xref: /linux/arch/mips/math-emu/dp_simple.c (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
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 union ieee754dp ieee754dp_neg(union ieee754dp x)
13 {
14 	union ieee754dp y;
15 
16 	if (ieee754_csr.abs2008) {
17 		y = x;
18 		DPSIGN(y) = !DPSIGN(x);
19 	} else {
20 		unsigned int oldrm;
21 
22 		oldrm = ieee754_csr.rm;
23 		ieee754_csr.rm = FPU_CSR_RD;
24 		y = ieee754dp_sub(ieee754dp_zero(0), x);
25 		ieee754_csr.rm = oldrm;
26 	}
27 	return y;
28 }
29 
30 union ieee754dp ieee754dp_abs(union ieee754dp x)
31 {
32 	union ieee754dp y;
33 
34 	if (ieee754_csr.abs2008) {
35 		y = x;
36 		DPSIGN(y) = 0;
37 	} else {
38 		unsigned int oldrm;
39 
40 		oldrm = ieee754_csr.rm;
41 		ieee754_csr.rm = FPU_CSR_RD;
42 		if (DPSIGN(x))
43 			y = ieee754dp_sub(ieee754dp_zero(0), x);
44 		else
45 			y = ieee754dp_add(ieee754dp_zero(0), x);
46 		ieee754_csr.rm = oldrm;
47 	}
48 	return y;
49 }
50