On 24/01/17 16:28, Christophe Lyon wrote:
On 24 January 2017 at 17:02, Kyrill Tkachov <kyrylo.tkac...@foss.arm.com> wrote:
On 24/01/17 15:21, Segher Boessenkool wrote:
On Tue, Jan 24, 2017 at 01:40:46PM +0100, Bernd Schmidt wrote:
On 01/24/2017 09:38 AM, Christophe Lyon wrote:
It seems that Bernd's patch causes regressions on arm-linux-gnueabihf
--with-cpu=cortex-a5 --with-fpu=vfpv3-d16-fp16:

   gcc.target/arm/vselvcdf.c scan-assembler-times vselvs.f64\td[0-9]+ 1
   gcc.target/arm/vselvcsf.c scan-assembler-times vselvs.f32\ts[0-9]+ 1
   gcc.target/arm/vselvsdf.c scan-assembler-times vselvs.f64\td[0-9]+ 1
   gcc.target/arm/vselvssf.c scan-assembler-times vselvs.f32\ts[0-9]+ 1

Maybe the upcoming patch from Segher intends to address this?
Not really.
Not at all, even, first I hear of this.  Please open a PR.

How exactly do I reproduce this - can you give me a command
line and expected assembly output (I'm having some trouble figuring out
the right set of switches)?
Same here.

I haven't looked at these in detail but these are the ARMv8 FP conditional
select tests
and they would be affected by if_then_else generation.

So something like -mfpu=neon-fp-armv8 -mfloat-abi=hard -O2 -mcpu=cortex-a5
would reproduce this.
Maybe the Cortex-A5 BRANCH_COST affects things...

Thanks Kyrill, and sorry for not replying earlier.
Yes something like that.

The configuration in question is configured with:
-target=arm-none-linux-gnueabihf --with-float=hard
--enable-build-with-cxx --with-mode=arm --with-cpu=cortex-a5
--with-fpu=vfpv3-d16-fp16

If you can't easily rebuild the whole toolchain, you can use an
arm-linux-gnueabihf toolchain and
use -mcpu=cortex-a5 -mfpu=vfpv3-d16-fp16 -mfloat-abi=hard.

The -mfpu is overridden in the testcase to add the ARMv8 instructions.
So to reproduce the compilation in that testcase you'd want -mfpu=fp-armv8 or
something equivalent rather than vfpv3-d16-fp16.

Thanks,
Kyrill


It's not the first time that Cortex-A5's BRANCH_COST implies
changes on a testcase.

Christophe

Kyrill



Segher


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