1 | 1 |
2 | satan.sa 3.3 12/19/90 2 | satan.sa 3.3 12/19/90
3 | 3 |
4 | The entry point satan computes the arc 4 | The entry point satan computes the arctangent of an
5 | input value. satand does the same exce 5 | input value. satand does the same except the input value is a
6 | denormalized number. 6 | denormalized number.
7 | 7 |
8 | Input: Double-extended value in memory 8 | Input: Double-extended value in memory location pointed to by address
9 | register a0. 9 | register a0.
10 | 10 |
11 | Output: Arctan(X) returned in floating 11 | Output: Arctan(X) returned in floating-point register Fp0.
12 | 12 |
13 | Accuracy and Monotonicity: The returne 13 | Accuracy and Monotonicity: The returned result is within 2 ulps in
14 | 64 significant bit, i.e. withi 14 | 64 significant bit, i.e. within 0.5001 ulp to 53 bits if the
15 | result is subsequently rounded 15 | result is subsequently rounded to double precision. The
16 | result is provably monotonic i 16 | result is provably monotonic in double precision.
17 | 17 |
18 | Speed: The program satan takes approxi 18 | Speed: The program satan takes approximately 160 cycles for input
19 | argument X such that 1/16 < |X 19 | argument X such that 1/16 < |X| < 16. For the other arguments,
20 | the program will run no worse 20 | the program will run no worse than 10% slower.
21 | 21 |
22 | Algorithm: 22 | Algorithm:
23 | Step 1. If |X| >= 16 or |X| < 1/16, go 23 | Step 1. If |X| >= 16 or |X| < 1/16, go to Step 5.
24 | 24 |
25 | Step 2. Let X = sgn * 2**k * 1.xxxxxxx 25 | Step 2. Let X = sgn * 2**k * 1.xxxxxxxx...x. Note that k = -4, -3,..., or 3.
26 | Define F = sgn * 2**k * 1.xxxx 26 | Define F = sgn * 2**k * 1.xxxx1, i.e. the first 5 significant bits
27 | of X with a bit-1 attached at 27 | of X with a bit-1 attached at the 6-th bit position. Define u
28 | to be u = (X-F) / (1 + X*F). 28 | to be u = (X-F) / (1 + X*F).
29 | 29 |
30 | Step 3. Approximate arctan(u) by a pol 30 | Step 3. Approximate arctan(u) by a polynomial poly.
31 | 31 |
32 | Step 4. Return arctan(F) + poly, arcta 32 | Step 4. Return arctan(F) + poly, arctan(F) is fetched from a table of values
33 | calculated beforehand. Exit. 33 | calculated beforehand. Exit.
34 | 34 |
35 | Step 5. If |X| >= 16, go to Step 7. 35 | Step 5. If |X| >= 16, go to Step 7.
36 | 36 |
37 | Step 6. Approximate arctan(X) by an od 37 | Step 6. Approximate arctan(X) by an odd polynomial in X. Exit.
38 | 38 |
39 | Step 7. Define X' = -1/X. Approximate 39 | Step 7. Define X' = -1/X. Approximate arctan(X') by an odd polynomial in X'.
40 | Arctan(X) = sign(X)*Pi/2 + arc 40 | Arctan(X) = sign(X)*Pi/2 + arctan(X'). Exit.
41 | 41 |
42 42
43 | Copyright (C) Motorola, Inc. 1 43 | Copyright (C) Motorola, Inc. 1990
44 | All Rights Reserved 44 | All Rights Reserved
45 | 45 |
46 | For details on the license for this fi 46 | For details on the license for this file, please see the
47 | file, README, in this same directory. 47 | file, README, in this same directory.
