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
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 }