Re: inhibit the sincos optimization when the target has sin and cos instructions

[Andrew Pinski <pinskia at gmail dot com>]

On Tue, May 17, 2016 at 2:10 PM, Cesar Philippidis
<cesar@codesourcery.com> wrote:
> On 05/13/2016 01:13 PM, Andrew Pinski wrote:
>> On Fri, May 13, 2016 at 12:58 PM, Richard Biener
>> <richard.guenther@gmail.com> wrote:
>>> On May 13, 2016 9:18:57 PM GMT+02:00, Cesar Philippidis <cesar@codesourcery.com> wrote:
>>>> The cse_sincos pass tries to optimize sequences such as
>>>>
>>>>  sin (x);
>>>>  cos (x);
>>>>
>>>> into a single call to sincos, or cexpi, when available. However, the
>>>> nvptx target has sin and cos instructions, albeit with some loss of
>>>> precision (so it's only enabled with -ffast-math). This patch teaches
>>>> cse_sincos pass to ignore sin, cos and cexpi instructions when the
>>>> target can expand those calls. This yields a 6x speedup in 314.omriq
>>> >from spec accel when running on Nvidia accelerators.
>>>>
>>>> Is this OK for trunk?
>>>
>>> Isn't there an optab for sincos?
>>
>> This is exactly what I was going to suggest.  This transformation
>> should be done in the back-end back to sin/cos instructions.
>
> I didn't realize that the 387 has sin, cos and sincos instructions,
> so yeah, my original patch is bad.
>
> Nathan, is this patch ok for trunk and gcc-6? It adds a new sincos
> pattern in the nvptx backend. I haven't testing a standalone nvptx
> toolchain prior to this patch, so I'm not sure if my test results
> look sane. I seem to be getting a different set of failures when I
> test a clean trunk build multiple times. I attached my results
> below for reference.


UNSPEC_SINCOS is unused so why add it?

Thanks,
Andrew Pinski


>
> Cesar
>
> g++.sum
> Tests that now fail, but worked before:
>
> nvptx-none-run: g++.dg/abi/param1.C  -std=c++14 execution test
>
> Tests that now work, but didn't before:
>
> nvptx-none-run: g++.dg/opt/pr30590.C  -std=gnu++98 execution test
> nvptx-none-run: g++.dg/opt/pr36187.C  -std=gnu++14 execution test
>
> gfortran.sum
> Tests that now fail, but worked before:
>
> nvptx-none-run: gfortran.dg/alloc_comp_assign_10.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
> nvptx-none-run: gfortran.dg/allocate_with_source_5.f90   -O1  execution test
> nvptx-none-run: gfortran.dg/func_assign_3.f90   -O3 -g  execution test
> nvptx-none-run: gfortran.dg/inline_sum_3.f90   -O1  execution test
> nvptx-none-run: gfortran.dg/inline_sum_3.f90   -O3 -g  execution test
> nvptx-none-run: gfortran.dg/internal_pack_15.f90   -O2  execution test
> nvptx-none-run: gfortran.dg/internal_pack_8.f90   -Os  execution test
> nvptx-none-run: gfortran.dg/intrinsic_ifunction_2.f90   -O0  execution test
> nvptx-none-run: gfortran.dg/intrinsic_ifunction_2.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
> nvptx-none-run: gfortran.dg/intrinsic_pack_5.f90   -O3 -g  execution test
> nvptx-none-run: gfortran.dg/intrinsic_product_1.f90   -O1  execution test
> nvptx-none-run: gfortran.dg/intrinsic_verify_1.f90   -O3 -g  execution test
> nvptx-none-run: gfortran.dg/is_iostat_end_eor_1.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
> nvptx-none-run: gfortran.dg/iso_c_binding_rename_1.f03   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
>
> Tests that now work, but didn't before:
>
> nvptx-none-run: gfortran.dg/char_pointer_assign.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
> nvptx-none-run: gfortran.dg/char_pointer_dummy.f90   -O1  execution test
> nvptx-none-run: gfortran.dg/char_pointer_dummy.f90   -Os  execution test
> nvptx-none-run: gfortran.dg/char_result_13.f90   -O3 -g  execution test
> nvptx-none-run: gfortran.dg/char_result_2.f90   -O1  execution test
> nvptx-none-run: gfortran.dg/char_type_len.f90   -Os  execution test
> nvptx-none-run: gfortran.dg/character_array_constructor_1.f90   -O0  execution test
> nvptx-none-run: gfortran.dg/nested_allocatables_1.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
>
> gcc.sum
> Tests that now fail, but worked before:
>
> nvptx-none-run: gcc.c-torture/execute/20100316-1.c   -Os  execution test
> nvptx-none-run: gcc.c-torture/execute/20100708-1.c   -O1  execution test
> nvptx-none-run: gcc.c-torture/execute/20100805-1.c   -O0  execution test
> nvptx-none-run: gcc.dg/torture/pr52028.c   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
> nvptx-none-run: gcc.dg/torture/pr52028.c   -O3 -g  execution test
>
> Tests that now work, but didn't before:
>
> nvptx-none-run: gcc.c-torture/execute/20091229-1.c   -O3 -g  execution test
> nvptx-none-run: gcc.c-torture/execute/20101013-1.c   -Os  execution test
> nvptx-none-run: gcc.c-torture/execute/20101025-1.c   -Os  execution test
> nvptx-none-run: gcc.c-torture/execute/20120105-1.c   -O0  execution test
> nvptx-none-run: gcc.c-torture/execute/20120111-1.c   -O0  execution test
>
> New tests that PASS:
>
> nvptx-none-run: gcc.target/nvptx/sincos-1.c (test for excess errors)
> nvptx-none-run: gcc.target/nvptx/sincos-1.c scan-assembler-times cos.approx.f32 1
> nvptx-none-run: gcc.target/nvptx/sincos-1.c scan-assembler-times sin.approx.f32 1
> nvptx-none-run: gcc.target/nvptx/sincos-2.c (test for excess errors)
> nvptx-none-run: gcc.target/nvptx/sincos-2.c execution test
>
>
>>> ISTR x87 handles this pass just fine and also can do sin and cos.
>>>
>>> Richard.
>>>
>>>> Cesar
>>>
>>>
>