++++++++++++++++++..................          
+*******+++++++++++++++++++++++++++++++++++++++.......................          
+******+++++++++++++++++++++++++++++++++++...........................           
+*****++++++++++++++++++++++++++++++++............................              
+*****++++++++++++++++++++++++++++...............................               
+****++++++++++++++++++++++++++......   .........................               
+***++++++++++++++++++++++++.........     ......    ...........                 
+***++++++++++++++++++++++............                                          
+**+++++++++++++++++++++..............                                          
+**+++++++++++++++++++................                                          
+*++++++++++++++++++.................                                           
+*++++++++++++++++............ ...                                              
+*++++++++++++++..............                                                  
+*+++....++++................                                                   
+*..........  ...........                                                       
+*                                                                              
+*..........  ...........                                                       
+*+++....++++................                                                   
+*++++++++++++++..............                                                  
+*++++++++++++++++............ ...                                              
+*++++++++++++++++++.................                                           
+**+++++++++++++++++++................                                          
+**+++++++++++++++++++++..............                                          
+***++++++++++++++++++++++............                                          
+***++++++++++++++++++++++++.........     ......    ...........                 
+****++++++++++++++++++++++++++......   .........................               
+*****++++++++++++++++++++++++++++...............................               
+*****++++++++++++++++++++++++++++++++............................              
+******+++++++++++++++++++++++++++++++++++...........................           
+*******+++++++++++++++++++++++++++++++++++++++.......................          
+********+++++++++++++++++++++++++++++++++++++++++++..................          
+Evaluated to 0.000000
+ready> mandel(-0.9, -1.4, 0.02, 0.03);
+*******************************************************************************
+*******************************************************************************
+*******************************************************************************
+**********+++++++++++++++++++++************************************************
+*+++++++++++++++++++++++++++++++++++++++***************************************
++++++++++++++++++++++++++++++++++++++++++++++**********************************
+++++++++++++++++++++++++++++++++++++++++++++++++++*****************************
+++++++++++++++++++++++++++++++++++++++++++++++++++++++*************************
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++**********************
++++++++++++++++++++++++++++++++++.........++++++++++++++++++*******************
++++++++++++++++++++++++++++++++....   ......+++++++++++++++++++****************
++++++++++++++++++++++++++++++.......  ........+++++++++++++++++++**************
+++++++++++++++++++++++++++++........   ........++++++++++++++++++++************
++++++++++++++++++++++++++++.........     ..  ...+++++++++++++++++++++**********
+++++++++++++++++++++++++++...........        ....++++++++++++++++++++++********
+++++++++++++++++++++++++.............       .......++++++++++++++++++++++******
++++++++++++++++++++++++.............        ........+++++++++++++++++++++++****
+++++++++++++++++++++++...........           ..........++++++++++++++++++++++***
+++++++++++++++++++++...........                .........++++++++++++++++++++++*
+++++++++++++++++++............                  ...........++++++++++++++++++++
+++++++++++++++++...............                 .............++++++++++++++++++
+++++++++++++++.................                 ...............++++++++++++++++
+++++++++++++..................                  .................++++++++++++++
++++++++++..................                      .................+++++++++++++
+++++++........        .                               .........  ..++++++++++++
+++............                                         ......    ....++++++++++
+..............                                                    ...++++++++++
+..............                                                    ....+++++++++
+..............                                                    .....++++++++
+.............                                                    ......++++++++
+...........                                                     .......++++++++
+.........                                                       ........+++++++
+.........                                                       ........+++++++
+.........                                                           ....+++++++
+........                                                             ...+++++++
+.......                                                              ...+++++++
+                                                                    ....+++++++
+                                                                   .....+++++++
+                                                                    ....+++++++
+                                                                    ....+++++++
+                                                                    ....+++++++
+Evaluated to 0.000000
+ready> ^D
+
+#include "llvm/DerivedTypes.h"
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/Module.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/PassManager.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Support/LLVMBuilder.h"
+#include <cstdio>
+#include <string>
+#include <map>
+#include <vector>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2, tok_extern = -3,
+
+  // primary
+  tok_identifier = -4, tok_number = -5,
+  
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10,
+  
+  // operators
+  tok_binary = -11, tok_unary = -12
+};
+
+static std::string IdentifierStr;  // Filled in if tok_identifier
+static double NumVal;              // Filled in if tok_number
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = getchar();
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = getchar())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = getchar();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do LastChar = getchar();
+    while (LastChar != EOF && LastChar != '\n' & LastChar != '\r');
+    
+    if (LastChar != EOF)
+      return gettok();
+  }
+  
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = getchar();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+
+/// ExprAST - Base class for all expression nodes.
+class ExprAST {
+public:
+  virtual ~ExprAST() {}
+  virtual Value *Codegen() = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+class NumberExprAST : public ExprAST {
+  double Val;
+public:
+  NumberExprAST(double val) : Val(val) {}
+  virtual Value *Codegen();
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+class VariableExprAST : public ExprAST {
+  std::string Name;
+public:
+  VariableExprAST(const std::string &name) : Name(name) {}
+  virtual Value *Codegen();
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+class UnaryExprAST : public ExprAST {
+  char Opcode;
+  ExprAST *Operand;
+public:
+  UnaryExprAST(char opcode, ExprAST *operand) 
+    : Opcode(opcode), Operand(operand) {}
+  virtual Value *Codegen();
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+class BinaryExprAST : public ExprAST {
+  char Op;
+  ExprAST *LHS, *RHS;
+public:
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
+    : Op(op), LHS(lhs), RHS(rhs) {}
+  virtual Value *Codegen();
+};
+
+/// CallExprAST - Expression class for function calls.
+class CallExprAST : public ExprAST {
+  std::string Callee;
+  std::vector<ExprAST*> Args;
+public:
+  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
+    : Callee(callee), Args(args) {}
+  virtual Value *Codegen();
+};
+
+/// IfExprAST - Expression class for if/then/else.
+class IfExprAST : public ExprAST {
+  ExprAST *Cond, *Then, *Else;
+public:
+  IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
+  : Cond(cond), Then(then), Else(_else) {}
+  virtual Value *Codegen();
+};
+
+/// ForExprAST - Expression class for for/in.
+class ForExprAST : public ExprAST {
+  std::string VarName;
+  ExprAST *Start, *End, *Step, *Body;
+public:
+  ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
+             ExprAST *step, ExprAST *body)
+    : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+  virtual Value *Codegen();
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+class PrototypeAST {
+  std::string Name;
+  std::vector<std::string> Args;
+  bool isOperator;
+  unsigned Precedence;  // Precedence if a binary op.
+public:
+  PrototypeAST(const std::string &name, const std::vector<std::string> &args,
+               bool isoperator = false, unsigned prec = 0)
+  : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
+  
+  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
+  
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size()-1];
+  }
+  
+  unsigned getBinaryPrecedence() const { return Precedence; }
+  
+  Function *Codegen();
+};
+
+/// FunctionAST - This class represents a function definition itself.
+class FunctionAST {
+  PrototypeAST *Proto;
+  ExprAST *Body;
+public:
+  FunctionAST(PrototypeAST *proto, ExprAST *body)
+    : Proto(proto), Body(body) {}
+  
+  Function *Codegen();
+};
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser it looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() {
+  return CurTok = gettok();
+}
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+  
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0) return -1;
+  return TokPrec;
+}
+
+/// Error* - These are little helper functions for error handling.
+ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
+PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
+FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
+
+static ExprAST *ParseExpression();
+
+/// identifierexpr
+///   ::= identifer
+///   ::= identifer '(' expression* ')'
+static ExprAST *ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+  
+  getNextToken();  // eat identifer.
+  
+  if (CurTok != '(') // Simple variable ref.
+    return new VariableExprAST(IdName);
+  
+  // Call.
+  getNextToken();  // eat (
+  std::vector<ExprAST*> Args;
+  if (CurTok != ')') {
+    while (1) {
+      ExprAST *Arg = ParseExpression();
+      if (!Arg) return 0;
+      Args.push_back(Arg);
+      
+      if (CurTok == ')') break;
+      
+      if (CurTok != ',')
+        return Error("Expected ')'");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+  
+  return new CallExprAST(IdName, Args);
+}
+
+/// numberexpr ::= number
+static ExprAST *ParseNumberExpr() {
+  ExprAST *Result = new NumberExprAST(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static ExprAST *ParseParenExpr() {
+  getNextToken();  // eat (.
+  ExprAST *V = ParseExpression();
+  if (!V) return 0;
+  
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken();  // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static ExprAST *ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  ExprAST *Cond = ParseExpression();
+  if (!Cond) return 0;
+  
+  if (CurTok != tok_then)
+    return Error("expected then");
+  getNextToken();  // eat the then
+  
+  ExprAST *Then = ParseExpression();
+  if (Then == 0) return 0;
+  
+  if (CurTok != tok_else)
+    return Error("expected else");
+  
+  getNextToken();
+  
+  ExprAST *Else = ParseExpression();
+  if (!Else) return 0;
+  
+  return new IfExprAST(Cond, Then, Else);
+}
+
+/// forexpr ::= 'for' identifer '=' expr ',' expr (',' expr)? 'in' expression
+static ExprAST *ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifer.
+  
+  if (CurTok != '=')
+    return Error("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  ExprAST *Start = ParseExpression();
+  if (Start == 0) return 0;
+  if (CurTok != ',')
+    return Error("expected ',' after for start value");
+  getNextToken();
+  
+  ExprAST *End = ParseExpression();
+  if (End == 0) return 0;
+  
+  // The step value is optional.
+  ExprAST *Step = 0;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (Step == 0) return 0;
+  }
+  
+  if (CurTok != tok_in)
+    return Error("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  ExprAST *Body = ParseExpression();
+  if (Body == 0) return 0;
+
+  return new ForExprAST(IdName, Start, End, Step, Body);
+}
+
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+static ExprAST *ParsePrimary() {
+  switch (CurTok) {
+  default: return Error("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  }
+}
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static ExprAST *ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+  
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (ExprAST *Operand = ParseUnary())
+    return new UnaryExprAST(Opc, Operand);
+  return 0;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+    
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+    
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    getNextToken();  // eat binop
+    
+    // Parse the unary expression after the binary operator.
+    ExprAST *RHS = ParseUnary();
+    if (!RHS) return 0;
+    
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec+1, RHS);
+      if (RHS == 0) return 0;
+    }
+    
+    // Merge LHS/RHS.
+    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+  }
+}
+
+/// expression
+///   ::= unary binoprhs
+///
+static ExprAST *ParseExpression() {
+  ExprAST *LHS = ParseUnary();
+  if (!LHS) return 0;
+  
+  return ParseBinOpRHS(0, LHS);
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static PrototypeAST *ParsePrototype() {
+  std::string FnName;
+  
+  int Kind = 0;  // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorP("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+    
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorP("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+  
+  if (CurTok != '(')
+    return ErrorP("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorP("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorP("Invalid number of operands for operator");
+  
+  return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static FunctionAST *ParseDefinition() {
+  getNextToken();  // eat def.
+  PrototypeAST *Proto = ParsePrototype();
+  if (Proto == 0) return 0;
+
+  if (ExprAST *E = ParseExpression())
+    return new FunctionAST(Proto, E);
+  return 0;
+}
+
+/// toplevelexpr ::= expression
+static FunctionAST *ParseTopLevelExpr() {
+  if (ExprAST *E = ParseExpression()) {
+    // Make an anonymous proto.
+    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
+    return new FunctionAST(Proto, E);
+  }
+  return 0;
+}
+
+/// external ::= 'extern' prototype
+static PrototypeAST *ParseExtern() {
+  getNextToken();  // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+static Module *TheModule;
+static LLVMFoldingBuilder Builder;
+static std::map<std::string, Value*> NamedValues;
+static FunctionPassManager *TheFPM;
+
+Value *ErrorV(const char *Str) { Error(Str); return 0; }
+
+Value *NumberExprAST::Codegen() {
+  return ConstantFP::get(Type::DoubleTy, APFloat(Val));
+}
+
+Value *VariableExprAST::Codegen() {
+  // Look this variable up in the function.
+  Value *V = NamedValues[Name];
+  return V ? V : ErrorV("Unknown variable name");
+}
+
+Value *UnaryExprAST::Codegen() {
+  Value *OperandV = Operand->Codegen();
+  if (OperandV == 0) return 0;
+  
+  Function *F = TheModule->getFunction(std::string("unary")+Opcode);
+  if (F == 0)
+    return ErrorV("Unknown unary operator");
+  
+  return Builder.CreateCall(F, OperandV, "unop");
+}
+
+
+Value *BinaryExprAST::Codegen() {
+  Value *L = LHS->Codegen();
+  Value *R = RHS->Codegen();
+  if (L == 0 || R == 0) return 0;
+  
+  switch (Op) {
+  case '+': return Builder.CreateAdd(L, R, "addtmp");
+  case '-': return Builder.CreateSub(L, R, "subtmp");
+  case '*': return Builder.CreateMul(L, R, "multmp");
+  case '<':
+    L = Builder.CreateFCmpULT(L, R, "multmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return Builder.CreateUIToFP(L, Type::DoubleTy, "booltmp");
+  default: break;
+  }
+  
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  Function *F = TheModule->getFunction(std::string("binary")+Op);
+  assert(F && "binary operator not found!");
+  
+  Value *Ops[] = { L, R };
+  return Builder.CreateCall(F, Ops, Ops+2, "binop");
+}
+
+Value *CallExprAST::Codegen() {
+  // Look up the name in the global module table.
+  Function *CalleeF = TheModule->getFunction(Callee);
+  if (CalleeF == 0)
+    return ErrorV("Unknown function referenced");
+  
+  // If argument mismatch error.
+  if (CalleeF->arg_size() != Args.size())
+    return ErrorV("Incorrect # arguments passed");
+
+  std::vector<Value*> ArgsV;
+  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+    ArgsV.push_back(Args[i]->Codegen());
+    if (ArgsV.back() == 0) return 0;
+  }
+  
+  return Builder.CreateCall(CalleeF, ArgsV.begin(), ArgsV.end(), "calltmp");
+}
+
+Value *IfExprAST::Codegen() {
+  Value *CondV = Cond->Codegen();
+  if (CondV == 0) return 0;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  CondV = Builder.CreateFCmpONE(CondV, 
+                                ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
+                                "ifcond");
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = new BasicBlock("then", TheFunction);
+  BasicBlock *ElseBB = new BasicBlock("else");
+  BasicBlock *MergeBB = new BasicBlock("ifcont");
+  
+  Builder.CreateCondBr(CondV, ThenBB, ElseBB);
+  
+  // Emit then value.
