diff options
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | sysdeps/x86_64/configure | 22 | ||||
| -rw-r--r-- | sysdeps/x86_64/configure.ac | 9 | ||||
| -rw-r--r-- | sysdeps/x86_64/fpu/Makefile | 12 |
4 files changed, 52 insertions, 0 deletions
@@ -1,3 +1,12 @@ +2019-07-24 H.J. Lu <hongjiu.lu@intel.com> + + [BZ #24603] + * sysdeps/x86_64/configure.ac: Check if -mprefer-vector-width=128 + works. + * sysdeps/x86_64/configure: Regenerated. + * sysdeps/x86_64/fpu/Makefile (CFLAGS-branred.c): New. Set + to -mprefer-vector-width=128 if supported. + 2019-07-24 Florian Weimer <fweimer@redhat.com> * scripts/build-many-glibcs.py (Context.checkout): Default to diff --git a/sysdeps/x86_64/configure b/sysdeps/x86_64/configure index 8674d14569..84f82c2406 100644 --- a/sysdeps/x86_64/configure +++ b/sysdeps/x86_64/configure @@ -54,6 +54,28 @@ fi config_vars="$config_vars config-cflags-avx512 = $libc_cv_cc_avx512" +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking -mprefer-vector-width=128" >&5 +$as_echo_n "checking -mprefer-vector-width=128... " >&6; } +if ${libc_cv_cc_mprefer_vector_width+:} false; then : + $as_echo_n "(cached) " >&6 +else + if { ac_try='${CC-cc} -mprefer-vector-width=128 -xc /dev/null -S -o /dev/null' + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 + (eval $ac_try) 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; }; then : + libc_cv_cc_mprefer_vector_width=yes +else + libc_cv_cc_mprefer_vector_width=no +fi + +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cc_mprefer_vector_width" >&5 +$as_echo "$libc_cv_cc_mprefer_vector_width" >&6; } +config_vars="$config_vars +config-cflags-mprefer-vector-width = $libc_cv_cc_mprefer_vector_width" + { $as_echo "$as_me:${as_lineno-$LINENO}: checking for Intel MPX support" >&5 $as_echo_n "checking for Intel MPX support... " >&6; } if ${libc_cv_asm_mpx+:} false; then : diff --git a/sysdeps/x86_64/configure.ac b/sysdeps/x86_64/configure.ac index b7d2c0124f..cdaba0c075 100644 --- a/sysdeps/x86_64/configure.ac +++ b/sysdeps/x86_64/configure.ac @@ -25,6 +25,15 @@ if test $libc_cv_cc_avx512 = yes; then fi LIBC_CONFIG_VAR([config-cflags-avx512], [$libc_cv_cc_avx512]) +dnl Check if -mprefer-vector-width=128 works. +AC_CACHE_CHECK(-mprefer-vector-width=128, libc_cv_cc_mprefer_vector_width, [dnl +LIBC_TRY_CC_OPTION([-mprefer-vector-width=128], + [libc_cv_cc_mprefer_vector_width=yes], + [libc_cv_cc_mprefer_vector_width=no]) +]) +LIBC_CONFIG_VAR([config-cflags-mprefer-vector-width], + [$libc_cv_cc_mprefer_vector_width]) + dnl Check whether asm supports Intel MPX AC_CACHE_CHECK(for Intel MPX support, libc_cv_asm_mpx, [dnl cat > conftest.s <<\EOF diff --git a/sysdeps/x86_64/fpu/Makefile b/sysdeps/x86_64/fpu/Makefile index 2b7d69bb50..74b14ba096 100644 --- a/sysdeps/x86_64/fpu/Makefile +++ b/sysdeps/x86_64/fpu/Makefile @@ -237,3 +237,15 @@ CFLAGS-test-float-libmvec-sincosf-avx512.c = -DREQUIRE_AVX512F CFLAGS-test-float-libmvec-sincosf-avx512-main.c = $(libmvec-sincos-cflags) $(float-vlen16-arch-ext-cflags) endif endif + +ifeq ($(subdir)$(config-cflags-mprefer-vector-width),mathyes) +# When compiled with -O3 -march=skylake, GCC 8 and 9 optimize some loops +# in branred.c with 256-bit vector instructions, which leads to store +# forward stall: +# +# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90579 +# +# Limit vector width to 128 bits to work around this issue. It improves +# performance of sin and cos by more than 40% on Skylake. +CFLAGS-branred.c = -mprefer-vector-width=128 +endif |