1 /**************************************************************************
2 *
3 * Copyright 2008 VMware, Inc.
4 * 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
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28
29
30 #include "pipe/p_config.h"
31 #include "util/u_math.h"
32 #include "util/u_cpu_detect.h"
33
34 #if defined(PIPE_ARCH_SSE)
35 #include <xmmintrin.h>
36 /* This is defined in pmmintrin.h, but it can only be included when -msse3 is
37 * used, so just define it here to avoid further. */
38 #define _MM_DENORMALS_ZERO_MASK 0x0040
39 #endif
40
41
42 /** 2^x, for x in [-1.0, 1.0) */
43 float pow2_table[POW2_TABLE_SIZE];
44
45
46 static void
init_pow2_table(void)47 init_pow2_table(void)
48 {
49 int i;
50 for (i = 0; i < POW2_TABLE_SIZE; i++)
51 pow2_table[i] = exp2f((i - POW2_TABLE_OFFSET) / POW2_TABLE_SCALE);
52 }
53
54
55 /** log2(x), for x in [1.0, 2.0) */
56 float log2_table[LOG2_TABLE_SIZE];
57
58
59 static void
init_log2_table(void)60 init_log2_table(void)
61 {
62 unsigned i;
63 for (i = 0; i < LOG2_TABLE_SIZE; i++)
64 log2_table[i] = (float) log2(1.0 + i * (1.0 / LOG2_TABLE_SCALE));
65 }
66
67
68 /**
69 * One time init for math utilities.
70 */
71 void
util_init_math(void)72 util_init_math(void)
73 {
74 static boolean initialized = FALSE;
75 if (!initialized) {
76 init_pow2_table();
77 init_log2_table();
78 initialized = TRUE;
79 }
80 }
81
82 /**
83 * Fetches the contents of the fpstate (mxcsr on x86) register.
84 *
85 * On platforms without support for it just returns 0.
86 */
87 unsigned
util_fpstate_get(void)88 util_fpstate_get(void)
89 {
90 unsigned mxcsr = 0;
91
92 #if defined(PIPE_ARCH_SSE)
93 if (util_cpu_caps.has_sse) {
94 mxcsr = _mm_getcsr();
95 }
96 #endif
97
98 return mxcsr;
99 }
100
101 /**
102 * Make sure that the fp treats the denormalized floating
103 * point numbers as zero.
104 *
105 * This is the behavior required by D3D10. OpenGL doesn't care.
106 */
107 unsigned
util_fpstate_set_denorms_to_zero(unsigned current_mxcsr)108 util_fpstate_set_denorms_to_zero(unsigned current_mxcsr)
109 {
110 #if defined(PIPE_ARCH_SSE)
111 if (util_cpu_caps.has_sse) {
112 /* Enable flush to zero mode */
113 current_mxcsr |= _MM_FLUSH_ZERO_MASK;
114 if (util_cpu_caps.has_daz) {
115 /* Enable denormals are zero mode */
116 current_mxcsr |= _MM_DENORMALS_ZERO_MASK;
117 }
118 util_fpstate_set(current_mxcsr);
119 }
120 #endif
121 return current_mxcsr;
122 }
123
124 /**
125 * Set the state of the fpstate (mxcsr on x86) register.
126 *
127 * On platforms without support for it's a noop.
128 */
129 void
util_fpstate_set(unsigned mxcsr)130 util_fpstate_set(unsigned mxcsr)
131 {
132 #if defined(PIPE_ARCH_SSE)
133 if (util_cpu_caps.has_sse) {
134 _mm_setcsr(mxcsr);
135 }
136 #endif
137 }
138