src/util/macros.h

   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(__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 /**
 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 #else
 268 #define ATTRIBUTE_NOINLINE
 269 #endif
 270
 271
 272 /**
 273  * Check that STRUCT::FIELD can hold MAXVAL.  We use a lot of bitfields
 274  * in Mesa/gallium.  We have to be sure they're of sufficient size to
 275  * hold the largest expected value.
 276  * Note that with MSVC, enums are signed and enum bitfields need one extra
 277  * high bit (always zero) to ensure the max value is handled correctly.
 278  * This macro will detect that with MSVC, but not GCC.
 279  */
 280 #define ASSERT_BITFIELD_SIZE(STRUCT, FIELD, MAXVAL) \
 281    do { \
 282       ASSERTED STRUCT s; \
 283       s.FIELD = (MAXVAL); \
 284       assert((int) s.FIELD == (MAXVAL) && "Insufficient bitfield size!"); \
 285    } while (0)
 286
 287
 288 /** Compute ceiling of integer quotient of A divided by B. */
 289 #define DIV_ROUND_UP( A, B )  ( ((A) + (B) - 1) / (B) )
 290
 291 /** Clamp X to [MIN,MAX].  Turn NaN into MIN, arbitrarily. */
 292 #define CLAMP( X, MIN, MAX )  ( (X)>(MIN) ? ((X)>(MAX) ? (MAX) : (X)) : (MIN) )
 293
 294 /* Syntax sugar occuring frequently in graphics code */
 295 #define SATURATE( X ) CLAMP(X, 0.0f, 1.0f)
 296
 297 /** Minimum of two values: */
 298 #define MIN2( A, B )   ( (A)<(B) ? (A) : (B) )
 299
 300 /** Maximum of two values: */
 301 #define MAX2( A, B )   ( (A)>(B) ? (A) : (B) )
 302
 303 /** Minimum and maximum of three values: */
 304 #define MIN3( A, B, C ) ((A) < (B) ? MIN2(A, C) : MIN2(B, C))
 305 #define MAX3( A, B, C ) ((A) > (B) ? MAX2(A, C) : MAX2(B, C))
 306
 307 /** Align a value to a power of two */
 308 #define ALIGN_POT(x, pot_align) (((x) + (pot_align) - 1) & ~((pot_align) - 1))
 309
 310 /**
 311  * Macro for declaring an explicit conversion operator.  Defaults to an
 312  * implicit conversion if C++11 is not supported.
 313  */
 314 #if __cplusplus >= 201103L
 315 #define EXPLICIT_CONVERSION explicit
 316 #elif defined(__cplusplus)
 317 #define EXPLICIT_CONVERSION
 318 #endif
 319
 320 /** Set a single bit */
 321 #define BITFIELD_BIT(b)      (1u << (b))
 322 /** Set all bits up to excluding bit b */
 323 #define BITFIELD_MASK(b)      \
 324    ((b) == 32 ? (~0u) : BITFIELD_BIT((b) % 32) - 1)
 325 /** Set count bits starting from bit b  */
 326 #define BITFIELD_RANGE(b, count) \
 327    (BITFIELD_MASK((b) + (count)) & ~BITFIELD_MASK(b))
 328
 329 /** Set a single bit */
 330 #define BITFIELD64_BIT(b)      (1ull << (b))
 331 /** Set all bits up to excluding bit b */
 332 #define BITFIELD64_MASK(b)      \
 333    ((b) == 64 ? (~0ull) : BITFIELD64_BIT(b) - 1)
 334 /** Set count bits starting from bit b  */
 335 #define BITFIELD64_RANGE(b, count) \
 336    (BITFIELD64_MASK((b) + (count)) & ~BITFIELD64_MASK(b))
 337
 338 /* TODO: In future we should try to move this to u_debug.h once header
 339  * dependencies are reorganised to allow this.
 340  */
 341 enum pipe_debug_type
 342 {
 343    PIPE_DEBUG_TYPE_OUT_OF_MEMORY = 1,
 344    PIPE_DEBUG_TYPE_ERROR,
 345    PIPE_DEBUG_TYPE_SHADER_INFO,
 346    PIPE_DEBUG_TYPE_PERF_INFO,
 347    PIPE_DEBUG_TYPE_INFO,
 348    PIPE_DEBUG_TYPE_FALLBACK,
 349    PIPE_DEBUG_TYPE_CONFORMANCE,
 350 };
 351
 352 #endif /* UTIL_MACROS_H */