1/* 2 * Copyright © 2014 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 */ 23 24#ifndef UTIL_MACROS_H 25#define UTIL_MACROS_H 26 27#include <assert.h> 28 29#include "c99_compat.h" 30 31/* Compute the size of an array */ 32#ifndef ARRAY_SIZE 33# define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) 34#endif 35 36/* For compatibility with Clang's __has_builtin() */ 37#ifndef __has_builtin 38# define __has_builtin(x) 0 39#endif 40 41/** 42 * __builtin_expect macros 43 */ 44#if !defined(HAVE___BUILTIN_EXPECT) 45# define __builtin_expect(x, y) (x) 46#endif 47 48#ifndef likely 49# ifdef HAVE___BUILTIN_EXPECT 50# define likely(x) __builtin_expect(!!(x), 1) 51# define unlikely(x) __builtin_expect(!!(x), 0) 52# else 53# define likely(x) (x) 54# define unlikely(x) (x) 55# endif 56#endif 57 58 59/** 60 * Static (compile-time) assertion. 61 * Basically, use COND to dimension an array. If COND is false/zero the 62 * array size will be -1 and we'll get a compilation error. 63 */ 64#define STATIC_ASSERT(COND) \ 65 do { \ 66 (void) sizeof(char [1 - 2*!(COND)]); \ 67 } while (0) 68 69 70/** 71 * Unreachable macro. Useful for suppressing "control reaches end of non-void 72 * function" warnings. 73 */ 74#ifdef HAVE___BUILTIN_UNREACHABLE 75#define unreachable(str) \ 76do { \ 77 assert(!str); \ 78 __builtin_unreachable(); \ 79} while (0) 80#elif defined (_MSC_VER) 81#define unreachable(str) \ 82do { \ 83 assert(!str); \ 84 __assume(0); \ 85} while (0) 86#else 87#define unreachable(str) assert(!str) 88#endif 89 90/** 91 * Assume macro. Useful for expressing our assumptions to the compiler, 92 * typically for purposes of silencing warnings. 93 */ 94#if __has_builtin(__builtin_assume) 95#define assume(expr) \ 96do { \ 97 assert(expr); \ 98 __builtin_assume(expr); \ 99} while (0) 100#elif defined HAVE___BUILTIN_UNREACHABLE 101#define assume(expr) ((expr) ? ((void) 0) \ 102 : (assert(!"assumption failed"), \ 103 __builtin_unreachable())) 104#elif defined (_MSC_VER) 105#define assume(expr) __assume(expr) 106#else 107#define assume(expr) assert(expr) 108#endif 109 110/* Attribute const is used for functions that have no effects other than their 111 * return value, and only rely on the argument values to compute the return 112 * value. As a result, calls to it can be CSEed. Note that using memory 113 * pointed to by the arguments is not allowed for const functions. 114 */ 115#ifdef HAVE_FUNC_ATTRIBUTE_CONST 116#define ATTRIBUTE_CONST __attribute__((__const__)) 117#else 118#define ATTRIBUTE_CONST 119#endif 120 121#ifdef HAVE_FUNC_ATTRIBUTE_FLATTEN 122#define FLATTEN __attribute__((__flatten__)) 123#else 124#define FLATTEN 125#endif 126 127#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT 128#define PRINTFLIKE(f, a) __attribute__ ((format(__printf__, f, a))) 129#else 130#define PRINTFLIKE(f, a) 131#endif 132 133#ifdef HAVE_FUNC_ATTRIBUTE_MALLOC 134#define MALLOCLIKE __attribute__((__malloc__)) 135#else 136#define MALLOCLIKE 137#endif 138 139/* Used to optionally mark structures with misaligned elements or size as 140 * packed, to trade off performance for space. 141 */ 142#ifdef HAVE_FUNC_ATTRIBUTE_PACKED 143#define PACKED __attribute__((__packed__)) 144#else 145#define PACKED 146#endif 147 148/* Attribute pure is used for functions that have no effects other than their 149 * return value. As a result, calls to it can be dead code eliminated. 150 */ 151#ifdef HAVE_FUNC_ATTRIBUTE_PURE 152#define ATTRIBUTE_PURE __attribute__((__pure__)) 153#else 154#define ATTRIBUTE_PURE 155#endif 156 157#ifdef HAVE_FUNC_ATTRIBUTE_RETURNS_NONNULL 158#define ATTRIBUTE_RETURNS_NONNULL __attribute__((__returns_nonnull__)) 159#else 160#define ATTRIBUTE_RETURNS_NONNULL 161#endif 162 163#ifdef __cplusplus 164/** 165 * Macro function that evaluates to true if T is a trivially 166 * destructible type -- that is, if its (non-virtual) destructor 167 * performs no action and all member variables and base classes are 168 * trivially destructible themselves. 169 */ 170# if (defined(__clang__) && defined(__has_feature)) 171# if __has_feature(has_trivial_destructor) 172# define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T) 173# endif 174# elif defined(__GNUC__) 175# if ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3))) 176# define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T) 177# endif 178# elif defined(_MSC_VER) && !defined(__INTEL_COMPILER) 179# if _MSC_VER >= 1800 180# define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T) 181# endif 182# endif 183# ifndef HAS_TRIVIAL_DESTRUCTOR 184 /* It's always safe (if inefficient) to assume that a 185 * destructor is non-trivial. 186 */ 187# define HAS_TRIVIAL_DESTRUCTOR(T) (false) 188# endif 189#endif 190 191/** 192 * PUBLIC/USED macros 193 * 194 * If we build the library with gcc's -fvisibility=hidden flag, we'll 195 * use the PUBLIC macro to mark functions that are to be exported. 196 * 197 * We also need to define a USED attribute, so the optimizer doesn't 198 * inline a static function that we later use in an alias. - ajax 199 */ 200#ifndef PUBLIC 201# if defined(__GNUC__) 202# define PUBLIC __attribute__((visibility("default"))) 203# define USED __attribute__((used)) 204# elif defined(_MSC_VER) 205# define PUBLIC __declspec(dllexport) 206# define USED 207# else 208# define PUBLIC 209# define USED 210# endif 211#endif 212 213#ifdef HAVE_FUNC_ATTRIBUTE_UNUSED 214#define UNUSED __attribute__((unused)) 215#else 216#define UNUSED 217#endif 218 219#define MAYBE_UNUSED UNUSED 220 221#ifdef HAVE_FUNC_ATTRIBUTE_WARN_UNUSED_RESULT 222#define MUST_CHECK __attribute__((warn_unused_result)) 223#else 224#define MUST_CHECK 225#endif 226 227#if defined(__GNUC__) 228#define ATTRIBUTE_NOINLINE __attribute__((noinline)) 229#else 230#define ATTRIBUTE_NOINLINE 231#endif 232 233/** Compute ceiling of integer quotient of A divided by B. */ 234#define DIV_ROUND_UP( A, B ) ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 ) 235 236/** Clamp X to [MIN,MAX] */ 237#define CLAMP( X, MIN, MAX ) ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) ) 238 239/** Minimum of two values: */ 240#define MIN2( A, B ) ( (A)<(B) ? (A) : (B) ) 241 242/** Maximum of two values: */ 243#define MAX2( A, B ) ( (A)>(B) ? (A) : (B) ) 244 245/** Minimum and maximum of three values: */ 246#define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C)) 247#define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C)) 248 249#endif /* UTIL_MACROS_H */ 250