48 48
49 |satan idnt 2,1 | Motorola 040 Floating Po 49 |satan idnt 2,1 | Motorola 040 Floating Point Software Package
50 50
51 |section 8 51 |section 8
52 52
53 #include "fpsp.h" 53 #include "fpsp.h"
54 54
55 BOUNDS1: .long 0x3FFB8000,0x4002FFFF 55 BOUNDS1: .long 0x3FFB8000,0x4002FFFF
56 56
57 ONE: .long 0x3F800000 57 ONE: .long 0x3F800000
58 58
59 .long 0x00000000 59 .long 0x00000000
60 60
61 ATANA3: .long 0xBFF6687E,0x314987D8 61 ATANA3: .long 0xBFF6687E,0x314987D8
62 ATANA2: .long 0x4002AC69,0x34A26DB3 62 ATANA2: .long 0x4002AC69,0x34A26DB3
63 63
64 ATANA1: .long 0xBFC2476F,0x4E1DA28E 64 ATANA1: .long 0xBFC2476F,0x4E1DA28E
65 ATANB6: .long 0x3FB34444,0x7F876989 65 ATANB6: .long 0x3FB34444,0x7F876989
66 66
67 ATANB5: .long 0xBFB744EE,0x7FAF45DB 67 ATANB5: .long 0xBFB744EE,0x7FAF45DB
68 ATANB4: .long 0x3FBC71C6,0x46940220 68 ATANB4: .long 0x3FBC71C6,0x46940220
69 69
70 ATANB3: .long 0xBFC24924,0x921872F9 70 ATANB3: .long 0xBFC24924,0x921872F9
71 ATANB2: .long 0x3FC99999,0x99998FA9 71 ATANB2: .long 0x3FC99999,0x99998FA9
72 72
73 ATANB1: .long 0xBFD55555,0x55555555 73 ATANB1: .long 0xBFD55555,0x55555555
74 ATANC5: .long 0xBFB70BF3,0x98539E6A 74 ATANC5: .long 0xBFB70BF3,0x98539E6A
75 75
76 ATANC4: .long 0x3FBC7187,0x962D1D7D 76 ATANC4: .long 0x3FBC7187,0x962D1D7D
77 ATANC3: .long 0xBFC24924,0x827107B8 77 ATANC3: .long 0xBFC24924,0x827107B8
78 78
79 ATANC2: .long 0x3FC99999,0x9996263E 79 ATANC2: .long 0x3FC99999,0x9996263E
80 ATANC1: .long 0xBFD55555,0x55555536 80 ATANC1: .long 0xBFD55555,0x55555536
81 81
82 PPIBY2: .long 0x3FFF0000,0xC90FDAA2,0x2168C235 82 PPIBY2: .long 0x3FFF0000,0xC90FDAA2,0x2168C235,0x00000000
83 NPIBY2: .long 0xBFFF0000,0xC90FDAA2,0x2168C235 83 NPIBY2: .long 0xBFFF0000,0xC90FDAA2,0x2168C235,0x00000000
84 PTINY: .long 0x00010000,0x80000000,0x00000000 84 PTINY: .long 0x00010000,0x80000000,0x00000000,0x00000000
85 NTINY: .long 0x80010000,0x80000000,0x00000000 85 NTINY: .long 0x80010000,0x80000000,0x00000000,0x00000000
86 86
87 ATANTBL: 87 ATANTBL:
88 .long 0x3FFB0000,0x83D152C5,0x060B7A 88 .long 0x3FFB0000,0x83D152C5,0x060B7A51,0x00000000
89 .long 0x3FFB0000,0x8BC85445,0x65498B 89 .long 0x3FFB0000,0x8BC85445,0x65498B8B,0x00000000
90 .long 0x3FFB0000,0x93BE4060,0x17626B 90 .long 0x3FFB0000,0x93BE4060,0x17626B0D,0x00000000
91 .long 0x3FFB0000,0x9BB3078D,0x35AEC2 91 .long 0x3FFB0000,0x9BB3078D,0x35AEC202,0x00000000
92 .long 0x3FFB0000,0xA3A69A52,0x5DDCE7 92 .long 0x3FFB0000,0xA3A69A52,0x5DDCE7DE,0x00000000
93 .long 0x3FFB0000,0xAB98E943,0x627656 93 .long 0x3FFB0000,0xAB98E943,0x62765619,0x00000000
94 .long 0x3FFB0000,0xB389E502,0xF9C598 94 .long 0x3FFB0000,0xB389E502,0xF9C59862,0x00000000
