src/mesa/main/imports.h

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * \file imports.h
  28  * Standard C library function wrappers.
  29  *
  30  * This file provides wrappers for all the standard C library functions
  31  * like malloc(), free(), printf(), getenv(), etc.
  32  */
  33
  34
  35 #ifndef IMPORTS_H
  36 #define IMPORTS_H
  37
  38
  39 #include <stdlib.h>
  40 #include <stdarg.h>
  41 #include <string.h>
  42 #include "compiler.h"
  43 #include "glheader.h"
  44 #include "util/bitscan.h"
  45
  46 #ifdef __cplusplus
  47 extern "C" {
  48 #endif
  49
  50
  51 /**********************************************************************/
  52 /** Memory macros */
  53 /*@{*/
  54
  55 /** Allocate a structure of type \p T */
  56 #define MALLOC_STRUCT(T)   (struct T *) malloc(sizeof(struct T))
  57 /** Allocate and zero a structure of type \p T */
  58 #define CALLOC_STRUCT(T)   (struct T *) calloc(1, sizeof(struct T))
  59
  60 /*@}*/
  61
  62
  63 /*
  64  * For GL_ARB_vertex_buffer_object we need to treat vertex array pointers
  65  * as offsets into buffer stores.  Since the vertex array pointer and
  66  * buffer store pointer are both pointers and we need to add them, we use
  67  * this macro.
  68  * Both pointers/offsets are expressed in bytes.
  69  */
  70 #define ADD_POINTERS(A, B)  ( (GLubyte *) (A) + (uintptr_t) (B) )
  71
  72
  73 /**
  74  * Sometimes we treat GLfloats as GLints.  On x86 systems, moving a float
  75  * as an int (thereby using integer registers instead of FP registers) is
  76  * a performance win.  Typically, this can be done with ordinary casts.
  77  * But with gcc's -fstrict-aliasing flag (which defaults to on in gcc 3.0)
  78  * these casts generate warnings.
  79  * The following union typedef is used to solve that.
  80  */
  81 typedef union { GLfloat f; GLint i; GLuint u; } fi_type;
  82
  83
  84
  85 /*@}*/
  86
  87
  88 /***
  89  *** LOG2: Log base 2 of float
  90  ***/
  91 static inline GLfloat LOG2(GLfloat x)
  92 {
  93 #if 0
  94    /* This is pretty fast, but not accurate enough (only 2 fractional bits).
  95     * Based on code from http://www.stereopsis.com/log2.html
  96     */
  97    const GLfloat y = x * x * x * x;
  98    const GLuint ix = *((GLuint *) &y);
  99    const GLuint exp = (ix >> 23) & 0xFF;
 100    const GLint log2 = ((GLint) exp) - 127;
 101    return (GLfloat) log2 * (1.0 / 4.0);  /* 4, because of x^4 above */
 102 #endif
 103    /* Pretty fast, and accurate.
 104     * Based on code from http://www.flipcode.com/totd/
 105     */
 106    fi_type num;
 107    GLint log_2;
 108    num.f = x;
 109    log_2 = ((num.i >> 23) & 255) - 128;
 110    num.i &= ~(255 << 23);
 111    num.i += 127 << 23;
 112    num.f = ((-1.0f/3) * num.f + 2) * num.f - 2.0f/3;
 113    return num.f + log_2;
 114 }
 115
 116
 117
 118 /**
 119  * finite macro.
 120  */
 121 #if defined(_MSC_VER)
 122 #  define finite _finite
 123 #endif
 124
 125
 126 /***
 127  *** IS_INF_OR_NAN: test if float is infinite or NaN
 128  ***/
 129 #if defined(isfinite)
 130 #define IS_INF_OR_NAN(x)        (!isfinite(x))
 131 #elif defined(finite)
 132 #define IS_INF_OR_NAN(x)        (!finite(x))
 133 #elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
 134 #define IS_INF_OR_NAN(x)        (!isfinite(x))
 135 #else
 136 #define IS_INF_OR_NAN(x)        (!finite(x))
 137 #endif
 138
 139
 140 /**
 141  * Convert float to int by rounding to nearest integer, away from zero.
 142  */
 143 static inline int IROUND(float f)
 144 {
 145    return (int) ((f >= 0.0F) ? (f + 0.5F) : (f - 0.5F));
 146 }
 147
 148 /**
 149  * Convert double to int by rounding to nearest integer, away from zero.
 150  */
 151 static inline int IROUNDD(double d)
 152 {
 153    return (int) ((d >= 0.0) ? (d + 0.5) : (d - 0.5));
 154 }
 155
 156 /**
 157  * Convert float to int64 by rounding to nearest integer.
 158  */
 159 static inline GLint64 IROUND64(float f)
 160 {
 161    return (GLint64) ((f >= 0.0F) ? (f + 0.5F) : (f - 0.5F));
 162 }
 163
 164
 165 /**
 166  * Convert positive float to int by rounding to nearest integer.
