[PATCH] Detect i586 and i686 features at run-time

[Mike Frysinger]

On 19 Aug 2015 04:19, H.J. Lu wrote:
> On Tue, Aug 18, 2015 at 9:20 PM, Mike Frysinger wrote:
> > On 18 Aug 2015 11:25, H.J. Lu wrote:
> >> We detect i586 and i686 features at run-time by checking CX8 and CMOV
> >> CPUID features bits.  We can use these information to select the best
> >> implementation in ix86 multiarch.
> >
> > there are i686's w/out cmov.  shouldn't multiarch implementations that use
> > certain insns be tied to those rather than a big knob like "i686" ?
> 
> For purpose glibc build, i686 has cmov:
> 
> [hjl@gnu-tools-1 glibc]$ grep cmov sysdeps/i386/i686/*.S
> sysdeps/i386/i686/strcmp.S: cmovbl %ecx, %eax
> sysdeps/i386/i686/strtok.S: cmove %eax, %edx
> sysdeps/i386/i686/strtok.S: cmovne %ecx, %edx

i think that deserves a comment in the source
-mike
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