1 /* 2 * Copyright (c) Facebook, Inc. 3 * All rights reserved. 4 * 5 * This source code is licensed under both the BSD-style license (found in the 6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found 7 * in the COPYING file in the root directory of this source tree). 8 * You may select, at your option, one of the above-listed licenses. 9 */ 10 11 #ifndef ZSTD_PORTABILITY_MACROS_H 12 #define ZSTD_PORTABILITY_MACROS_H 13 14 /** 15 * This header file contains macro defintions to support portability. 16 * This header is shared between C and ASM code, so it MUST only 17 * contain macro definitions. It MUST not contain any C code. 18 * 19 * This header ONLY defines macros to detect platforms/feature support. 20 * 21 */ 22 23 24 /* compat. with non-clang compilers */ 25 #ifndef __has_attribute 26 #define __has_attribute(x) 0 27 #endif 28 29 /* compat. with non-clang compilers */ 30 #ifndef __has_builtin 31 # define __has_builtin(x) 0 32 #endif 33 34 /* compat. with non-clang compilers */ 35 #ifndef __has_feature 36 # define __has_feature(x) 0 37 #endif 38 39 /* detects whether we are being compiled under msan */ 40 #ifndef ZSTD_MEMORY_SANITIZER 41 # if __has_feature(memory_sanitizer) 42 # define ZSTD_MEMORY_SANITIZER 1 43 # else 44 # define ZSTD_MEMORY_SANITIZER 0 45 # endif 46 #endif 47 48 /* detects whether we are being compiled under asan */ 49 #ifndef ZSTD_ADDRESS_SANITIZER 50 # if __has_feature(address_sanitizer) 51 # define ZSTD_ADDRESS_SANITIZER 1 52 # elif defined(__SANITIZE_ADDRESS__) 53 # define ZSTD_ADDRESS_SANITIZER 1 54 # else 55 # define ZSTD_ADDRESS_SANITIZER 0 56 # endif 57 #endif 58 59 /* detects whether we are being compiled under dfsan */ 60 #ifndef ZSTD_DATAFLOW_SANITIZER 61 # if __has_feature(dataflow_sanitizer) 62 # define ZSTD_DATAFLOW_SANITIZER 1 63 # else 64 # define ZSTD_DATAFLOW_SANITIZER 0 65 # endif 66 #endif 67 68 /* Mark the internal assembly functions as hidden */ 69 #ifdef __ELF__ 70 # define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func 71 #else 72 # define ZSTD_HIDE_ASM_FUNCTION(func) 73 #endif 74 75 /* Enable runtime BMI2 dispatch based on the CPU. 76 * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default. 77 */ 78 #ifndef DYNAMIC_BMI2 79 #if ((defined(__clang__) && __has_attribute(__target__)) \ 80 || (defined(__GNUC__) \ 81 && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \ 82 && (defined(__x86_64__) || defined(_M_X64)) \ 83 && !defined(__BMI2__) 84 # define DYNAMIC_BMI2 1 85 #else 86 # define DYNAMIC_BMI2 0 87 #endif 88 #endif 89 90 /** 91 * Only enable assembly for GNUC comptabile compilers, 92 * because other platforms may not support GAS assembly syntax. 93 * 94 * Only enable assembly for Linux / MacOS, other platforms may 95 * work, but they haven't been tested. This could likely be 96 * extended to BSD systems. 97 * 98 * Disable assembly when MSAN is enabled, because MSAN requires 99 * 100% of code to be instrumented to work. 100 */ 101 #if defined(__GNUC__) 102 # if defined(__linux__) || defined(__linux) || defined(__APPLE__) 103 # if ZSTD_MEMORY_SANITIZER 104 # define ZSTD_ASM_SUPPORTED 0 105 # elif ZSTD_DATAFLOW_SANITIZER 106 # define ZSTD_ASM_SUPPORTED 0 107 # else 108 # define ZSTD_ASM_SUPPORTED 1 109 # endif 110 # else 111 # define ZSTD_ASM_SUPPORTED 0 112 # endif 113 #else 114 # define ZSTD_ASM_SUPPORTED 0 115 #endif 116 117 /** 118 * Determines whether we should enable assembly for x86-64 119 * with BMI2. 120 * 121 * Enable if all of the following conditions hold: 122 * - ASM hasn't been explicitly disabled by defining ZSTD_DISABLE_ASM 123 * - Assembly is supported 124 * - We are compiling for x86-64 and either: 125 * - DYNAMIC_BMI2 is enabled 126 * - BMI2 is supported at compile time 127 */ 128 #if !defined(ZSTD_DISABLE_ASM) && \ 129 ZSTD_ASM_SUPPORTED && \ 130 defined(__x86_64__) && \ 131 (DYNAMIC_BMI2 || defined(__BMI2__)) 132 # define ZSTD_ENABLE_ASM_X86_64_BMI2 1 133 #else 134 # define ZSTD_ENABLE_ASM_X86_64_BMI2 0 135 #endif 136 137 #endif /* ZSTD_PORTABILITY_MACROS_H */ 138