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