xref: /illumos-gate/usr/src/lib/libc/sparc/fp/_Q_add.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include "quad.h"
28 
29 #ifdef __sparcv9
30 
31 /*
32  * _Qp_add(pz, ox, oy) sets *pz = *ox + *oy.
33  */
34 void
35 _Qp_add(union longdouble *pz, const union longdouble *ox,
36 	const union longdouble *oy)
37 
38 #else
39 
40 /*
41  * _Q_add(ox, oy) returns *ox + *oy.
42  */
43 union longdouble
44 _Q_add(const union longdouble *ox, const union longdouble *oy)
45 
46 #endif	/* __sparcv9 */
47 
48 {
49 	union longdouble	z;
50 	const union longdouble	*x, *y;
51 	unsigned int		xm, ym, tm, fsr;
52 
53 	/* sort so |x| >= |y| */
54 	xm = ox->l.msw & 0x7fffffff;
55 	ym = oy->l.msw & 0x7fffffff;
56 	if (ym > xm || ym == xm && (oy->l.frac2 > ox->l.frac2 ||
57 	    oy->l.frac2 == ox->l.frac2 && (oy->l.frac3 > ox->l.frac3 ||
58 	    oy->l.frac3 == ox->l.frac3 && oy->l.frac4 > ox->l.frac4))) {
59 		y = ox;
60 		x = oy;
61 		tm = xm;
62 		xm = ym;
63 		ym = tm;
64 	} else {
65 		x = ox;
66 		y = oy;
67 	}
68 
69 	/* get the fsr */
70 	__quad_getfsrp(&fsr);
71 
72 	/* handle nan and inf cases */
73 	if (xm >= 0x7fff0000) {
74 		/* x is nan or inf */
75 		if (ym >= 0x7fff0000) {
76 			/* y is nan or inf */
77 			if ((ym & 0xffff) | y->l.frac2 | y->l.frac3 |
78 			    y->l.frac4) {
79 				/* y is nan; x must be nan too */
80 				/* the following logic implements V9 app. B */
81 				if (!(ym & 0x8000)) {
82 					/* y is snan, signal invalid */
83 					if (fsr & FSR_NVM) {
84 						__quad_faddq(ox, oy, &Z);
85 					} else {
86 						Z = (xm & 0x8000)? *y : *oy;
87 						Z.l.msw |= 0x8000;
88 						fsr = (fsr & ~FSR_CEXC) |
89 						    FSR_NVA | FSR_NVC;
90 						__quad_setfsrp(&fsr);
91 					}
92 					QUAD_RETURN(Z);
93 				}
94 				/* x and y are both qnan */
95 				Z = *oy;
96 				QUAD_RETURN(Z);
97 			}
98 			if (!((xm & 0xffff) | x->l.frac2 | x->l.frac3 |
99 			    x->l.frac4)) {
100 				/* x and y are both inf */
101 				if ((x->l.msw ^ y->l.msw) & 0x80000000) {
102 					/* inf - inf, signal invalid */
103 					if (fsr & FSR_NVM) {
104 						__quad_faddq(ox, oy, &Z);
105 					} else {
106 						Z.l.msw = 0x7fffffff;
107 						Z.l.frac2 = Z.l.frac3 =
108 						    Z.l.frac4 = 0xffffffff;
109 						fsr = (fsr & ~FSR_CEXC) |
110 						    FSR_NVA | FSR_NVC;
111 						__quad_setfsrp(&fsr);
112 					}
113 					QUAD_RETURN(Z);
114 				}
115 				/* inf + inf, return inf */
116 				Z = *x;
117 				QUAD_RETURN(Z);
118 			}
119 		}
120 		if ((xm & 0xffff) | x->l.frac2 | x->l.frac3 | x->l.frac4) {
121 			/* x is nan */
122 			if (!(xm & 0x8000)) {
123 				/* snan, signal invalid */
124 				if (fsr & FSR_NVM) {
125 					__quad_faddq(ox, oy, &Z);
126 				} else {
127 					Z = *x;
128 					Z.l.msw |= 0x8000;
129 					fsr = (fsr & ~FSR_CEXC) | FSR_NVA |
130 					    FSR_NVC;
131 					__quad_setfsrp(&fsr);
132 				}
133 				QUAD_RETURN(Z);
134 			}
135 			Z = *x;
136 			QUAD_RETURN(Z);
137 		}
138 		/* x is inf */
139 		Z = *x;
140 		QUAD_RETURN(Z);
141 	}
142 
143 	/* now x and y are finite and |x| >= |y| */
144 	fsr &= ~FSR_CEXC;
145 	z.l.msw = (x->l.msw & 0x80000000);
146 	if ((x->l.msw ^ y->l.msw) & 0x80000000)
147 		__quad_mag_sub(x, y, &z, &fsr);
148 	else
149 		__quad_mag_add(x, y, &z, &fsr);
150 	if ((fsr & FSR_CEXC) & (fsr >> 23)) {
151 		__quad_setfsrp(&fsr);
152 		__quad_faddq(ox, oy, &Z);
153 	} else {
154 		Z = z;
155 		fsr |= (fsr & 0x1f) << 5;
156 		__quad_setfsrp(&fsr);
157 	}
158 	QUAD_RETURN(Z);
159 }
160