[LLVMdev] detailed comparison of generated code size for LLVM and other compilers

Renato Golin rengolin at systemcall.org
Mon Dec 14 15:29:33 PST 2009


2009/12/14 Chris Lattner <clattner at apple.com>:
> I'd recommend targeting (with both -march and -mtune) a simple and
> commonly available CPU type like "core2" or "pentium4".  ICC should
> have both of these and gcc/llvm definitely do.

While I would say that, to be fair, the comparison should be made with
the same options (-O3 only or something of the sort), ICC is specific
for Intel and GCC is highly tuned to, which is not the case of LLVM.
Still, if the target is specified, I'd assume we should enable all
tested and proven (AFAP) optimizations to that particular platform by
default.

So, my question is: are those optimizations turned off by default
because they're experimental?

--renato

http://systemcall.org/

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