glibc/sysdeps/x86/cpu-tunables.c
Paul Eggert 5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00

386 lines
11 KiB
C

/* x86 CPU feature tuning.
This file is part of the GNU C Library.
Copyright (C) 2017-2019 Free Software Foundation, Inc.
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/>. */
#if HAVE_TUNABLES
# define TUNABLE_NAMESPACE cpu
# include <stdbool.h>
# include <stdint.h>
# include <unistd.h> /* Get STDOUT_FILENO for _dl_printf. */
# include <elf/dl-tunables.h>
# include <string.h>
# include <cpu-features.h>
# include <ldsodefs.h>
/* We can't use IFUNC memcmp nor strlen in init_cpu_features from libc.a
since IFUNC must be set up by init_cpu_features. */
# if defined USE_MULTIARCH && !defined SHARED
# ifdef __x86_64__
# define DEFAULT_MEMCMP __memcmp_sse2
# else
# define DEFAULT_MEMCMP __memcmp_ia32
# endif
extern __typeof (memcmp) DEFAULT_MEMCMP;
# else
# define DEFAULT_MEMCMP memcmp
# endif
# define CHECK_GLIBC_IFUNC_CPU_OFF(f, cpu_features, name, len) \
_Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \
if (!DEFAULT_MEMCMP (f, #name, len)) \
{ \
cpu_features->cpuid[index_cpu_##name].reg_##name \
&= ~bit_cpu_##name; \
break; \
}
/* Disable an ARCH feature NAME. We don't enable an ARCH feature which
isn't available. */
# define CHECK_GLIBC_IFUNC_ARCH_OFF(f, cpu_features, name, len) \
_Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \
if (!DEFAULT_MEMCMP (f, #name, len)) \
{ \
cpu_features->feature[index_arch_##name] \
&= ~bit_arch_##name; \
break; \
}
/* Enable/disable an ARCH feature NAME. */
# define CHECK_GLIBC_IFUNC_ARCH_BOTH(f, cpu_features, name, disable, \
len) \
_Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \
if (!DEFAULT_MEMCMP (f, #name, len)) \
{ \
if (disable) \
cpu_features->feature[index_arch_##name] \
&= ~bit_arch_##name; \
else \
cpu_features->feature[index_arch_##name] \
|= bit_arch_##name; \
break; \
}
/* Enable/disable an ARCH feature NAME. Enable an ARCH feature only
if the ARCH feature NEED is also enabled. */
# define CHECK_GLIBC_IFUNC_ARCH_NEED_ARCH_BOTH(f, cpu_features, name, \
need, disable, len) \
_Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \
if (!DEFAULT_MEMCMP (f, #name, len)) \
{ \
if (disable) \
cpu_features->feature[index_arch_##name] \
&= ~bit_arch_##name; \
else if (CPU_FEATURES_ARCH_P (cpu_features, need)) \
cpu_features->feature[index_arch_##name] \
|= bit_arch_##name; \
break; \
}
/* Enable/disable an ARCH feature NAME. Enable an ARCH feature only
if the CPU feature NEED is also enabled. */
# define CHECK_GLIBC_IFUNC_ARCH_NEED_CPU_BOTH(f, cpu_features, name, \
need, disable, len) \
_Static_assert (sizeof (#name) - 1 == len, #name " != " #len); \
if (!DEFAULT_MEMCMP (f, #name, len)) \
{ \
if (disable) \
cpu_features->feature[index_arch_##name] \
&= ~bit_arch_##name; \
else if (CPU_FEATURES_CPU_P (cpu_features, need)) \
cpu_features->feature[index_arch_##name] \
|= bit_arch_##name; \
break; \
}
attribute_hidden
void
TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *valp)
{
/* The current IFUNC selection is based on microbenchmarks in glibc.
It should give the best performance for most workloads. But other
choices may have better performance for a particular workload or on
the hardware which wasn't available when the selection was made.
The environment variable:
GLIBC_TUNABLES=glibc.cpu.hwcaps=-xxx,yyy,-zzz,....
can be used to enable CPU/ARCH feature yyy, disable CPU/ARCH feature
yyy and zzz, where the feature name is case-sensitive and has to
match the ones in cpu-features.h. It can be used by glibc developers
to tune for a new processor or override the IFUNC selection to
improve performance for a particular workload.
