1 // SPDX-License-Identifier: GPL-2.0
2 /*---------------------------------------------------------------------------+
3  |  reg_convert.c                                                            |
4  |                                                                           |
5  |  Convert register representation.                                         |
6  |                                                                           |
7  | Copyright (C) 1992,1993,1994,1996,1997                                    |
8  |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
9  |                  E-mail   billm@suburbia.net                              |
10  |                                                                           |
11  |                                                                           |
12  +---------------------------------------------------------------------------*/
13 
14 #include "exception.h"
15 #include "fpu_emu.h"
16 
FPU_to_exp16(FPU_REG const * a,FPU_REG * x)17 int FPU_to_exp16(FPU_REG const *a, FPU_REG *x)
18 {
19 	int sign = getsign(a);
20 
21 	*(long long *)&(x->sigl) = *(const long long *)&(a->sigl);
22 
23 	/* Set up the exponent as a 16 bit quantity. */
24 	setexponent16(x, exponent(a));
25 
26 	if (exponent16(x) == EXP_UNDER) {
27 		/* The number is a de-normal or pseudodenormal. */
28 		/* We only deal with the significand and exponent. */
29 
30 		if (x->sigh & 0x80000000) {
31 			/* Is a pseudodenormal. */
32 			/* This is non-80486 behaviour because the number
33 			   loses its 'denormal' identity. */
34 			addexponent(x, 1);
35 		} else {
36 			/* Is a denormal. */
37 			addexponent(x, 1);
38 			FPU_normalize_nuo(x);
39 		}
40 	}
41 
42 	if (!(x->sigh & 0x80000000)) {
43 		EXCEPTION(EX_INTERNAL | 0x180);
44 	}
45 
46 	return sign;
47 }
48