[llvm-commits] [llvm] r82796 - in /llvm/trunk: lib/Analysis/ValueTracking.cpp test/Transforms/InstCombine/no-negzero.ll

Dale Johannesen dalej at apple.com
Fri Sep 25 15:54:50 CDT 2009


Author: johannes
Date: Fri Sep 25 15:54:50 2009
New Revision: 82796

URL: http://llvm.org/viewvc/llvm-project?rev=82796&view=rev
Log:
Handle sqrt in CannotBeNegativeZero.  absf and absl
appear to be misspellings, removed in favor of fabs*.


Added:
    llvm/trunk/test/Transforms/InstCombine/no-negzero.ll
Modified:
    llvm/trunk/lib/Analysis/ValueTracking.cpp

Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=82796&r1=82795&r2=82796&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Fri Sep 25 15:54:50 2009
@@ -840,9 +840,13 @@
       if (F->isDeclaration()) {
         // abs(x) != -0.0
         if (F->getName() == "abs") return true;
-        // abs[lf](x) != -0.0
-        if (F->getName() == "absf") return true;
-        if (F->getName() == "absl") return true;
+        // fabs[lf](x) != -0.0
+        if (F->getName() == "fabs") return true;
+        if (F->getName() == "fabsf") return true;
+        if (F->getName() == "fabsl") return true;
+        if (F->getName() == "sqrt" || F->getName() == "sqrtf" ||
+            F->getName() == "sqrtl")
+          return CannotBeNegativeZero(CI->getOperand(1), Depth+1);
       }
     }
   

Added: llvm/trunk/test/Transforms/InstCombine/no-negzero.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/no-negzero.ll?rev=82796&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/no-negzero.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/no-negzero.ll Fri Sep 25 15:54:50 2009
@@ -0,0 +1,33 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+; ModuleID = '3555a.c'
+; sqrt(fabs) cannot be negative zero, so we should eliminate the fadd.
+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 = "i386-apple-darwin9.8"
+
+; CHECK: @mysqrt
+; CHECK-NOT: fadd
+; CHECK: ret
+define double @mysqrt(double %x) nounwind {
+entry:
+  %x_addr = alloca double                         ; <double*> [#uses=2]
+  %retval = alloca double, align 8                ; <double*> [#uses=2]
+  %0 = alloca double, align 8                     ; <double*> [#uses=2]
+  %"alloca point" = bitcast i32 0 to i32          ; <i32> [#uses=0]
+  store double %x, double* %x_addr
+  %1 = load double* %x_addr, align 8              ; <double> [#uses=1]
+  %2 = call double @fabs(double %1) nounwind readnone ; <double> [#uses=1]
+  %3 = call double @sqrt(double %2) nounwind readonly ; <double> [#uses=1]
+  %4 = fadd double %3, 0.000000e+00               ; <double> [#uses=1]
+  store double %4, double* %0, align 8
+  %5 = load double* %0, align 8                   ; <double> [#uses=1]
+  store double %5, double* %retval, align 8
+  br label %return
+
+return:                                           ; preds = %entry
+  %retval1 = load double* %retval                 ; <double> [#uses=1]
+  ret double %retval1
+}
+
+declare double @fabs(double)
+
+declare double @sqrt(double) nounwind readonly





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