95 .long 0x3FFB0000,0xBB797E43,0x6B09E6 95 .long 0x3FFB0000,0xBB797E43,0x6B09E6FB,0x00000000
96 .long 0x3FFB0000,0xC367A5C7,0x39E5F4 96 .long 0x3FFB0000,0xC367A5C7,0x39E5F446,0x00000000
97 .long 0x3FFB0000,0xCB544C61,0xCFF7D5 97 .long 0x3FFB0000,0xCB544C61,0xCFF7D5C6,0x00000000
98 .long 0x3FFB0000,0xD33F62F8,0x248853 98 .long 0x3FFB0000,0xD33F62F8,0x2488533E,0x00000000
99 .long 0x3FFB0000,0xDB28DA81,0x62404C 99 .long 0x3FFB0000,0xDB28DA81,0x62404C77,0x00000000
100 .long 0x3FFB0000,0xE310A407,0x8AD34F 100 .long 0x3FFB0000,0xE310A407,0x8AD34F18,0x00000000
101 .long 0x3FFB0000,0xEAF6B0A8,0x188EE1 101 .long 0x3FFB0000,0xEAF6B0A8,0x188EE1EB,0x00000000
102 .long 0x3FFB0000,0xF2DAF194,0x9DBE79 102 .long 0x3FFB0000,0xF2DAF194,0x9DBE79D5,0x00000000
103 .long 0x3FFB0000,0xFABD5813,0x61D47E 103 .long 0x3FFB0000,0xFABD5813,0x61D47E3E,0x00000000
104 .long 0x3FFC0000,0x8346AC21,0x0959EC 104 .long 0x3FFC0000,0x8346AC21,0x0959ECC4,0x00000000
105 .long 0x3FFC0000,0x8B232A08,0x304282 105 .long 0x3FFC0000,0x8B232A08,0x304282D8,0x00000000
106 .long 0x3FFC0000,0x92FB70B8,0xD29AE2 106 .long 0x3FFC0000,0x92FB70B8,0xD29AE2F9,0x00000000
107 .long 0x3FFC0000,0x9ACF476F,0x5CCD1C 107 .long 0x3FFC0000,0x9ACF476F,0x5CCD1CB4,0x00000000
108 .long 0x3FFC0000,0xA29E7630,0x4954F2 108 .long 0x3FFC0000,0xA29E7630,0x4954F23F,0x00000000
109 .long 0x3FFC0000,0xAA68C5D0,0x8AB852 109 .long 0x3FFC0000,0xAA68C5D0,0x8AB85230,0x00000000
110 .long 0x3FFC0000,0xB22DFFFD,0x9D539F 110 .long 0x3FFC0000,0xB22DFFFD,0x9D539F83,0x00000000
111 .long 0x3FFC0000,0xB9EDEF45,0x3E900E 111 .long 0x3FFC0000,0xB9EDEF45,0x3E900EA5,0x00000000
112 .long 0x3FFC0000,0xC1A85F1C,0xC75E3E 112 .long 0x3FFC0000,0xC1A85F1C,0xC75E3EA5,0x00000000
113 .long 0x3FFC0000,0xC95D1BE8,0x28138D 113 .long 0x3FFC0000,0xC95D1BE8,0x28138DE6,0x00000000
114 .long 0x3FFC0000,0xD10BF300,0x840D2D 114 .long 0x3FFC0000,0xD10BF300,0x840D2DE4,0x00000000
115 .long 0x3FFC0000,0xD8B4B2BA,0x6BC05E 115 .long 0x3FFC0000,0xD8B4B2BA,0x6BC05E7A,0x00000000
116 .long 0x3FFC0000,0xE0572A6B,0xB42335 116 .long 0x3FFC0000,0xE0572A6B,0xB42335F6,0x00000000
117 .long 0x3FFC0000,0xE7F32A70,0xEA9CAA 117 .long 0x3FFC0000,0xE7F32A70,0xEA9CAA8F,0x00000000
118 .long 0x3FFC0000,0xEF888432,0x64ECEF 118 .long 0x3FFC0000,0xEF888432,0x64ECEFAA,0x00000000
119 .long 0x3FFC0000,0xF7170A28,0xECC066 119 .long 0x3FFC0000,0xF7170A28,0xECC06666,0x00000000
120 .long 0x3FFD0000,0x812FD288,0x332DAD 120 .long 0x3FFD0000,0x812FD288,0x332DAD32,0x00000000
121 .long 0x3FFD0000,0x88A8D1B1,0x218E4D 121 .long 0x3FFD0000,0x88A8D1B1,0x218E4D64,0x00000000
122 .long 0x3FFD0000,0x9012AB3F,0x23E4AE 122 .long 0x3FFD0000,0x9012AB3F,0x23E4AEE8,0x00000000
123 .long 0x3FFD0000,0x976CC3D4,0x11E7F1 123 .long 0x3FFD0000,0x976CC3D4,0x11E7F1B9,0x00000000
