On Sat, 18 May 2013 12:14:35 -0700 Matt Turner <matts...@gentoo.org> wrote:
> > MMX2/MMXEXT still confuses me. > > SSE1 and /Enhanced/ 3DNow! added some extra MMX instructions. Some > (pshufw and pmulhuw particularly) turn out to be rather useful in > software compositing. I use them in the pixman MMX code. > > See http://mattst88.com/programming/asmref/ (Sorry about the broken > search box. It works, you just don't see what you type) Oh I am going to get a lot of use out of this. > Set Requires = Enhanced 3DNow!. The instructions that are listed as > 'Enhanced 3DNow! or SSE1' are what are known as MMX2 or MMXEXT. > > The particularly annoying thing about using them is that there's no > -mmmx2 or -mmmxext, but turning on -msse causes illegal instructions > to be generated for old AMD or Geode CPUs, while -m3dnow causes the > same problems for Intel CPUs. And, there's not actually even an > -m3dnowext flag (anymore?) anyway, so it's kind of a mess. Ah, that explains why I always thought they were Enh 3DNow options. Looks like I have them spread out between MMX and Enh 3DNow in analyze-x86. Oops. -- Ryan Hill psn: dirtyepic_sk gcc-porting/toolchain/wxwidgets @ gentoo.org 47C3 6D62 4864 0E49 8E9E 7F92 ED38 BD49 957A 8463
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