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

[Renato Golin]

2009/12/15 Chris Lattner <clattner at apple.com>:
> "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.

This might be a very stupid question, but can we not choose to disable
SSE code generating in a case-by-case basis, even when those
optimizations are turned on?

In that case, I imagine that 1.0 is considered double and would
normally fill one or two registers, thus easy enough to return it via
registers. Unless, of course, the ABI mandates that SSE is
all-or-nothing...

cheers,
--renato

http://systemcall.org/

Reclaim your digital rights, eliminate DRM, learn more at
http://www.defectivebydesign.org/what_is_drm