1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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/fpu.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 { 0xffff0000 | __INITIAL_FPUCW__, 44 0xffff0000, 45 0xffffffff, 46 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 47 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff } 48 }, 49 __INITIAL_MXCSR__ 50 }; 51 52 extern inline int feclearexcept(int __excepts); 53 extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts); 54 55 int 56 fesetexceptflag(const fexcept_t *flagp, int excepts) 57 { 58 fenv_t env; 59 60 __fnstenv(&env.__x87); 61 env.__x87.__status &= ~excepts; 62 env.__x87.__status |= *flagp & excepts; 63 __fldenv(env.__x87); 64 65 __stmxcsr(&env.__mxcsr); 66 env.__mxcsr &= ~excepts; 67 env.__mxcsr |= *flagp & excepts; 68 __ldmxcsr(env.__mxcsr); 69 70 return (0); 71 } 72 73 int 74 feraiseexcept(int excepts) 75 { 76 fexcept_t ex = excepts; 77 78 fesetexceptflag(&ex, excepts); 79 __fwait(); 80 return (0); 81 } 82 83 extern inline int fetestexcept(int __excepts); 84 extern inline int fegetround(void); 85 extern inline int fesetround(int __round); 86 87 int 88 fegetenv(fenv_t *envp) 89 { 90 91 __fnstenv(&envp->__x87); 92 __stmxcsr(&envp->__mxcsr); 93 /* 94 * fnstenv masks all exceptions, so we need to restore the 95 * control word to avoid this side effect. 96 */ 97 __fldcw(envp->__x87.__control); 98 return (0); 99 } 100 101 int 102 feholdexcept(fenv_t *envp) 103 { 104 __uint32_t mxcsr; 105 106 __stmxcsr(&mxcsr); 107 __fnstenv(&envp->__x87); 108 __fnclex(); 109 envp->__mxcsr = mxcsr; 110 mxcsr &= ~FE_ALL_EXCEPT; 111 mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT; 112 __ldmxcsr(mxcsr); 113 return (0); 114 } 115 116 extern inline int fesetenv(const fenv_t *__envp); 117 118 int 119 feupdateenv(const fenv_t *envp) 120 { 121 __uint32_t mxcsr; 122 __uint16_t status; 123 124 __fnstsw(&status); 125 __stmxcsr(&mxcsr); 126 fesetenv(envp); 127 feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT); 128 return (0); 129 } 130 131 int 132 __feenableexcept(int mask) 133 { 134 __uint32_t mxcsr, omask; 135 __uint16_t control; 136 137 mask &= FE_ALL_EXCEPT; 138 __fnstcw(&control); 139 __stmxcsr(&mxcsr); 140 omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; 141 control &= ~mask; 142 __fldcw(control); 143 mxcsr &= ~(mask << _SSE_EMASK_SHIFT); 144 __ldmxcsr(mxcsr); 145 return (omask); 146 } 147 148 int 149 __fedisableexcept(int mask) 150 { 151 __uint32_t mxcsr, omask; 152 __uint16_t control; 153 154 mask &= FE_ALL_EXCEPT; 155 __fnstcw(&control); 156 __stmxcsr(&mxcsr); 157 omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; 158 control |= mask; 159 __fldcw(control); 160 mxcsr |= mask << _SSE_EMASK_SHIFT; 161 __ldmxcsr(mxcsr); 162 return (omask); 163 } 164 165 __weak_reference(__feenableexcept, feenableexcept); 166 __weak_reference(__fedisableexcept, fedisableexcept); 167