Messages in this thread | | | Date | Wed, 4 Feb 2015 07:50:33 +1100 | From | NeilBrown <> | Subject | Re: [PATCH] x86/raid6: correctly check for assembler capabilities |
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On Tue, 03 Feb 2015 21:31:30 +0100 Paul Bolle <pebolle@tiscali.nl> wrote:
> On Fri, 2015-01-23 at 08:29 +0000, Jan Beulich wrote: > > Just like for AVX2 (which simply needs an #if -> #ifdef conversion), > > SSSE3 assembler support should be checked for before using it. > > > > Signed-off-by: Jan Beulich <jbeulich@suse.com> > > Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> > > Cc: Neil Brown <neilb@suse.de> > > This patch became commit be46ac86a81b ("x86/raid6: correctly check for > assembler capabilities") in today's linux-next (ie, next-20150203). I > noticed because a script I use to check linux-next spotted a potential > problem with it. > > > --- > > arch/x86/Makefile | 1 + > > lib/raid6/algos.c | 2 +- > > lib/raid6/recov_avx2.c | 2 +- > > lib/raid6/recov_ssse3.c | 6 ++++++ > > 4 files changed, 9 insertions(+), 2 deletions(-) > > > > --- 3.19-rc5/arch/x86/Makefile > > +++ 3.19-rc5-raid6-SSSE3/arch/x86/Makefile > > @@ -148,6 +148,7 @@ cfi-sections := $(call as-instr,.cfi_sec > > > > # does binutils support specific instructions? > > asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1) > > +asinstr += $(call as-instr,pshufb %xmm0$(comma)%xmm0,-DCONFIG_AS_SSSE3=1) > > This Makefile defines a preprocessor macro with a CONFIG_ prefix. Almost > all macros with that prefix are defined through the kconfig system. A > handful, like CONFIG_AS_SSSE3 and a few other macros defined in this > Makefile, are not. Apparently this is a pet peeve I share with few > people, but would any other prefix than CONFIG_ work for you too?
Actually the prefix of this macro is "CONFIG_AS_", not "CONFIG_" :-) CONFIG_AS_ is reserved for assembly magic, and is never used by the the kconfig system.
(Well..... I might have made bits of that up, but "git grep 'config AS_'" doesn't find anything).
NeilBrown
> > > asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1) > > avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1) > > avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1) > > > Paul Bolle
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