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ieee754.c
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1 /* ieee754 floating point arithmetic
2  * single and double precision
3  *
4  * BUGS
5  * not much dp done
6  * doesn't generate IEEE754_INEXACT
7  *
8  */
9 /*
10  * MIPS floating point support
11  * Copyright (C) 1994-2000 Algorithmics Ltd.
12  *
13  * ########################################################################
14  *
15  * This program is free software; you can distribute it and/or modify it
16  * under the terms of the GNU General Public License (Version 2) as
17  * published by the Free Software Foundation.
18  *
19  * This program is distributed in the hope it will be useful, but WITHOUT
20  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
21  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22  * for more details.
23  *
24  * You should have received a copy of the GNU General Public License along
25  * with this program; if not, write to the Free Software Foundation, Inc.,
26  * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
27  *
28  * ########################################################################
29  */
30 
31 
32 #include "ieee754int.h"
33 #include "ieee754sp.h"
34 #include "ieee754dp.h"
35 
36 #define DP_EBIAS 1023
37 #define DP_EMIN (-1022)
38 #define DP_EMAX 1023
39 
40 #define SP_EBIAS 127
41 #define SP_EMIN (-126)
42 #define SP_EMAX 127
43 
44 /* special constants
45 */
46 
47 
48 #if (defined(BYTE_ORDER) && BYTE_ORDER == LITTLE_ENDIAN) || defined(__MIPSEL__)
49 #define SPSTR(s, b, m) {m, b, s}
50 #define DPSTR(s, b, mh, ml) {ml, mh, b, s}
51 #endif
52 
53 #ifdef __MIPSEB__
54 #define SPSTR(s, b, m) {s, b, m}
55 #define DPSTR(s, b, mh, ml) {s, b, mh, ml}
56 #endif
57 
58 const struct ieee754dp_konst __ieee754dp_spcvals[] = {
59  DPSTR(0, DP_EMIN - 1 + DP_EBIAS, 0, 0), /* + zero */
60  DPSTR(1, DP_EMIN - 1 + DP_EBIAS, 0, 0), /* - zero */
61  DPSTR(0, DP_EBIAS, 0, 0), /* + 1.0 */
62  DPSTR(1, DP_EBIAS, 0, 0), /* - 1.0 */
63  DPSTR(0, 3 + DP_EBIAS, 0x40000, 0), /* + 10.0 */
64  DPSTR(1, 3 + DP_EBIAS, 0x40000, 0), /* - 10.0 */
65  DPSTR(0, DP_EMAX + 1 + DP_EBIAS, 0, 0), /* + infinity */
66  DPSTR(1, DP_EMAX + 1 + DP_EBIAS, 0, 0), /* - infinity */
67  DPSTR(0, DP_EMAX+1+DP_EBIAS, 0x7FFFF, 0xFFFFFFFF), /* + indef quiet Nan */
68  DPSTR(0, DP_EMAX + DP_EBIAS, 0xFFFFF, 0xFFFFFFFF), /* + max */
69  DPSTR(1, DP_EMAX + DP_EBIAS, 0xFFFFF, 0xFFFFFFFF), /* - max */
70  DPSTR(0, DP_EMIN + DP_EBIAS, 0, 0), /* + min normal */
71  DPSTR(1, DP_EMIN + DP_EBIAS, 0, 0), /* - min normal */
72  DPSTR(0, DP_EMIN - 1 + DP_EBIAS, 0, 1), /* + min denormal */
73  DPSTR(1, DP_EMIN - 1 + DP_EBIAS, 0, 1), /* - min denormal */
74  DPSTR(0, 31 + DP_EBIAS, 0, 0), /* + 1.0e31 */
75  DPSTR(0, 63 + DP_EBIAS, 0, 0), /* + 1.0e63 */
76 };
77 
78 const struct ieee754sp_konst __ieee754sp_spcvals[] = {
79  SPSTR(0, SP_EMIN - 1 + SP_EBIAS, 0), /* + zero */
80  SPSTR(1, SP_EMIN - 1 + SP_EBIAS, 0), /* - zero */
81  SPSTR(0, SP_EBIAS, 0), /* + 1.0 */
82  SPSTR(1, SP_EBIAS, 0), /* - 1.0 */
83  SPSTR(0, 3 + SP_EBIAS, 0x200000), /* + 10.0 */
84  SPSTR(1, 3 + SP_EBIAS, 0x200000), /* - 10.0 */
85  SPSTR(0, SP_EMAX + 1 + SP_EBIAS, 0), /* + infinity */
86  SPSTR(1, SP_EMAX + 1 + SP_EBIAS, 0), /* - infinity */
87  SPSTR(0, SP_EMAX+1+SP_EBIAS, 0x3FFFFF), /* + indef quiet Nan */
88  SPSTR(0, SP_EMAX + SP_EBIAS, 0x7FFFFF), /* + max normal */
89  SPSTR(1, SP_EMAX + SP_EBIAS, 0x7FFFFF), /* - max normal */
90  SPSTR(0, SP_EMIN + SP_EBIAS, 0), /* + min normal */
91  SPSTR(1, SP_EMIN + SP_EBIAS, 0), /* - min normal */
92  SPSTR(0, SP_EMIN - 1 + SP_EBIAS, 1), /* + min denormal */
93  SPSTR(1, SP_EMIN - 1 + SP_EBIAS, 1), /* - min denormal */
94  SPSTR(0, 31 + SP_EBIAS, 0), /* + 1.0e31 */
95  SPSTR(0, 63 + SP_EBIAS, 0), /* + 1.0e63 */
96 };
97 
98 
99 int ieee754si_xcpt(int r, const char *op, ...)
100 {
101  struct ieee754xctx ax;
102 
103  if (!TSTX())
104  return r;
105  ax.op = op;
106  ax.rt = IEEE754_RT_SI;
107  ax.rv.si = r;
108  va_start(ax.ap, op);
109  ieee754_xcpt(&ax);
110  va_end(ax.ap);
111  return ax.rv.si;
112 }
113 
114 s64 ieee754di_xcpt(s64 r, const char *op, ...)
115 {
116  struct ieee754xctx ax;
117 
118  if (!TSTX())
119  return r;
120  ax.op = op;
121  ax.rt = IEEE754_RT_DI;
122  ax.rv.di = r;
123  va_start(ax.ap, op);
124  ieee754_xcpt(&ax);
125  va_end(ax.ap);
126  return ax.rv.di;
127 }
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