2 * Copyright (c) Facebook, Inc.
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.
11 #ifndef ZSTD_PORTABILITY_MACROS_H
12 #define ZSTD_PORTABILITY_MACROS_H
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.
19 * This header ONLY defines macros to detect platforms/feature support.
24 /* compat. with non-clang compilers */
25 #ifndef __has_attribute
26 #define __has_attribute(x) 0
29 /* compat. with non-clang compilers */
31 # define __has_builtin(x) 0
34 /* compat. with non-clang compilers */
36 # define __has_feature(x) 0
39 /* detects whether we are being compiled under msan */
41 /* detects whether we are being compiled under asan */
43 /* detects whether we are being compiled under dfsan */
45 /* Mark the internal assembly functions as hidden */
47 # define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func
49 # define ZSTD_HIDE_ASM_FUNCTION(func)
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.
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)) \
61 # define DYNAMIC_BMI2 1
63 # define DYNAMIC_BMI2 0
68 * Only enable assembly for GNUC comptabile compilers,
69 * because other platforms may not support GAS assembly syntax.
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.
75 * Disable assembly when MSAN is enabled, because MSAN requires
76 * 100% of code to be instrumented to work.
78 #define ZSTD_ASM_SUPPORTED 1
81 * Determines whether we should enable assembly for x86-64
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
91 #define ZSTD_ENABLE_ASM_X86_64_BMI2 0
93 #endif /* ZSTD_PORTABILITY_MACROS_H */