| Brandon Maier | dbe88da | 2023-01-12 10:27:45 -0600 | [diff] [blame] | 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 */ |