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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 "errors.h"
45 #include "util/bitscan.h"
46 
47 #ifdef __cplusplus
48 extern "C" {
49 #endif
50 
51 
52 /**********************************************************************/
53 /** Memory macros */
54 /*@{*/
55 
56 /** Allocate a structure of type \p T */
57 #define MALLOC_STRUCT(T)   (struct T *) malloc(sizeof(struct T))
58 /** Allocate and zero a structure of type \p T */
59 #define CALLOC_STRUCT(T)   (struct T *) calloc(1, sizeof(struct T))
60 
61 /*@}*/
62 
63 
64 /*
65  * For GL_ARB_vertex_buffer_object we need to treat vertex array pointers
66  * as offsets into buffer stores.  Since the vertex array pointer and
67  * buffer store pointer are both pointers and we need to add them, we use
68  * this macro.
69  * Both pointers/offsets are expressed in bytes.
70  */
71 #define ADD_POINTERS(A, B)  ( (GLubyte *) (A) + (uintptr_t) (B) )
72 
73 
74 /**
75  * Sometimes we treat GLfloats as GLints.  On x86 systems, moving a float
76  * as an int (thereby using integer registers instead of FP registers) is
77  * a performance win.  Typically, this can be done with ordinary casts.
78  * But with gcc's -fstrict-aliasing flag (which defaults to on in gcc 3.0)
79  * these casts generate warnings.
80  * The following union typedef is used to solve that.
81  */
82 typedef union { GLfloat f; GLint i; GLuint u; } fi_type;
83 
84 
85 
86 #if defined(_MSC_VER)
87 #define strcasecmp(s1, s2) _stricmp(s1, s2)
88 #endif
89 /*@}*/
90 
91 
92 /***
93  *** LOG2: Log base 2 of float
94  ***/
LOG2(GLfloat x)95 static inline GLfloat LOG2(GLfloat x)
96 {
97 #if 0
98    /* This is pretty fast, but not accurate enough (only 2 fractional bits).
99     * Based on code from http://www.stereopsis.com/log2.html
100     */
101    const GLfloat y = x * x * x * x;
102    const GLuint ix = *((GLuint *) &y);
103    const GLuint exp = (ix >> 23) & 0xFF;
104    const GLint log2 = ((GLint) exp) - 127;
105    return (GLfloat) log2 * (1.0 / 4.0);  /* 4, because of x^4 above */
106 #endif
107    /* Pretty fast, and accurate.
108     * Based on code from http://www.flipcode.com/totd/
109     */
110    fi_type num;
111    GLint log_2;
112    num.f = x;
113    log_2 = ((num.i >> 23) & 255) - 128;
114    num.i &= ~(255 << 23);
115    num.i += 127 << 23;
116    num.f = ((-1.0f/3) * num.f + 2) * num.f - 2.0f/3;
117    return num.f + log_2;
118 }
119 
120 
121 
122 /**
123  * finite macro.
124  */
125 #if defined(_MSC_VER)
126 #  define finite _finite
127 #endif
128 
129 
130 /***
131  *** IS_INF_OR_NAN: test if float is infinite or NaN
132  ***/
133 #if defined(isfinite)
134 #define IS_INF_OR_NAN(x)        (!isfinite(x))
135 #elif defined(finite)
136 #define IS_INF_OR_NAN(x)        (!finite(x))
137 #elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
138 #define IS_INF_OR_NAN(x)        (!isfinite(x))
139 #else
140 #define IS_INF_OR_NAN(x)        (!finite(x))
141 #endif
142 
143 
144 /**
145  * Convert float to int by rounding to nearest integer, away from zero.
146  */
IROUND(float f)147 static inline int IROUND(float f)
148 {
149    return (int) ((f >= 0.0F) ? (f + 0.5F) : (f - 0.5F));
150 }
151 
152 /**
153  * Convert double to int by rounding to nearest integer, away from zero.
154  */
IROUNDD(double d)155 static inline int IROUNDD(double d)
156 {
157    return (int) ((d >= 0.0) ? (d + 0.5) : (d - 0.5));
158 }
159 
160 /**
161  * Convert float to int64 by rounding to nearest integer.
162  */
IROUND64(float f)163 static inline GLint64 IROUND64(float f)
164 {
165    return (GLint64) ((f >= 0.0F) ? (f + 0.5F) : (f - 0.5F));
166 }
167 
168 
169 /**
170  * Convert positive float to int by rounding to nearest integer.
171  */
IROUND_POS(float f)172 static inline int IROUND_POS(float f)
173 {
174    assert(f >= 0.0F);
175    return (int) (f + 0.5F);
176 }
177 
178 /** Return (as an integer) floor of float */
IFLOOR(float f)179 static inline int IFLOOR(float f)
180 {
181 #if defined(USE_X86_ASM) && defined(__GNUC__) && defined(__i386__)
182    /*
183     * IEEE floor for computers that round to nearest or even.
184     * 'f' must be between -4194304 and 4194303.
185     * This floor operation is done by "(iround(f + .5) + iround(f - .5)) >> 1",
186     * but uses some IEEE specific tricks for better speed.
