xref: /openbmc/linux/arch/mips/math-emu/dp_simple.c (revision a2818ee4)
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 	union ieee754dp y;
27 
28 	if (ieee754_csr.abs2008) {
29 		y = x;
30 		DPSIGN(y) = !DPSIGN(x);
31 	} else {
32 		unsigned int oldrm;
33 
34 		oldrm = ieee754_csr.rm;
35 		ieee754_csr.rm = FPU_CSR_RD;
36 		y = ieee754dp_sub(ieee754dp_zero(0), x);
37 		ieee754_csr.rm = oldrm;
38 	}
39 	return y;
40 }
41 
42 union ieee754dp ieee754dp_abs(union ieee754dp x)
43 {
44 	union ieee754dp y;
45 
46 	if (ieee754_csr.abs2008) {
47 		y = x;
48 		DPSIGN(y) = 0;
49 	} else {
50 		unsigned int oldrm;
51 
52 		oldrm = ieee754_csr.rm;
53 		ieee754_csr.rm = FPU_CSR_RD;
54 		if (DPSIGN(x))
55 			y = ieee754dp_sub(ieee754dp_zero(0), x);
56 		else
57 			y = ieee754dp_add(ieee754dp_zero(0), x);
58 		ieee754_csr.rm = oldrm;
59 	}
60 	return y;
61 }
62