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
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    {
28      /* The number is a de-normal or pseudodenormal. */
29      /* We only deal with the significand and exponent. */
30
31      if (x->sigh & 0x80000000)
32	{
33	  /* Is a pseudodenormal. */
34	  /* This is non-80486 behaviour because the number
35	     loses its 'denormal' identity. */
36	  addexponent(x, 1);
37	}
38      else
39	{
40	  /* Is a denormal. */
41	  addexponent(x, 1);
42	  FPU_normalize_nuo(x);
43	}
44    }
45
46  if ( !(x->sigh & 0x80000000) )
47    {
48      EXCEPTION(EX_INTERNAL | 0x180);
49    }
50
51  return sign;
52}
53