Messages in this thread | | | From | Nick Desaulniers <> | Date | Tue, 17 Aug 2021 11:22:26 -0700 | Subject | Re: [PATCH 2/2] x86, Makefile: Add new generic x86-64 settings v2/v3/v4 |
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On Tue, Aug 17, 2021 at 11:17 AM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Tue, Aug 17, 2021 at 7:24 AM torvic9 via Clang Built Linux > <clang-built-linux@googlegroups.com> wrote: > > > > Add new generic x86-64 CPU tunings introduced with recent versions of > > gcc and clang, as documented in x86-64-psABI [1]. > > > > This is taken straight from graysky's CPU optimization patch with minor > > modifications [2]. > > > > [1] https://gitlab.com/x86-psABIs/x86-64-ABI/-/commit/77566eb03bc6a326811cb7e9a6b9396884b67c7c > > [2] https://github.com/graysky2/kernel_compiler_patch > > > > Signed-off-by: Tor Vic <torvic9@mailbox.org> > > --- > > arch/x86/Kconfig.cpu | 26 +++++++++++++++++++++++++- > > arch/x86/Makefile.cpu | 6 ++++++ > > 2 files changed, 31 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu > > index 814fe0d349b0..a2c872aa5a0b 100644 > > --- a/arch/x86/Kconfig.cpu > > +++ b/arch/x86/Kconfig.cpu > > @@ -294,6 +294,30 @@ config GENERIC_CPU > > Generic x86-64 CPU. > > Run equally well on all x86-64 CPUs. > > > > +config GENERIC_CPU_V2 > > + bool "Generic-x86-64-v2" > > + depends on ( CC_IS_GCC && GCC_VERSION > 110000 ) || ( CC_IS_CLANG && CLANG_VERSION >= 120000 ) > > Can we stick with either > or >=, but at least be consistent? Also, > there's unnecessary whitespace inside the parens that could be > removed.
Ah, cc-option can be used from Kconfig. Perhaps a cc-option call to -march=x86-64-vX with a comment about which compiler versions first supported these (so that we can remove the feature test when the minimum supported toolchains are advanced) would be better?
> > > + depends on X86_64 > > + help > > + Generic x86-64 CPU. > > + Run equally well on all x86-64 CPUs with min support of x86-64-v2. > > + > > +config GENERIC_CPU_V3 > > + bool "Generic-x86-64-v3" > > + depends on ( CC_IS_GCC && GCC_VERSION > 110000 ) || ( CC_IS_CLANG && CLANG_VERSION >= 120000 ) > > + depends on X86_64 > > + help > > + Generic x86-64-v3 CPU with v3 instructions. > > + Run equally well on all x86-64 CPUs with min support of x86-64-v3. > > + > > +config GENERIC_CPU_V4 > > + bool "Generic-x86-64-v4" > > + depends on ( CC_IS_GCC && GCC_VERSION > 110000 ) || ( CC_IS_CLANG && CLANG_VERSION >= 120000 ) > > + depends on X86_64 > > + help > > + Generic x86-64 CPU with v4 instructions. > > + Run equally well on all x86-64 CPUs with min support of x86-64-v4. > > + > > endchoice > > > > config X86_GENERIC > > @@ -318,7 +342,7 @@ config X86_INTERNODE_CACHE_SHIFT > > config X86_L1_CACHE_SHIFT > > int > > default "7" if MPENTIUM4 || MPSC > > - default "6" if MK7 || MK8 || MPENTIUMM || MCORE2 || MATOM || MVIAC7 || X86_GENERIC || GENERIC_CPU > > + default "6" if MK7 || MK8 || MPENTIUMM || MCORE2 || MATOM || MVIAC7 || X86_GENERIC || GENERIC_CPU || GENERIC_CPU_V2 || GENERIC_CPU_V3 || GENERIC_CPU_V4 > > default "4" if MELAN || M486SX || M486 || MGEODEGX1 > > default "5" if MWINCHIP3D || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX > > > > diff --git a/arch/x86/Makefile.cpu b/arch/x86/Makefile.cpu > > index fb407ae94d90..f190feefe964 100644 > > --- a/arch/x86/Makefile.cpu > > +++ b/arch/x86/Makefile.cpu > > @@ -10,3 +10,9 @@ cflags-$(CONFIG_MCORE2) += \ > > cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \ > > $(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic)) > > cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic) > > + > > +# New generic x86-64 CPU options. > > +# Don't call the compiler, we have Kconfig compiler checks for these. > > You'd be surprised how quickly using time-relative words like "New" > bitrot. My copy of "Modern C++" already doesn't feel very "modern" for > example. I'd just drop the comment block here; we don't need a > comment every time we skip cc-option checks. Thanks for the patches! > > > +cflags-$(CONFIG_GENERIC_CPU_V2) += -march=x86-64-v2 > > +cflags-$(CONFIG_GENERIC_CPU_V3) += -march=x86-64-v3 > > +cflags-$(CONFIG_GENERIC_CPU_V4) += -march=x86-64-v4 > > -- > -- > Thanks, > ~Nick Desaulniers
-- Thanks, ~Nick Desaulniers
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