[PATCH, dataflow]: Fix PR55845, 454.calculix miscompares on x86 AVX due to movement of vzeroupper

[Uros Bizjak]

On Tue, Jan 8, 2013 at 12:26 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Mon, Jan 07, 2013 at 05:52:23PM +0100, Uros Bizjak wrote:
>> TBH, I'm not that familiar with the RTL infrastructure enough to
>> answer these questions. While I can spend some time on this problem,
>> and probably waste quite some reviewer's time, the problem is not that
>> trivial as I hoped to be, so I would kindly ask someone with better
>> understanding of this part of the compiler for the proper solution.
>
> After discussion with rth on IRC, this modified patch just uses
> volatile_insn_p, making all UNSPEC_VOLATILE (wherever in insn) and asm
> volatile into a complete scheduling barrier for optimizations that use this
> function.

Thanks!

Just two little nits in the testcase:

> +foo (int size, double y[], double x[])

foo (int size, double *y, double *x)

> +  return (sum);

return sum;

Uros.