forked from gcc-mirror/gcc
-
Notifications
You must be signed in to change notification settings - Fork 0
/
decContext.c
219 lines (208 loc) · 9.26 KB
/
decContext.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
/* Decimal context module for the decNumber C Library.
Copyright (C) 2005 Free Software Foundation, Inc.
Contributed by IBM Corporation. Author Mike Cowlishaw.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
/* This module compirises the routines for handling the arithmetic
context structures. */
#include <string.h> /* for strcmp */
#include "config.h"
#include "decContext.h" /* context and base types */
#include "decNumberLocal.h" /* decNumber local types, etc. */
/* ------------------------------------------------------------------ */
/* decContextDefault -- initialize a context structure */
/* */
/* context is the structure to be initialized */
/* kind selects the required set of default values, one of: */
/* DEC_INIT_BASE -- select ANSI X3-274 defaults */
/* DEC_INIT_DECIMAL32 -- select IEEE 754r defaults, 32-bit */
/* DEC_INIT_DECIMAL64 -- select IEEE 754r defaults, 64-bit */
/* DEC_INIT_DECIMAL128 -- select IEEE 754r defaults, 128-bit */
/* For any other value a valid context is returned, but with */
/* Invalid_operation set in the status field. */
/* returns a context structure with the appropriate initial values. */
/* ------------------------------------------------------------------ */
decContext *
decContextDefault (decContext * context, Int kind)
{
/* set defaults... */
context->digits = 9; /* 9 digits */
context->emax = DEC_MAX_EMAX; /* 9-digit exponents */
context->emin = DEC_MIN_EMIN; /* .. balanced */
context->round = DEC_ROUND_HALF_UP; /* 0.5 rises */
context->traps = DEC_Errors; /* all but informational */
context->status = 0; /* cleared */
context->clamp = 0; /* no clamping */
#if DECSUBSET
context->extended = 0; /* cleared */
#endif
switch (kind)
{
case DEC_INIT_BASE:
/* [use defaults] */
break;
case DEC_INIT_DECIMAL32:
context->digits = 7; /* digits */
context->emax = 96; /* Emax */
context->emin = -95; /* Emin */
context->round = DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
context->traps = 0; /* no traps set */
context->clamp = 1; /* clamp exponents */
#if DECSUBSET
context->extended = 1; /* set */
#endif
break;
case DEC_INIT_DECIMAL64:
context->digits = 16; /* digits */
context->emax = 384; /* Emax */
context->emin = -383; /* Emin */
context->round = DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
context->traps = 0; /* no traps set */
context->clamp = 1; /* clamp exponents */
#if DECSUBSET
context->extended = 1; /* set */
#endif
break;
case DEC_INIT_DECIMAL128:
context->digits = 34; /* digits */
context->emax = 6144; /* Emax */
context->emin = -6143; /* Emin */
context->round = DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
context->traps = 0; /* no traps set */
context->clamp = 1; /* clamp exponents */
#if DECSUBSET
context->extended = 1; /* set */
#endif
break;
default: /* invalid Kind */
/* use defaults, and .. */
decContextSetStatus (context, DEC_Invalid_operation); /* trap */
}
return context;
} /* decContextDefault */
/* ------------------------------------------------------------------ */
/* decContextStatusToString -- convert status flags to a string */
/* */
/* context is a context with valid status field */
/* */
/* returns a constant string describing the condition. If multiple */
/* (or no) flags are set, a generic constant message is returned. */
/* ------------------------------------------------------------------ */
const char *
decContextStatusToString (const decContext * context)
{
Int status = context->status;
if (status == DEC_Conversion_syntax)
return DEC_Condition_CS;
if (status == DEC_Division_by_zero)