+  Builder.SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->Codegen();
+  if (ThenV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = Builder.GetInsertBlock();
+  
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  Builder.SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->Codegen();
+  if (ElseV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = Builder.GetInsertBlock();
+  
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  Builder.SetInsertPoint(MergeBB);
+  PHINode *PN = Builder.CreatePHI(Type::DoubleTy, "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::Codegen() {
+  // Output this as:
+  //   ...
+  //   start = startexpr
+  //   goto loop
+  // loop: 
+  //   variable = phi [start, loopheader], [nextvariable, loopend]
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   nextvariable = variable + step
+  //   endcond = endexpr
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->Codegen();
+  if (StartVal == 0) return 0;
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+  BasicBlock *PreheaderBB = Builder.GetInsertBlock();
+  BasicBlock *LoopBB = new BasicBlock("loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  Builder.CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  Builder.SetInsertPoint(LoopBB);
+  
+  // Start the PHI node with an entry for Start.
+  PHINode *Variable = Builder.CreatePHI(Type::DoubleTy, VarName.c_str());
+  Variable->addIncoming(StartVal, PreheaderBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  Value *OldVal = NamedValues[VarName];
+  NamedValues[VarName] = Variable;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (Body->Codegen() == 0)
+    return 0;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->Codegen();
+    if (StepVal == 0) return 0;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(Type::DoubleTy, APFloat(1.0));
+  }
+  
+  Value *NextVar = Builder.CreateAdd(Variable, StepVal, "nextvar");
+
+  // Compute the end condition.
+  Value *EndCond = End->Codegen();
+  if (EndCond == 0) return EndCond;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = Builder.CreateFCmpONE(EndCond, 
+                                  ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *LoopEndBB = Builder.GetInsertBlock();
+  BasicBlock *AfterBB = new BasicBlock("afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  Builder.SetInsertPoint(AfterBB);
+  
+  // Add a new entry to the PHI node for the backedge.
+  Variable->addIncoming(NextVar, LoopEndBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    NamedValues[VarName] = OldVal;
+  else
+    NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::DoubleTy);
+}
+
+Function *PrototypeAST::Codegen() {
+  // Make the function type:  double(double,double) etc.
+  std::vector<const Type*> Doubles(Args.size(), Type::DoubleTy);
+  FunctionType *FT = FunctionType::get(Type::DoubleTy, Doubles, false);
+  
+  Function *F = new Function(FT, Function::ExternalLinkage, Name, TheModule);
+  
+  // If F conflicted, there was already something named 'Name'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != Name) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = TheModule->getFunction(Name);
+    
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorF("redefinition of function");
+      return 0;
+    }
+    
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorF("redefinition of function with different # args");
+      return 0;
+    }
+  }
+  
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx) {
+    AI->setName(Args[Idx]);
+    
+    // Add arguments to variable symbol table.
+    NamedValues[Args[Idx]] = AI;
+  }
+  
+  return F;
+}
+
+Function *FunctionAST::Codegen() {
+  NamedValues.clear();
+  
+  Function *TheFunction = Proto->Codegen();
+  if (TheFunction == 0)
+    return 0;
+  
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = new BasicBlock("entry", TheFunction);
+  Builder.SetInsertPoint(BB);
+  
+  if (Value *RetVal = Body->Codegen()) {
+    // Finish off the function.
+    Builder.CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    // Optimize the function.
+    TheFPM->run(*TheFunction);
+    
+    return TheFunction;
+  }
+  
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+
+  if (Proto->isBinaryOp())
+    BinopPrecedence.erase(Proto->getOperatorName());
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static ExecutionEngine *TheExecutionEngine;
+
+static void HandleDefinition() {
+  if (FunctionAST *F = ParseDefinition()) {
+    if (Function *LF = F->Codegen()) {
+      fprintf(stderr, "Read function definition:");
+      LF->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern() {
+  if (PrototypeAST *P = ParseExtern()) {
+    if (Function *F = P->Codegen()) {
+      fprintf(stderr, "Read extern: ");
+      F->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression() {
+  // Evaluate a top level expression into an anonymous function.
+  if (FunctionAST *F = ParseTopLevelExpr()) {
+    if (Function *LF = F->Codegen()) {
+      // JIT the function, returning a function pointer.
+      void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
+      
+      // Cast it to the right type (takes no arguments, returns a double) so we
+      // can call it as a native function.
+      double (*FP)() = (double (*)())FPtr;
+      fprintf(stderr, "Evaluated to %f\n", FP());
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  while (1) {
+    fprintf(stderr, "ready> ");
+    switch (CurTok) {
+    case tok_eof:    return;
+    case ';':        getNextToken(); break;  // ignore top level semicolons.
+    case tok_def:    HandleDefinition(); break;
+    case tok_extern: HandleExtern(); break;
+    default:         HandleTopLevelExpression(); break;
+    }
+  }
+}
+
+
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" 
+double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" 
+double printd(double X) {
+  printf("%f\n", X);
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['*'] = 40;  // highest.
+
+  // Prime the first token.
+  fprintf(stderr, "ready> ");
+  getNextToken();
+
+  // Make the module, which holds all the code.
+  TheModule = new Module("my cool jit");
+  
+  // Create the JIT.
+  TheExecutionEngine = ExecutionEngine::create(TheModule);
+
+  {
+    ExistingModuleProvider OurModuleProvider(TheModule);
+    FunctionPassManager OurFPM(&OurModuleProvider);
+      
+    // Set up the optimizer pipeline.  Start with registering info about how the
+    // target lays out data structures.
+    OurFPM.add(new TargetData(*TheExecutionEngine->getTargetData()));
+    // Do simple "peephole" optimizations and bit-twiddling optzns.
+    OurFPM.add(createInstructionCombiningPass());
+    // Reassociate expressions.
+    OurFPM.add(createReassociatePass());
+    // Eliminate Common SubExpressions.
+    OurFPM.add(createGVNPass());
+    // Simplify the control flow graph (deleting unreachable blocks, etc).
+    OurFPM.add(createCFGSimplificationPass());
+    // Set the global so the code gen can use this.
+    TheFPM = &OurFPM;
+
+    // Run the main "interpreter loop" now.
+    MainLoop();
+    
+    TheFPM = 0;
+  }  // Free module provider and pass manager.
+                                   
+                                   
+  // Print out all of the generated code.
+  TheModule->dump();
+  return 0;
+}
 
@@ -593,7 +593,7 @@
 
mandelconverge
+int G, H;
+int test(_Bool Condition) {
+  int X;
+  if (Condition)
+    X = G;
+  else
+    X = H;
+  return X;
+}
+
+ at G = weak global i32 0   ; type of @G is i32*
+ at H = weak global i32 0   ; type of @H is i32*
+
+define i32 @test(i1 %Condition) {
+entry:
+	br i1 %Condition, label %cond_true, label %cond_false
+
+cond_true:
+	%X.0 = load i32* @G
+	br label %cond_next
+
+cond_false:
+	%X.1 = load i32* @H
+	br label %cond_next
+
+cond_next:
+	%X.2 = phi i32 [ %X.1, %cond_false ], [ %X.0, %cond_true ]
+	ret i32 %X.2
+}
+
+define i32 @test(i1 %Condition) {
+entry:
+	%X = alloca i32           ; type of %X is i32*.
