[LLVMdev] detailed comparison of generated code size for LLVM and other compilers
dalej at apple.com
Mon Dec 14 13:27:03 PST 2009
On Dec 14, 2009, at 12:23 PMPST, John Regehr wrote:
>>> There are probably other differing defaults besides frame
>>> pointers. Stack
>>> protectors, perhaps.
>> Yes, that's another good example,
> Ok-- I assume I should just add '-fno-stack-protector' to the llvm-
> gcc and
> clang command lines? I had totally missed that something like this
> turned on by default.
> I'll re-run everything with this change, with frame pointers
> omitted, and
> dropping testcases that contain uses of uninititalized locals and post
> here again when that's done.
You'll probably need to some digging to make sure the defaults are
exactly comparable. Are SSE and/or MMX used? This affects floating
point codegen quite a bit. Are the target CPUs the same?
I think some useful information is going to come out of this, but
there's some cruft to clear out first.
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