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
17int 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