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