1 /*- 2 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/cdefs.h> 30 #include <sys/types.h> 31 #include <machine/fpu.h> 32 #include <fenv.h> 33 34 const fenv_t __fe_dfl_env = { 35 { 0xffff0000 | __INITIAL_FPUCW__, 36 0xffff0000, 37 0xffffffff, 38 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 39 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff } 40 }, 41 __INITIAL_MXCSR__ 42 }; 43 44 int 45 fesetexceptflag(const fexcept_t *flagp, int excepts) 46 { 47 fenv_t env; 48 49 __fnstenv(&env.__x87); 50 env.__x87.__status &= ~excepts; 51 env.__x87.__status |= *flagp & excepts; 52 __fldenv(env.__x87); 53 54 __stmxcsr(&env.__mxcsr); 55 env.__mxcsr &= ~excepts; 56 env.__mxcsr |= *flagp & excepts; 57 __ldmxcsr(env.__mxcsr); 58 59 return (0); 60 } 61 62 int 63 feraiseexcept(int excepts) 64 { 65 fexcept_t ex = excepts; 66 67 fesetexceptflag(&ex, excepts); 68 __fwait(); 69 return (0); 70 } 71 72 int 73 fegetenv(fenv_t *envp) 74 { 75 76 __fnstenv(&envp->__x87); 77 __stmxcsr(&envp->__mxcsr); 78 /* 79 * fnstenv masks all exceptions, so we need to restore the 80 * control word to avoid this side effect. 81 */ 82 __fldcw(envp->__x87.__control); 83 return (0); 84 } 85 86 int 87 feholdexcept(fenv_t *envp) 88 { 89 int mxcsr; 90 91 __stmxcsr(&mxcsr); 92 __fnstenv(&envp->__x87); 93 __fnclex(); 94 envp->__mxcsr = mxcsr; 95 mxcsr &= ~FE_ALL_EXCEPT; 96 mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT; 97 __ldmxcsr(mxcsr); 98 return (0); 99 } 100 101 int 102 feupdateenv(const fenv_t *envp) 103 { 104 int mxcsr, status; 105 106 __fnstsw(&status); 107 __stmxcsr(&mxcsr); 108 fesetenv(envp); 109 feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT); 110 return (0); 111 } 112 113 int 114 __feenableexcept(int mask) 115 { 116 int mxcsr, control, omask; 117 118 mask &= FE_ALL_EXCEPT; 119 __fnstcw(&control); 120 __stmxcsr(&mxcsr); 121 omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; 122 control &= ~mask; 123 __fldcw(control); 124 mxcsr &= ~(mask << _SSE_EMASK_SHIFT); 125 __ldmxcsr(mxcsr); 126 return (~omask); 127 } 128 129 int 130 __fedisableexcept(int mask) 131 { 132 int mxcsr, control, omask; 133 134 mask &= FE_ALL_EXCEPT; 135 __fnstcw(&control); 136 __stmxcsr(&mxcsr); 137 omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; 138 control |= mask; 139 __fldcw(control); 140 mxcsr |= mask << _SSE_EMASK_SHIFT; 141 __ldmxcsr(mxcsr); 142 return (~omask); 143 } 144 145 __weak_reference(__feenableexcept, feenableexcept); 146 __weak_reference(__fedisableexcept, fedisableexcept); 147