On Thu, Nov 29, 2007 at 12:58:55PM +0100, Sylvain Pion wrote: > Michael Meissner a écrit : > >One of the things that I've been interested in is adding support to GCC to > >compile individual functions with specific target options. I first > >presented a > >draft at the Google mini-summit, and then another draft at the GCC > >developer > >summit last July. > > > >In the x86 world this would mean saying that an individual function can use > >SSE5 instructions or SSE4.1 instructions. This would simplify things for > >people who need to write high performance libraries that run on different > >architectures, and need to be optimal on each platform. Ultimately, the > >goal > >is to allow hotspot functions to be compiled several times with different > >target specific optimizations. I would welcome any thoughts or suggestions > >about this proposal. > > I'm wondering if this proposal would support specifying things > like adding -frounding-math when compiling specific functions. > ( This particular case is connected to pragma FENV_ACCESS though. )
I imagine it could be made to work once the infrastructure is in place. I had forgotten about the C99 math pragmas. > Also, would this work when the functions is inline? > I mean the case when the caller does not have the same attribute, > but the inlined code of the callee still respects the attribute > set for the inlined callee. Right now I specify that for stage 1 if a generic function calls a function with target specific support, that it not be inlined. However a function with target specific support can call and inline either generic functions or other functions with the same target specific options. -- Michael Meissner, AMD 90 Central Street, MS 83-29, Boxborough, MA, 01719, USA [EMAIL PROTECTED]
