xref: /linux/arch/mips/math-emu/dp_cmp.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* IEEE754 floating point arithmetic
3  * double precision: common utilities
4  */
5 /*
6  * MIPS floating point support
7  * Copyright (C) 1994-2000 Algorithmics Ltd.
8  */
9 
10 #include "ieee754dp.h"
11 
12 int ieee754dp_cmp(union ieee754dp x, union ieee754dp y, int cmp, int sig)
13 {
14 	s64 vx;
15 	s64 vy;
16 
17 	COMPXDP;
18 	COMPYDP;
19 
20 	EXPLODEXDP;
21 	EXPLODEYDP;
22 	FLUSHXDP;
23 	FLUSHYDP;
24 	ieee754_clearcx();	/* Even clear inexact flag here */
25 
26 	if (ieee754_class_nan(xc) || ieee754_class_nan(yc)) {
27 		if (sig ||
28 		    xc == IEEE754_CLASS_SNAN || yc == IEEE754_CLASS_SNAN)
29 			ieee754_setcx(IEEE754_INVALID_OPERATION);
30 		return (cmp & IEEE754_CUN) != 0;
31 	} else {
32 		vx = x.bits;
33 		vy = y.bits;
34 
35 		if (vx < 0)
36 			vx = -vx ^ DP_SIGN_BIT;
37 		if (vy < 0)
38 			vy = -vy ^ DP_SIGN_BIT;
39 
40 		if (vx < vy)
41 			return (cmp & IEEE754_CLT) != 0;
42 		else if (vx == vy)
43 			return (cmp & IEEE754_CEQ) != 0;
44 		else
45 			return (cmp & IEEE754_CGT) != 0;
46 	}
47 }
48