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On Fri, Jul 06, 2018 at 09:55:36AM -0400, Amit Pawar wrote: > From Zen onwards this will be enabled. It was disabled for the > Excavator case and will remain disabled. Wasn't it also disabled for Bulldozer and older models? > Reviewd-by: Carlos O'Donell <carlos@redhat.com> > --- > ChangeLog | 7 +++++++ > sysdeps/x86/cpu-features.c | 18 +++++++++++++----- > 2 files changed, 20 insertions(+), 5 deletions(-) > > diff --git a/ChangeLog b/ChangeLog > index 5a1f291b85..7fe8e2463e 100644 > --- a/ChangeLog > +++ b/ChangeLog > @@ -1,3 +1,10 @@ > +2018-07-06 Amit Pawar <amit.pawar@amd.com> > + > + * sysdeps/x86/cpu-features.c (get_common_indeces): > + AVX_Fast_Unaligned_Load is enabled when AVX2 is detected. > + * sysdeps/x86/cpu-features.c (init_cpu_features): > + AVX_Fast_Unaligned_Load is disabled for Excavator core. > + > 2018-07-05 Florian Weimer <fweimer@redhat.com> > > * csu/Makefile (CFLAGS-static-reloc.os): Build with stack > diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c > index 0fc3674c4b..d41ebde823 100644 > --- a/sysdeps/x86/cpu-features.c > +++ b/sysdeps/x86/cpu-features.c > @@ -78,8 +78,15 @@ get_common_indeces (struct cpu_features *cpu_features, > /* The following features depend on AVX being usable. */ > /* Determine if AVX2 is usable. */ > if (CPU_FEATURES_CPU_P (cpu_features, AVX2)) > + { > cpu_features->feature[index_arch_AVX2_Usable] > |= bit_arch_AVX2_Usable; > + > + /* Unaligned load with 256-bit AVX registers are faster on > + Intel/AMD processors with AVX2. */ > + cpu_features->feature[index_arch_AVX_Fast_Unaligned_Load] > + |= bit_arch_AVX_Fast_Unaligned_Load; > + } > /* Determine if FMA is usable. */ > if (CPU_FEATURES_CPU_P (cpu_features, FMA)) > cpu_features->feature[index_arch_FMA_Usable] > @@ -298,11 +305,6 @@ init_cpu_features (struct cpu_features *cpu_features) > } > } > > - /* Unaligned load with 256-bit AVX registers are faster on > - Intel processors with AVX2. */ > - if (CPU_FEATURES_ARCH_P (cpu_features, AVX2_Usable)) > - cpu_features->feature[index_arch_AVX_Fast_Unaligned_Load] > - |= bit_arch_AVX_Fast_Unaligned_Load; > > /* Since AVX512ER is unique to Xeon Phi, set Prefer_No_VZEROUPPER > if AVX512ER is available. Don't use AVX512 to avoid lower CPU > @@ -351,9 +353,15 @@ init_cpu_features (struct cpu_features *cpu_features) > #endif > /* "Excavator" */ > if (model >= 0x60 && model <= 0x7f) > + { > cpu_features->feature[index_arch_Fast_Unaligned_Load] > |= (bit_arch_Fast_Unaligned_Load > | bit_arch_Fast_Copy_Backward); > + > + /* Unaligned AVX loads are slower.*/ > + cpu_features->feature[index_arch_AVX_Fast_Unaligned_Load] > + &= ~bit_arch_AVX_Fast_Unaligned_Load; > + } > } > } > else > -- > 2.17.1
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