1 /* IEEE754 floating point arithmetic
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
8 * ########################################################################
10 * This program is free software; you can distribute it and/or modify it
11 * under the terms of the GNU General Public License (Version 2) as
12 * published by the Free Software Foundation.
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
23 * ########################################################################
27 #include "ieee754sp.h"
29 ieee754sp ieee754sp_div(ieee754sp x, ieee754sp y)
42 switch (CLPAIR(xc, yc)) {
43 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
44 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
45 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
46 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
47 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
48 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
49 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
50 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
51 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
52 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
53 case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
54 SETCX(IEEE754_INVALID_OPERATION);
55 return ieee754sp_nanxcpt(ieee754sp_indef(), "div", x, y);
57 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
58 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
59 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
60 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
63 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
64 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
65 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
66 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
67 case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
74 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
75 SETCX(IEEE754_INVALID_OPERATION);
76 return ieee754sp_xcpt(ieee754sp_indef(), "div", x, y);
78 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
79 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
80 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
81 return ieee754sp_zero(xs ^ ys);
83 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
84 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
85 case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
86 return ieee754sp_inf(xs ^ ys);
91 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
92 SETCX(IEEE754_INVALID_OPERATION);
93 return ieee754sp_xcpt(ieee754sp_indef(), "div", x, y);
95 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
96 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
97 SETCX(IEEE754_ZERO_DIVIDE);
98 return ieee754sp_xcpt(ieee754sp_inf(xs ^ ys), "div", x, y);
100 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
101 case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
102 return ieee754sp_zero(xs == ys ? 0 : 1);
104 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
107 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
111 case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
115 case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
118 assert(xm & SP_HIDDEN_BIT);
119 assert(ym & SP_HIDDEN_BIT);
121 /* provide rounding space */
126 /* now the dirty work */
132 for (bm = SP_MBIT(SP_MBITS + 2); bm; bm >>= 1) {
143 rm |= 1; /* have remainder, set sticky */
147 /* normalise rm to rounding precision ?
149 while ((rm >> (SP_MBITS + 3)) == 0) {
154 SPNORMRET2(xs == ys ? 0 : 1, re, rm, "div", x, y);