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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 #include "c11_compat.h"
31 
32 /* Compute the size of an array */
33 #ifndef ARRAY_SIZE
34 #  define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
35 #endif
36 
37 /* For compatibility with Clang's __has_builtin() */
38 #ifndef __has_builtin
39 #  define __has_builtin(x) 0
40 #endif
41 
42 /**
43  * __builtin_expect macros
44  */
45 #if !defined(HAVE___BUILTIN_EXPECT)
46 #  define __builtin_expect(x, y) (x)
47 #endif
48 
49 #ifndef likely
50 #  ifdef HAVE___BUILTIN_EXPECT
51 #    define likely(x)   __builtin_expect(!!(x), 1)
52 #    define unlikely(x) __builtin_expect(!!(x), 0)
53 #  else
54 #    define likely(x)   (x)
55 #    define unlikely(x) (x)
56 #  endif
57 #endif
58 
59 
60 /**
61  * Static (compile-time) assertion.
62  * Basically, use COND to dimension an array.  If COND is false/zero the
63  * array size will be -1 and we'll get a compilation error.
64  */
65 #define STATIC_ASSERT(COND) \
66    do { \
67       (void) sizeof(char [1 - 2*!(COND)]); \
68    } while (0)
69 
70 
71 /**
72  * Unreachable macro. Useful for suppressing "control reaches end of non-void
73  * function" warnings.
74  */
75 #if defined(HAVE___BUILTIN_UNREACHABLE) || __has_builtin(__builtin_unreachable)
76 #define unreachable(str)    \
77 do {                        \
78    assert(!str);            \
79    __builtin_unreachable(); \
80 } while (0)
81 #elif defined (_MSC_VER)
82 #define unreachable(str)    \
83 do {                        \
84    assert(!str);            \
85    __assume(0);             \
86 } while (0)
87 #else
88 #define unreachable(str) assert(!str)
89 #endif
90 
91 /**
92  * Assume macro. Useful for expressing our assumptions to the compiler,
93  * typically for purposes of silencing warnings.
94  */
95 #if __has_builtin(__builtin_assume)
96 #define assume(expr)       \
97 do {                       \
98    assert(expr);           \
99    __builtin_assume(expr); \
100 } while (0)
101 #elif defined HAVE___BUILTIN_UNREACHABLE
102 #define assume(expr) ((expr) ? ((void) 0) \
103                              : (assert(!"assumption failed"), \
104                                 __builtin_unreachable()))
105 #elif defined (_MSC_VER)
106 #define assume(expr) __assume(expr)
107 #else
108 #define assume(expr) assert(expr)
109 #endif
110 
111 /* Attribute const is used for functions that have no effects other than their
112  * return value, and only rely on the argument values to compute the return
113  * value.  As a result, calls to it can be CSEed.  Note that using memory
114  * pointed to by the arguments is not allowed for const functions.
115  */
116 #ifdef HAVE_FUNC_ATTRIBUTE_CONST
117 #define ATTRIBUTE_CONST __attribute__((__const__))
118 #else
119 #define ATTRIBUTE_CONST
120 #endif
121 
122 #ifdef HAVE_FUNC_ATTRIBUTE_FLATTEN
123 #define FLATTEN __attribute__((__flatten__))
124 #else
125 #define FLATTEN
126 #endif
127 
128 #ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
129 #define PRINTFLIKE(f, a) __attribute__ ((format(__printf__, f, a)))
130 #else
131 #define PRINTFLIKE(f, a)
132 #endif
133 
134 #ifdef HAVE_FUNC_ATTRIBUTE_MALLOC
135 #define MALLOCLIKE __attribute__((__malloc__))
136 #else
137 #define MALLOCLIKE
138 #endif
139 
140 /* Forced function inlining */
141 /* Note: Clang also sets __GNUC__ (see other cases below) */
142 #ifndef ALWAYS_INLINE
143 #  if defined(__GNUC__)
144 #    define ALWAYS_INLINE inline __attribute__((always_inline))
145 #  elif defined(_MSC_VER)
146 #    define ALWAYS_INLINE __forceinline
147 #  else
148 #    define ALWAYS_INLINE inline
149 #  endif
150 #endif
151 
152 /* Used to optionally mark structures with misaligned elements or size as
153  * packed, to trade off performance for space.
