[PATCH] Remove vectorizer reduction operand swapping

[Richard Biener]

On Fri, 20 Sep 2019, Rainer Orth wrote:

> Hi Richard,
> 
> > On Thu, 19 Sep 2019, Richard Sandiford wrote:
> >
> >> Richard Biener <rguenther@suse.de> writes:
> >> > It shouldn't be neccessary.
> >> 
> >> SVE is the counter-example :-)  But the fix is simpler than the code
> >> you removed, so it's still a net win.
> >
> > Yeah, I meant it shouldn't be necessary to swap operands of the
> > original scalar stmts since we keep track of the "order" via
> > reduc_index.
> >
> >> Fixes various vect.exp and aarch64-sve.exp ICEs.  OK if it passes
> >> proper testing?
> >
> > OK.
> 
> I suspect this patch caused
> 
> +FAIL: gcc.dg/pr88031.c (internal compiler error)
> +FAIL: gcc.dg/pr88031.c (test for excess errors)
> 
> I'm seeing it on 32 and 64-bit Solaris/x86, but there are also several
> reports on aarch64, armv8l, i686, powerpc64*, s390x, x86_64.

PR91822, should be fixed now.

Richard.