Re: match.pd patch: min(-x, -y), min(~x, ~y)

[Kyrill Tkachov <kyrylo dot tkachov at foss dot arm dot com>]

On 22/04/16 12:20, Kyrill Tkachov wrote:
> On 22/04/16 11:34, Marc Glisse wrote:
> > On Fri, 22 Apr 2016, Kyrill Tkachov wrote:
> >
> > > On 22/04/16 10:43, Kyrill Tkachov wrote:
> > > > On 22/04/16 10:42, Marc Glisse wrote:
> > > > > On Fri, 22 Apr 2016, Kyrill Tkachov wrote:
> > > > >
> > > > > > > 2016-04-21  Marc Glisse <marc.glisse@inria.fr>
> > > > > > >
> > > > > > > gcc/
> > > > > > >     * match.pd (min(-x, -y), max(-x, -y), min(~x, ~y), max(~x, ~y)):
> > > > > > >     New transformations.
> > > > > > >
> > > > > > > gcc/testsuite/
> > > > > > >     * gcc.dg/tree-ssa/minmax-2.c: New testcase.
> > > > > >
> > > > > > I see the new testcase failing on aarch64:
> > > > > > FAIL: gcc.dg/tree-ssa/minmax-2.c scan-tree-dump optimized "__builtin_fmin"
> > > > >
> > > > > Strange, it seems to work in https://gcc.gnu.org/ml/gcc-testresults/2016-04/msg02120.html
> > > > >
> > > > > Is that on some freestanding kind of setup where the builtin might be disabled?
> > > >
> > > > Ah, this is aarch64-none-elf which uses newlib as the C library.
> > > > Let me check on aarch64-none-linux-gnu and get back to you.
> > >
> > > Yeah, I see it passing on aarch64-none-linux-gnu.
> > > Do we have an appropriate effective target check to gate this test on?
> >
> > I don't know, I have a hard time finding something related. I am not even convinced the test should be skipped. It looks like __builtin_fmax was recognized, otherwise you would get a warning and a conversion int-double. Maybe 
> > gimple_call_combined_fn rejects it? Ah, builtins.def declares it with DEF_C99_BUILTIN, which checks targetm.libc_has_function (function_c99_misc). I assume newlib fails that check? That would make c99_runtime a relevant target check.
>
> Yeah, adding the below makes this test UNSUPPORTED on aarch64-none-elf.
> /* { dg-add-options c99_runtime } */
> /* { dg-require-effective-target c99_runtime } */
>
> I'll prepare a patch.

Sorry for the delay, here it is.
Ok to commit?

Thanks,
Kyrill

2016-04-25  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

    * gcc.dg/tree-ssa/minmax-2.c: Require c99_runtime and add the
    associated options.

> Thanks,
> Kyrill

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-2.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-2.c
index 98c38b1aa773d04a5d7cb36df73db8924d83ed65..87ff94cef1f3b178b315358f246c9a3f32383945 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/minmax-2.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-2.c
@@ -1,5 +1,7 @@
 /* { dg-do compile } */
 /* { dg-options "-O -fstrict-overflow -fdump-tree-optimized" } */
+/* { dg-add-options c99_runtime } */
+/* { dg-require-effective-target c99_runtime } */
 
 static int max(int a,int b){return (a<b)?b:a;}
 int f(int x,int y){return max(-x,-y);}