xref: /openbmc/linux/arch/mips/math-emu/dp_simple.c (revision 3f7cac41)
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 union ieee754dp ieee754dp_neg(union ieee754dp x)
25 {
26 	COMPXDP;
27 
28 	EXPLODEXDP;
29 	ieee754_clearcx();
30 	FLUSHXDP;
31 
32 	/*
33 	 * Invert the sign ALWAYS to prevent an endless recursion on
34 	 * pow() in libc.
35 	 */
36 	/* quick fix up */
37 	DPSIGN(x) ^= 1;
38 
39 	if (xc == IEEE754_CLASS_SNAN) {
40 		union ieee754dp y = ieee754dp_indef();
41 		ieee754_setcx(IEEE754_INVALID_OPERATION);
42 		DPSIGN(y) = DPSIGN(x);
43 		return ieee754dp_nanxcpt(y);
44 	}
45 
46 	return x;
47 }
48 
49 union ieee754dp ieee754dp_abs(union ieee754dp x)
50 {
51 	COMPXDP;
52 
53 	EXPLODEXDP;
54 	ieee754_clearcx();
55 	FLUSHXDP;
56 
57 	/* Clear sign ALWAYS, irrespective of NaN */
58 	DPSIGN(x) = 0;
59 
60 	if (xc == IEEE754_CLASS_SNAN) {
61 		ieee754_setcx(IEEE754_INVALID_OPERATION);
62 		return ieee754dp_nanxcpt(ieee754dp_indef());
63 	}
64 
65 	return x;
66 }
67