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 #if defined(_MSC_VER)
  86 #define strcasecmp(s1, s2) _stricmp(s1, s2)
  87 #endif
  88 /*@}*/
  89
  90
  91 /***
  92  *** LOG2: Log base 2 of float
  93  ***/
  94 static inline GLfloat LOG2(GLfloat x)
  95 {
  96 #if 0
  97    /* This is pretty fast, but not accurate enough (only 2 fractional bits).
  98     * Based on code from http://www.stereopsis.com/log2.html
  99     */
 100    const GLfloat y = x * x * x * x;
 101    const GLuint ix = *((GLuint *) &y);
 102    const GLuint exp = (ix >> 23) & 0xFF;
 103    const GLint log2 = ((GLint) exp) - 127;
 104    return (GLfloat) log2 * (1.0 / 4.0);  /* 4, because of x^4 above */
 105 #endif
 106    /* Pretty fast, and accurate.
 107     * Based on code from http://www.flipcode.com/totd/
 108     */
 109    fi_type num;
 110    GLint log_2;
 111    num.f = x;
 112    log_2 = ((num.i >> 23) & 255) - 128;
 113    num.i &= ~(255 << 23);
 114    num.i += 127 << 23;
 115    num.f = ((-1.0f/3) * num.f + 2) * num.f - 2.0f/3;
 116    return num.f + log_2;
 117 }
 118
 119
 120
 121 /**
 122  * finite macro.
 123  */
 124 #if defined(_MSC_VER)
 125 #  define finite _finite
 126 #endif
 127
 128
 129 /***
 130  *** IS_INF_OR_NAN: test if float is infinite or NaN
 131  ***/
 132 #if defined(isfinite)
 133 #define IS_INF_OR_NAN(x)        (!isfinite(x))
 134 #elif defined(finite)
 135 #define IS_INF_OR_NAN(x)        (!finite(x))
 136 #elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
 137 #define IS_INF_OR_NAN(x)        (!isfinite(x))
 138 #else
 139 #define IS_INF_OR_NAN(x)        (!finite(x))
 140 #endif
 141
 142
 143 /**
 144  * Convert float to int by rounding to nearest integer, away from zero.
 145  */
 146 static inline int IROUND(float f)
 147 {
 148    return (int) ((f >= 0.0F) ? (f + 0.5F) : (f - 0.5F));
 149 }
 150
 151 /**
 152  * Convert double to int by rounding to nearest integer, away from zero.
 153  */
 154 static inline int IROUNDD(double d)
 155 {
 156    return (int) ((d >= 0.0) ? (d + 0.5) : (d - 0.5));
 157 }
 158
 159 /**
 160  * Convert float to int64 by rounding to nearest integer.
 161  */
 162 static inline GLint64 IROUND64(float f)
 163 {
 164    return (GLint64) ((f >= 0.0F) ? (f + 0.5F) : (f - 0.5F));
 165 }
 166
 167
 168 /**
 169  * Convert positive float to int by rounding to nearest integer.
 170  */
 171 static inline int IROUND_POS(float f)
 172 {
 173    assert(f >= 0.0F);
 174    return (int) (f + 0.5F);
 175 }
 176
 177 /** Return (as an integer) floor of float */
 178 static inline int IFLOOR(float f)
 179 {
 180 #if defined(USE_X86_ASM) && defined(__GNUC__) && defined(__i386__)
 181    /*
 182     * IEEE floor for computers that round to nearest or even.
 183     * 'f' must be between -4194304 and 4194303.
 184     * This floor operation is done by "(iround(f + .5) + iround(f - .5)) >> 1",
 185     * but uses some IEEE specific tricks for better speed.
 186     * Contributed by Josh Vanderhoof
 187     */
 188    int ai, bi;
 189    double af, bf;
 190    af = (3 << 22) + 0.5 + (double)f;
 191    bf = (3 << 22) + 0.5 - (double)f;
 192    /* GCC generates an extra fstp/fld without this. */
 193    __asm__ ("fstps %0" : "=m" (ai) : "t" (af) : "st");
 194    __asm__ ("fstps %0" : "=m" (bi) : "t" (bf) : "st");
 195    return (ai - bi) >> 1;
 196 #else
 197    int ai, bi;
 198    double af, bf;
 199    fi_type u;
 200    af = (3 << 22) + 0.5 + (double)f;
 201    bf = (3 << 22) + 0.5 - (double)f;
 202    u.f = (float) af;  ai = u.i;
 203    u.f = (float) bf;  bi = u.i;
 204    return (ai - bi) >> 1;
 205 #endif
 206 }
 207
 208
 209 /**
 210  * Is x a power of two?