+	...
+	%tmp = load i32* %X       ; load the stack value %X from the stack.
+	%tmp2 = add i32 %tmp, 1   ; increment it
+	store i32 %tmp2, i32* %X  ; store it back
+	...
+
+ at G = weak global i32 0   ; type of @G is i32*
+ at H = weak global i32 0   ; type of @H is i32*
+
+define i32 @test(i1 %Condition) {
+entry:
+	%X = alloca i32           ; type of %X is i32*.
+	br i1 %Condition, label %cond_true, label %cond_false
+
+cond_true:
+	%X.0 = load i32* @G
+        store i32 %X.0, i32* %X   ; Update X
+	br label %cond_next
+
+cond_false:
+	%X.1 = load i32* @H
+        store i32 %X.1, i32* %X   ; Update X
+	br label %cond_next
+
+cond_next:
+	%X.2 = load i32* %X       ; Read X
+	ret i32 %X.2
+}
+
+$ llvm-as < example.ll | opt -mem2reg | llvm-dis
+ at G = weak global i32 0
+ at H = weak global i32 0
+
+define i32 @test(i1 %Condition) {
+entry:
+	br i1 %Condition, label %cond_true, label %cond_false
+
+cond_true:
+	%X.0 = load i32* @G
+	br label %cond_next
+
+cond_false:
+	%X.1 = load i32* @H
+	br label %cond_next
+
+cond_next:
+	%X.01 = phi i32 [ %X.1, %cond_false ], [ %X.0, %cond_true ]
+	ret i32 %X.01
+}
+
+   # Compile
+   g++ -g toy.cpp `llvm-config --cppflags --ldflags --libs core jit native` -O3 -o toy
+   # Run
+   ./toy
+
+
for (...)                for (...)
+  if (c)                   if (c)
+    X1 = ...                 X1 = ...
+  else                     else
+    X2 = ...                 X2 = ...
+  X3 = phi(X1, X2)         X3 = phi(X1, X2)
+... = X3 + 4              X4 = phi(X3)
+                          ... = X4 + 4
-indvars
for (...)                  if (lic)
+  A                          for (...)
+  if (lic)                     A; B; C
+    B                      else
+  C                          for (...)
+                               A; C
malloc
free
@malloc
@free
llvm.gc*
-enable-correct-eh-support
setjmp
longjmp
longjmp
__llvm_sjljeh_throw_longjmp()
setjmp
setjmp
setjmp
longjmp
longjmp
invoke
longjmp
switch
alloca
load
store
alloca
phi
load
store
ret
x == y
x
y
void test(int *p, int *q)
+{
+  if (p != q)
+    return;
+
+  if (*p != *q)
+    foo(); // unreachable
+}
invoke
call
@malloc
@free
malloc
free
-mem2reg
load
alloca
load
phi
alloca
alloca
alloca
alloca
mem2reg
scalarrepl
mem2reg
exit(3)
main()
return 3
strip
fib
llvm-as
%x = add int %x, %x
+# Define ':' for sequencing: as a low-precedence operator that ignores operands
+# and just returns the RHS.
+def binary : 1 (x y) y;
+
+# Recursive fib, we could do this before.
+def fib(x)
+  if (x < 3) then
+    1
+  else
+    fib(x-1)+fib(x-2);
+
+# Iterative fib.
+def fibi(x)
+  var a = 1, b = 1, c in
+  (for i = 3, i &;t; x in 
+     c = a + b :
+     a = b :
+     b = c) :
+  b;
+
+# Call it. 
+fibi(10);
+
NamedValues
NamedValues
+static std::map<std::string, AllocaInst*> NamedValues;
+
+/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+/// the function.  This is used for mutable variables etc.
+static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+                                          const std::string &VarName) {
+  LLVMBuilder TmpB(&TheFunction->getEntryBlock(),
+                   TheFunction->getEntryBlock().begin());
+  return TmpB.CreateAlloca(Type::DoubleTy, 0, VarName.c_str());
+}
+
+Value *VariableExprAST::Codegen() {
+  // Look this variable up in the function.
+  Value *V = NamedValues[Name];
+  if (V == 0) return ErrorV("Unknown variable name");
+
+  // Load the value.
+  return Builder.CreateLoad(V, Name.c_str());
+}
+
ForExprAST::Codegen
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Create an alloca for the variable in the entry block.
+  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+  
+    // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->Codegen();
+  if (StartVal == 0) return 0;
+  
+  // Store the value into the alloca.
+  Builder.CreateStore(StartVal, Alloca);
+  ...
+
+  // Compute the end condition.
+  Value *EndCond = End->Codegen();
+  if (EndCond == 0) return EndCond;
+  
+  // Reload, increment, and restore the alloca.  This handles the case where
+  // the body of the loop mutates the variable.
+  Value *CurVar = Builder.CreateLoad(Alloca);
+  Value *NextVar = Builder.CreateAdd(CurVar, StepVal, "nextvar");
+  Builder.CreateStore(NextVar, Alloca);
+  ...
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F) {
+  Function::arg_iterator AI = F->arg_begin();
+  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+    // Store the initial value into the alloca.
+    Builder.CreateStore(AI, Alloca);
+
+    // Add arguments to variable symbol table.
+    NamedValues[Args[Idx]] = Alloca;
+  }
+}
+
FunctionAST::Codegen
+    // Set up the optimizer pipeline.  Start with registering info about how the
+    // target lays out data structures.
+    OurFPM.add(new TargetData(*TheExecutionEngine->getTargetData()));
+    // Promote allocas to registers.
+    OurFPM.add(createPromoteMemoryToRegisterPass());
+    // Do simple "peephole" optimizations and bit-twiddling optzns.
+    OurFPM.add(createInstructionCombiningPass());
+    // Reassociate expressions.
