[PATCH v2 2/3] x86_64: Add glibc-hwcaps support
H.J. Lu
hjl.tools@gmail.com
Mon Oct 12 18:11:11 GMT 2020
On Mon, Oct 12, 2020 at 8:23 AM Florian Weimer via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> The subdirectories match those in the x86-64 psABI:
>
> https://gitlab.com/x86-psABIs/x86-64-ABI/-/commit/77566eb03bc6a326811cb7e9a6b9396884b67c7c
> ---
> sysdeps/x86_64/Makefile | 36 +++++++++++++++-
> sysdeps/x86_64/dl-hwcaps-subdirs.c | 66 ++++++++++++++++++++++++++++++
> sysdeps/x86_64/tst-glibc-hwcaps.c | 65 +++++++++++++++++++++++++++++
> 3 files changed, 166 insertions(+), 1 deletion(-)
> create mode 100644 sysdeps/x86_64/dl-hwcaps-subdirs.c
> create mode 100644 sysdeps/x86_64/tst-glibc-hwcaps.c
>
> diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
> index 42b97c5cc7..16030715e7 100644
> --- a/sysdeps/x86_64/Makefile
> +++ b/sysdeps/x86_64/Makefile
> @@ -144,7 +144,41 @@ CFLAGS-tst-auditmod10b.c += $(AVX512-CFLAGS)
> CFLAGS-tst-avx512-aux.c += $(AVX512-CFLAGS)
> CFLAGS-tst-avx512mod.c += $(AVX512-CFLAGS)
> endif
> -endif
> +
> +$(objpfx)tst-glibc-hwcaps: \
> + $(objpfx)markermod2-1.so $(objpfx)markermod3-1.so $(objpfx)markermod4-1.so
> +$(objpfx)tst-glibc-hwcaps.out: \
> + $(objpfx)markermod2.so \
> + $(objpfx)glibc-hwcaps/x86-64-v2/markermod2.so \
> + $(objpfx)markermod3.so \
> + $(objpfx)glibc-hwcaps/x86-64-v2/markermod3.so \
> + $(objpfx)glibc-hwcaps/x86-64-v3/markermod3.so \
> + $(objpfx)markermod4.so \
> + $(objpfx)glibc-hwcaps/x86-64-v2/markermod4.so \
> + $(objpfx)glibc-hwcaps/x86-64-v3/markermod4.so \
> + $(objpfx)glibc-hwcaps/x86-64-v4/markermod4.so \
> +
> +$(objpfx)glibc-hwcaps/x86-64-v2/markermod2.so: $(objpfx)markermod2-2.so
> + $(make-target-directory)
> + cp $< $@
> +$(objpfx)glibc-hwcaps/x86-64-v2/markermod3.so: $(objpfx)markermod3-2.so
> + $(make-target-directory)
> + cp $< $@
> +$(objpfx)glibc-hwcaps/x86-64-v3/markermod3.so: $(objpfx)markermod3-3.so
> + $(make-target-directory)
> + cp $< $@
> +$(objpfx)glibc-hwcaps/x86-64-v2/markermod4.so: $(objpfx)markermod4-2.so
> + $(make-target-directory)
> + cp $< $@
> +$(objpfx)glibc-hwcaps/x86-64-v3/markermod4.so: $(objpfx)markermod4-3.so
> + $(make-target-directory)
> + cp $< $@
> +$(objpfx)glibc-hwcaps/x86-64-v4/markermod4.so: $(objpfx)markermod4-4.so
> + $(make-target-directory)
> + cp $< $@
> +
> +
> +endif # $(subdir) == elf
>
> ifeq ($(subdir),csu)
> gen-as-const-headers += tlsdesc.sym rtld-offsets.sym
> diff --git a/sysdeps/x86_64/dl-hwcaps-subdirs.c b/sysdeps/x86_64/dl-hwcaps-subdirs.c
> new file mode 100644
> index 0000000000..c4d8b3a02a
> --- /dev/null
> +++ b/sysdeps/x86_64/dl-hwcaps-subdirs.c
> @@ -0,0 +1,66 @@
> +/* Architecture-specific glibc-hwcaps subdirectories. x86 version.
> + Copyright (C) 2020 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <dl-hwcaps.h>
> +#include <cpu-features.h>
>
Please use <sys/platform/x86.h>.
