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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)[0]))
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)    \
76 do {                        \
77    assert(!str);            \
78    __builtin_unreachable(); \
79 } while (0)
80 #elif defined (_MSC_VER)
81 #define unreachable(str)    \
82 do {                        \
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)       \
96 do {                       \
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 /* 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
145 #  else
146 #    define ALWAYS_INLINE inline
147 #  endif
148 #endif
149 
150 /* Used to optionally mark structures with misaligned elements or size as
151  * packed, to trade off performance for space.
152  */
153 #ifdef HAVE_FUNC_ATTRIBUTE_PACKED
154 #define PACKED __attribute__((__packed__))
155 #else
156 #define PACKED
157 #endif
158 
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.
161  */
162 #ifdef HAVE_FUNC_ATTRIBUTE_PURE
163 #define ATTRIBUTE_PURE __attribute__((__pure__))
164 #else
165 #define ATTRIBUTE_PURE
166 #endif
167 
168 #ifdef HAVE_FUNC_ATTRIBUTE_RETURNS_NONNULL
169 #define ATTRIBUTE_RETURNS_NONNULL __attribute__((__returns_nonnull__))
170 #else
171 #define ATTRIBUTE_RETURNS_NONNULL
172 #endif
173 
174 #ifndef NORETURN
175 #  ifdef _MSC_VER
176 #    define NORETURN __declspec(noreturn)
177 #  elif defined HAVE_FUNC_ATTRIBUTE_NORETURN
178 #    define NORETURN __attribute__((__noreturn__))
179 #  else
180 #    define NORETURN
181 #  endif
182 #endif
183 
184 #ifdef __cplusplus
185 /**
186  * Macro function that evaluates to true if T is a trivially
187  * destructible type -- that is, if its (non-virtual) destructor
188  * performs no action and all member variables and base classes are
189  * trivially destructible themselves.
190  */
191 #   if (defined(__clang__) && defined(__has_feature))
192 #      if __has_feature(has_trivial_destructor)
193 #         define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
194 #      endif
195 #   elif defined(__GNUC__)
196 #      if ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3)))
197 #         define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
198 #      endif
199 #   elif defined(_MSC_VER) && !defined(__INTEL_COMPILER)
200 #      if _MSC_VER >= 1800
201 #         define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
202 #      endif
203 #   endif
204 #   ifndef HAS_TRIVIAL_DESTRUCTOR
205        /* It's always safe (if inefficient) to assume that a
206         * destructor is non-trivial.
207         */
208 #      define HAS_TRIVIAL_DESTRUCTOR(T) (false)
209 #   endif
210 #endif
211 
212 /**
213  * PUBLIC/USED macros
214  *
215  * If we build the library with gcc's -fvisibility=hidden flag, we'll
216  * use the PUBLIC macro to mark functions that are to be exported.
217  *
218  * We also need to define a USED attribute, so the optimizer doesn't
219  * inline a static function that we later use in an alias. - ajax
220  */
221 #ifndef PUBLIC
222 #  if defined(__GNUC__)
223 #    define PUBLIC __attribute__((visibility("default")))
224 #    define USED __attribute__((used))
225 #  elif defined(_MSC_VER)
226 #    define PUBLIC __declspec(dllexport)
227 #    define USED
228 #  else
229 #    define PUBLIC
230 #    define USED
231 #  endif
232 #endif
233 
234 #ifdef HAVE_FUNC_ATTRIBUTE_UNUSED
235 #define UNUSED __attribute__((unused))
236 #else
237 #define UNUSED
238 #endif
239 
240 #define MAYBE_UNUSED UNUSED
241 
242 #ifdef HAVE_FUNC_ATTRIBUTE_WARN_UNUSED_RESULT
243 #define MUST_CHECK __attribute__((warn_unused_result))
244 #else
245 #define MUST_CHECK
246 #endif
247 
248 #if defined(__GNUC__)
249 #define ATTRIBUTE_NOINLINE __attribute__((noinline))
250 #else
251 #define ATTRIBUTE_NOINLINE
252 #endif
253 
254 
255 /**
256  * Check that STRUCT::FIELD can hold MAXVAL.  We use a lot of bitfields
257  * in Mesa/gallium.  We have to be sure they're of sufficient size to
258  * hold the largest expected value.
259  * Note that with MSVC, enums are signed and enum bitfields need one extra
260  * high bit (always zero) to ensure the max value is handled correctly.
261  * This macro will detect that with MSVC, but not GCC.
262  */
263 #define ASSERT_BITFIELD_SIZE(STRUCT, FIELD, MAXVAL) \
264    do { \
265       MAYBE_UNUSED STRUCT s;                \
266       s.FIELD = (MAXVAL); \
267       assert((int) s.FIELD == (MAXVAL) && "Insufficient bitfield size!"); \
268    } while (0)
269 
270 
271 /** Compute ceiling of integer quotient of A divided by B. */
272 #define DIV_ROUND_UP( A, B )  ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
273 
274 /** Clamp X to [MIN,MAX].  Turn NaN into MIN, arbitrarily. */
275 #define CLAMP( X, MIN, MAX )  ( (X)>(MIN) ? ((X)>(MAX) ? (MAX) : (X)) : (MIN) )
276 
277 /** Minimum of two values: */
278 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
279 
280 /** Maximum of two values: */
281 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
282 
283 /** Minimum and maximum of three values: */
284 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
285 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
286 
287 #endif /* UTIL_MACROS_H */
288