xref: /openbmc/linux/arch/mips/math-emu/dp_simple.c (revision 2209bcb1)
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  * ########################################################################
9  *
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.
13  *
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
17  *  for more details.
18  *
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.
22  *
23  * ########################################################################
24  */
25 
26 
27 #include "ieee754dp.h"
28 
29 int ieee754dp_finite(union ieee754dp x)
30 {
31 	return DPBEXP(x) != DP_EMAX + 1 + DP_EBIAS;
32 }
33 
34 union ieee754dp ieee754dp_copysign(union ieee754dp x, union ieee754dp y)
35 {
36 	CLEARCX;
37 	DPSIGN(x) = DPSIGN(y);
38 	return x;
39 }
40 
41 
42 union ieee754dp ieee754dp_neg(union ieee754dp x)
43 {
44 	COMPXDP;
45 
46 	EXPLODEXDP;
47 	CLEARCX;
48 	FLUSHXDP;
49 
50 	/*
51 	 * Invert the sign ALWAYS to prevent an endless recursion on
52 	 * pow() in libc.
53 	 */
54 	/* quick fix up */
55 	DPSIGN(x) ^= 1;
56 
57 	if (xc == IEEE754_CLASS_SNAN) {
58 		union ieee754dp y = ieee754dp_indef();
59 		SETCX(IEEE754_INVALID_OPERATION);
60 		DPSIGN(y) = DPSIGN(x);
61 		return ieee754dp_nanxcpt(y, "neg");
62 	}
63 
64 	return x;
65 }
66 
67 
68 union ieee754dp ieee754dp_abs(union ieee754dp x)
69 {
70 	COMPXDP;
71 
72 	EXPLODEXDP;
73 	CLEARCX;
74 	FLUSHXDP;
75 
76 	/* Clear sign ALWAYS, irrespective of NaN */
77 	DPSIGN(x) = 0;
78 
79 	if (xc == IEEE754_CLASS_SNAN) {
80 		SETCX(IEEE754_INVALID_OPERATION);
81 		return ieee754dp_nanxcpt(ieee754dp_indef(), "abs");
82 	}
83 
84 	return x;
85 }
86