sysdeps/x86/isa-level.h

   1 /* Header defining the minimum x86 ISA level
   2    Copyright (C) 2022-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    In addition to the permissions in the GNU Lesser General Public
  11    License, the Free Software Foundation gives you unlimited
  12    permission to link the compiled version of this file with other
  13    programs, and to distribute those programs without any restriction
  14    coming from the use of this file.  (The Lesser General Public
  15    License restrictions do apply in other respects; for example, they
  16    cover modification of the file, and distribution when not linked
  17    into another program.)
  18
  19    The GNU C Library is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22    Lesser General Public License for more details.
  23
  24    You should have received a copy of the GNU Lesser General Public
  25    License along with the GNU C Library; if not, see
  26    <https://www.gnu.org/licenses/>.  */
  27
  28 #ifndef _ISA_LEVEL_H
  29 #define _ISA_LEVEL_H
  30
  31 #if defined __SSE__ && defined __SSE2__
  32 /* NB: ISAs, excluding MMX, in x86-64 ISA level baseline are used.  */
  33 # define __X86_ISA_V1 1
  34 #else
  35 # define __X86_ISA_V1 0
  36 #endif
  37
  38 #if __X86_ISA_V1 && defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16               \
  39     && defined HAVE_X86_LAHF_SAHF && defined __POPCNT__ && defined __SSE3__   \
  40     && defined __SSSE3__ && defined __SSE4_1__ && defined __SSE4_2__
  41 /* NB: ISAs in x86-64 ISA level v2 are used.  */
  42 # define __X86_ISA_V2 1
  43 #else
  44 # define __X86_ISA_V2 0
  45 #endif
  46
  47 #if __X86_ISA_V2 && defined __AVX__ && defined __AVX2__ && defined __F16C__   \
  48     && defined __FMA__ && defined __LZCNT__ && defined HAVE_X86_MOVBE         \
  49     && defined __BMI__ && defined __BMI2__
  50 /* NB: ISAs in x86-64 ISA level v3 are used.  */
  51 # define __X86_ISA_V3 1
  52 #else
  53 # define __X86_ISA_V3 0
  54 #endif
  55
  56 #if __X86_ISA_V3 && defined __AVX512F__ && defined __AVX512BW__               \
  57     && defined __AVX512CD__ && defined __AVX512DQ__ && defined __AVX512VL__
  58 /* NB: ISAs in x86-64 ISA level v4 are used.  */
  59 # define __X86_ISA_V4 1
  60 #else
  61 # define __X86_ISA_V4 0
  62 #endif
  63
  64 #define MINIMUM_X86_ISA_LEVEL                                                 \
  65   (__X86_ISA_V1 + __X86_ISA_V2 + __X86_ISA_V3 + __X86_ISA_V4)
  66
  67 /* Depending on the minimum ISA level, a feature check result can be a
  68    compile-time constant.. */
  69
  70
  71 /* For CPU_FEATURE_USABLE_P.  */
  72
  73 /* ISA level >= 4 guaranteed includes.  */
  74 #define AVX512F_X86_ISA_LEVEL 4
  75 #define AVX512VL_X86_ISA_LEVEL 4
  76 #define AVX512BW_X86_ISA_LEVEL 4
  77 #define AVX512DQ_X86_ISA_LEVEL 4
  78
  79 /* ISA level >= 3 guaranteed includes.  */
  80 #define AVX_X86_ISA_LEVEL 3
  81 #define AVX2_X86_ISA_LEVEL 3
  82 #define BMI1_X86_ISA_LEVEL 3
  83 #define BMI2_X86_ISA_LEVEL 3
  84 #define LZCNT_X86_ISA_LEVEL 3
  85 #define MOVBE_X86_ISA_LEVEL 3
  86
  87 /* ISA level >= 2 guaranteed includes.  */
  88 #define SSE4_2_X86_ISA_LEVEL 2
  89 #define SSE4_1_X86_ISA_LEVEL 2
  90 #define SSSE3_X86_ISA_LEVEL 2
  91
  92
  93 /* For X86_ISA_CPU_FEATURES_ARCH_P.  */
  94
  95 /* NB: This feature is enabled when ISA level >= 3, which was disabled
  96    for the following CPUs:
  97         - AMD Excavator
  98    when ISA level < 3.  */
  99 #define AVX_Fast_Unaligned_Load_X86_ISA_LEVEL 3
 100
 101 /* NB: This feature is disabled when ISA level >= 3, which was enabled
 102    for the following CPUs:
 103         - Intel KNL
 104    when ISA level < 3.  */
 105 #define Prefer_No_VZEROUPPER_X86_ISA_LEVEL 3
 106
 107 /* NB: This feature is disable when ISA level >= 3.  All CPUs with
 108    this feature don't run on glibc built with ISA level >= 3.  */
 109 #define Slow_SSE42_X86_ISA_LEVEL 3
 110
 111 /* Feature(s) enabled when ISA level >= 2.  */
 112 #define Fast_Unaligned_Load_X86_ISA_LEVEL 2
 113
 114 /* NB: This feature is disable when ISA level >= 2, which was enabled
 115    for the early Atom CPUs.  */
 116 #define Slow_BSF_X86_ISA_LEVEL 2
 117
 118
 119 /* Both X86_ISA_CPU_FEATURE_USABLE_P and X86_ISA_CPU_FEATURES_ARCH_P
 120    macros are wrappers for the respective CPU_FEATURE{S}_{USABLE|ARCH}_P
 121    runtime checks.  They differ in two ways.
 122
 123     1.  The USABLE_P version is evaluated to true when the feature
 124         is enabled.
 125
 126     2.  The ARCH_P version has a third argument `not`.  The `not`
 127         argument can either be `!` or empty.  If the feature is
 128         enabled above an ISA level, the third argument should be empty
 129         and the expression is evaluated to true when the feature is
 130         enabled.  If the feature is disabled above an ISA level, the
 131         third argument should be `!` and the expression is evaluated
 132         to true when the feature is disabled.
 133  */
 134
 135 #define X86_ISA_CPU_FEATURE_USABLE_P(ptr, name)                        \
 136   (((name##_X86_ISA_LEVEL) <= MINIMUM_X86_ISA_LEVEL)                   \
 137    || CPU_FEATURE_USABLE_P (ptr, name))
 138
 139 #define X86_ISA_CPU_FEATURES_ARCH_P(ptr, name, not)                    \
 140   (((name##_X86_ISA_LEVEL) <= MINIMUM_X86_ISA_LEVEL)                   \
 141    || not CPU_FEATURES_ARCH_P (ptr, name))
 142
 143 #define ISA_SHOULD_BUILD(isa_build_level)                              \
 144   (MINIMUM_X86_ISA_LEVEL <= (isa_build_level) && IS_IN (libc))         \
 145    || defined ISA_DEFAULT_IMPL
 146
 147 #endif