xref: /linux/arch/mips/math-emu/sp_2008class.c (revision fcc8487d477a3452a1d0ccbdd4c5e0e1e3cb8bed)
1 /*
2  * IEEE754 floating point arithmetic
3  * single precision: CLASS.f
4  * FPR[fd] = class(FPR[fs])
5  *
6  * MIPS floating point support
7  * Copyright (C) 2015 Imagination Technologies, Ltd.
8  * Author: Markos Chandras <markos.chandras@imgtec.com>
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 as published by the
12  *  Free Software Foundation; version 2 of the License.
13  */
14 
15 #include "ieee754sp.h"
16 
17 int ieee754sp_2008class(union ieee754sp x)
18 {
19 	COMPXSP;
20 
21 	EXPLODEXSP;
22 
23 	/*
24 	 * 10 bit mask as follows:
25 	 *
26 	 * bit0 = SNAN
27 	 * bit1 = QNAN
28 	 * bit2 = -INF
29 	 * bit3 = -NORM
30 	 * bit4 = -DNORM
31 	 * bit5 = -ZERO
32 	 * bit6 = INF
33 	 * bit7 = NORM
34 	 * bit8 = DNORM
35 	 * bit9 = ZERO
36 	 */
37 
38 	switch(xc) {
39 	case IEEE754_CLASS_SNAN:
40 		return 0x01;
41 	case IEEE754_CLASS_QNAN:
42 		return 0x02;
43 	case IEEE754_CLASS_INF:
44 		return 0x04 << (xs ? 0 : 4);
45 	case IEEE754_CLASS_NORM:
46 		return 0x08 << (xs ? 0 : 4);
47 	case IEEE754_CLASS_DNORM:
48 		return 0x10 << (xs ? 0 : 4);
49 	case IEEE754_CLASS_ZERO:
50 		return 0x20 << (xs ? 0 : 4);
51 	default:
52 		pr_err("Unknown class: %d\n", xc);
53 		return 0;
54 	}
55 }
56