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) */
43float pow2_table[POW2_TABLE_SIZE];
44
45
46static void
47init_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) */
56float log2_table[LOG2_TABLE_SIZE];
57
58
59static void
60init_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 */
71void
72util_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 */
87unsigned
88util_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 */
107unsigned
108util_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 */
129void
130util_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