 211  */
 212 static inline int
 213 _mesa_is_pow_two(int x)
 214 {
 215    return !(x & (x - 1));
 216 }
 217
 218 /**
 219  * Round given integer to next higer power of two
 220  * If X is zero result is undefined.
 221  *
 222  * Source for the fallback implementation is
 223  * Sean Eron Anderson's webpage "Bit Twiddling Hacks"
 224  * http://graphics.stanford.edu/~seander/bithacks.html
 225  *
 226  * When using builtin function have to do some work
 227  * for case when passed values 1 to prevent hiting
 228  * undefined result from __builtin_clz. Undefined
 229  * results would be different depending on optimization
 230  * level used for build.
 231  */
 232 static inline int32_t
 233 _mesa_next_pow_two_32(uint32_t x)
 234 {
 235 #ifdef HAVE___BUILTIN_CLZ
 236         uint32_t y = (x != 1);
 237         return (1 + y) << ((__builtin_clz(x - y) ^ 31) );
 238 #else
 239         x--;
 240         x |= x >> 1;
 241         x |= x >> 2;
 242         x |= x >> 4;
 243         x |= x >> 8;
 244         x |= x >> 16;
 245         x++;
 246         return x;
 247 #endif
 248 }
 249
 250 static inline int64_t
 251 _mesa_next_pow_two_64(uint64_t x)
 252 {
 253 #ifdef HAVE___BUILTIN_CLZLL
 254         uint64_t y = (x != 1);
 255         STATIC_ASSERT(sizeof(x) == sizeof(long long));
 256         return (1 + y) << ((__builtin_clzll(x - y) ^ 63));
 257 #else
 258         x--;
 259         x |= x >> 1;
 260         x |= x >> 2;
 261         x |= x >> 4;
 262         x |= x >> 8;
 263         x |= x >> 16;
 264         x |= x >> 32;
 265         x++;
 266         return x;
 267 #endif
 268 }
 269
 270
 271 /*
 272  * Returns the floor form of binary logarithm for a 32-bit integer.
 273  */
 274 static inline GLuint
 275 _mesa_logbase2(GLuint n)
 276 {
 277 #ifdef HAVE___BUILTIN_CLZ
 278    return (31 - __builtin_clz(n | 1));
 279 #else
 280    GLuint pos = 0;
 281    if (n >= 1<<16) { n >>= 16; pos += 16; }
 282    if (n >= 1<< 8) { n >>=  8; pos +=  8; }
 283    if (n >= 1<< 4) { n >>=  4; pos +=  4; }
 284    if (n >= 1<< 2) { n >>=  2; pos +=  2; }
 285    if (n >= 1<< 1) {           pos +=  1; }
 286    return pos;
 287 #endif
 288 }
 289
 290
 291 /**
 292  * Return 1 if this is a little endian machine, 0 if big endian.
 293  */
 294 static inline GLboolean
 295 _mesa_little_endian(void)
 296 {
 297    const GLuint ui = 1; /* intentionally not static */
 298    return *((const GLubyte *) &ui);
 299 }
 300
 301
 302
 303 /**********************************************************************
 304  * Functions
 305  */
 306
 307 extern void *
 308 _mesa_align_malloc( size_t bytes, unsigned long alignment );
 309
 310 extern void *
 311 _mesa_align_calloc( size_t bytes, unsigned long alignment );
 312
 313 extern void
 314 _mesa_align_free( void *ptr );
 315
 316 extern void *
 317 _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
 318                     unsigned long alignment);
 319
 320 extern int
 321 _mesa_snprintf( char *str, size_t size, const char *fmt, ... ) PRINTFLIKE(3, 4);
 322
 323 extern int
 324 _mesa_vsnprintf(char *str, size_t size, const char *fmt, va_list arg);
 325
 326
 327 #if defined(_WIN32) && !defined(strtok_r)
 328 #define strtok_r strtok_s
 329 #endif
 330
 331 #ifdef __cplusplus
 332 }
 333 #endif
 334
 335
 336 #endif /* IMPORTS_H */