1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IEEE754 floating point arithmetic
4  * double precision: CLASS.f
5  * FPR[fd] = class(FPR[fs])
6  *
7  * MIPS floating point support
8  * Copyright (C) 2015 Imagination Technologies, Ltd.
9  * Author: Markos Chandras <markos.chandras@imgtec.com>
10  */
11 
12 #include "ieee754dp.h"
13 
14 int ieee754dp_2008class(union ieee754dp x)
15 {
16 	COMPXDP;
17 
18 	EXPLODEXDP;
19 
20 	/*
21 	 * 10 bit mask as follows:
22 	 *
23 	 * bit0 = SNAN
24 	 * bit1 = QNAN
25 	 * bit2 = -INF
26 	 * bit3 = -NORM
27 	 * bit4 = -DNORM
28 	 * bit5 = -ZERO
29 	 * bit6 = INF
30 	 * bit7 = NORM
31 	 * bit8 = DNORM
32 	 * bit9 = ZERO
33 	 */
34 
35 	switch(xc) {
36 	case IEEE754_CLASS_SNAN:
37 		return 0x01;
38 	case IEEE754_CLASS_QNAN:
39 		return 0x02;
40 	case IEEE754_CLASS_INF:
41 		return 0x04 << (xs ? 0 : 4);
42 	case IEEE754_CLASS_NORM:
43 		return 0x08 << (xs ? 0 : 4);
44 	case IEEE754_CLASS_DNORM:
45 		return 0x10 << (xs ? 0 : 4);
46 	case IEEE754_CLASS_ZERO:
47 		return 0x20 << (xs ? 0 : 4);
48 	default:
49 		pr_err("Unknown class: %d\n", xc);
50 		return 0;
51 	}
52 }
53