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
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
/* $OpenBSD: frnd.c,v 1.8 2003/04/10 17:27:58 mickey Exp $ */
/*
(c) Copyright 1986 HEWLETT-PACKARD COMPANY
To anyone who acknowledges that this file is provided "AS IS"
without any express or implied warranty:
permission to use, copy, modify, and distribute this file
for any purpose is hereby granted without fee, provided that
the above copyright notice and this notice appears in all
copies, and that the name of Hewlett-Packard Company not be
used in advertising or publicity pertaining to distribution
of the software without specific, written prior permission.
Hewlett-Packard Company makes no representations about the
suitability of this software for any purpose.
*/
/* @(#)frnd.c: Revision: 2.7.88.1 Date: 93/12/07 15:06:24 */
#include "float.h"
#include "sgl_float.h"
#include "dbl_float.h"
#include "quad_float.h"
#include "cnv_float.h"
/*
* Single Floating-point Round to Integer
*/
/*ARGSUSED*/
int
sgl_frnd(srcptr, null, dstptr, status)
sgl_floating_point *srcptr, *null, *dstptr;
unsigned int *status;
{
register unsigned int src, result;
register int src_exponent;
register int inexact = FALSE;
src = *srcptr;
/*
* check source operand for NaN or infinity
*/
if ((src_exponent = Sgl_exponent(src)) == SGL_INFINITY_EXPONENT) {
/*
* is signaling NaN?
*/
if (Sgl_isone_signaling(src)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Sgl_set_quiet(src);
}
/*
* return quiet NaN or infinity
*/
*dstptr = src;
return(NOEXCEPTION);
}
/*
* Need to round?
*/
if ((src_exponent -= SGL_BIAS) >= SGL_P - 1) {
*dstptr = src;
return(NOEXCEPTION);
}
/*
* Generate result
*/
if (src_exponent >= 0) {
Sgl_clear_exponent_set_hidden(src);
result = src;
Sgl_rightshift(result,(SGL_P-1) - (src_exponent));
/* check for inexact */
if (Sgl_isinexact_to_fix(src,src_exponent)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Sgl_iszero_sign(src)) Sgl_increment(result);
break;
case ROUNDMINUS:
if (Sgl_isone_sign(src)) Sgl_increment(result);
break;
case ROUNDNEAREST:
if (Sgl_isone_roundbit(src,src_exponent))
if (Sgl_isone_stickybit(src,src_exponent)
|| (Sgl_isone_lowmantissa(result)))
Sgl_increment(result);
}
}
Sgl_leftshift(result,(SGL_P-1) - (src_exponent));
if (Sgl_isone_hiddenoverflow(result))
Sgl_set_exponent(result,src_exponent + (SGL_BIAS+1));
else Sgl_set_exponent(result,src_exponent + SGL_BIAS);
}
else {
result = src; /* set sign */
Sgl_setzero_exponentmantissa(result);
/* check for inexact */
if (Sgl_isnotzero_exponentmantissa(src)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Sgl_iszero_sign(src))
Sgl_set_exponent(result,SGL_BIAS);
break;
case ROUNDMINUS:
if (Sgl_isone_sign(src))
Sgl_set_exponent(result,SGL_BIAS);
break;
case ROUNDNEAREST:
if (src_exponent == -1)
if (Sgl_isnotzero_mantissa(src))
Sgl_set_exponent(result,SGL_BIAS);
}
}
}
*dstptr = result;
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
/*
* Double Floating-point Round to Integer
*/
/*ARGSUSED*/
int
dbl_frnd(srcptr, null, dstptr, status)
dbl_floating_point *srcptr, *null, *dstptr;
unsigned int *status;
{
register unsigned int srcp1, srcp2, resultp1, resultp2;
register int src_exponent;
register int inexact = FALSE;
Dbl_copyfromptr(srcptr,srcp1,srcp2);
/*
* check source operand for NaN or infinity
*/
if ((src_exponent = Dbl_exponent(srcp1)) == DBL_INFINITY_EXPONENT) {
/*
* is signaling NaN?
*/
if (Dbl_isone_signaling(srcp1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_set_quiet(srcp1);
}
/*
* return quiet NaN or infinity
*/
Dbl_copytoptr(srcp1,srcp2,dstptr);
return(NOEXCEPTION);
}
/*
* Need to round?
*/
if ((src_exponent -= DBL_BIAS) >= DBL_P - 1) {
Dbl_copytoptr(srcp1,srcp2,dstptr);
return(NOEXCEPTION);
}
/*
* Generate result
*/
if (src_exponent >= 0) {
Dbl_clear_exponent_set_hidden(srcp1);
resultp1 = srcp1;
resultp2 = srcp2;
Dbl_rightshift(resultp1,resultp2,(DBL_P-1) - (src_exponent));
/* check for inexact */
if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(srcp1))
Dbl_increment(resultp1,resultp2);
break;
case ROUNDMINUS:
if (Dbl_isone_sign(srcp1))
Dbl_increment(resultp1,resultp2);
break;
case ROUNDNEAREST:
if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent)
|| (Dbl_isone_lowmantissap2(resultp2)))
Dbl_increment(resultp1,resultp2);
}
}
Dbl_leftshift(resultp1,resultp2,(DBL_P-1) - (src_exponent));
if (Dbl_isone_hiddenoverflow(resultp1))
Dbl_set_exponent(resultp1,src_exponent + (DBL_BIAS+1));
else Dbl_set_exponent(resultp1,src_exponent + DBL_BIAS);
}
else {
resultp1 = srcp1; /* set sign */
Dbl_setzero_exponentmantissa(resultp1,resultp2);
/* check for inexact */
if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
inexact = TRUE;
/* round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(srcp1))
Dbl_set_exponent(resultp1,DBL_BIAS);
break;
case ROUNDMINUS:
if (Dbl_isone_sign(srcp1))
Dbl_set_exponent(resultp1,DBL_BIAS);
break;
case ROUNDNEAREST:
if (src_exponent == -1)
if (Dbl_isnotzero_mantissa(srcp1,srcp2))
Dbl_set_exponent(resultp1,DBL_BIAS);
}
}
}
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
/*ARGSUSED*/
int
quad_frnd(srcptr, null, dstptr, status)
quad_floating_point *srcptr, *null, *dstptr;
unsigned int *status;
{
return(UNIMPLEMENTEDEXCEPTION);
}
|