124 .long 0x3FFD0000,0x9EB68949,0x3889A2 124 .long 0x3FFD0000,0x9EB68949,0x3889A227,0x00000000
125 .long 0x3FFD0000,0xA5EF72C3,0x448736 125 .long 0x3FFD0000,0xA5EF72C3,0x4487361B,0x00000000
126 .long 0x3FFD0000,0xAD1700BA,0xF07A72 126 .long 0x3FFD0000,0xAD1700BA,0xF07A7227,0x00000000
127 .long 0x3FFD0000,0xB42CBCFA,0xFD37EF 127 .long 0x3FFD0000,0xB42CBCFA,0xFD37EFB7,0x00000000
128 .long 0x3FFD0000,0xBB303A94,0x0BA80F 128 .long 0x3FFD0000,0xBB303A94,0x0BA80F89,0x00000000
129 .long 0x3FFD0000,0xC22115C6,0xFCAEBB 129 .long 0x3FFD0000,0xC22115C6,0xFCAEBBAF,0x00000000
130 .long 0x3FFD0000,0xC8FEF3E6,0x863312 130 .long 0x3FFD0000,0xC8FEF3E6,0x86331221,0x00000000
131 .long 0x3FFD0000,0xCFC98330,0xB4000C 131 .long 0x3FFD0000,0xCFC98330,0xB4000C70,0x00000000
132 .long 0x3FFD0000,0xD6807AA1,0x102C5B 132 .long 0x3FFD0000,0xD6807AA1,0x102C5BF9,0x00000000
133 .long 0x3FFD0000,0xDD2399BC,0x31252A 133 .long 0x3FFD0000,0xDD2399BC,0x31252AA3,0x00000000
134 .long 0x3FFD0000,0xE3B2A855,0x6B8FC5 134 .long 0x3FFD0000,0xE3B2A855,0x6B8FC517,0x00000000
135 .long 0x3FFD0000,0xEA2D764F,0x643159 135 .long 0x3FFD0000,0xEA2D764F,0x64315989,0x00000000
136 .long 0x3FFD0000,0xF3BF5BF8,0xBAD1A2 136 .long 0x3FFD0000,0xF3BF5BF8,0xBAD1A21D,0x00000000
137 .long 0x3FFE0000,0x801CE39E,0x0D205C 137 .long 0x3FFE0000,0x801CE39E,0x0D205C9A,0x00000000
138 .long 0x3FFE0000,0x8630A2DA,0xDA1ED0 138 .long 0x3FFE0000,0x8630A2DA,0xDA1ED066,0x00000000
139 .long 0x3FFE0000,0x8C1AD445,0xF3E09B 139 .long 0x3FFE0000,0x8C1AD445,0xF3E09B8C,0x00000000
140 .long 0x3FFE0000,0x91DB8F16,0x64F350 140 .long 0x3FFE0000,0x91DB8F16,0x64F350E2,0x00000000
141 .long 0x3FFE0000,0x97731420,0x365E53 141 .long 0x3FFE0000,0x97731420,0x365E538C,0x00000000
142 .long 0x3FFE0000,0x9CE1C8E6,0xA0B8CD 142 .long 0x3FFE0000,0x9CE1C8E6,0xA0B8CDBA,0x00000000
143 .long 0x3FFE0000,0xA22832DB,0xCADAAE 143 .long 0x3FFE0000,0xA22832DB,0xCADAAE09,0x00000000
144 .long 0x3FFE0000,0xA746F2DD,0xB76022 144 .long 0x3FFE0000,0xA746F2DD,0xB7602294,0x00000000
145 .long 0x3FFE0000,0xAC3EC0FB,0x997DD6 145 .long 0x3FFE0000,0xAC3EC0FB,0x997DD6A2,0x00000000
146 .long 0x3FFE0000,0xB110688A,0xEBDC6F 146 .long 0x3FFE0000,0xB110688A,0xEBDC6F6A,0x00000000
147 .long 0x3FFE0000,0xB5BCC490,0x59ECC4 147 .long 0x3FFE0000,0xB5BCC490,0x59ECC4B0,0x00000000
148 .long 0x3FFE0000,0xBA44BC7D,0xD47078 148 .long 0x3FFE0000,0xBA44BC7D,0xD470782F,0x00000000
149 .long 0x3FFE0000,0xBEA94144,0xFD049A 149 .long 0x3FFE0000,0xBEA94144,0xFD049AAC,0x00000000
150 .long 0x3FFE0000,0xC2EB4ABB,0x661628 150 .long 0x3FFE0000,0xC2EB4ABB,0x661628B6,0x00000000
151 .long 0x3FFE0000,0xC70BD54C,0xE602EE 151 .long 0x3FFE0000,0xC70BD54C,0xE602EE14,0x00000000
