1
/*---------------------------------------------------------------------------+
4
| Set FPU register tags. |
7
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
8
| E-mail billm@jacobi.maths.monash.edu.au |
11
+---------------------------------------------------------------------------*/
14
#include "fpu_system.h"
15
#include "exception.h"
19
fpu_tag_word |= 3 << ((top & 7) * 2);
25
return (fpu_tag_word >> ((top & 7) * 2)) & 3;
28
int FPU_gettagi(int stnr)
30
return (fpu_tag_word >> (((top + stnr) & 7) * 2)) & 3;
33
int FPU_gettag(int regnr)
35
return (fpu_tag_word >> ((regnr & 7) * 2)) & 3;
38
void FPU_settag0(int tag)
42
fpu_tag_word &= ~(3 << (regnr * 2));
43
fpu_tag_word |= (tag & 3) << (regnr * 2);
46
void FPU_settagi(int stnr, int tag)
48
int regnr = stnr + top;
50
fpu_tag_word &= ~(3 << (regnr * 2));
51
fpu_tag_word |= (tag & 3) << (regnr * 2);
54
void FPU_settag(int regnr, int tag)
57
fpu_tag_word &= ~(3 << (regnr * 2));
58
fpu_tag_word |= (tag & 3) << (regnr * 2);
61
int FPU_Special(FPU_REG const *ptr)
63
int exp = exponent(ptr);
65
if (exp == EXP_BIAS + EXP_UNDER)
67
else if (exp != EXP_BIAS + EXP_OVER)
69
else if ((ptr->sigh == 0x80000000) && (ptr->sigl == 0))
74
int isNaN(FPU_REG const *ptr)
76
return ((exponent(ptr) == EXP_BIAS + EXP_OVER)
77
&& !((ptr->sigh == 0x80000000) && (ptr->sigl == 0)));
80
int FPU_empty_i(int stnr)
82
int regnr = (top + stnr) & 7;
84
return ((fpu_tag_word >> (regnr * 2)) & 3) == TAG_Empty;
87
int FPU_stackoverflow(FPU_REG ** st_new_ptr)
89
*st_new_ptr = &st(-1);
91
return ((fpu_tag_word >> (((top - 1) & 7) * 2)) & 3) != TAG_Empty;
94
void FPU_copy_to_regi(FPU_REG const *r, u_char tag, int stnr)
96
reg_copy(r, &st(stnr));
97
FPU_settagi(stnr, tag);
100
void FPU_copy_to_reg1(FPU_REG const *r, u_char tag)
106
void FPU_copy_to_reg0(FPU_REG const *r, u_char tag)
113
fpu_tag_word &= ~(3 << (regnr * 2));
114
fpu_tag_word |= (tag & 3) << (regnr * 2);