Re: [TESTING] ssse3 backport from gcc 4.3

On Thu Mar 10 11, Dimitry Andric wrote:
> On 2011-03-09 22:18, David Schultz wrote:
> >The proliferation of -mno-sse -mno-sse2 -mno-sse3 options in the
> >makefiles is probably not needed: I'm pretty sure -mno-sse implies
> >the other two, unless -msse3 is specified explicitly.
> 
> Indeed, contrib/gcc/config/i386/i386.c has:
> 
> static bool
> ix86_handle_option (size_t code, const char *arg ATTRIBUTE_UNUSED, int 
> value)
> {
> ...
>     case OPT_msse:
>       if (!value)
>         {
>           target_flags &= ~(MASK_SSE2 | MASK_SSE3);
>           target_flags_explicit |= MASK_SSE2 | MASK_SSE3;
>         }
>       return true;
> 
> E.g -mno-sse disables SSE2 and SSE3, unless you explicitly add -msse2 or
> -msse3 options.  In Martin's patch, this fragment uses MASK_SSSE3 too.

+1 for removing -mno-sse2, -mno-sse3 and -mno-ssse3 throughout the source
tree.

...also -mfpmath=387 is still present for amd64 and i don't think it's
necessary. with -mno-sse i don't think -mfpmath=sse remains the default for
amd64.

> 
> Clang has a similar mechanism, -mno-sse disables all 'higher' SSE
> variants too.

-- 
a13x