On Mon, 2022-12-26 at 09:44 +0100, Alexander Kanavin wrote: > Qemu 7.2 finally allows us to move beyond building for original Core 2/Core > i7 era hardware, > and this patch adds support for the newer generations. But first, a bit of > background: > > Recently toolchains gained support for specifying x86-64 'levels' of > instruction set support; v3 corresponds to 2013-era Haswell CPUs > (and later), with AVX, AVX2 and a few other instructions that > were introduced in that generation. I believe this is preferrable > to picking a specific CPU model as the baseline. > > Here's Phoronix's feature article that explains the feature and the available > levels: > > "Both LLVM Clang 12 and GCC 11 are ready to go in offering the new x86-64-v2, > x86-64-v3, and x86-64-v4 targets. > > These x86_64 micro-architecture feature levels have been about coming up with > a few "classes" of Intel/AMD CPU processor support rather than continuing to > rely on just the x86_64 baseline or targeting a > specific CPU family for optimizations. These new levels make it easier to > raise the base requirements around Linux x86-64 whether it be for a Linux > distribution or a particular software application where > the developer/ISV may be wanting to compile with greater instruction set > extensions enabled in catering to more recent Intel/AMD CPUs." > > https://www.phoronix.com/news/GCC-11-x86-64-Feature-Levels > > Here's gcc docs for it: > https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html > > And here's the formal specification (click on the pdf link): > https://gitlab.com/x86-psABIs/x86-64-ABI > > The actual tune file was created by copying corei7 tunes and doing > search/replace on them. Qemu options were dropped as unnecessary. > > Signed-off-by: Alexander Kanavin <[email protected]> > --- > .../machine/include/x86/tune-x86-64-v3.inc | 35 +++++++++++++++++++ > 1 file changed, 35 insertions(+) > create mode 100644 meta/conf/machine/include/x86/tune-x86-64-v3.inc > > diff --git a/meta/conf/machine/include/x86/tune-x86-64-v3.inc > b/meta/conf/machine/include/x86/tune-x86-64-v3.inc > new file mode 100644 > index 0000000000..365e23b49b > --- /dev/null > +++ b/meta/conf/machine/include/x86/tune-x86-64-v3.inc > @@ -0,0 +1,35 @@ > +# Settings for the GCC(1) cpu-type "x86-64-v3": > +# > +# CPUs with AVX, AVX2, BMI1, BMI2, F16C, FMA, LZCNT, MOVBE, XSAVE. > +# (but not AVX512). > +# See https://www.phoronix.com/news/GCC-11-x86-64-Feature-Levels for > details. > +# > +# This tune is recommended for Intel Haswell/AMD Excavator CPUs (and later). > +# > +DEFAULTTUNE ?= "x86-64-v3-64" > + > +# Include the previous tune to pull in PACKAGE_EXTRA_ARCHS > +require conf/machine/include/x86/tune-corei7.inc > + > +# Extra tune features > +TUNEVALID[x86-64-v3] = "Enable x86-64-v3 specific processor optimizations" > +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'x86-64-v3', ' > -march=x86-64-v3', '', d)}" > + > +# Extra tune selections > +AVAILTUNES += "x86-64-v3-32" > +TUNE_FEATURES:tune-x86-64-v3-32 = "${TUNE_FEATURES:tune-x86} x86-64-v3" > +BASE_LIB:tune-x86-64-v3-32 = "lib" > +TUNE_PKGARCH:tune-x86-64-v3-32 = "x86-64-v3-32" > +PACKAGE_EXTRA_ARCHS:tune-x86-64-v3-32 = > "${PACKAGE_EXTRA_ARCHS:tune-corei7-32} x86-64-v3-32" > + > +AVAILTUNES += "x86-64-v3-64" > +TUNE_FEATURES:tune-x86-64-v3-64 = "${TUNE_FEATURES:tune-x86-64} x86-64-v3" > +BASE_LIB:tune-x86-64-v3-64 = "lib64" > +TUNE_PKGARCH:tune-x86-64-v3-64 = "x86-64-v3-64" > +PACKAGE_EXTRA_ARCHS:tune-x86-64-v3-64 = > "${PACKAGE_EXTRA_ARCHS:tune-corei7-64} x86-64-v3-64" > + > +AVAILTUNES += "x86-64-v3-64-x32" > +TUNE_FEATURES:tune-x86-64-v3-64-x32 = "${TUNE_FEATURES:tune-x86-64-x32} > x86-64-v3" > +BASE_LIB:tune-x86-64-v3-64-x32 = "libx32" > +TUNE_PKGARCH:tune-x86-64-v3-64-x32 = "x86-64-v3-64-x32" > +PACKAGE_EXTRA_ARCHS:tune-x86-64-v3-64-x32 = > "${PACKAGE_EXTRA_ARCHS:tune-corei7-64-x32} x86-64-v3-64-x32"
I suspect we may want to call the x86-64-v3-64 tune simply "x86-64-v3"? Also, does a 32 bit version of the tune make sense? Is that useful to anyone? I appreciate the x32 case is marginal as well but at least there it is something designed for 64 bit processors. Cheers, Richard
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