Re: FW: [r16-3364 Regression] FAIL: gcc.target/i386/shift-gf2p8affine-7.c scan-assembler-times vgf2p8affineqb 53 on Linux/x86_64

On Thu, Aug 28, 2025 at 2:06 PM Andi Kleen <[email protected]> wrote:
>
> On Wed, Aug 27, 2025 at 02:11:44AM +0000, Jiang, Haochen wrote:
> > On Linux/x86_64,
> >
> > 001cd39749f94ece8276b63f91eb864babb81a5d is the first bad commit
> > commit 001cd39749f94ece8276b63f91eb864babb81a5d
> > Author: Andi Kleen <[email protected]>
> > Date:   Sun Aug 3 17:35:39 2025 -0700
> >
> >     Use x86 GFNI for vectorized constant byte shifts/rotates
> >
> > caused
> >
> > FAIL: gcc.target/i386/shift-gf2p8affine-5.c scan-assembler-times vgf2p8affineqb 31
> > FAIL: gcc.target/i386/shift-gf2p8affine-6.c scan-assembler-times vgf2p8affineqb 0
> > FAIL: gcc.target/i386/shift-gf2p8affine-7.c scan-assembler-times vgf2p8affineqb 53
>
> Hmm it works for me and your configuration doesn't look that different.
> I believe the test is a bit sensitive on the target tuning, but
> you shouldn't use anything special here.

I can reproduce with the provided command line:

spawn -ignore SIGHUP
/export/build/gnu/tools-build/gcc-gitlab-test-debug/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/tools-build/gcc-gitlab-test-debug/build-x86_64-linux/gcc/
/export/gnu/import/git/gitlab/x86-gcc-test/gcc/testsuite/gcc.target/i386/shift-gf2p8affine-5.c
-m32 -march=cascadelake -fdiagnostics-plain-output -mgfni -mavx -O3
-Wno-shift-count-negative -ffat-lto-objects -fno-ident -S -o
shift-gf2p8affine-5.s
PASS: gcc.target/i386/shift-gf2p8affine-5.c (test for excess errors)
gcc.target/i386/shift-gf2p8affine-5.c: vgf2p8affineqb found 52 times
FAIL: gcc.target/i386/shift-gf2p8affine-5.c scan-assembler-times
vgf2p8affineqb 31

> Can you send a few lines around it from the logs? Like
>
> find -name gcc.log | xargs grep -C5 'FAIL.*gf2p8affine'
>
> -Andi
>
>
> >
> > with GCC configured with
> >
> > ../../gcc/configure --prefix=/export/users3/haochenj/src/gcc-bisect/master/master/r16-3364/usr --enable-clocale=gnu --with-system-zlib --with-demangler-in-ld --with-fpmath=sse --enable-languages=c,c++,fortran --enable-cet --without-isl --enable-libmpx x86_64-linux --disable-bootstrap
> >
> > To reproduce:
> >
> > $ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/shift-gf2p8affine-5.c --target_board='unix{-m32\ -march=cascadelake}'"
> > $ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/shift-gf2p8affine-5.c --target_board='unix{-m64\ -march=cascadelake}'"
> > $ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/shift-gf2p8affine-6.c --target_board='unix{-m32\ -march=cascadelake}'"
> > $ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/shift-gf2p8affine-6.c --target_board='unix{-m64\ -march=cascadelake}'"
> > $ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/shift-gf2p8affine-7.c --target_board='unix{-m32\ -march=cascadelake}'"
> > $ cd {build_dir}/gcc && make check RUNTESTFLAGS="i386.exp=gcc.target/i386/shift-gf2p8affine-7.c --target_board='unix{-m64\ -march=cascadelake}'"
> >
> > (Please directly reply to this email for question about this report.)
> > (If you met problems with cascadelake related, disabling AVX512F in command line might save that.)
> > (However, please make sure that there is no potential problems with AVX512.)
> >



-- 
H.J.