> +const char _dl_hwcaps_subdirs[] = "x86-64-v4:x86-64-v3:x86-64-v2";
> +enum { subdirs_count = 3 };
> +
> +uint32_t
> +_dl_hwcaps_subdirs_active (void)
> +{
> + int active = 0;
> +
> + /* Test in reverse preference order. */
> +
> + /* x86-64-v2. */
> + if (!(CPU_FEATURE_USABLE (CMPXCHG16B)
> + && CPU_FEATURE_USABLE (LAHF64_SAHF64)
> + && CPU_FEATURE_USABLE (POPCNT)
> + && CPU_FEATURE_USABLE (SSE3)
> + && CPU_FEATURE_USABLE (SSE4_1)
> + && CPU_FEATURE_USABLE (SSE4_2)
> + && CPU_FEATURE_USABLE (SSSE3)))
> + return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> + ++active;
> +
> + /* x86-64-v3. */
> + if (!(CPU_FEATURE_USABLE (AVX)
> + && CPU_FEATURE_USABLE (AVX2)
> + && CPU_FEATURE_USABLE (BMI1)
> + && CPU_FEATURE_USABLE (BMI2)
> + && CPU_FEATURE_USABLE (F16C)
> + && CPU_FEATURE_USABLE (FMA)
> + && CPU_FEATURE_USABLE (LZCNT)
> + && CPU_FEATURE_USABLE (MOVBE)
> + && CPU_FEATURE_USABLE (OSXSAVE)))
> + return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> + ++active;
> +
> + /* x86-64-v4. */
> + if (!(CPU_FEATURE_USABLE (AVX512F)
> + && CPU_FEATURE_USABLE (AVX512BW)
> + && CPU_FEATURE_USABLE (AVX512CD)
> + && CPU_FEATURE_USABLE (AVX512DQ)
> + && CPU_FEATURE_USABLE (AVX512VL)))
> + return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> + ++active;
> +
> + return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> +}
> diff --git a/sysdeps/x86_64/tst-glibc-hwcaps.c b/sysdeps/x86_64/tst-glibc-hwcaps.c
> new file mode 100644
> index 0000000000..b46e7cb236
> --- /dev/null
> +++ b/sysdeps/x86_64/tst-glibc-hwcaps.c
> @@ -0,0 +1,65 @@
> +/* glibc-hwcaps subdirectory test. x86_64 version.
> + Copyright (C) 2020 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <stdio.h>
> +#include <support/check.h>
> +#include <sys/param.h>
Please include <sys/platform/x86.h>.
> +extern int marker2 (void);
> +extern int marker3 (void);
> +extern int marker4 (void);
> +
> +/* Return the x86-64-vN level, 1 for the baseline. */
> +static int
> +compute_level (void)
> +{
> + /* These checks are not entirely accurate because they are limited
> + by GCC capabilities. But wrong results will only result from
> + inconsistent CPU models involving virtualization. */
Please use
const struct cpu_features *cpu_features
= __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
if (CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
&& CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
&& CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
&& CPU_FEATURE_USABLE_P (cpu_features, MMX)
&& CPU_FEATURE_USABLE_P (cpu_features, SSE)
&& CPU_FEATURE_USABLE_P (cpu_features, SSE2)
&& CPU_FEATURE_USABLE_P (cpu_features, SSE3)
&& CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
&& CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
&& CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
...
> + if (!(__builtin_cpu_supports ("sse3")
> + && __builtin_cpu_supports ("sse4.1")
> + && __builtin_cpu_supports ("sse4.2")
> + && __builtin_cpu_supports ("ssse3")))
> + return 1;
> + if (!(__builtin_cpu_supports ("avx")
> + && __builtin_cpu_supports ("avx2")
> + && __builtin_cpu_supports ("bmi")
> + && __builtin_cpu_supports ("bmi2")
> + && __builtin_cpu_supports ("fma")))
> + return 2;
> + if (!(__builtin_cpu_supports ("avx512f")
> + && __builtin_cpu_supports ("avx512bw")
> + && __builtin_cpu_supports ("avx512cd")
> + && __builtin_cpu_supports ("avx512dq")
> + && __builtin_cpu_supports ("avx512vl")))
> + return 3;
> + return 4;
> +}
> +
> +static int
> +do_test (void)
> +{
> + int level = compute_level ();
> + printf ("info: detected x86-64 micro-architecture level: %d\n", level);
> + TEST_COMPARE (marker2 (), MIN (level, 2));
> + TEST_COMPARE (marker3 (), MIN (level, 3));
> + TEST_COMPARE (marker4 (), MIN (level, 4));
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
> --
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>
--
H.J.
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