2 * Copyright © 2014 Intel Corporation
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:
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
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
29 #include "c99_compat.h"
31 /* Compute the size of an array */
33 # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
36 /* For compatibility with Clang's __has_builtin() */
38 # define __has_builtin(x) 0
42 * __builtin_expect macros
44 #if !defined(HAVE___BUILTIN_EXPECT)
45 # define __builtin_expect(x, y) (x)
49 # ifdef HAVE___BUILTIN_EXPECT
50 # define likely(x) __builtin_expect(!!(x), 1)
51 # define unlikely(x) __builtin_expect(!!(x), 0)
53 # define likely(x) (x)
54 # define unlikely(x) (x)
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.
64 #define STATIC_ASSERT(COND) \
66 (void) sizeof(char [1 - 2*!(COND)]); \
71 * Unreachable macro. Useful for suppressing "control reaches end of non-void
74 #ifdef HAVE___BUILTIN_UNREACHABLE
75 #define unreachable(str) \
78 __builtin_unreachable(); \
80 #elif defined (_MSC_VER)
81 #define unreachable(str) \
87 #define unreachable(str) assert(!str)
91 * Assume macro. Useful for expressing our assumptions to the compiler,
92 * typically for purposes of silencing warnings.
94 #if __has_builtin(__builtin_assume)
95 #define assume(expr) \
98 __builtin_assume(expr); \
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)
107 #define assume(expr) assert(expr)
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.
115 #ifdef HAVE_FUNC_ATTRIBUTE_CONST
116 #define ATTRIBUTE_CONST __attribute__((__const__))
118 #define ATTRIBUTE_CONST
121 #ifdef HAVE_FUNC_ATTRIBUTE_FLATTEN
122 #define FLATTEN __attribute__((__flatten__))
127 #ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
128 #define PRINTFLIKE(f, a) __attribute__ ((format(__printf__, f, a)))
130 #define PRINTFLIKE(f, a)
133 #ifdef HAVE_FUNC_ATTRIBUTE_MALLOC
134 #define MALLOCLIKE __attribute__((__malloc__))
139 /* Forced function inlining */
140 #ifndef ALWAYS_INLINE
141 # if defined(__GNUC__) || defined(__clang__)
142 # define ALWAYS_INLINE inline __attribute__((always_inline))
143 # elif defined(_MSC_VER)
144 # define ALWAYS_INLINE __forceinline
146 # define ALWAYS_INLINE inline
150 /* Used to optionally mark structures with misaligned elements or size as
151 * packed, to trade off performance for space.
153 #ifdef HAVE_FUNC_ATTRIBUTE_PACKED
154 #define PACKED __attribute__((__packed__))
159 /* Attribute pure is used for functions that have no effects other than their
160 * return value. As a result, calls to it can be dead code eliminated.
162 #ifdef HAVE_FUNC_ATTRIBUTE_PURE
163 #define ATTRIBUTE_PURE __attribute__((__pure__))
165 #define ATTRIBUTE_PURE
168 #ifdef HAVE_FUNC_ATTRIBUTE_RETURNS_NONNULL
169 #define ATTRIBUTE_RETURNS_NONNULL __attribute__((__returns_nonnull__))
171 #define ATTRIBUTE_RETURNS_NONNULL
176 * Macro function that evaluates to true if T is a trivially
177 * destructible type -- that is, if its (non-virtual) destructor
178 * performs no action and all member variables and base classes are
179 * trivially destructible themselves.
181 # if (defined(__clang__) && defined(__has_feature))
182 # if __has_feature(has_trivial_destructor)
183 # define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
185 # elif defined(__GNUC__)
186 # if ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3)))
187 # define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
189 # elif defined(_MSC_VER) && !defined(__INTEL_COMPILER)
190 # if _MSC_VER >= 1800
191 # define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
194 # ifndef HAS_TRIVIAL_DESTRUCTOR
195 /* It's always safe (if inefficient) to assume that a
196 * destructor is non-trivial.
198 # define HAS_TRIVIAL_DESTRUCTOR(T) (false)
205 * If we build the library with gcc's -fvisibility=hidden flag, we'll
206 * use the PUBLIC macro to mark functions that are to be exported.
208 * We also need to define a USED attribute, so the optimizer doesn't
209 * inline a static function that we later use in an alias. - ajax
212 # if defined(__GNUC__)
213 # define PUBLIC __attribute__((visibility("default")))
214 # define USED __attribute__((used))
215 # elif defined(_MSC_VER)
216 # define PUBLIC __declspec(dllexport)
224 #ifdef HAVE_FUNC_ATTRIBUTE_UNUSED
225 #define UNUSED __attribute__((unused))
230 #define MAYBE_UNUSED UNUSED
232 #ifdef HAVE_FUNC_ATTRIBUTE_WARN_UNUSED_RESULT
233 #define MUST_CHECK __attribute__((warn_unused_result))
238 #if defined(__GNUC__)
239 #define ATTRIBUTE_NOINLINE __attribute__((noinline))
241 #define ATTRIBUTE_NOINLINE
244 /** Compute ceiling of integer quotient of A divided by B. */
245 #define DIV_ROUND_UP( A, B ) ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
247 /** Clamp X to [MIN,MAX]. Turn NaN into MIN, arbitrarily. */
248 #define CLAMP( X, MIN, MAX ) ( (X)>(MIN) ? ((X)>(MAX) ? (MAX) : (X)) : (MIN) )
250 /** Minimum of two values: */
251 #define MIN2( A, B ) ( (A)<(B) ? (A) : (B) )
253 /** Maximum of two values: */
254 #define MAX2( A, B ) ( (A)>(B) ? (A) : (B) )
256 /** Minimum and maximum of three values: */
257 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
258 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
260 #endif /* UTIL_MACROS_H */