+    OurFPM.add(createReassociatePass());
+
+define double @fib(double %x) {
+entry:
+	%x1 = alloca double
+	store double %x, double* %x1
+	%x2 = load double* %x1
+	%multmp = fcmp ult double %x2, 3.000000e+00
+	%booltmp = uitofp i1 %multmp to double
+	%ifcond = fcmp one double %booltmp, 0.000000e+00
+	br i1 %ifcond, label %then, label %else
+
+then:		; preds = %entry
+	br label %ifcont
+
+else:		; preds = %entry
+	%x3 = load double* %x1
+	%subtmp = sub double %x3, 1.000000e+00
+	%calltmp = call double @fib( double %subtmp )
+	%x4 = load double* %x1
+	%subtmp5 = sub double %x4, 2.000000e+00
+	%calltmp6 = call double @fib( double %subtmp5 )
+	%addtmp = add double %calltmp, %calltmp6
+	br label %ifcont
+
+ifcont:		; preds = %else, %then
+	%iftmp = phi double [ 1.000000e+00, %then ], [ %addtmp, %else ]
+	ret double %iftmp
+}
+
+define double @fib(double %x) {
+entry:
+	%multmp = fcmp ult double %x, 3.000000e+00
+	%booltmp = uitofp i1 %multmp to double
+	%ifcond = fcmp one double %booltmp, 0.000000e+00
+	br i1 %ifcond, label %then, label %else
+
+then:
+	br label %ifcont
+
+else:
+	%subtmp = sub double %x, 1.000000e+00
+	%calltmp = call double @fib( double %subtmp )
+	%subtmp5 = sub double %x, 2.000000e+00
+	%calltmp6 = call double @fib( double %subtmp5 )
+	%addtmp = add double %calltmp, %calltmp6
+	br label %ifcont
+
+ifcont:		; preds = %else, %then
+	%iftmp = phi double [ 1.000000e+00, %then ], [ %addtmp, %else ]
+	ret double %iftmp
+}
+
+define double @fib(double %x) {
+entry:
+	%multmp = fcmp ult double %x, 3.000000e+00
+	%booltmp = uitofp i1 %multmp to double
+	%ifcond = fcmp ueq double %booltmp, 0.000000e+00
+	br i1 %ifcond, label %else, label %ifcont
+
+else:
+	%subtmp = sub double %x, 1.000000e+00
+	%calltmp = call double @fib( double %subtmp )
+	%subtmp5 = sub double %x, 2.000000e+00
+	%calltmp6 = call double @fib( double %subtmp5 )
+	%addtmp = add double %calltmp, %calltmp6
+	ret double %addtmp
+
+ifcont:
+	ret double 1.000000e+00
+}
+
+ int main() {
+   // Install standard binary operators.
+   // 1 is lowest precedence.
+   BinopPrecedence['='] = 2;
+   BinopPrecedence['<'] = 10;
+   BinopPrecedence['+'] = 20;
+   BinopPrecedence['-'] = 20;
+
+Value *BinaryExprAST::Codegen() {
+  // Special case '=' because we don't want to emit the LHS as an expression.
+  if (Op == '=') {
+    // Assignment requires the LHS to be an identifier.
+    VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS);
+    if (!LHSE)
+      return ErrorV("destination of '=' must be a variable");
+
+    // Codegen the RHS.
+    Value *Val = RHS->Codegen();
+    if (Val == 0) return 0;
+
+    // Look up the name.
+    Value *Variable = NamedValues[LHSE->getName()];
+    if (Variable == 0) return ErrorV("Unknown variable name");
+
+    Builder.CreateStore(Val, Variable);
+    return Val;
+  }
+  ...  
+
+# Function to print a double.
+extern printd(x);
+
+# Define ':' for sequencing: as a low-precedence operator that ignores operands
+# and just returns the RHS.
+def binary : 1 (x y) y;
+
+def test(x)
+  printd(x) :
+  x = 4 :
+  printd(x);
+
+test(123);
+
+enum Token {
+  ...
+  // var definition
+  tok_var = -13
+...
+}
+...
+static int gettok() {
+...
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    if (IdentifierStr == "var") return tok_var;
+    return tok_identifier;
+...
+
+/// VarExprAST - Expression class for var/in
+class VarExprAST : public ExprAST {
+  std::vector<std::pair<std::string, ExprAST*> > VarNames;
+  ExprAST *Body;
+public:
+  VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
+             ExprAST *body)
+  : VarNames(varnames), Body(body) {}
+  
+  virtual Value *Codegen();
+};
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+///   ::= varexpr
+static ExprAST *ParsePrimary() {
+  switch (CurTok) {
+  default: return Error("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  case tok_var:        return ParseVarExpr();
+  }
+}
+
+/// varexpr ::= 'var' identifer ('=' expression)? 
+//                    (',' identifer ('=' expression)?)* 'in' expression
+static ExprAST *ParseVarExpr() {
+  getNextToken();  // eat the var.
+
+  std::vector<std::pair<std::string, ExprAST*> > VarNames;
+
+  // At least one variable name is required.
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after var");
+
VarNames
+  while (1) {
+    std::string Name = IdentifierStr;
+    getNextToken();  // eat identifer.
+
+    // Read the optional initializer.
+    ExprAST *Init = 0;
+    if (CurTok == '=') {
+      getNextToken(); // eat the '='.
+      
+      Init = ParseExpression();
+      if (Init == 0) return 0;
+    }
+    
+    VarNames.push_back(std::make_pair(Name, Init));
+    
+    // End of var list, exit loop.
+    if (CurTok != ',') break;
+    getNextToken(); // eat the ','.
+    
+    if (CurTok != tok_identifier)
+      return Error("expected identifier list after var");
+  }
+
+  // At this point, we have to have 'in'.
+  if (CurTok != tok_in)
+    return Error("expected 'in' keyword after 'var'");
+  getNextToken();  // eat 'in'.
+  
+  ExprAST *Body = ParseExpression();
+  if (Body == 0) return 0;
+  
+  return new VarExprAST(VarNames, Body);
+}
+
+Value *VarExprAST::Codegen() {
+  std::vector<AllocaInst *> OldBindings;
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Register all variables and emit their initializer.
+  for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
+    const std::string &VarName = VarNames[i].first;
+    ExprAST *Init = VarNames[i].second;
+
+    // Emit the initializer before adding the variable to scope, this prevents
+    // the initializer from referencing the variable itself, and permits stuff
+    // like this:
+    //  var a = 1 in
+    //    var a = a in ...   # refers to outer 'a'.
+    Value *InitVal;
+    if (Init) {
+      InitVal = Init->Codegen();
+      if (InitVal == 0) return 0;
+    } else { // If not specified, use 0.0.
+      InitVal = ConstantFP::get(Type::DoubleTy, APFloat(0.0));
+    }
+    
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+    Builder.CreateStore(InitVal, Alloca);
+
+    // Remember the old variable binding so that we can restore the binding when
+    // we unrecurse.
+    OldBindings.push_back(NamedValues[VarName]);
+    
+    // Remember this binding.
+    NamedValues[VarName] = Alloca;
+  }
+
+  // Codegen the body, now that all vars are in scope.
+  Value *BodyVal = Body->Codegen();
+  if (BodyVal == 0) return 0;
+
+  // Pop all our variables from scope.
+  for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
+    NamedValues[VarNames[i].first] = OldBindings[i];
+
+  // Return the body computation.
+  return BodyVal;
+}
+
+#include "llvm/DerivedTypes.h"
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/Module.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/PassManager.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Support/LLVMBuilder.h"
+#include <cstdio>
+#include <string>
+#include <map>
+#include <vector>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2, tok_extern = -3,
+
+  // primary
+  tok_identifier = -4, tok_number = -5,
+  
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10,
+  
+  // operators
+  tok_binary = -11, tok_unary = -12,
+  
+  // var definition
+  tok_var = -13
+};
+
+static std::string IdentifierStr;  // Filled in if tok_identifier
+static double NumVal;              // Filled in if tok_number
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = getchar();
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = getchar())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    if (IdentifierStr == "var") return tok_var;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = getchar();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do LastChar = getchar();
+    while (LastChar != EOF && LastChar != '\n' & LastChar != '\r');
+    
+    if (LastChar != EOF)
+      return gettok();
+  }
+  
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = getchar();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+
+/// ExprAST - Base class for all expression nodes.
