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 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 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 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 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 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 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