154  */
155 #ifdef HAVE_FUNC_ATTRIBUTE_PACKED
156 #define PACKED __attribute__((__packed__))
157 #else
158 #define PACKED
159 #endif
160 
161 /* Attribute pure is used for functions that have no effects other than their
162  * return value.  As a result, calls to it can be dead code eliminated.
163  */
164 #ifdef HAVE_FUNC_ATTRIBUTE_PURE
165 #define ATTRIBUTE_PURE __attribute__((__pure__))
166 #else
167 #define ATTRIBUTE_PURE
168 #endif
169 
170 #ifdef HAVE_FUNC_ATTRIBUTE_RETURNS_NONNULL
171 #define ATTRIBUTE_RETURNS_NONNULL __attribute__((__returns_nonnull__))
172 #else
173 #define ATTRIBUTE_RETURNS_NONNULL
174 #endif
175 
176 #ifndef NORETURN
177 #  ifdef _MSC_VER
178 #    define NORETURN __declspec(noreturn)
179 #  elif defined HAVE_FUNC_ATTRIBUTE_NORETURN
180 #    define NORETURN __attribute__((__noreturn__))
181 #  else
182 #    define NORETURN
183 #  endif
184 #endif
185 
186 #ifdef __cplusplus
187 /**
188  * Macro function that evaluates to true if T is a trivially
189  * destructible type -- that is, if its (non-virtual) destructor
190  * performs no action and all member variables and base classes are
191  * trivially destructible themselves.
192  */
193 #   if (defined(__clang__) && defined(__has_feature))
194 #      if __has_feature(has_trivial_destructor)
195 #         define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
196 #      endif
197 #   elif defined(__GNUC__)
198 #      if ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3)))
199 #         define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
200 #      endif
201 #   elif defined(_MSC_VER) && !defined(__INTEL_COMPILER)
202 #      define HAS_TRIVIAL_DESTRUCTOR(T) __has_trivial_destructor(T)
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(_WIN32)
223 #    define PUBLIC __declspec(dllexport)
224 #    define USED
225 #  elif defined(__GNUC__)
226 #    define PUBLIC __attribute__((visibility("default")))
227 #    define USED __attribute__((used))
228 #  else
229 #    define PUBLIC
230 #    define USED
231 #  endif
232 #endif
233 
234 /**
235  * UNUSED marks variables (or sometimes functions) that have to be defined,
236  * but are sometimes (or always) unused beyond that. A common case is for
237  * a function parameter to be used in some build configurations but not others.
238  * Another case is fallback vfuncs that don't do anything with their params.
239  *
240  * Note that this should not be used for identifiers used in `assert()`;
241  * see ASSERTED below.
242  */
243 #ifdef HAVE_FUNC_ATTRIBUTE_UNUSED
244 #define UNUSED __attribute__((unused))
245 #else
246 #define UNUSED
247 #endif
248 
249 /**
250  * Use ASSERTED to indicate that an identifier is unused outside of an `assert()`,
251  * so that assert-free builds don't get "unused variable" warnings.
252  */
253 #ifdef NDEBUG
254 #define ASSERTED UNUSED
255 #else
256 #define ASSERTED
257 #endif
258 
259 #ifdef HAVE_FUNC_ATTRIBUTE_WARN_UNUSED_RESULT
260 #define MUST_CHECK __attribute__((warn_unused_result))
261 #else
262 #define MUST_CHECK
263 #endif
264 
265 #if defined(__GNUC__)
266 #define ATTRIBUTE_NOINLINE __attribute__((noinline))
267 #elif defined(_MSC_VER)
268 #define ATTRIBUTE_NOINLINE __declspec(noinline)
269 #else
270 #define ATTRIBUTE_NOINLINE
271 #endif
272 
273 
274 /**
275  * Check that STRUCT::FIELD can hold MAXVAL.  We use a lot of bitfields
276  * in Mesa/gallium.  We have to be sure they're of sufficient size to
277  * hold the largest expected value.
