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gerrit-public.fairphone.software / kernel / msm-4.9 / 309f15d8bbe122c5fd0f1b1a2aa1ab79a66608b6 / . / arch / mips / math-emu / sp_fmin.c
blob: c51385f46b09968611764d26db082cbf680e8744 [file] [log] [blame]
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]1/*
2 * IEEE754 floating point arithmetic
3 * single precision: MIN{,A}.f
4 * MIN : Scalar Floating-Point Minimum
5 * MINA: Scalar Floating-Point argument with Minimum Absolute Value
6 *
7 * MIN.S : FPR[fd] = minNum(FPR[fs],FPR[ft])
8 * MINA.S: FPR[fd] = maxNumMag(FPR[fs],FPR[ft])
9 *
10 * MIPS floating point support
11 * Copyright (C) 2015 Imagination Technologies, Ltd.
12 * Author: Markos Chandras <markos.chandras@imgtec.com>
13 *
14 * This program is free software; you can distribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the
16 * Free Software Foundation; version 2 of the License.
17 */
18
19#include "ieee754sp.h"
20
21union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y)
22{
23 COMPXSP;
24 COMPYSP;
25
26 EXPLODEXSP;
27 EXPLODEYSP;
28
29 FLUSHXSP;
30 FLUSHYSP;
31
32 ieee754_clearcx();
33
34 switch (CLPAIR(xc, yc)) {
35 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
36 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
37 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
38 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
39 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
40 return ieee754sp_nanxcpt(y);
41
42 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
43 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
44 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
45 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
46 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
47 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
48 return ieee754sp_nanxcpt(x);
49
Aleksandar Markovicb2341492017-07-27 18:08:48 +0200[diff] [blame]50 /*
51 * Quiet NaN handling
52 */
53
54 /*
55 * The case of both inputs quiet NaNs
56 */
57 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
58 return x;
59
60 /*
61 * The cases of exactly one input quiet NaN (numbers
62 * are here preferred as returned values to NaNs)
63 */
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]64 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
65 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
66 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
67 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
68 return x;
69
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]70 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
71 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
72 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
73 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
74 return y;
75
76 /*
77 * Infinity and zero handling
78 */
79 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
80 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
81 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
82 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
83 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
84 return xs ? x : y;
85
86 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
87 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
88 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
89 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
90 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
91 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
92 return ys ? y : x;
93
94 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
Aleksandar Markovic694f6ea2017-07-27 18:08:49 +0200[diff] [blame]95 return ieee754sp_zero(xs | ys);
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]96
97 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
98 SPDNORMX;
99
100 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
101 SPDNORMY;
102 break;
103
104 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
105 SPDNORMX;
106 }
107
108 /* Finally get to do some computation */
109
110 assert(xm & SP_HIDDEN_BIT);
111 assert(ym & SP_HIDDEN_BIT);
112
113 /* Compare signs */
114 if (xs > ys)
115 return x;
116 else if (xs < ys)
117 return y;
118
Aleksandar Markovicd2b6fcb2017-07-27 18:08:50 +0200[diff] [blame]119 /* Signs of inputs are the same, let's compare exponents */
120 if (xs == 0) {
121 /* Inputs are both positive */
122 if (xe > ye)
123 return y;
124 else if (xe < ye)
125 return x;
126 } else {
127 /* Inputs are both negative */
128 if (xe > ye)
129 return x;
130 else if (xe < ye)
131 return y;
132 }
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]133
Aleksandar Markovicd2b6fcb2017-07-27 18:08:50 +0200[diff] [blame]134 /* Signs and exponents of inputs are equal, let's compare mantissas */
135 if (xs == 0) {
136 /* Inputs are both positive, with equal signs and exponents */
137 if (xm <= ym)
138 return x;
139 return y;
140 }
141 /* Inputs are both negative, with equal signs and exponents */
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]142 if (xm <= ym)
Aleksandar Markovicd2b6fcb2017-07-27 18:08:50 +0200[diff] [blame]143 return y;
144 return x;
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]145}
146
147union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y)
148{
149 COMPXSP;
150 COMPYSP;
151
152 EXPLODEXSP;
153 EXPLODEYSP;
154
155 FLUSHXSP;
156 FLUSHYSP;
157
158 ieee754_clearcx();
159
160 switch (CLPAIR(xc, yc)) {
161 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
162 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
163 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
164 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
165 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
166 return ieee754sp_nanxcpt(y);
167
168 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
169 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
170 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
171 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
172 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
173 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
174 return ieee754sp_nanxcpt(x);
175
Aleksandar Markovicb2341492017-07-27 18:08:48 +0200[diff] [blame]176 /*
177 * Quiet NaN handling
178 */
179
180 /*
181 * The case of both inputs quiet NaNs
182 */
183 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
184 return x;
185
186 /*
187 * The cases of exactly one input quiet NaN (numbers
188 * are here preferred as returned values to NaNs)
189 */
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]190 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
191 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
192 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
193 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
194 return x;
195
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]196 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
197 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
198 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
199 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
200 return y;
201
202 /*
203 * Infinity and zero handling
204 */
Aleksandar Markovicf7d36f62017-07-27 18:08:52 +0200[diff] [blame]205 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
206 return ieee754sp_inf(xs | ys);
207
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]208 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
209 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
210 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
211 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
212 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
Aleksandar Markovic9381a992017-07-27 18:08:53 +0200[diff] [blame]213 return y;
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]214
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]215 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
216 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
217 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
218 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
219 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
Aleksandar Markovic9381a992017-07-27 18:08:53 +0200[diff] [blame]220 return x;
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]221
222 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
Aleksandar Markovic694f6ea2017-07-27 18:08:49 +0200[diff] [blame]223 return ieee754sp_zero(xs | ys);
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]224
225 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
226 SPDNORMX;
227
228 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
229 SPDNORMY;
230 break;
231
232 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
233 SPDNORMX;
234 }
235
236 /* Finally get to do some computation */
237
238 assert(xm & SP_HIDDEN_BIT);
239 assert(ym & SP_HIDDEN_BIT);
240
241 /* Compare exponent */
242 if (xe > ye)
243 return y;
244 else if (xe < ye)
245 return x;
246
247 /* Compare mantissa */
Aleksandar Markovica04d5372017-07-27 18:08:51 +0200[diff] [blame]248 if (xm < ym)
249 return x;
250 else if (xm > ym)
251 return y;
252 else if (xs == 1)
Markos Chandras4e9561b2015-08-13 09:56:35 +0200[diff] [blame]253 return x;
254 return y;
255}