/*
* Copyright (c) Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
#ifndef ZSTD_PORTABILITY_MACROS_H
#define ZSTD_PORTABILITY_MACROS_H
/*
* This header file contains macro defintions to support portability.
* This header is shared between C and ASM code, so it MUST only
* contain macro definitions. It MUST not contain any C code.
*
* This header ONLY defines macros to detect platforms/feature support.
*
*/
/* compat. with non-clang compilers */
#ifndef __has_attribute
#define __has_attribute(x) 0
#endif
/* compat. with non-clang compilers */
#ifndef __has_builtin
# define __has_builtin(x) 0
#endif
/* compat. with non-clang compilers */
#ifndef __has_feature
# define __has_feature(x) 0
#endif
/* detects whether we are being compiled under msan */
/* detects whether we are being compiled under asan */
/* detects whether we are being compiled under dfsan */
/* Mark the internal assembly functions as hidden */
#ifdef __ELF__
# define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func
#else
# define ZSTD_HIDE_ASM_FUNCTION(func)
#endif
/* Enable runtime BMI2 dispatch based on the CPU.
* Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default.
*/
#ifndef DYNAMIC_BMI2
#if ((defined(__clang__) && __has_attribute(__target__)) \
|| (defined(__GNUC__) \
&& (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \
&& (defined(__x86_64__) || defined(_M_X64)) \
&& !defined(__BMI2__)
# define DYNAMIC_BMI2 1
#else
# define DYNAMIC_BMI2 0
#endif
#endif
/*
* Only enable assembly for GNUC comptabile compilers,
* because other platforms may not support GAS assembly syntax.
*
* Only enable assembly for Linux / MacOS, other platforms may
* work, but they haven't been tested. This could likely be
* extended to BSD systems.
*
* Disable assembly when MSAN is enabled, because MSAN requires
* 100% of code to be instrumented to work.
*/
#define ZSTD_ASM_SUPPORTED 1
/*
* Determines whether we should enable assembly for x86-64
* with BMI2.
*
* Enable if all of the following conditions hold:
* - ASM hasn't been explicitly disabled by defining ZSTD_DISABLE_ASM
* - Assembly is supported
* - We are compiling for x86-64 and either:
* - DYNAMIC_BMI2 is enabled
* - BMI2 is supported at compile time
*/
#define ZSTD_ENABLE_ASM_X86_64_BMI2 0
#endif /* ZSTD_PORTABILITY_MACROS_H */