1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/cdefs.h> 32 #include <sys/types.h> 33 #include <machine/npx.h> 34 35 #define __fenv_static 36 #include "fenv.h" 37 38 #ifdef __GNUC_GNU_INLINE__ 39 #error "This file must be compiled with C99 'inline' semantics" 40 #endif 41 42 const fenv_t __fe_dfl_env = { 43 __INITIAL_NPXCW__, 44 0x0000, 45 0x0000, 46 0x1f80, 47 0xffffffff, 48 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 49 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff } 50 }; 51 52 enum __sse_support __has_sse = 53 #ifdef __SSE__ 54 __SSE_YES; 55 #else 56 __SSE_UNK; 57 #endif 58 59 #define getfl(x) __asm __volatile("pushfl\n\tpopl %0" : "=mr" (*(x))) 60 #define setfl(x) __asm __volatile("pushl %0\n\tpopfl" : : "g" (x)) 61 #define cpuid_dx(x) __asm __volatile("pushl %%ebx\n\tmovl $1, %%eax\n\t" \ 62 "cpuid\n\tpopl %%ebx" \ 63 : "=d" (*(x)) : : "eax", "ecx") 64 65 /* 66 * Test for SSE support on this processor. We need to do this because 67 * we need to use ldmxcsr/stmxcsr to get correct results if any part 68 * of the program was compiled to use SSE floating-point, but we can't 69 * use SSE on older processors. 70 */ 71 int 72 __test_sse(void) 73 { 74 int flag, nflag; 75 int dx_features; 76 77 /* Am I a 486? */ 78 getfl(&flag); 79 nflag = flag ^ 0x200000; 80 setfl(nflag); 81 getfl(&nflag); 82 if (flag != nflag) { 83 /* Not a 486, so CPUID should work. */ 84 cpuid_dx(&dx_features); 85 if (dx_features & 0x2000000) { 86 __has_sse = __SSE_YES; 87 return (1); 88 } 89 } 90 __has_sse = __SSE_NO; 91 return (0); 92 } 93 94 extern inline int feclearexcept(int __excepts); 95 extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts); 96 97 int 98 fesetexceptflag(const fexcept_t *flagp, int excepts) 99 { 100 fenv_t env; 101 __uint32_t mxcsr; 102 103 __fnstenv(&env); 104 env.__status &= ~excepts; 105 env.__status |= *flagp & excepts; 106 __fldenv(&env); 107 108 if (__HAS_SSE()) { 109 __stmxcsr(&mxcsr); 110 mxcsr &= ~excepts; 111 mxcsr |= *flagp & excepts; 112 __ldmxcsr(&mxcsr); 113 } 114 115 return (0); 116 } 117 118 int 119 feraiseexcept(int excepts) 120 { 121 fexcept_t ex = excepts; 122 123 fesetexceptflag(&ex, excepts); 124 __fwait(); 125 return (0); 126 } 127 128 extern inline int fetestexcept(int __excepts); 129 extern inline int fegetround(void); 130 extern inline int fesetround(int __round); 131 132 int 133 fegetenv(fenv_t *envp) 134 { 135 __uint32_t mxcsr; 136 137 __fnstenv(envp); 138 /* 139 * fnstenv masks all exceptions, so we need to restore 140 * the old control word to avoid this side effect. 141 */ 142 __fldcw(&envp->__control); 143 if (__HAS_SSE()) { 144 __stmxcsr(&mxcsr); 145 __set_mxcsr(*envp, mxcsr); 146 } 147 return (0); 148 } 149 150 int 151 feholdexcept(fenv_t *envp) 152 { 153 __uint32_t mxcsr; 154 155 __fnstenv(envp); 156 __fnclex(); 157 if (__HAS_SSE()) { 158 __stmxcsr(&mxcsr); 159 __set_mxcsr(*envp, mxcsr); 160 mxcsr &= ~FE_ALL_EXCEPT; 161 mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT; 162 __ldmxcsr(&mxcsr); 163 } 164 return (0); 165 } 166 167 extern inline int fesetenv(const fenv_t *__envp); 168 169 int 170 feupdateenv(const fenv_t *envp) 171 { 172 __uint32_t mxcsr; 173 __uint16_t status; 174 175 __fnstsw(&status); 176 if (__HAS_SSE()) 177 __stmxcsr(&mxcsr); 178 else 179 mxcsr = 0; 180 fesetenv(envp); 181 feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT); 182 return (0); 183 } 184 185 int 186 __feenableexcept(int mask) 187 { 188 __uint32_t mxcsr, omask; 189 __uint16_t control; 190 191 mask &= FE_ALL_EXCEPT; 192 __fnstcw(&control); 193 if (__HAS_SSE()) 194 __stmxcsr(&mxcsr); 195 else 196 mxcsr = 0; 197 omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; 198 control &= ~mask; 199 __fldcw(&control); 200 if (__HAS_SSE()) { 201 mxcsr &= ~(mask << _SSE_EMASK_SHIFT); 202 __ldmxcsr(&mxcsr); 203 } 204 return (omask); 205 } 206 207 int 208 __fedisableexcept(int mask) 209 { 210 __uint32_t mxcsr, omask; 211 __uint16_t control; 212 213 mask &= FE_ALL_EXCEPT; 214 __fnstcw(&control); 215 if (__HAS_SSE()) 216 __stmxcsr(&mxcsr); 217 else 218 mxcsr = 0; 219 omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; 220 control |= mask; 221 __fldcw(&control); 222 if (__HAS_SSE()) { 223 mxcsr |= mask << _SSE_EMASK_SHIFT; 224 __ldmxcsr(&mxcsr); 225 } 226 return (omask); 227 } 228 229 __weak_reference(__feenableexcept, feenableexcept); 230 __weak_reference(__fedisableexcept, fedisableexcept); 231