On Thu, Nov 07, 2024 at 10:54:40AM +0000, Andrew Stubbs wrote:
> On 07/11/2024 00:37, haochen.jiang wrote:
> > d334f729e53867b838e867375b3f475ba793d96e is the first bad commit
> > commit d334f729e53867b838e867375b3f475ba793d96e
> > Author: Andrew Stubbs <a...@baylibre.com>
> > Date: Wed Nov 6 12:26:08 2024 +0000
> >
> > openmp: Add testcases for omp_max_vf
> >
> > caused
> >
> > FAIL: gcc.dg/gomp/max_vf-1.c scan-tree-dump-times ompexp "\\+ 16" 1
> > FAIL: gcc.dg/gomp/max_vf-1.c scan-tree-dump-times ompexp "\\* 16" 2
> > FAIL: gcc.dg/gomp/max_vf-1.c scan-tree-dump-times ompexp
> > "__builtin_GOMP_parallel_loop_nonmonotonic_dynamic \\(.*, 16, 0\\);" 1
> >
> > with GCC configured with
> >
> > ../../gcc/configure
> > --prefix=/export/users/haochenj/src/gcc-bisect/master/master/r15-4988/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="gomp.exp=gcc.dg/gomp/max_vf-1.c --target_board='unix{-m32\
> > -march=cascadelake}'"
> > $ cd {build_dir}/gcc && make check
> > RUNTESTFLAGS="gomp.exp=gcc.dg/gomp/max_vf-1.c --target_board='unix{-m64\
> > -march=cascadelake}'"
>
> This problem was supposed to be avoided by explicitly passing "-msse2" in
> the testcase. Apparently -march=cascadelake silently overrides that setting
> ... maybe don't do that?
What do yo mean by overrides?
-march=cascadelake -msse2
(or the other ordering too) certainly doesn't override the enabling of SSE2,
the -mISA and -mno-ISA flags take precedence over -march=; though other
flags can be set too from the -march= or its default set when configuring
the compiler.
So, if the testcase relies on SSE2 enabled and SSE3 not enabled, it should
use -msse2 -mno-sse3.
Seems the testcase actually relies on AVX not being enabled, so it should
use "-msse2 -mno-avx".
That will work fine even with -march=cascadelake, whether it is the default
or requested through --target_board.
Jakub