278  * Note that with MSVC, enums are signed and enum bitfields need one extra
279  * high bit (always zero) to ensure the max value is handled correctly.
280  * This macro will detect that with MSVC, but not GCC.
281  */
282 #define ASSERT_BITFIELD_SIZE(STRUCT, FIELD, MAXVAL) \
283    do { \
284       ASSERTED STRUCT s; \
285       s.FIELD = (MAXVAL); \
286       assert((int) s.FIELD == (MAXVAL) && "Insufficient bitfield size!"); \
287    } while (0)
288 
289 
290 /** Compute ceiling of integer quotient of A divided by B. */
291 #define DIV_ROUND_UP( A, B )  ( ((A) + (B) - 1) / (B) )
292 
293 /** Clamp X to [MIN,MAX].  Turn NaN into MIN, arbitrarily. */
294 #define CLAMP( X, MIN, MAX )  ( (X)>(MIN) ? ((X)>(MAX) ? (MAX) : (X)) : (MIN) )
295 
296 /* Syntax sugar occuring frequently in graphics code */
297 #define SATURATE( X ) CLAMP(X, 0.0f, 1.0f)
298 
299 /** Minimum of two values: */
300 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
301 
302 /** Maximum of two values: */
303 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
304 
305 /** Minimum and maximum of three values: */
306 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
307 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
308 
309 /** Align a value to a power of two */
310 #define ALIGN_POT(x, pot_align) (((x) + (pot_align) - 1) & ~((pot_align) - 1))
311 
312 /**
313  * Macro for declaring an explicit conversion operator.  Defaults to an
314  * implicit conversion if C++11 is not supported.
315  */
316 #if __cplusplus >= 201103L
317 #define EXPLICIT_CONVERSION explicit
318 #elif defined(__cplusplus)
319 #define EXPLICIT_CONVERSION
320 #endif
321 
322 /** Set a single bit */
323 #define BITFIELD_BIT(b)      (1u << (b))
324 /** Set all bits up to excluding bit b */
325 #define BITFIELD_MASK(b)      \
326    ((b) == 32 ? (~0u) : BITFIELD_BIT((b) % 32) - 1)
327 /** Set count bits starting from bit b  */
328 #define BITFIELD_RANGE(b, count) \
329    (BITFIELD_MASK((b) + (count)) & ~BITFIELD_MASK(b))
330 
331 /** Set a single bit */
332 #define BITFIELD64_BIT(b)      (1ull << (b))
333 /** Set all bits up to excluding bit b */
334 #define BITFIELD64_MASK(b)      \
335    ((b) == 64 ? (~0ull) : BITFIELD64_BIT(b) - 1)
336 /** Set count bits starting from bit b  */
337 #define BITFIELD64_RANGE(b, count) \
338    (BITFIELD64_MASK((b) + (count)) & ~BITFIELD64_MASK(b))
339 
340 /* TODO: In future we should try to move this to u_debug.h once header
341  * dependencies are reorganised to allow this.
342  */
343 enum pipe_debug_type
344 {
345    PIPE_DEBUG_TYPE_OUT_OF_MEMORY = 1,
346    PIPE_DEBUG_TYPE_ERROR,
347    PIPE_DEBUG_TYPE_SHADER_INFO,
348    PIPE_DEBUG_TYPE_PERF_INFO,
349    PIPE_DEBUG_TYPE_INFO,
350    PIPE_DEBUG_TYPE_FALLBACK,
351    PIPE_DEBUG_TYPE_CONFORMANCE,
352 };
353 
354 #if !defined(alignof) && !defined(__cplusplus)
355 #if __STDC_VERSION__ >= 201112L
356 #define alignof(t) _Alignof(t)
357 #elif defined(_MSC_VER)
358 #define alignof(t) __alignof(t)
359 #else
360 #define alignof(t) __alignof__(t)
361 #endif
362 #endif
363 
364 #endif /* UTIL_MACROS_H */
365