1 | /* Copyright (C) 1997-2014 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, see |
16 | <http://www.gnu.org/licenses/>. */ |
17 | |
18 | #ifndef _FENV_H |
19 | # error "Never use <bits/fenv.h> directly; include <fenv.h> instead." |
20 | #endif |
21 | |
22 | /* Define bits representing the exception. We use the bit positions |
23 | of the appropriate bits in the FPU control word. */ |
24 | enum |
25 | { |
26 | FE_INVALID = |
27 | #define FE_INVALID 0x01 |
28 | FE_INVALID, |
29 | __FE_DENORM = 0x02, |
30 | FE_DIVBYZERO = |
31 | #define FE_DIVBYZERO 0x04 |
32 | FE_DIVBYZERO, |
33 | FE_OVERFLOW = |
34 | #define FE_OVERFLOW 0x08 |
35 | FE_OVERFLOW, |
36 | FE_UNDERFLOW = |
37 | #define FE_UNDERFLOW 0x10 |
38 | FE_UNDERFLOW, |
39 | FE_INEXACT = |
40 | #define FE_INEXACT 0x20 |
41 | FE_INEXACT |
42 | }; |
43 | |
44 | #define FE_ALL_EXCEPT \ |
45 | (FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID) |
46 | |
47 | /* The ix87 FPU supports all of the four defined rounding modes. We |
48 | use again the bit positions in the FPU control word as the values |
49 | for the appropriate macros. */ |
50 | enum |
51 | { |
52 | FE_TONEAREST = |
53 | #define FE_TONEAREST 0 |
54 | FE_TONEAREST, |
55 | FE_DOWNWARD = |
56 | #define FE_DOWNWARD 0x400 |
57 | FE_DOWNWARD, |
58 | FE_UPWARD = |
59 | #define FE_UPWARD 0x800 |
60 | FE_UPWARD, |
61 | FE_TOWARDZERO = |
62 | #define FE_TOWARDZERO 0xc00 |
63 | FE_TOWARDZERO |
64 | }; |
65 | |
66 | |
67 | /* Type representing exception flags. */ |
68 | typedef unsigned short int fexcept_t; |
69 | |
70 | |
71 | /* Type representing floating-point environment. This structure |
72 | corresponds to the layout of the block written by the `fstenv' |
73 | instruction and has additional fields for the contents of the MXCSR |
74 | register as written by the `stmxcsr' instruction. */ |
75 | typedef struct |
76 | { |
77 | unsigned short int __control_word; |
78 | unsigned short int __glibc_reserved1; |
79 | unsigned short int __status_word; |
80 | unsigned short int __glibc_reserved2; |
81 | unsigned short int __tags; |
82 | unsigned short int __glibc_reserved3; |
83 | unsigned int __eip; |
84 | unsigned short int __cs_selector; |
85 | unsigned int __opcode:11; |
86 | unsigned int __glibc_reserved4:5; |
87 | unsigned int __data_offset; |
88 | unsigned short int __data_selector; |
89 | unsigned short int __glibc_reserved5; |
90 | #ifdef __x86_64__ |
91 | unsigned int __mxcsr; |
92 | #endif |
93 | } |
94 | fenv_t; |
95 | |
96 | /* If the default argument is used we use this value. */ |
97 | #define FE_DFL_ENV ((const fenv_t *) -1) |
98 | |
99 | #ifdef __USE_GNU |
100 | /* Floating-point environment where none of the exception is masked. */ |
101 | # define FE_NOMASK_ENV ((const fenv_t *) -2) |
102 | #endif |
103 | |
104 | |
105 | #ifdef __USE_EXTERN_INLINES |
106 | __BEGIN_DECLS |
107 | |
108 | /* Optimized versions. */ |
109 | extern int __REDIRECT_NTH (__feraiseexcept_renamed, (int), feraiseexcept); |
110 | __extern_inline int |
111 | __NTH (feraiseexcept (int __excepts)) |
112 | { |
113 | if (__builtin_constant_p (__excepts) |
114 | && (__excepts & ~(FE_INVALID | FE_DIVBYZERO)) == 0) |
115 | { |
116 | if ((FE_INVALID & __excepts) != 0) |
117 | { |
118 | /* One example of an invalid operation is 0.0 / 0.0. */ |
119 | float __f = 0.0; |
120 | |
121 | # ifdef __SSE_MATH__ |
122 | __asm__ __volatile__ ("divss %0, %0 " : : "x" (__f)); |
123 | # else |
124 | __asm__ __volatile__ ("fdiv %%st, %%st(0); fwait" |
125 | : "=t" (__f) : "0" (__f)); |
126 | # endif |
127 | (void) &__f; |
128 | } |
129 | if ((FE_DIVBYZERO & __excepts) != 0) |
130 | { |
131 | float __f = 1.0; |
132 | float __g = 0.0; |
133 | |
134 | # ifdef __SSE_MATH__ |
135 | __asm__ __volatile__ ("divss %1, %0" : : "x" (__f), "x" (__g)); |
136 | # else |
137 | __asm__ __volatile__ ("fdivp %%st, %%st(1); fwait" |
138 | : "=t" (__f) : "0" (__f), "u" (__g) : "st(1)" ); |
139 | # endif |
140 | (void) &__f; |
141 | } |
142 | |
143 | return 0; |
144 | } |
145 | |
146 | return __feraiseexcept_renamed (__excepts); |
147 | } |
148 | |
149 | __END_DECLS |
150 | #endif |
151 | |