xref: /openbmc/linux/arch/mips/math-emu/dp_cmp.c (revision 293d5b43)
1 /* IEEE754 floating point arithmetic
2  * double precision: common utilities
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 "ieee754dp.h"
23 
24 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cmp, int sig)
25 {
26 	s64 vx;
27 	s64 vy;
28 
29 	COMPXDP;
30 	COMPYDP;
31 
32 	EXPLODEXDP;
33 	EXPLODEYDP;
34 	FLUSHXDP;
35 	FLUSHYDP;
36 	ieee754_clearcx();	/* Even clear inexact flag here */
37 
38 	if (ieee754_class_nan(xc) || ieee754_class_nan(yc)) {
39 		if (sig ||
40 		    xc == IEEE754_CLASS_SNAN || yc == IEEE754_CLASS_SNAN)
41 			ieee754_setcx(IEEE754_INVALID_OPERATION);
42 		return (cmp & IEEE754_CUN) != 0;
43 	} else {
44 		vx = x.bits;
45 		vy = y.bits;
46 
47 		if (vx < 0)
48 			vx = -vx ^ DP_SIGN_BIT;
49 		if (vy < 0)
50 			vy = -vy ^ DP_SIGN_BIT;
51 
52 		if (vx < vy)
53 			return (cmp & IEEE754_CLT) != 0;
54 		else if (vx == vy)
55 			return (cmp & IEEE754_CEQ) != 0;
56 		else
57 			return (cmp & IEEE754_CGT) != 0;
58 	}
59 }
60