+class ExprAST {
+public:
+  virtual ~ExprAST() {}
+  virtual Value *Codegen() = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+class NumberExprAST : public ExprAST {
+  double Val;
+public:
+  NumberExprAST(double val) : Val(val) {}
+  virtual Value *Codegen();
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+class VariableExprAST : public ExprAST {
+  std::string Name;
+public:
+  VariableExprAST(const std::string &name) : Name(name) {}
+  const std::string &getName() const { return Name; }
+  virtual Value *Codegen();
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+class UnaryExprAST : public ExprAST {
+  char Opcode;
+  ExprAST *Operand;
+public:
+  UnaryExprAST(char opcode, ExprAST *operand) 
+    : Opcode(opcode), Operand(operand) {}
+  virtual Value *Codegen();
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+class BinaryExprAST : public ExprAST {
+  char Op;
+  ExprAST *LHS, *RHS;
+public:
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
+    : Op(op), LHS(lhs), RHS(rhs) {}
+  virtual Value *Codegen();
+};
+
+/// CallExprAST - Expression class for function calls.
+class CallExprAST : public ExprAST {
+  std::string Callee;
+  std::vector<ExprAST*> Args;
+public:
+  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
+    : Callee(callee), Args(args) {}
+  virtual Value *Codegen();
+};
+
+/// IfExprAST - Expression class for if/then/else.
+class IfExprAST : public ExprAST {
+  ExprAST *Cond, *Then, *Else;
+public:
+  IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
+  : Cond(cond), Then(then), Else(_else) {}
+  virtual Value *Codegen();
+};
+
+/// ForExprAST - Expression class for for/in.
+class ForExprAST : public ExprAST {
+  std::string VarName;
+  ExprAST *Start, *End, *Step, *Body;
+public:
+  ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
+             ExprAST *step, ExprAST *body)
+    : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+  virtual Value *Codegen();
+};
+
+/// VarExprAST - Expression class for var/in
+class VarExprAST : public ExprAST {
+  std::vector<std::pair<std::string, ExprAST*> > VarNames;
+  ExprAST *Body;
+public:
+  VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
+             ExprAST *body)
+  : VarNames(varnames), Body(body) {}
+  
+  virtual Value *Codegen();
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+class PrototypeAST {
+  std::string Name;
+  std::vector<std::string> Args;
+  bool isOperator;
+  unsigned Precedence;  // Precedence if a binary op.
+public:
+  PrototypeAST(const std::string &name, const std::vector<std::string> &args,
+               bool isoperator = false, unsigned prec = 0)
+  : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
+  
+  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
+  
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size()-1];
+  }
+  
+  unsigned getBinaryPrecedence() const { return Precedence; }
+  
+  Function *Codegen();
+  
+  void CreateArgumentAllocas(Function *F);
+};
+
+/// FunctionAST - This class represents a function definition itself.
+class FunctionAST {
+  PrototypeAST *Proto;
+  ExprAST *Body;
+public:
+  FunctionAST(PrototypeAST *proto, ExprAST *body)
+    : Proto(proto), Body(body) {}
+  
+  Function *Codegen();
+};
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser it looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() {
+  return CurTok = gettok();
+}
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+  
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0) return -1;
+  return TokPrec;
+}
+
+/// Error* - These are little helper functions for error handling.
+ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
+PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
+FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
+
+static ExprAST *ParseExpression();
+
+/// identifierexpr
+///   ::= identifer
+///   ::= identifer '(' expression* ')'
+static ExprAST *ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+  
+  getNextToken();  // eat identifer.
+  
+  if (CurTok != '(') // Simple variable ref.
+    return new VariableExprAST(IdName);
+  
+  // Call.
+  getNextToken();  // eat (
+  std::vector<ExprAST*> Args;
+  if (CurTok != ')') {
+    while (1) {
+      ExprAST *Arg = ParseExpression();
+      if (!Arg) return 0;
+      Args.push_back(Arg);
+      
+      if (CurTok == ')') break;
+      
+      if (CurTok != ',')
+        return Error("Expected ')'");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+  
+  return new CallExprAST(IdName, Args);
+}
+
+/// numberexpr ::= number
+static ExprAST *ParseNumberExpr() {
+  ExprAST *Result = new NumberExprAST(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static ExprAST *ParseParenExpr() {
+  getNextToken();  // eat (.
+  ExprAST *V = ParseExpression();
+  if (!V) return 0;
+  
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken();  // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static ExprAST *ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  ExprAST *Cond = ParseExpression();
+  if (!Cond) return 0;
+  
+  if (CurTok != tok_then)
+    return Error("expected then");
+  getNextToken();  // eat the then
+  
+  ExprAST *Then = ParseExpression();
+  if (Then == 0) return 0;
+  
+  if (CurTok != tok_else)
+    return Error("expected else");
+  
+  getNextToken();
+  
+  ExprAST *Else = ParseExpression();
+  if (!Else) return 0;
+  
+  return new IfExprAST(Cond, Then, Else);
+}
+
+/// forexpr ::= 'for' identifer '=' expr ',' expr (',' expr)? 'in' expression
+static ExprAST *ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifer.
+  
+  if (CurTok != '=')
+    return Error("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  ExprAST *Start = ParseExpression();
+  if (Start == 0) return 0;
+  if (CurTok != ',')
+    return Error("expected ',' after for start value");
+  getNextToken();
+  
+  ExprAST *End = ParseExpression();
+  if (End == 0) return 0;
+  
+  // The step value is optional.
+  ExprAST *Step = 0;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (Step == 0) return 0;
+  }
+  
+  if (CurTok != tok_in)
+    return Error("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  ExprAST *Body = ParseExpression();
+  if (Body == 0) return 0;
+
+  return new ForExprAST(IdName, Start, End, Step, Body);
+}
+
+/// varexpr ::= 'var' identifer ('=' expression)? 
+//                    (',' identifer ('=' expression)?)* 'in' expression
+static ExprAST *ParseVarExpr() {
+  getNextToken();  // eat the var.
+
+  std::vector<std::pair<std::string, ExprAST*> > VarNames;
+
+  // At least one variable name is required.
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after var");
+  
+  while (1) {
+    std::string Name = IdentifierStr;
+    getNextToken();  // eat identifer.
+
+    // Read the optional initializer.
+    ExprAST *Init = 0;
+    if (CurTok == '=') {
+      getNextToken(); // eat the '='.
+      
+      Init = ParseExpression();
+      if (Init == 0) return 0;
+    }
+    
+    VarNames.push_back(std::make_pair(Name, Init));
+    
+    // End of var list, exit loop.
+    if (CurTok != ',') break;
+    getNextToken(); // eat the ','.
+    
+    if (CurTok != tok_identifier)
+      return Error("expected identifier list after var");
+  }
+  
+  // At this point, we have to have 'in'.
+  if (CurTok != tok_in)
+    return Error("expected 'in' keyword after 'var'");
+  getNextToken();  // eat 'in'.
