llvm dev - Dec 2009 - [LLVMdev] detailed comparison of generated code size for LLVM and other compilers

> The issue here is more arbitrary differences due to different default
> code generation choices; for example, clang defaults to generating
> SSE2 code, while llvm-gcc defaults to using x87 FP.
Aha, this explains some apparently bizarre results such as the second one 
(018427, d) on this page:

http://embed.cs.utah.edu/embarrassing/dec_09/harvest/llvm-gcc-head_clang-head/

I had been wondering about this one.

John

> Aha, this explains some apparently bizarre results such as the second one
> (018427, d) on this page:
Right. However, I saw the opposite case with sse2 code being 4x larger

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University

On Dec 14, 2009, at 5:01 PM, Anton Korobeynikov wrote:
>> Aha, this explains some apparently bizarre results such as the  
>> second one
>> (018427, d) on this page:
> Right. However, I saw the opposite case with sse2 code being 4x larger
"return 1.0" is an example that is larger with SSE codegen, because  
the ABI requires stuff in the FP stack.  X86-64 doesn't have this issue.

-Chris