On Tue, Apr 08, 2014 at 10:53:19AM +0200, Andreas Krebbel wrote:
> On 04/08/2014 10:41 AM, Jakub Jelinek wrote:
> > On Tue, Apr 08, 2014 at 10:26:30AM +0200, Richard Biener wrote:
> >> On Mon, Apr 7, 2014 at 6:22 PM, Andreas Krebbel
> >> <kreb...@linux.vnet.ibm.com> wrote:
> >>> On Mon, Apr 07, 2014 at 04:19:06PM +0200, Richard Biener wrote:
> >>>> The adjusted testcases now fail on x86_64/i?86 at least. See PR60776.
> >>>
> >>> They seem to require at least -O2 on x86 with that change. Ok to apply?
> >>
> >> Hmm, they passed before your change. Do you mean that this was
> >> by accident (and only because of the special return value)? If so then
> >> the patch is ok.
> >
> > The reason why it worked with the if ... return 1; else return 0; case is
> > that in that case it has already been expanded as store flag insn and thus
> > in that case ce1 pass didn't discover the conditional move there, thus no
> > dead code waiting to be eliminated after ce1 and still present during
> > combine pass.
> >
> > Another alternative for -O2 would be -O -fno-if-conversion I guess.
>
> I could also revert the testcase changes and add -mbranch-cost=2 for s390?!
That doesn't seem to work (at least for me with cross-compiler to s390x).
> >
> > OT, when touching the testcase, I'd say it would be better if you've
> > converted it to single dg-options + /* { dg-additional-options
> > "-march=z900" { target s390*-*-* } } */
>
> Ok.
Thanks.
Jakub
