1 // SPDX-License-Identifier: GPL-2.0-only
2 /* IEEE754 floating point arithmetic
6 * MIPS floating point support
7 * Copyright (C) 1994-2000 Algorithmics Ltd.
10 #include "ieee754sp.h"
12 union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y)
29 switch (CLPAIR(xc, yc)) {
30 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
31 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
32 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
33 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
34 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
35 return ieee754sp_nanxcpt(y);
37 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
38 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
39 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
40 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
41 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
42 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
43 return ieee754sp_nanxcpt(x);
45 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
46 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
47 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
48 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
51 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
52 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
53 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
54 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
55 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
62 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
63 ieee754_setcx(IEEE754_INVALID_OPERATION);
64 return ieee754sp_indef();
66 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
67 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
68 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
69 return ieee754sp_zero(xs ^ ys);
71 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
72 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
73 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
74 return ieee754sp_inf(xs ^ ys);
79 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
80 ieee754_setcx(IEEE754_INVALID_OPERATION);
81 return ieee754sp_indef();
83 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
84 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
85 ieee754_setcx(IEEE754_ZERO_DIVIDE);
86 return ieee754sp_inf(xs ^ ys);
88 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
89 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
90 return ieee754sp_zero(xs == ys ? 0 : 1);
92 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
95 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
99 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
103 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
106 assert(xm & SP_HIDDEN_BIT);
107 assert(ym & SP_HIDDEN_BIT);
109 /* provide rounding space */
113 /* now the dirty work */
118 for (bm = SP_MBIT(SP_FBITS + 2); bm; bm >>= 1) {
130 rm |= 1; /* have remainder, set sticky */
134 /* normalise rm to rounding precision ?
136 while ((rm >> (SP_FBITS + 3)) == 0) {
141 return ieee754sp_format(xs == ys ? 0 : 1, re, rm);