1 /* Copyright (C) 1997, 1998, 1999, 2000, 2011 Free Software Foundation, Inc. 2 This file is part of the GNU C Library. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Lesser General Public 6 License as published by the Free Software Foundation; either 7 version 2.1 of the License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with the GNU C Library; if not, write to the Free 16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 17 02111-1307 USA. */ 18 19 #ifndef _FENV_H 20 # error "Never use <bits/fenv.h> directly; include <fenv.h> instead." 21 #endif 22 23 24 /* Define bits representing the exception. We use the bit positions 25 of the appropriate bits in the FPU control word. */ 26 enum 27 { 28 FE_INVALID = 0x01, 29 #define FE_INVALID FE_INVALID 30 __FE_DENORM = 0x02, 31 FE_DIVBYZERO = 0x04, 32 #define FE_DIVBYZERO FE_DIVBYZERO 33 FE_OVERFLOW = 0x08, 34 #define FE_OVERFLOW FE_OVERFLOW 35 FE_UNDERFLOW = 0x10, 36 #define FE_UNDERFLOW FE_UNDERFLOW 37 FE_INEXACT = 0x20 38 #define FE_INEXACT FE_INEXACT 39 }; 40 41 #define FE_ALL_EXCEPT \ 42 (FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID) 43 44 /* The ix87 FPU supports all of the four defined rounding modes. We 45 use again the bit positions in the FPU control word as the values 46 for the appropriate macros. */ 47 enum 48 { 49 FE_TONEAREST = 0, 50 #define FE_TONEAREST FE_TONEAREST 51 FE_DOWNWARD = 0x400, 52 #define FE_DOWNWARD FE_DOWNWARD 53 FE_UPWARD = 0x800, 54 #define FE_UPWARD FE_UPWARD 55 FE_TOWARDZERO = 0xc00 56 #define FE_TOWARDZERO FE_TOWARDZERO 57 }; 58 59 60 /* Type representing exception flags. */ 61 typedef unsigned short int fexcept_t; 62 63 64 /* Type representing floating-point environment. This function corresponds 65 to the layout of the block written by the `fstenv'. */ 66 typedef struct 67 { 68 unsigned short int __control_word; 69 unsigned short int __unused1; 70 unsigned short int __status_word; 71 unsigned short int __unused2; 72 unsigned short int __tags; 73 unsigned short int __unused3; 74 unsigned int __eip; 75 unsigned short int __cs_selector; 76 unsigned int __opcode:11; 77 unsigned int __unused4:5; 78 unsigned int __data_offset; 79 unsigned short int __data_selector; 80 unsigned short int __unused5; 81 } 82 fenv_t; 83 84 /* If the default argument is used we use this value. */ 85 #define FE_DFL_ENV ((__const fenv_t *) -1) 86 87 #ifdef __USE_GNU 88 /* Floating-point environment where none of the exception is masked. */ 89 # define FE_NOMASK_ENV ((__const fenv_t *) -2) 90 #endif 91 92 93 #ifdef __USE_EXTERN_INLINES 94 __BEGIN_DECLS 95 96 /* Optimized versions. */ 97 extern int __REDIRECT_NTH (__feraiseexcept_renamed, (int), feraiseexcept); 98 __extern_inline int 99 __NTH (feraiseexcept (int __excepts)) 100 { 101 if (__builtin_constant_p (__excepts) 102 && (__excepts & ~(FE_INVALID | FE_DIVBYZERO)) == 0) 103 { 104 if ((FE_INVALID & __excepts) != 0) 105 { 106 /* One example of a invalid operation is 0.0 / 0.0. */ 107 float __f = 0.0; 108 109 # ifdef __SSE_MATH__ 110 __asm__ __volatile__ ("divss %0, %0 " : : "x" (__f)); 111 # else 112 __asm__ __volatile__ ("fdiv %%st, %%st(0); fwait" 113 : "=t" (__f) : "0" (__f)); 114 # endif 115 (void) &__f; 116 } 117 if ((FE_DIVBYZERO & __excepts) != 0) 118 { 119 float __f = 1.0; 120 float __g = 0.0; 121 122 # ifdef __SSE_MATH__ 123 __asm__ __volatile__ ("divss %1, %0" : : "x" (__f), "x" (__g)); 124 # else 125 __asm__ __volatile__ ("fdivp %%st(1), %%st; fwait" 126 : "=t" (__f) : "0" (__f), "u" (__g) : "st(1)"); 127 # endif 128 (void) &__f; 129 } 130 131 return 0; 132 } 133 134 return __feraiseexcept_renamed (__excepts); 135 } 136 137 __END_DECLS 138 #endif 139
