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1// SPDX-License-Identifier: GPL-2.0-only
2/* IEEE754 floating point arithmetic
3 * single precision
4 */
5/*
6 * MIPS floating point support
7 * Copyright (C) 1994-2000 Algorithmics Ltd.
8 */
9
10#include "ieee754sp.h"
11
12s64 ieee754sp_tlong(union ieee754sp x)
13{
14 u32 residue;
15 int round;
16 int sticky;
17 int odd;
18
19 COMPXDP; /* <-- need 64-bit mantissa tmp */
20
21 ieee754_clearcx();
22
23 EXPLODEXSP;
24 FLUSHXSP;
25
26 switch (xc) {
27 case IEEE754_CLASS_SNAN:
28 case IEEE754_CLASS_QNAN:
29 ieee754_setcx(IEEE754_INVALID_OPERATION);
30 return ieee754di_indef();
31
32 case IEEE754_CLASS_INF:
33 ieee754_setcx(IEEE754_INVALID_OPERATION);
34 return ieee754di_overflow(xs);
35
36 case IEEE754_CLASS_ZERO:
37 return 0;
38
39 case IEEE754_CLASS_DNORM:
40 case IEEE754_CLASS_NORM:
41 break;
42 }
43 if (xe >= 63) {
44 /* look for valid corner case */
45 if (xe == 63 && xs && xm == SP_HIDDEN_BIT)
46 return -0x8000000000000000LL;
47 /* Set invalid. We will only use overflow for floating
48 point overflow */
49 ieee754_setcx(IEEE754_INVALID_OPERATION);
50 return ieee754di_overflow(xs);
51 }
52 /* oh gawd */
53 if (xe > SP_FBITS) {
54 xm <<= xe - SP_FBITS;
55 } else if (xe < SP_FBITS) {
56 if (xe < -1) {
57 residue = xm;
58 round = 0;
59 sticky = residue != 0;
60 xm = 0;
61 } else {
62 residue = xm << (32 - SP_FBITS + xe);
63 round = (residue >> 31) != 0;
64 sticky = (residue << 1) != 0;
65 xm >>= SP_FBITS - xe;
66 }
67 odd = (xm & 0x1) != 0x0;
68 switch (ieee754_csr.rm) {
69 case FPU_CSR_RN:
70 if (round && (sticky || odd))
71 xm++;
72 break;
73 case FPU_CSR_RZ:
74 break;
75 case FPU_CSR_RU: /* toward +Infinity */
76 if ((round || sticky) && !xs)
77 xm++;
78 break;
79 case FPU_CSR_RD: /* toward -Infinity */
80 if ((round || sticky) && xs)
81 xm++;
82 break;
83 }
84 if ((xm >> 63) != 0) {
85 /* This can happen after rounding */
86 ieee754_setcx(IEEE754_INVALID_OPERATION);
87 return ieee754di_overflow(xs);
88 }
89 if (round || sticky)
90 ieee754_setcx(IEEE754_INEXACT);
91 }
92 if (xs)
93 return -xm;
94 else
95 return xm;
96}
1/* IEEE754 floating point arithmetic
2 * single precision
3 */
4/*
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
7 *
8 * This program is free software; you can distribute it and/or modify it
9 * under the terms of the GNU General Public License (Version 2) as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 */
21
22#include "ieee754sp.h"
23#include "ieee754dp.h"
24
25s64 ieee754sp_tlong(union ieee754sp x)
26{
27 u32 residue;
28 int round;
29 int sticky;
30 int odd;
31
32 COMPXDP; /* <-- need 64-bit mantissa tmp */
33
34 ieee754_clearcx();
35
36 EXPLODEXSP;
37 FLUSHXSP;
38
39 switch (xc) {
40 case IEEE754_CLASS_SNAN:
41 case IEEE754_CLASS_QNAN:
42 ieee754_setcx(IEEE754_INVALID_OPERATION);
43 return ieee754di_indef();
44
45 case IEEE754_CLASS_INF:
46 ieee754_setcx(IEEE754_INVALID_OPERATION);
47 return ieee754di_overflow(xs);
48
49 case IEEE754_CLASS_ZERO:
50 return 0;
51
52 case IEEE754_CLASS_DNORM:
53 case IEEE754_CLASS_NORM:
54 break;
55 }
56 if (xe >= 63) {
57 /* look for valid corner case */
58 if (xe == 63 && xs && xm == SP_HIDDEN_BIT)
59 return -0x8000000000000000LL;
60 /* Set invalid. We will only use overflow for floating
61 point overflow */
62 ieee754_setcx(IEEE754_INVALID_OPERATION);
63 return ieee754di_overflow(xs);
64 }
65 /* oh gawd */
66 if (xe > SP_FBITS) {
67 xm <<= xe - SP_FBITS;
68 } else if (xe < SP_FBITS) {
69 if (xe < -1) {
70 residue = xm;
71 round = 0;
72 sticky = residue != 0;
73 xm = 0;
74 } else {
75 residue = xm << (32 - SP_FBITS + xe);
76 round = (residue >> 31) != 0;
77 sticky = (residue << 1) != 0;
78 xm >>= SP_FBITS - xe;
79 }
80 odd = (xm & 0x1) != 0x0;
81 switch (ieee754_csr.rm) {
82 case FPU_CSR_RN:
83 if (round && (sticky || odd))
84 xm++;
85 break;
86 case FPU_CSR_RZ:
87 break;
88 case FPU_CSR_RU: /* toward +Infinity */
89 if ((round || sticky) && !xs)
90 xm++;
91 break;
92 case FPU_CSR_RD: /* toward -Infinity */
93 if ((round || sticky) && xs)
94 xm++;
95 break;
96 }
97 if ((xm >> 63) != 0) {
98 /* This can happen after rounding */
99 ieee754_setcx(IEEE754_INVALID_OPERATION);
100 return ieee754di_overflow(xs);
101 }
102 if (round || sticky)
103 ieee754_setcx(IEEE754_INEXACT);
104 }
105 if (xs)
106 return -xm;
107 else
108 return xm;
109}