diff options
Diffstat (limited to 'arch/i386/math-emu/reg_constant.c')
-rw-r--r-- | arch/i386/math-emu/reg_constant.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/i386/math-emu/reg_constant.c b/arch/i386/math-emu/reg_constant.c new file mode 100644 index 00000000000..a8501580196 --- /dev/null +++ b/arch/i386/math-emu/reg_constant.c | |||
@@ -0,0 +1,120 @@ | |||
1 | /*---------------------------------------------------------------------------+ | ||
2 | | reg_constant.c | | ||
3 | | | | ||
4 | | All of the constant FPU_REGs | | ||
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 "fpu_emu.h" | ||
15 | #include "status_w.h" | ||
16 | #include "reg_constant.h" | ||
17 | #include "control_w.h" | ||
18 | |||
19 | |||
20 | #define MAKE_REG(s,e,l,h) { l, h, \ | ||
21 | ((EXTENDED_Ebias+(e)) | ((SIGN_##s != 0)*0x8000)) } | ||
22 | |||
23 | FPU_REG const CONST_1 = MAKE_REG(POS, 0, 0x00000000, 0x80000000); | ||
24 | #if 0 | ||
25 | FPU_REG const CONST_2 = MAKE_REG(POS, 1, 0x00000000, 0x80000000); | ||
26 | FPU_REG const CONST_HALF = MAKE_REG(POS, -1, 0x00000000, 0x80000000); | ||
27 | #endif /* 0 */ | ||
28 | static FPU_REG const CONST_L2T = MAKE_REG(POS, 1, 0xcd1b8afe, 0xd49a784b); | ||
29 | static FPU_REG const CONST_L2E = MAKE_REG(POS, 0, 0x5c17f0bc, 0xb8aa3b29); | ||
30 | FPU_REG const CONST_PI = MAKE_REG(POS, 1, 0x2168c235, 0xc90fdaa2); | ||
31 | FPU_REG const CONST_PI2 = MAKE_REG(POS, 0, 0x2168c235, 0xc90fdaa2); | ||
32 | FPU_REG const CONST_PI4 = MAKE_REG(POS, -1, 0x2168c235, 0xc90fdaa2); | ||
33 | static FPU_REG const CONST_LG2 = MAKE_REG(POS, -2, 0xfbcff799, 0x9a209a84); | ||
34 | static FPU_REG const CONST_LN2 = MAKE_REG(POS, -1, 0xd1cf79ac, 0xb17217f7); | ||
35 | |||
36 | /* Extra bits to take pi/2 to more than 128 bits precision. */ | ||
37 | FPU_REG const CONST_PI2extra = MAKE_REG(NEG, -66, | ||
38 | 0xfc8f8cbb, 0xece675d1); | ||
39 | |||
40 | /* Only the sign (and tag) is used in internal zeroes */ | ||
41 | FPU_REG const CONST_Z = MAKE_REG(POS, EXP_UNDER, 0x0, 0x0); | ||
42 | |||
43 | /* Only the sign and significand (and tag) are used in internal NaNs */ | ||
44 | /* The 80486 never generates one of these | ||
45 | FPU_REG const CONST_SNAN = MAKE_REG(POS, EXP_OVER, 0x00000001, 0x80000000); | ||
46 | */ | ||
47 | /* This is the real indefinite QNaN */ | ||
48 | FPU_REG const CONST_QNaN = MAKE_REG(NEG, EXP_OVER, 0x00000000, 0xC0000000); | ||
49 | |||
50 | /* Only the sign (and tag) is used in internal infinities */ | ||
51 | FPU_REG const CONST_INF = MAKE_REG(POS, EXP_OVER, 0x00000000, 0x80000000); | ||
52 | |||
53 | |||
54 | static void fld_const(FPU_REG const *c, int adj, u_char tag) | ||
55 | { | ||
56 | FPU_REG *st_new_ptr; | ||
57 | |||
58 | if ( STACK_OVERFLOW ) | ||
59 | { | ||
60 | FPU_stack_overflow(); | ||
61 | return; | ||
62 | } | ||
63 | push(); | ||
64 | reg_copy(c, st_new_ptr); | ||
65 | st_new_ptr->sigl += adj; /* For all our fldxxx constants, we don't need to | ||
66 | borrow or carry. */ | ||
67 | FPU_settag0(tag); | ||
68 | clear_C1(); | ||
69 | } | ||
70 | |||
71 | /* A fast way to find out whether x is one of RC_DOWN or RC_CHOP | ||
72 | (and not one of RC_RND or RC_UP). | ||
73 | */ | ||
74 | #define DOWN_OR_CHOP(x) (x & RC_DOWN) | ||
75 | |||
76 | static void fld1(int rc) | ||
77 | { | ||
78 | fld_const(&CONST_1, 0, TAG_Valid); | ||
79 | } | ||
80 | |||
81 | static void fldl2t(int rc) | ||
82 | { | ||
83 | fld_const(&CONST_L2T, (rc == RC_UP) ? 1 : 0, TAG_Valid); | ||
84 | } | ||
85 | |||
86 | static void fldl2e(int rc) | ||
87 | { | ||
88 | fld_const(&CONST_L2E, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid); | ||
89 | } | ||
90 | |||
91 | static void fldpi(int rc) | ||
92 | { | ||
93 | fld_const(&CONST_PI, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid); | ||
94 | } | ||
95 | |||
96 | static void fldlg2(int rc) | ||
97 | { | ||
98 | fld_const(&CONST_LG2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid); | ||
99 | } | ||
100 | |||
101 | static void fldln2(int rc) | ||
102 | { | ||
103 | fld_const(&CONST_LN2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid); | ||
104 | } | ||
105 | |||
106 | static void fldz(int rc) | ||
107 | { | ||
108 | fld_const(&CONST_Z, 0, TAG_Zero); | ||
109 | } | ||
110 | |||
111 | typedef void (*FUNC_RC)(int); | ||
112 | |||
113 | static FUNC_RC constants_table[] = { | ||
114 | fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC)FPU_illegal | ||
115 | }; | ||
116 | |||
117 | void fconst(void) | ||
118 | { | ||
119 | (constants_table[FPU_rm])(control_word & CW_RC); | ||
120 | } | ||