Polyhedron performance regression

[Richard Guenther]

On 11/13/06, Richard Guenther <richard.guenther@gmail.com> wrote:
> On 11/13/06, Paul Richard Thomas <paul.richard.thomas@gmail.com> wrote:
> > Richard,
> >
> > > I bet we are missing an inline x86_64 variant.  But it should be not too
> > > hard to implement.
> >
> > 'tis what I thought.
> >
> > My view is that Steve is right about right and slow; however it is a
> > very visible right and slow.  Which is the right button to press to
> > have the inline version crafted for us?
>
> I can do expanders for fmod and remainder.

I sort of take that back ;)  But at least for the fortran MODULO you should
be able to emit A - FLOOR (A / P) * P as in the definition.  Currently
it seems at least FMOD is called in the expansion.  With the above
definition used for expansion you'd get

        cvtss2sd        %xmm0, %xmm3
        movsd   (%rsi), %xmm2
        movapd  %xmm3, %xmm0
        divsd   %xmm2, %xmm0
        cvttsd2si       %xmm0, %eax
        cvtsi2sd        %eax, %xmm1
        ucomisd %xmm1, %xmm0
        jae     .L2
        subl    $1, %eax
        cvtsi2sd        %eax, %xmm1
.L2:
        mulsd   %xmm2, %xmm1
        movapd  %xmm3, %xmm0
        subsd   %xmm1, %xmm0

exact IEC 60559 semantics for remainder will probably not be suitable
for inlining.  But I can try...

Richard.