 167  */
 168 static inline int IROUND_POS(float f)
 169 {
 170    assert(f >= 0.0F);
 171    return (int) (f + 0.5F);
 172 }
 173
 174 /** Return (as an integer) floor of float */
 175 static inline int IFLOOR(float f)
 176 {
 177 #if defined(USE_X86_ASM) && defined(__GNUC__) && defined(__i386__)
 178    /*
 179     * IEEE floor for computers that round to nearest or even.
 180     * 'f' must be between -4194304 and 4194303.
 181     * This floor operation is done by "(iround(f + .5) + iround(f - .5)) >> 1",
 182     * but uses some IEEE specific tricks for better speed.
 183     * Contributed by Josh Vanderhoof
 184     */
 185    int ai, bi;
 186    double af, bf;
 187    af = (3 << 22) + 0.5 + (double)f;
 188    bf = (3 << 22) + 0.5 - (double)f;
 189    /* GCC generates an extra fstp/fld without this. */
 190    __asm__ ("fstps %0" : "=m" (ai) : "t" (af) : "st");
 191    __asm__ ("fstps %0" : "=m" (bi) : "t" (bf) : "st");
 192    return (ai - bi) >> 1;
 193 #else
 194    int ai, bi;
 195    double af, bf;
 196    fi_type u;
 197    af = (3 << 22) + 0.5 + (double)f;
 198    bf = (3 << 22) + 0.5 - (double)f;
 199    u.f = (float) af;  ai = u.i;
 200    u.f = (float) bf;  bi = u.i;
 201    return (ai - bi) >> 1;
 202 #endif
 203 }
 204
 205
 206 /**
 207  * Is x a power of two?
 208  */
 209 static inline int
 210 _mesa_is_pow_two(int x)
 211 {
 212    return !(x & (x - 1));
 213 }
 214
 215 /**
 216  * Round given integer to next higer power of two
 217  * If X is zero result is undefined.
 218  *
 219  * Source for the fallback implementation is
 220  * Sean Eron Anderson's webpage "Bit Twiddling Hacks"
 221  * http://graphics.stanford.edu/~seander/bithacks.html
 222  *
 223  * When using builtin function have to do some work
 224  * for case when passed values 1 to prevent hiting
 225  * undefined result from __builtin_clz. Undefined
 226  * results would be different depending on optimization
 227  * level used for build.
 228  */
 229 static inline int32_t
 230 _mesa_next_pow_two_32(uint32_t x)
 231 {
 232 #ifdef HAVE___BUILTIN_CLZ
 233         uint32_t y = (x != 1);
 234         return (1 + y) << ((__builtin_clz(x - y) ^ 31) );
 235 #else
 236         x--;
 237         x |= x >> 1;
 238         x |= x >> 2;
 239         x |= x >> 4;
 240         x |= x >> 8;
 241         x |= x >> 16;
 242         x++;
 243         return x;
 244 #endif
 245 }
 246
 247 static inline int64_t
 248 _mesa_next_pow_two_64(uint64_t x)
 249 {
 250 #ifdef HAVE___BUILTIN_CLZLL
 251         uint64_t y = (x != 1);
 252         STATIC_ASSERT(sizeof(x) == sizeof(long long));
 253         return (1 + y) << ((__builtin_clzll(x - y) ^ 63));
 254 #else
 255         x--;
 256         x |= x >> 1;
 257         x |= x >> 2;
 258         x |= x >> 4;
 259         x |= x >> 8;
 260         x |= x >> 16;
 261         x |= x >> 32;
 262         x++;
 263         return x;
 264 #endif
 265 }
 266
 267
 268 /*
 269  * Returns the floor form of binary logarithm for a 32-bit integer.
 270  */
 271 static inline GLuint
 272 _mesa_logbase2(GLuint n)
 273 {
 274 #ifdef HAVE___BUILTIN_CLZ
 275    return (31 - __builtin_clz(n | 1));
 276 #else
 277    GLuint pos = 0;
 278    if (n >= 1<<16) { n >>= 16; pos += 16; }
 279    if (n >= 1<< 8) { n >>=  8; pos +=  8; }
 280    if (n >= 1<< 4) { n >>=  4; pos +=  4; }
 281    if (n >= 1<< 2) { n >>=  2; pos +=  2; }
 282    if (n >= 1<< 1) {           pos +=  1; }
 283    return pos;
 284 #endif
 285 }
 286
 287
 288 /**********************************************************************
 289  * Functions
 290  */
 291
 292 extern void *
 293 _mesa_align_malloc( size_t bytes, unsigned long alignment );
 294
 295 extern void *
 296 _mesa_align_calloc( size_t bytes, unsigned long alignment );
 297
 298 extern void
 299 _mesa_align_free( void *ptr );
 300
 301 extern void *
 302 _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
 303                     unsigned long alignment);
 304
 305 extern int
 306 _mesa_snprintf( char *str, size_t size, const char *fmt, ... ) PRINTFLIKE(3, 4);
 307
 308 extern int
 309 _mesa_vsnprintf(char *str, size_t size, const char *fmt, va_list arg);
 310
 311
 312 #if defined(_WIN32) && !defined(HAVE_STRTOK_R)
 313 #define strtok_r strtok_s
 314 #endif
 315
 316 #ifdef __cplusplus
 317 }
 318 #endif
 319
 320
 321 #endif /* IMPORTS_H */