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 41 /* detects whether we are being compiled under asan */ 42 43 /* detects whether we are being compiled under dfsan */ 44 45 /* Mark the internal assembly functions as hidden */ 46 #ifdef __ELF__ 47 # define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func 48 #else 49 # define ZSTD_HIDE_ASM_FUNCTION(func) 50 #endif 51 52 /* Enable runtime BMI2 dispatch based on the CPU. 53 * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default. 54 */ 55 #ifndef DYNAMIC_BMI2 56 #if ((defined(__clang__) && __has_attribute(__target__)) \ 57 || (defined(__GNUC__) \ 58 && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \ 59 && (defined(__x86_64__) || defined(_M_X64)) \ 60 && !defined(__BMI2__) 61 # define DYNAMIC_BMI2 1 62 #else 63 # define DYNAMIC_BMI2 0 64 #endif 65 #endif 66 67 /* 68 * Only enable assembly for GNUC comptabile compilers, 69 * because other platforms may not support GAS assembly syntax. 70 * 71 * Only enable assembly for Linux / MacOS, other platforms may 72 * work, but they haven't been tested. This could likely be 73 * extended to BSD systems. 74 * 75 * Disable assembly when MSAN is enabled, because MSAN requires 76 * 100% of code to be instrumented to work. 77 */ 78 #define ZSTD_ASM_SUPPORTED 1 79 80 /* 81 * Determines whether we should enable assembly for x86-64 82 * with BMI2. 83 * 84 * Enable if all of the following conditions hold: 85 * - ASM hasn't been explicitly disabled by defining ZSTD_DISABLE_ASM 86 * - Assembly is supported 87 * - We are compiling for x86-64 and either: 88 * - DYNAMIC_BMI2 is enabled 89 * - BMI2 is supported at compile time 90 */ 91 #define ZSTD_ENABLE_ASM_X86_64_BMI2 0 92 93 #endif /* ZSTD_PORTABILITY_MACROS_H */ 94