+  
+  ExprAST *Body = ParseExpression();
+  if (Body == 0) return 0;
+  
+  return new VarExprAST(VarNames, Body);
+}
+
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+///   ::= varexpr
+static ExprAST *ParsePrimary() {
+  switch (CurTok) {
+  default: return Error("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  case tok_var:        return ParseVarExpr();
+  }
+}
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static ExprAST *ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+  
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (ExprAST *Operand = ParseUnary())
+    return new UnaryExprAST(Opc, Operand);
+  return 0;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+    
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+    
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    getNextToken();  // eat binop
+    
+    // Parse the unary expression after the binary operator.
+    ExprAST *RHS = ParseUnary();
+    if (!RHS) return 0;
+    
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec+1, RHS);
+      if (RHS == 0) return 0;
+    }
+    
+    // Merge LHS/RHS.
+    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+  }
+}
+
+/// expression
+///   ::= unary binoprhs
+///
+static ExprAST *ParseExpression() {
+  ExprAST *LHS = ParseUnary();
+  if (!LHS) return 0;
+  
+  return ParseBinOpRHS(0, LHS);
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static PrototypeAST *ParsePrototype() {
+  std::string FnName;
+  
+  int Kind = 0;  // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorP("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+    
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorP("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+  
+  if (CurTok != '(')
+    return ErrorP("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorP("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorP("Invalid number of operands for operator");
+  
+  return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static FunctionAST *ParseDefinition() {
+  getNextToken();  // eat def.
+  PrototypeAST *Proto = ParsePrototype();
+  if (Proto == 0) return 0;
+
+  if (ExprAST *E = ParseExpression())
+    return new FunctionAST(Proto, E);
+  return 0;
+}
+
+/// toplevelexpr ::= expression
+static FunctionAST *ParseTopLevelExpr() {
+  if (ExprAST *E = ParseExpression()) {
+    // Make an anonymous proto.
+    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
+    return new FunctionAST(Proto, E);
+  }
+  return 0;
+}
+
+/// external ::= 'extern' prototype
+static PrototypeAST *ParseExtern() {
+  getNextToken();  // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+static Module *TheModule;
+static LLVMFoldingBuilder Builder;
+static std::map<std::string, AllocaInst*> NamedValues;
+static FunctionPassManager *TheFPM;
+
+Value *ErrorV(const char *Str) { Error(Str); return 0; }
+
+/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+/// the function.  This is used for mutable variables etc.
+static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+                                          const std::string &VarName) {
+  LLVMBuilder TmpB(&TheFunction->getEntryBlock(),
+                   TheFunction->getEntryBlock().begin());
+  return TmpB.CreateAlloca(Type::DoubleTy, 0, VarName.c_str());
+}
+
+
+Value *NumberExprAST::Codegen() {
+  return ConstantFP::get(Type::DoubleTy, APFloat(Val));
+}
+
+Value *VariableExprAST::Codegen() {
+  // Look this variable up in the function.
+  Value *V = NamedValues[Name];
+  if (V == 0) return ErrorV("Unknown variable name");
+
+  // Load the value.
+  return Builder.CreateLoad(V, Name.c_str());
+}
+
+Value *UnaryExprAST::Codegen() {
+  Value *OperandV = Operand->Codegen();
+  if (OperandV == 0) return 0;
+  
+  Function *F = TheModule->getFunction(std::string("unary")+Opcode);
+  if (F == 0)
+    return ErrorV("Unknown unary operator");
+  
+  return Builder.CreateCall(F, OperandV, "unop");
+}
+
+
+Value *BinaryExprAST::Codegen() {
+  // Special case '=' because we don't want to emit the LHS as an expression.
+  if (Op == '=') {
+    // Assignment requires the LHS to be an identifier.
+    VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS);
+    if (!LHSE)
+      return ErrorV("destination of '=' must be a variable");
+    // Codegen the RHS.
+    Value *Val = RHS->Codegen();
+    if (Val == 0) return 0;
+
+    // Look up the name.
+    Value *Variable = NamedValues[LHSE->getName()];
+    if (Variable == 0) return ErrorV("Unknown variable name");
+
+    Builder.CreateStore(Val, Variable);
+    return Val;
+  }
+  
+  
+  Value *L = LHS->Codegen();
+  Value *R = RHS->Codegen();
+  if (L == 0 || R == 0) return 0;
+  
+  switch (Op) {
+  case '+': return Builder.CreateAdd(L, R, "addtmp");
+  case '-': return Builder.CreateSub(L, R, "subtmp");
+  case '*': return Builder.CreateMul(L, R, "multmp");
+  case '<':
+    L = Builder.CreateFCmpULT(L, R, "multmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return Builder.CreateUIToFP(L, Type::DoubleTy, "booltmp");
+  default: break;
+  }
+  
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  Function *F = TheModule->getFunction(std::string("binary")+Op);
+  assert(F && "binary operator not found!");
+  
+  Value *Ops[] = { L, R };
+  return Builder.CreateCall(F, Ops, Ops+2, "binop");
+}
+
+Value *CallExprAST::Codegen() {
+  // Look up the name in the global module table.
+  Function *CalleeF = TheModule->getFunction(Callee);
+  if (CalleeF == 0)
+    return ErrorV("Unknown function referenced");
+  
+  // If argument mismatch error.
+  if (CalleeF->arg_size() != Args.size())
+    return ErrorV("Incorrect # arguments passed");
+
+  std::vector<Value*> ArgsV;
+  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+    ArgsV.push_back(Args[i]->Codegen());
+    if (ArgsV.back() == 0) return 0;
+  }
+  
+  return Builder.CreateCall(CalleeF, ArgsV.begin(), ArgsV.end(), "calltmp");
+}
+
+Value *IfExprAST::Codegen() {
+  Value *CondV = Cond->Codegen();
+  if (CondV == 0) return 0;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  CondV = Builder.CreateFCmpONE(CondV, 
+                                ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
+                                "ifcond");
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = new BasicBlock("then", TheFunction);
+  BasicBlock *ElseBB = new BasicBlock("else");
+  BasicBlock *MergeBB = new BasicBlock("ifcont");
+  
+  Builder.CreateCondBr(CondV, ThenBB, ElseBB);
+  
+  // Emit then value.
+  Builder.SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->Codegen();
+  if (ThenV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = Builder.GetInsertBlock();
+  
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  Builder.SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->Codegen();
+  if (ElseV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = Builder.GetInsertBlock();
+  
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  Builder.SetInsertPoint(MergeBB);
+  PHINode *PN = Builder.CreatePHI(Type::DoubleTy, "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::Codegen() {
+  // Output this as:
+  //   var = alloca double
+  //   ...
+  //   start = startexpr
+  //   store start -> var
+  //   goto loop
+  // loop: 
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   endcond = endexpr
+  //
+  //   curvar = load var
+  //   nextvar = curvar + step
+  //   store nextvar -> var
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Create an alloca for the variable in the entry block.
+  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->Codegen();
+  if (StartVal == 0) return 0;
+  
+  // Store the value into the alloca.
+  Builder.CreateStore(StartVal, Alloca);
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  BasicBlock *PreheaderBB = Builder.GetInsertBlock();
+  BasicBlock *LoopBB = new BasicBlock("loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  Builder.CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  Builder.SetInsertPoint(LoopBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  AllocaInst *OldVal = NamedValues[VarName];
+  NamedValues[VarName] = Alloca;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (Body->Codegen() == 0)
+    return 0;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->Codegen();
+    if (StepVal == 0) return 0;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(Type::DoubleTy, APFloat(1.0));
+  }
+  
+  // Compute the end condition.