187     * Contributed by Josh Vanderhoof
188     */
189    int ai, bi;
190    double af, bf;
191    af = (3 << 22) + 0.5 + (double)f;
192    bf = (3 << 22) + 0.5 - (double)f;
193    /* GCC generates an extra fstp/fld without this. */
194    __asm__ ("fstps %0" : "=m" (ai) : "t" (af) : "st");
195    __asm__ ("fstps %0" : "=m" (bi) : "t" (bf) : "st");
196    return (ai - bi) >> 1;
197 #else
198    int ai, bi;
199    double af, bf;
200    fi_type u;
201    af = (3 << 22) + 0.5 + (double)f;
202    bf = (3 << 22) + 0.5 - (double)f;
203    u.f = (float) af;  ai = u.i;
204    u.f = (float) bf;  bi = u.i;
205    return (ai - bi) >> 1;
206 #endif
207 }
208 
209 
210 /**
211  * Is x a power of two?
212  */
213 static inline int
_mesa_is_pow_two(int x)214 _mesa_is_pow_two(int x)
215 {
216    return !(x & (x - 1));
217 }
218 
219 /**
220  * Round given integer to next higer power of two
221  * If X is zero result is undefined.
222  *
223  * Source for the fallback implementation is
224  * Sean Eron Anderson's webpage "Bit Twiddling Hacks"
225  * http://graphics.stanford.edu/~seander/bithacks.html
226  *
227  * When using builtin function have to do some work
228  * for case when passed values 1 to prevent hiting
229  * undefined result from __builtin_clz. Undefined
230  * results would be different depending on optimization
231  * level used for build.
232  */
233 static inline int32_t
_mesa_next_pow_two_32(uint32_t x)234 _mesa_next_pow_two_32(uint32_t x)
235 {
236 #ifdef HAVE___BUILTIN_CLZ
237 	uint32_t y = (x != 1);
238 	return (1 + y) << ((__builtin_clz(x - y) ^ 31) );
239 #else
240 	x--;
241 	x |= x >> 1;
242 	x |= x >> 2;
243 	x |= x >> 4;
244 	x |= x >> 8;
245 	x |= x >> 16;
246 	x++;
247 	return x;
248 #endif
249 }
250 
251 static inline int64_t
_mesa_next_pow_two_64(uint64_t x)252 _mesa_next_pow_two_64(uint64_t x)
253 {
254 #ifdef HAVE___BUILTIN_CLZLL
255 	uint64_t y = (x != 1);
256 	STATIC_ASSERT(sizeof(x) == sizeof(long long));
257 	return (1 + y) << ((__builtin_clzll(x - y) ^ 63));
258 #else
259 	x--;
260 	x |= x >> 1;
261 	x |= x >> 2;
262 	x |= x >> 4;
263 	x |= x >> 8;
264 	x |= x >> 16;
265 	x |= x >> 32;
266 	x++;
267 	return x;
268 #endif
269 }
270 
271 
272 /*
273  * Returns the floor form of binary logarithm for a 32-bit integer.
274  */
275 static inline GLuint
_mesa_logbase2(GLuint n)276 _mesa_logbase2(GLuint n)
277 {
278 #ifdef HAVE___BUILTIN_CLZ
279    return (31 - __builtin_clz(n | 1));
280 #else
281    GLuint pos = 0;
282    if (n >= 1<<16) { n >>= 16; pos += 16; }
283    if (n >= 1<< 8) { n >>=  8; pos +=  8; }
284    if (n >= 1<< 4) { n >>=  4; pos +=  4; }
285    if (n >= 1<< 2) { n >>=  2; pos +=  2; }
286    if (n >= 1<< 1) {           pos +=  1; }
287    return pos;
288 #endif
289 }
290 
291 
292 /**
293  * Return 1 if this is a little endian machine, 0 if big endian.
294  */
295 static inline GLboolean
_mesa_little_endian(void)296 _mesa_little_endian(void)
297 {
298    const GLuint ui = 1; /* intentionally not static */
299    return *((const GLubyte *) &ui);
300 }
301 
302 
303 
304 /**********************************************************************
305  * Functions
306  */
307 
308 extern void *
309 _mesa_align_malloc( size_t bytes, unsigned long alignment );
310 
311 extern void *
312 _mesa_align_calloc( size_t bytes, unsigned long alignment );
313 
314 extern void
315 _mesa_align_free( void *ptr );
316 
317 extern void *
318 _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
319                     unsigned long alignment);
320 
321 #ifdef HAVE___BUILTIN_POPCOUNT
322 #define _mesa_bitcount(i) __builtin_popcount(i)
323 #else
324 extern unsigned int
325 _mesa_bitcount(unsigned int n);
326 #endif
327 
328 #ifdef HAVE___BUILTIN_POPCOUNTLL
329 #define _mesa_bitcount_64(i) __builtin_popcountll(i)
330 #else
331 extern unsigned int
332 _mesa_bitcount_64(uint64_t n);
333 #endif
334 
335 
336 extern int
337 _mesa_snprintf( char *str, size_t size, const char *fmt, ... ) PRINTFLIKE(3, 4);
338 
339 extern int
340 _mesa_vsnprintf(char *str, size_t size, const char *fmt, va_list arg);
341 
342 
343 #if defined(_MSC_VER) && !defined(snprintf)
344 #define snprintf _snprintf
345 #endif
346 
347 #if defined(_WIN32) && !defined(strtok_r)
348 #define strtok_r strtok_s
349 #endif
350 
351 #ifdef __cplusplus
352 }
353 #endif
354 
355 
356 #endif /* IMPORTS_H */
357