[LLVMdev] RFA: TREE_READONLY in LLVM-GCC
clattner at apple.com
Sun Jan 4 14:47:02 CST 2009
On Jan 4, 2009, at 3:44 AM, Bill Wendling wrote:
> Hi LLVM-GCC hackers!
> I have a global variable that I want to mark as "TREE_READONLY" so
> that it will become a "constant" in LLVM IR. This is for the new
> blocks-related stuff, but that's not necessarily important for this
> question. In particular, I want to mark the "block_holder" created in
> "build_block_literal_tmp()" as read-only.
> My question to you is: Considering that LLVM-GCC uses only a small
> part of the GCC source base, what affect will marking the
> "block_holder" variable as TREE_READONLY have? Does LLVM-GCC run
> through code that looks at this flag and act differently before it
> generates the LLVM IR?
I think this change is fine and should go into the normal apple GCC as
well. Setting TREE_READONLY means that it can go into the "constant"
section of the executable, go in ROM, etc. This is the same as the
llvm constant bit on globals.
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