1 /* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */ 2 /* 3 * Copyright (c) Meta Platforms, Inc. and affiliates. 4 * All rights reserved. 5 * 6 * This source code is licensed under both the BSD-style license (found in the 7 * LICENSE file in the root directory of this source tree) and the GPLv2 (found 8 * in the COPYING file in the root directory of this source tree). 9 * You may select, at your option, one of the above-listed licenses. 10 */ 11 12 #ifndef ZSTD_PORTABILITY_MACROS_H 13 #define ZSTD_PORTABILITY_MACROS_H 14 15 /* 16 * This header file contains macro definitions to support portability. 17 * This header is shared between C and ASM code, so it MUST only 18 * contain macro definitions. It MUST not contain any C code. 19 * 20 * This header ONLY defines macros to detect platforms/feature support. 21 * 22 */ 23 24 25 /* compat. with non-clang compilers */ 26 #ifndef __has_attribute 27 #define __has_attribute(x) 0 28 #endif 29 30 /* compat. with non-clang compilers */ 31 #ifndef __has_builtin 32 # define __has_builtin(x) 0 33 #endif 34 35 /* compat. with non-clang compilers */ 36 #ifndef __has_feature 37 # define __has_feature(x) 0 38 #endif 39 40 /* detects whether we are being compiled under msan */ 41 42 /* detects whether we are being compiled under asan */ 43 44 /* detects whether we are being compiled under dfsan */ 45 46 /* Mark the internal assembly functions as hidden */ 47 #ifdef __ELF__ 48 # define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func 49 #elif defined(__APPLE__) 50 # define ZSTD_HIDE_ASM_FUNCTION(func) .private_extern func 51 #else 52 # define ZSTD_HIDE_ASM_FUNCTION(func) 53 #endif 54 55 /* Compile time determination of BMI2 support */ 56 57 58 /* Enable runtime BMI2 dispatch based on the CPU. 59 * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default. 60 */ 61 #ifndef DYNAMIC_BMI2 62 # if ((defined(__clang__) && __has_attribute(__target__)) \ 63 || (defined(__GNUC__) \ 64 && (__GNUC__ >= 11))) \ 65 && (defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)) \ 66 && !defined(__BMI2__) 67 # define DYNAMIC_BMI2 1 68 # else 69 # define DYNAMIC_BMI2 0 70 # endif 71 #endif 72 73 /* 74 * Only enable assembly for GNU C compatible compilers, 75 * because other platforms may not support GAS assembly syntax. 76 * 77 * Only enable assembly for Linux / MacOS / Win32, other platforms may 78 * work, but they haven't been tested. This could likely be 79 * extended to BSD systems. 80 * 81 * Disable assembly when MSAN is enabled, because MSAN requires 82 * 100% of code to be instrumented to work. 83 */ 84 #define ZSTD_ASM_SUPPORTED 1 85 86 /* 87 * Determines whether we should enable assembly for x86-64 88 * with BMI2. 89 * 90 * Enable if all of the following conditions hold: 91 * - ASM hasn't been explicitly disabled by defining ZSTD_DISABLE_ASM 92 * - Assembly is supported 93 * - We are compiling for x86-64 and either: 94 * - DYNAMIC_BMI2 is enabled 95 * - BMI2 is supported at compile time 96 */ 97 #define ZSTD_ENABLE_ASM_X86_64_BMI2 0 98 99 /* 100 * For x86 ELF targets, add .note.gnu.property section for Intel CET in 101 * assembly sources when CET is enabled. 102 * 103 * Additionally, any function that may be called indirectly must begin 104 * with ZSTD_CET_ENDBRANCH. 105 */ 106 #if defined(__ELF__) && (defined(__x86_64__) || defined(__i386__)) \ 107 && defined(__has_include) 108 # if __has_include(<cet.h>) 109 # include <cet.h> 110 # define ZSTD_CET_ENDBRANCH _CET_ENDBR 111 # endif 112 #endif 113 114 #ifndef ZSTD_CET_ENDBRANCH 115 # define ZSTD_CET_ENDBRANCH 116 #endif 117 118 #endif /* ZSTD_PORTABILITY_MACROS_H */ 119