lkml.org 
[lkml]   [2021]   [Aug]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Date
    SubjectRe: [PATCH 2/2] x86, Makefile: Add new generic x86-64 settings v2/v3/v4
    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.

    > + 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
    \
     
     \ /
      Last update: 2021-08-17 20:18    [W:2.669 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site