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

[Marc Glisse <marc dot glisse at inria dot fr>]

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.

--
Marc Glisse