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| author | Harry van Haaren <harry.van.haaren@intel.com> | 2020-07-29 11:59:34 +0100 |
|---|---|---|
| committer | Ian Stokes <ian.stokes@intel.com> | 2020-08-05 15:57:40 +0100 |
| commit | 930f135f5ddc4372c1615bc7674dda35c229b6bd (patch) | |
| tree | 708b7a448ba3b8bf2ec0a4a7dc4b5a4e9b09b7ea /m4 | |
| parent | ba5e3117828f6cc2a0c9eefd292b2b4f7da75e6b (diff) | |
| download | openvswitch-930f135f5ddc4372c1615bc7674dda35c229b6bd.tar.gz | |
configure: explicitly disable avx512 if bintuils check fails
This commit explicitly disables avx512f if the binutils assembler
check fails to correctly assemble its input.
Without this fix, there is a possibility that users can see undefined
behaviour when compiling with -march=native on a CPU which supports
avx512 and with a buggy binutils version (v2.30 and 2.31), without a
backported fix, if the compiler's vectorizing optimizations convert
scalar code to avx512 instructions.
Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>
Diffstat (limited to 'm4')
| -rw-r--r-- | m4/openvswitch.m4 | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/m4/openvswitch.m4 b/m4/openvswitch.m4 index 7c9a507e5..6fe79297e 100644 --- a/m4/openvswitch.m4 +++ b/m4/openvswitch.m4 @@ -426,8 +426,12 @@ AC_DEFUN([OVS_CHECK_BINUTILS_AVX512], CFLAGS="$CFLAGS -DHAVE_LD_AVX512_GOOD" else ovs_cv_binutils_avx512_good=no + dnl Explicitly disallow avx512f to stop compiler auto-vectorizing + dnl and causing zmm usage with buggy binutils versions. + CFLAGS="$CFLAGS -mno-avx512f" fi else + dnl non x86_64 architectures don't have avx512, so not affected ovs_cv_binutils_avx512_good=no fi]) rm $OBJFILE |