diff options
Diffstat (limited to 'arch/i386/math-emu/fpu_etc.c')
-rw-r--r-- | arch/i386/math-emu/fpu_etc.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/i386/math-emu/fpu_etc.c b/arch/i386/math-emu/fpu_etc.c new file mode 100644 index 000000000000..e3b5d465587f --- /dev/null +++ b/arch/i386/math-emu/fpu_etc.c | |||
@@ -0,0 +1,143 @@ | |||
1 | /*---------------------------------------------------------------------------+ | ||
2 | | fpu_etc.c | | ||
3 | | | | ||
4 | | Implement a few FPU instructions. | | ||
5 | | | | ||
6 | | Copyright (C) 1992,1993,1994,1997 | | ||
7 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | | ||
8 | | Australia. E-mail billm@suburbia.net | | ||
9 | | | | ||
10 | | | | ||
11 | +---------------------------------------------------------------------------*/ | ||
12 | |||
13 | #include "fpu_system.h" | ||
14 | #include "exception.h" | ||
15 | #include "fpu_emu.h" | ||
16 | #include "status_w.h" | ||
17 | #include "reg_constant.h" | ||
18 | |||
19 | |||
20 | static void fchs(FPU_REG *st0_ptr, u_char st0tag) | ||
21 | { | ||
22 | if ( st0tag ^ TAG_Empty ) | ||
23 | { | ||
24 | signbyte(st0_ptr) ^= SIGN_NEG; | ||
25 | clear_C1(); | ||
26 | } | ||
27 | else | ||
28 | FPU_stack_underflow(); | ||
29 | } | ||
30 | |||
31 | |||
32 | static void fabs(FPU_REG *st0_ptr, u_char st0tag) | ||
33 | { | ||
34 | if ( st0tag ^ TAG_Empty ) | ||
35 | { | ||
36 | setpositive(st0_ptr); | ||
37 | clear_C1(); | ||
38 | } | ||
39 | else | ||
40 | FPU_stack_underflow(); | ||
41 | } | ||
42 | |||
43 | |||
44 | static void ftst_(FPU_REG *st0_ptr, u_char st0tag) | ||
45 | { | ||
46 | switch (st0tag) | ||
47 | { | ||
48 | case TAG_Zero: | ||
49 | setcc(SW_C3); | ||
50 | break; | ||
51 | case TAG_Valid: | ||
52 | if (getsign(st0_ptr) == SIGN_POS) | ||
53 | setcc(0); | ||
54 | else | ||
55 | setcc(SW_C0); | ||
56 | break; | ||
57 | case TAG_Special: | ||
58 | switch ( FPU_Special(st0_ptr) ) | ||
59 | { | ||
60 | case TW_Denormal: | ||
61 | if (getsign(st0_ptr) == SIGN_POS) | ||
62 | setcc(0); | ||
63 | else | ||
64 | setcc(SW_C0); | ||
65 | if ( denormal_operand() < 0 ) | ||
66 | { | ||
67 | #ifdef PECULIAR_486 | ||
68 | /* This is weird! */ | ||
69 | if (getsign(st0_ptr) == SIGN_POS) | ||
70 | setcc(SW_C3); | ||
71 | #endif /* PECULIAR_486 */ | ||
72 | return; | ||
73 | } | ||
74 | break; | ||
75 | case TW_NaN: | ||
76 | setcc(SW_C0|SW_C2|SW_C3); /* Operand is not comparable */ | ||
77 | EXCEPTION(EX_Invalid); | ||
78 | break; | ||
79 | case TW_Infinity: | ||
80 | if (getsign(st0_ptr) == SIGN_POS) | ||
81 | setcc(0); | ||
82 | else | ||
83 | setcc(SW_C0); | ||
84 | break; | ||
85 | default: | ||
86 | setcc(SW_C0|SW_C2|SW_C3); /* Operand is not comparable */ | ||
87 | EXCEPTION(EX_INTERNAL|0x14); | ||
88 | break; | ||
89 | } | ||
90 | break; | ||
91 | case TAG_Empty: | ||
92 | setcc(SW_C0|SW_C2|SW_C3); | ||
93 | EXCEPTION(EX_StackUnder); | ||
94 | break; | ||
95 | } | ||
96 | } | ||
97 | |||
98 | |||
99 | static void fxam(FPU_REG *st0_ptr, u_char st0tag) | ||
100 | { | ||
101 | int c = 0; | ||
102 | switch (st0tag) | ||
103 | { | ||
104 | case TAG_Empty: | ||
105 | c = SW_C3|SW_C0; | ||
106 | break; | ||
107 | case TAG_Zero: | ||
108 | c = SW_C3; | ||
109 | break; | ||
110 | case TAG_Valid: | ||
111 | c = SW_C2; | ||
112 | break; | ||
113 | case TAG_Special: | ||
114 | switch ( FPU_Special(st0_ptr) ) | ||
115 | { | ||
116 | case TW_Denormal: | ||
117 | c = SW_C2|SW_C3; /* Denormal */ | ||
118 | break; | ||
119 | case TW_NaN: | ||
120 | /* We also use NaN for unsupported types. */ | ||
121 | if ( (st0_ptr->sigh & 0x80000000) && (exponent(st0_ptr) == EXP_OVER) ) | ||
122 | c = SW_C0; | ||
123 | break; | ||
124 | case TW_Infinity: | ||
125 | c = SW_C2|SW_C0; | ||
126 | break; | ||
127 | } | ||
128 | } | ||
129 | if ( getsign(st0_ptr) == SIGN_NEG ) | ||
130 | c |= SW_C1; | ||
131 | setcc(c); | ||
132 | } | ||
133 | |||
134 | |||
135 | static FUNC_ST0 const fp_etc_table[] = { | ||
136 | fchs, fabs, (FUNC_ST0)FPU_illegal, (FUNC_ST0)FPU_illegal, | ||
137 | ftst_, fxam, (FUNC_ST0)FPU_illegal, (FUNC_ST0)FPU_illegal | ||
138 | }; | ||
139 | |||
140 | void FPU_etc(void) | ||
141 | { | ||
142 | (fp_etc_table[FPU_rm])(&st(0), FPU_gettag0()); | ||
143 | } | ||