xref: /OK3568_Linux_fs/kernel/arch/mips/math-emu/dp_2008class.c (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * IEEE754 floating point arithmetic
4*4882a593Smuzhiyun  * double precision: CLASS.f
5*4882a593Smuzhiyun  * FPR[fd] = class(FPR[fs])
6*4882a593Smuzhiyun  *
7*4882a593Smuzhiyun  * MIPS floating point support
8*4882a593Smuzhiyun  * Copyright (C) 2015 Imagination Technologies, Ltd.
9*4882a593Smuzhiyun  * Author: Markos Chandras <markos.chandras@imgtec.com>
10*4882a593Smuzhiyun  */
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #include "ieee754dp.h"
13*4882a593Smuzhiyun 
ieee754dp_2008class(union ieee754dp x)14*4882a593Smuzhiyun int ieee754dp_2008class(union ieee754dp x)
15*4882a593Smuzhiyun {
16*4882a593Smuzhiyun 	COMPXDP;
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun 	EXPLODEXDP;
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun 	/*
21*4882a593Smuzhiyun 	 * 10 bit mask as follows:
22*4882a593Smuzhiyun 	 *
23*4882a593Smuzhiyun 	 * bit0 = SNAN
24*4882a593Smuzhiyun 	 * bit1 = QNAN
25*4882a593Smuzhiyun 	 * bit2 = -INF
26*4882a593Smuzhiyun 	 * bit3 = -NORM
27*4882a593Smuzhiyun 	 * bit4 = -DNORM
28*4882a593Smuzhiyun 	 * bit5 = -ZERO
29*4882a593Smuzhiyun 	 * bit6 = INF
30*4882a593Smuzhiyun 	 * bit7 = NORM
31*4882a593Smuzhiyun 	 * bit8 = DNORM
32*4882a593Smuzhiyun 	 * bit9 = ZERO
33*4882a593Smuzhiyun 	 */
34*4882a593Smuzhiyun 
35*4882a593Smuzhiyun 	switch(xc) {
36*4882a593Smuzhiyun 	case IEEE754_CLASS_SNAN:
37*4882a593Smuzhiyun 		return 0x01;
38*4882a593Smuzhiyun 	case IEEE754_CLASS_QNAN:
39*4882a593Smuzhiyun 		return 0x02;
40*4882a593Smuzhiyun 	case IEEE754_CLASS_INF:
41*4882a593Smuzhiyun 		return 0x04 << (xs ? 0 : 4);
42*4882a593Smuzhiyun 	case IEEE754_CLASS_NORM:
43*4882a593Smuzhiyun 		return 0x08 << (xs ? 0 : 4);
44*4882a593Smuzhiyun 	case IEEE754_CLASS_DNORM:
45*4882a593Smuzhiyun 		return 0x10 << (xs ? 0 : 4);
46*4882a593Smuzhiyun 	case IEEE754_CLASS_ZERO:
47*4882a593Smuzhiyun 		return 0x20 << (xs ? 0 : 4);
48*4882a593Smuzhiyun 	default:
49*4882a593Smuzhiyun 		pr_err("Unknown class: %d\n", xc);
50*4882a593Smuzhiyun 		return 0;
51*4882a593Smuzhiyun 	}
52*4882a593Smuzhiyun }
53