+  Value *EndCond = End->Codegen();
+  if (EndCond == 0) return EndCond;
+  
+  // Reload, increment, and restore the alloca.  This handles the case where
+  // the body of the loop mutates the variable.
+  Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
+  Value *NextVar = Builder.CreateAdd(CurVar, StepVal, "nextvar");
+  Builder.CreateStore(NextVar, Alloca);
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = Builder.CreateFCmpONE(EndCond, 
+                                  ConstantFP::get(Type::DoubleTy, APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *LoopEndBB = Builder.GetInsertBlock();
+  BasicBlock *AfterBB = new BasicBlock("afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  Builder.SetInsertPoint(AfterBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    NamedValues[VarName] = OldVal;
+  else
+    NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::DoubleTy);
+}
+
+Value *VarExprAST::Codegen() {
+  std::vector<AllocaInst *> OldBindings;
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Register all variables and emit their initializer.
+  for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
+    const std::string &VarName = VarNames[i].first;
+    ExprAST *Init = VarNames[i].second;
+    
+    // Emit the initializer before adding the variable to scope, this prevents
+    // the initializer from referencing the variable itself, and permits stuff
+    // like this:
+    //  var a = 1 in
+    //    var a = a in ...   # refers to outer 'a'.
+    Value *InitVal;
+    if (Init) {
+      InitVal = Init->Codegen();
+      if (InitVal == 0) return 0;
+    } else { // If not specified, use 0.0.
+      InitVal = ConstantFP::get(Type::DoubleTy, APFloat(0.0));
+    }
+    
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+    Builder.CreateStore(InitVal, Alloca);
+
+    // Remember the old variable binding so that we can restore the binding when
+    // we unrecurse.
+    OldBindings.push_back(NamedValues[VarName]);
+    
+    // Remember this binding.
+    NamedValues[VarName] = Alloca;
+  }
+  
+  // Codegen the body, now that all vars are in scope.
+  Value *BodyVal = Body->Codegen();
+  if (BodyVal == 0) return 0;
+  
+  // Pop all our variables from scope.
+  for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
+    NamedValues[VarNames[i].first] = OldBindings[i];
+
+  // Return the body computation.
+  return BodyVal;
+}
+
+
+Function *PrototypeAST::Codegen() {
+  // Make the function type:  double(double,double) etc.
+  std::vector<const Type*> Doubles(Args.size(), Type::DoubleTy);
+  FunctionType *FT = FunctionType::get(Type::DoubleTy, Doubles, false);
+  
+  Function *F = new Function(FT, Function::ExternalLinkage, Name, TheModule);
+  
+  // If F conflicted, there was already something named 'Name'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != Name) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = TheModule->getFunction(Name);
+    
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorF("redefinition of function");
+      return 0;
+    }
+    
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorF("redefinition of function with different # args");
+      return 0;
+    }
+  }
+  
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx)
+    AI->setName(Args[Idx]);
+    
+  return F;
+}
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F) {
+  Function::arg_iterator AI = F->arg_begin();
+  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+    // Store the initial value into the alloca.
+    Builder.CreateStore(AI, Alloca);
+
+    // Add arguments to variable symbol table.
+    NamedValues[Args[Idx]] = Alloca;
+  }
+}
+
+
+Function *FunctionAST::Codegen() {
+  NamedValues.clear();
+  
+  Function *TheFunction = Proto->Codegen();
+  if (TheFunction == 0)
+    return 0;
+  
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = new BasicBlock("entry", TheFunction);
+  Builder.SetInsertPoint(BB);
+  
+  // Add all arguments to the symbol table and create their allocas.
+  Proto->CreateArgumentAllocas(TheFunction);
+  
+  if (Value *RetVal = Body->Codegen()) {
+    // Finish off the function.
+    Builder.CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    // Optimize the function.
+    TheFPM->run(*TheFunction);
+    
+    return TheFunction;
+  }
+  
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+
+  if (Proto->isBinaryOp())
+    BinopPrecedence.erase(Proto->getOperatorName());
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static ExecutionEngine *TheExecutionEngine;
+
+static void HandleDefinition() {
+  if (FunctionAST *F = ParseDefinition()) {
+    if (Function *LF = F->Codegen()) {
+      fprintf(stderr, "Read function definition:");
+      LF->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern() {
+  if (PrototypeAST *P = ParseExtern()) {
+    if (Function *F = P->Codegen()) {
+      fprintf(stderr, "Read extern: ");
+      F->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression() {
+  // Evaluate a top level expression into an anonymous function.
+  if (FunctionAST *F = ParseTopLevelExpr()) {
+    if (Function *LF = F->Codegen()) {
+      // JIT the function, returning a function pointer.
+      void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
+      
+      // Cast it to the right type (takes no arguments, returns a double) so we
+      // can call it as a native function.
+      double (*FP)() = (double (*)())FPtr;
+      fprintf(stderr, "Evaluated to %f\n", FP());
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  while (1) {
+    fprintf(stderr, "ready> ");
+    switch (CurTok) {
+    case tok_eof:    return;
+    case ';':        getNextToken(); break;  // ignore top level semicolons.
+    case tok_def:    HandleDefinition(); break;
+    case tok_extern: HandleExtern(); break;
+    default:         HandleTopLevelExpression(); break;
+    }
+  }
+}
+
+
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" 
+double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" 
+double printd(double X) {
+  printf("%f\n", X);
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['='] = 2;
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['*'] = 40;  // highest.
+
+  // Prime the first token.
+  fprintf(stderr, "ready> ");
+  getNextToken();
+
+  // Make the module, which holds all the code.
+  TheModule = new Module("my cool jit");
+  
+  // Create the JIT.
+  TheExecutionEngine = ExecutionEngine::create(TheModule);
+
+  {
+    ExistingModuleProvider OurModuleProvider(TheModule);
+    FunctionPassManager OurFPM(&OurModuleProvider);
+      
+    // Set up the optimizer pipeline.  Start with registering info about how the
+    // target lays out data structures.
+    OurFPM.add(new TargetData(*TheExecutionEngine->getTargetData()));
+    // Promote allocas to registers.
+    OurFPM.add(createPromoteMemoryToRegisterPass());
+    // Do simple "peephole" optimizations and bit-twiddling optzns.
+    OurFPM.add(createInstructionCombiningPass());
+    // Reassociate expressions.
+    OurFPM.add(createReassociatePass());
+    // Eliminate Common SubExpressions.
+    OurFPM.add(createGVNPass());
+    // Simplify the control flow graph (deleting unreachable blocks, etc).
+    OurFPM.add(createCFGSimplificationPass());
+
+    // Set the global so the code gen can use this.
+    TheFPM = &OurFPM;
+
+    // Run the main "interpreter loop" now.
+    MainLoop();
+    
+    TheFPM = 0;
+  }  // Free module provider and pass manager.
+                                   
+                                   
+  // Print out all of the generated code.
+  TheModule->dump();
+  return 0;
+}
 
GlobalVariable
llvm-gcc -g -O0