xref: /openbmc/linux/arch/mips/math-emu/dp_simple.c (revision 75bf465f0bc33e9b776a46d6a1b9b990f5fb7c37)
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  
ieee754dp_neg(union ieee754dp x)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  
ieee754dp_abs(union ieee754dp x)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