NOTE: the IFUNC selection may change over time. Please check all
multiarch implementations when experimenting. */
const char *p = valp->strval;
struct cpu_features *cpu_features = &GLRO(dl_x86_cpu_features);
size_t len;
do
{
const char *c, *n;
bool disable;
size_t nl;
for (c = p; *c != ','; c++)
if (*c == '\0')
break;
len = c - p;
disable = *p == '-';
if (disable)
{
n = p + 1;
nl = len - 1;
}
else
{
n = p;
nl = len;
}
switch (nl)
{
default:
break;
case 3:
if (disable)
{
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX, 3);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, CX8, 3);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, FMA, 3);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, HTT, 3);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, IBT, 3);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, RTM, 3);
}
break;
case 4:
if (disable)
{
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX2, 4);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, BMI1, 4);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, BMI2, 4);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, CMOV, 4);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, ERMS, 4);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, FMA4, 4);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, SSE2, 4);
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features, I586, 4);
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features, I686, 4);
}
break;
case 5:
if (disable)
{
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, LZCNT, 5);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, MOVBE, 5);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, SHSTK, 5);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, SSSE3, 5);
}
break;
case 6:
if (disable)
{
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, POPCNT, 6);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, SSE4_1, 6);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, SSE4_2, 6);
}
break;
case 7:
if (disable)
{
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX512F, 7);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, OSXSAVE, 7);
}
break;
case 8:
if (disable)
{
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX512CD, 8);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX512BW, 8);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX512DQ, 8);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX512ER, 8);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX512PF, 8);
CHECK_GLIBC_IFUNC_CPU_OFF (n, cpu_features, AVX512VL, 8);
}
CHECK_GLIBC_IFUNC_ARCH_BOTH (n, cpu_features, Slow_BSF,
disable, 8);
break;
case 10:
if (disable)
{
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features, AVX_Usable,
10);
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features, FMA_Usable,
10);
}
break;
case 11:
if (disable)
{
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features, AVX2_Usable,
11);
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features, FMA4_Usable,
11);
}
CHECK_GLIBC_IFUNC_ARCH_BOTH (n, cpu_features, Prefer_ERMS,
disable, 11);
CHECK_GLIBC_IFUNC_ARCH_NEED_CPU_BOTH (n, cpu_features,
Slow_SSE4_2, SSE4_2,
disable, 11);
CHECK_GLIBC_IFUNC_ARCH_BOTH (n, cpu_features, Prefer_FSRM,
disable, 11);
break;
case 13:
if (disable)
{
/* Update xsave_state_size to XSAVE state size. */
cpu_features->xsave_state_size
= cpu_features->xsave_state_full_size;
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features,
XSAVEC_Usable, 13);
}
break;
case 14:
if (disable)
{
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features,
AVX512F_Usable, 14);
}
break;
case 15:
if (disable)
{
CHECK_GLIBC_IFUNC_ARCH_OFF (n, cpu_features,
AVX512DQ_Usable, 15);
}
CHECK_GLIBC_IFUNC_ARCH_BOTH (n, cpu_features, Fast_Rep_String,
disable, 15);
break;
case 16:
{
CHECK_GLIBC_IFUNC_ARCH_NEED_ARCH_BOTH
(n, cpu_features, Prefer_No_AVX512, AVX512F_Usable,
disable, 16);
}
break;
case 18:
{
CHECK_GLIBC_IFUNC_ARCH_BOTH (n, cpu_features,
Fast_Copy_Backward, disable,
18);
}
break;
case 19:
{
CHECK_GLIBC_IFUNC_ARCH_BOTH (n, cpu_features,
Fast_Unaligned_Load, disable,
19);
CHECK_GLIBC_IFUNC_ARCH_BOTH (n, cpu_features,
Fast_Unaligned_Copy, disable,
19);
}
break;
case 20:
{
CHECK_GLIBC_IFUNC_ARCH_NEED_ARCH_BOTH
(n, cpu_features, Prefer_No_VZEROUPPER, AVX_Usable,
disable, 20);
}
break;
case 21:
{
CHECK_GLIBC_IFUNC_ARCH_BOTH (n, cpu_features,
Prefer_MAP_32BIT_EXEC, disable,
21);
}
break;
case 23:
{
CHECK_GLIBC_IFUNC_ARCH_NEED_ARCH_BOTH
(n, cpu_features, AVX_Fast_Unaligned_Load, AVX_Usable,
disable, 23);
}
break;
case 24:
{
CHECK_GLIBC_IFUNC_ARCH_NEED_ARCH_BOTH
(n, cpu_features, MathVec_Prefer_No_AVX512,
AVX512F_Usable, disable, 24);
}
break;
case 26:
{
CHECK_GLIBC_IFUNC_ARCH_NEED_CPU_BOTH
(n, cpu_features, Prefer_PMINUB_for_stringop, SSE2,
disable, 26);
}
break;
}
p += len + 1;
}
while (*p != '\0');
}
# if CET_ENABLED
# include <cet-tunables.h>
attribute_hidden
void
TUNABLE_CALLBACK (set_x86_ibt) (tunable_val_t *valp)
{
if (DEFAULT_MEMCMP (valp->strval, "on", sizeof ("on")) == 0)
{
GL(dl_x86_feature_1)[1] &= ~((1 << CET_MAX) - 1);
GL(dl_x86_feature_1)[1] |= CET_ALWAYS_ON;
}
else if (DEFAULT_MEMCMP (valp->strval, "off", sizeof ("off")) == 0)
{
GL(dl_x86_feature_1)[1] &= ~((1 << CET_MAX) - 1);
GL(dl_x86_feature_1)[1] |= CET_ALWAYS_OFF;
}
else if (DEFAULT_MEMCMP (valp->strval, "permissive",
sizeof ("permissive")) == 0)
{
GL(dl_x86_feature_1)[1] &= ~((1 << CET_MAX) - 1);
GL(dl_x86_feature_1)[1] |= CET_PERMISSIVE;
}
}
attribute_hidden
void
TUNABLE_CALLBACK (set_x86_shstk) (tunable_val_t *valp)
{
if (DEFAULT_MEMCMP (valp->strval, "on", sizeof ("on")) == 0)
{
GL(dl_x86_feature_1)[1] &= ~(((1 << CET_MAX) - 1) << CET_MAX);
GL(dl_x86_feature_1)[1] |= (CET_ALWAYS_ON << CET_MAX);
}
else if (DEFAULT_MEMCMP (valp->strval, "off", sizeof ("off")) == 0)
{
GL(dl_x86_feature_1)[1] &= ~(((1 << CET_MAX) - 1) << CET_MAX);
GL(dl_x86_feature_1)[1] |= (CET_ALWAYS_OFF << CET_MAX);
}
else if (DEFAULT_MEMCMP (valp->strval, "permissive",
sizeof ("permissive")) == 0)
{
GL(dl_x86_feature_1)[1] &= ~(((1 << CET_MAX) - 1) << CET_MAX);
GL(dl_x86_feature_1)[1] |= (CET_PERMISSIVE << CET_MAX);
}
}
# endif
#endif