return DEC_Condition_DZ;
if (status == DEC_Division_impossible)
return DEC_Condition_DI;
if (status == DEC_Division_undefined)
return DEC_Condition_DU;
if (status == DEC_Inexact)
return DEC_Condition_IE;
if (status == DEC_Insufficient_storage)
return DEC_Condition_IS;
if (status == DEC_Invalid_context)
return DEC_Condition_IC;
if (status == DEC_Invalid_operation)
return DEC_Condition_IO;
#if DECSUBSET
if (status == DEC_Lost_digits)
return DEC_Condition_LD;
#endif
if (status == DEC_Overflow)
return DEC_Condition_OV;
if (status == DEC_Clamped)
return DEC_Condition_PA;
if (status == DEC_Rounded)
return DEC_Condition_RO;
if (status == DEC_Subnormal)
return DEC_Condition_SU;
if (status == DEC_Underflow)
return DEC_Condition_UN;
if (status == 0)
return DEC_Condition_ZE;
return DEC_Condition_MU; /* Multiple errors */
} /* decContextStatusToString */
/* ------------------------------------------------------------------ */
/* decContextSetStatusFromString -- set status from a string */
/* */
/* context is the controlling context */
/* string is a string exactly equal to one that might be returned */
/* by decContextStatusToString */
/* */
/* The status bit corresponding to the string is set, and a trap */
/* is raised if appropriate. */
/* */
/* returns the context structure, unless the string is equal to */
/* DEC_Condition_MU or is not recognized. In these cases NULL is */
/* returned. */
/* ------------------------------------------------------------------ */
decContext *
decContextSetStatusFromString (decContext * context, const char *string)
{
if (strcmp (string, DEC_Condition_CS) == 0)
return decContextSetStatus (context, DEC_Conversion_syntax);
if (strcmp (string, DEC_Condition_DZ) == 0)
return decContextSetStatus (context, DEC_Division_by_zero);
if (strcmp (string, DEC_Condition_DI) == 0)
return decContextSetStatus (context, DEC_Division_impossible);
if (strcmp (string, DEC_Condition_DU) == 0)
return decContextSetStatus (context, DEC_Division_undefined);
if (strcmp (string, DEC_Condition_IE) == 0)
return decContextSetStatus (context, DEC_Inexact);
if (strcmp (string, DEC_Condition_IS) == 0)
return decContextSetStatus (context, DEC_Insufficient_storage);
if (strcmp (string, DEC_Condition_IC) == 0)
return decContextSetStatus (context, DEC_Invalid_context);
if (strcmp (string, DEC_Condition_IO) == 0)
return decContextSetStatus (context, DEC_Invalid_operation);
#if DECSUBSET
if (strcmp (string, DEC_Condition_LD) == 0)
return decContextSetStatus (context, DEC_Lost_digits);
#endif
if (strcmp (string, DEC_Condition_OV) == 0)
return decContextSetStatus (context, DEC_Overflow);
if (strcmp (string, DEC_Condition_PA) == 0)
return decContextSetStatus (context, DEC_Clamped);
if (strcmp (string, DEC_Condition_RO) == 0)
return decContextSetStatus (context, DEC_Rounded);
if (strcmp (string, DEC_Condition_SU) == 0)
return decContextSetStatus (context, DEC_Subnormal);
if (strcmp (string, DEC_Condition_UN) == 0)
return decContextSetStatus (context, DEC_Underflow);
if (strcmp (string, DEC_Condition_ZE) == 0)
return context;
return NULL; /* Multiple status, or unknown */
} /* decContextSetStatusFromString */
/* ------------------------------------------------------------------ */
/* decContextSetStatus -- set status and raise trap if appropriate */
/* */
/* context is the controlling context */
/* status is the DEC_ exception code */
/* returns the context structure */
/* */
/* Control may never return from this routine, if there is a signal */
/* handler and it takes a long jump. */
/* ------------------------------------------------------------------ */
decContext *
decContextSetStatus (decContext * context, uInt status)
{
context->status |= status;
if (status & context->traps)
raise (SIGFPE);
return context;
} /* decContextSetStatus */