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 | |