Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[linux-2.6] / arch / x86 / math-emu / reg_convert.c
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
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     {
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