1 /* $NetBSD: fenv.c,v 1.3 2017/12/30 17:59:24 martin Exp $ */ 2 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: src/lib/msun/alpha/fenv.c,v 1.2 2005/03/16 19:03:44 das Exp $ 29 */ 30 #include <sys/cdefs.h> 31 __RCSID("$NetBSD: fenv.c,v 1.3 2017/12/30 17:59:24 martin Exp $"); 32 33 #include "namespace.h" 34 35 #include <machine/sysarch.h> 36 #include <fenv.h> 37 38 #ifdef __weak_alias 39 __weak_alias(fegetenv,_fegetenv) 40 __weak_alias(feholdexcept,_feholdexcept) 41 __weak_alias(fesetenv,_fesetenv) 42 __weak_alias(feupdateenv,_feupdateenv) 43 __weak_alias(feenableexcept,_feenableexcept) 44 __weak_alias(fedisableexcept,_fedisableexcept) 45 __weak_alias(fegetexcept,_fegetexcept) 46 #endif 47 48 const fenv_t __fe_dfl_env = 0x680e000000000000ULL; 49 50 /* 51 * The lower 49 bits of the FPCR are unused by the hardware, so we use 52 * the lower order bits to store the kernel's idea of the FP mask as 53 * described in the Alpha Architecture Manual. 54 */ 55 int 56 fegetenv(fenv_t *envp) 57 { 58 struct alpha_fp_except_args p; 59 union __fpcr r; 60 61 /* 62 * The syscall acts as an implicit exception barrier, so we 63 * only need to issue an excb after the mf_fpcr to ensure that 64 * the read is executed before any subsequent FP ops. 65 */ 66 p.mask = sysarch(ALPHA_FPGETMASK, 0); 67 __mf_fpcr(&r.__d); 68 *envp = r.__bits | p.mask; 69 __excb(); 70 return 0; 71 } 72 73 int 74 feholdexcept(fenv_t *envp) 75 { 76 struct alpha_fp_except_args p; 77 union __fpcr r; 78 79 p.mask = sysarch(ALPHA_FPGETMASK, 0); 80 __mf_fpcr(&r.__d); 81 *envp = r.__bits | p.mask; 82 r.__bits &= ~((fenv_t)FE_ALL_EXCEPT << _FPUSW_SHIFT); 83 __mt_fpcr(r.__d); 84 if (p.mask & FE_ALL_EXCEPT) { 85 p.mask = 0; 86 sysarch(ALPHA_FPSETMASK, &p); 87 } 88 __excb(); 89 return 0; 90 } 91 92 int 93 fesetenv(const fenv_t *envp) 94 { 95 struct alpha_fp_except_args p; 96 union __fpcr r; 97 98 p.mask = *envp & FE_ALL_EXCEPT; 99 sysarch(ALPHA_FPSETMASK, &p); 100 r.__bits = *envp & ~FE_ALL_EXCEPT; 101 __mt_fpcr(r.__d); 102 __excb(); 103 return 0; 104 } 105 106 int 107 feupdateenv(const fenv_t *envp) 108 { 109 struct alpha_fp_except_args p; 110 union __fpcr oldr, newr; 111 112 p.mask = *envp & FE_ALL_EXCEPT; 113 sysarch(ALPHA_FPSETMASK, &p); 114 __mf_fpcr(&oldr.__d); 115 newr.__bits = *envp & ~FE_ALL_EXCEPT; 116 __excb(); 117 __mt_fpcr(newr.__d); 118 feraiseexcept((oldr.__bits >> _FPUSW_SHIFT) & FE_ALL_EXCEPT); 119 return 0; 120 } 121 122 int 123 feenableexcept(int mask) 124 { 125 struct alpha_fp_except_args p; 126 127 p.mask = sysarch(ALPHA_FPGETMASK, 0); 128 p.mask |= (mask & FE_ALL_EXCEPT); 129 sysarch(ALPHA_FPSETMASK, &p); 130 return p.mask; 131 } 132 133 int 134 fedisableexcept(int mask) 135 { 136 struct alpha_fp_except_args p; 137 138 p.mask = sysarch(ALPHA_FPGETMASK, 0); 139 p.mask &= ~(mask & FE_ALL_EXCEPT); 140 sysarch(ALPHA_FPSETMASK, &p); 141 return p.mask; 142 } 143 144 int 145 fegetexcept(void) 146 { 147 148 return sysarch(ALPHA_FPGETMASK, 0); 149 } 150