xref: /openbmc/linux/arch/mips/math-emu/dp_simple.c (revision a09d2831)
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  * http://www.algor.co.uk
8  *
9  * ########################################################################
10  *
11  *  This program is free software; you can distribute it and/or modify it
12  *  under the terms of the GNU General Public License (Version 2) as
13  *  published by the Free Software Foundation.
14  *
15  *  This program is distributed in the hope it will be useful, but WITHOUT
16  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18  *  for more details.
19  *
20  *  You should have received a copy of the GNU General Public License along
21  *  with this program; if not, write to the Free Software Foundation, Inc.,
22  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
23  *
24  * ########################################################################
25  */
26 
27 
28 #include "ieee754dp.h"
29 
30 int ieee754dp_finite(ieee754dp x)
31 {
32 	return DPBEXP(x) != DP_EMAX + 1 + DP_EBIAS;
33 }
34 
35 ieee754dp ieee754dp_copysign(ieee754dp x, ieee754dp y)
36 {
37 	CLEARCX;
38 	DPSIGN(x) = DPSIGN(y);
39 	return x;
40 }
41 
42 
43 ieee754dp ieee754dp_neg(ieee754dp x)
44 {
45 	COMPXDP;
46 
47 	EXPLODEXDP;
48 	CLEARCX;
49 	FLUSHXDP;
50 
51 	/*
52 	 * Invert the sign ALWAYS to prevent an endless recursion on
53 	 * pow() in libc.
54 	 */
55 	/* quick fix up */
56 	DPSIGN(x) ^= 1;
57 
58 	if (xc == IEEE754_CLASS_SNAN) {
59 		ieee754dp y = ieee754dp_indef();
60 		SETCX(IEEE754_INVALID_OPERATION);
61 		DPSIGN(y) = DPSIGN(x);
62 		return ieee754dp_nanxcpt(y, "neg");
63 	}
64 
65 	return x;
66 }
67 
68 
69 ieee754dp ieee754dp_abs(ieee754dp x)
70 {
71 	COMPXDP;
72 
73 	EXPLODEXDP;
74 	CLEARCX;
75 	FLUSHXDP;
76 
77 	/* Clear sign ALWAYS, irrespective of NaN */
78 	DPSIGN(x) = 0;
79 
80 	if (xc == IEEE754_CLASS_SNAN) {
81 		return ieee754dp_nanxcpt(ieee754dp_indef(), "abs");
82 	}
83 
84 	return x;
85 }
86