152 .long 0x3FFE0000,0xCD000549,0xADEC71 152 .long 0x3FFE0000,0xCD000549,0xADEC7159,0x00000000
153 .long 0x3FFE0000,0xD48457D2,0xD8EA4E 153 .long 0x3FFE0000,0xD48457D2,0xD8EA4EA3,0x00000000
154 .long 0x3FFE0000,0xDB948DA7,0x12DECE 154 .long 0x3FFE0000,0xDB948DA7,0x12DECE3B,0x00000000
155 .long 0x3FFE0000,0xE23855F9,0x69E809 155 .long 0x3FFE0000,0xE23855F9,0x69E8096A,0x00000000
156 .long 0x3FFE0000,0xE8771129,0xC43532 156 .long 0x3FFE0000,0xE8771129,0xC4353259,0x00000000
157 .long 0x3FFE0000,0xEE57C16E,0x0D379C 157 .long 0x3FFE0000,0xEE57C16E,0x0D379C0D,0x00000000
158 .long 0x3FFE0000,0xF3E10211,0xA87C37 158 .long 0x3FFE0000,0xF3E10211,0xA87C3779,0x00000000
159 .long 0x3FFE0000,0xF919039D,0x758B8D 159 .long 0x3FFE0000,0xF919039D,0x758B8D41,0x00000000
160 .long 0x3FFE0000,0xFE058B8F,0x64935F 160 .long 0x3FFE0000,0xFE058B8F,0x64935FB3,0x00000000
161 .long 0x3FFF0000,0x8155FB49,0x7B685D 161 .long 0x3FFF0000,0x8155FB49,0x7B685D04,0x00000000
162 .long 0x3FFF0000,0x83889E35,0x49D108 162 .long 0x3FFF0000,0x83889E35,0x49D108E1,0x00000000
163 .long 0x3FFF0000,0x859CFA76,0x511D72 163 .long 0x3FFF0000,0x859CFA76,0x511D724B,0x00000000
164 .long 0x3FFF0000,0x87952ECF,0xFF8131 164 .long 0x3FFF0000,0x87952ECF,0xFF8131E7,0x00000000
165 .long 0x3FFF0000,0x89732FD1,0x955764 165 .long 0x3FFF0000,0x89732FD1,0x9557641B,0x00000000
166 .long 0x3FFF0000,0x8B38CAD1,0x01932A 166 .long 0x3FFF0000,0x8B38CAD1,0x01932A35,0x00000000
167 .long 0x3FFF0000,0x8CE7A8D8,0x301EE6 167 .long 0x3FFF0000,0x8CE7A8D8,0x301EE6B5,0x00000000
168 .long 0x3FFF0000,0x8F46A39E,0x2EAE52 168 .long 0x3FFF0000,0x8F46A39E,0x2EAE5281,0x00000000
169 .long 0x3FFF0000,0x922DA7D7,0x918884 169 .long 0x3FFF0000,0x922DA7D7,0x91888487,0x00000000
170 .long 0x3FFF0000,0x94D19FCB,0xDEDF52 170 .long 0x3FFF0000,0x94D19FCB,0xDEDF5241,0x00000000
171 .long 0x3FFF0000,0x973AB944,0x19D2A0 171 .long 0x3FFF0000,0x973AB944,0x19D2A08B,0x00000000
172 .long 0x3FFF0000,0x996FF00E,0x08E10B 172 .long 0x3FFF0000,0x996FF00E,0x08E10B96,0x00000000
173 .long 0x3FFF0000,0x9B773F95,0x12321D 173 .long 0x3FFF0000,0x9B773F95,0x12321DA7,0x00000000
174 .long 0x3FFF0000,0x9D55CC32,0x0F9356 174 .long 0x3FFF0000,0x9D55CC32,0x0F935624,0x00000000
175 .long 0x3FFF0000,0x9F100575,0x006CC5 175 .long 0x3FFF0000,0x9F100575,0x006CC571,0x00000000
176 .long 0x3FFF0000,0xA0A9C290,0xD97CC0 176 .long 0x3FFF0000,0xA0A9C290,0xD97CC06C,0x00000000
177 .long 0x3FFF0000,0xA22659EB,0xEBC063 177 .long 0x3FFF0000,0xA22659EB,0xEBC0630A,0x00000000
178 .long 0x3FFF0000,0xA388B4AF,0xF6EF0E 178 .long 0x3FFF0000,0xA388B4AF,0xF6EF0EC9,0x00000000
179 .long 0x3FFF0000,0xA4D35F10,0x61D292 179 .long 0x3FFF0000,0xA4D35F10,0x61D292C4,0x00000000
180 .long 0x3FFF0000,0xA60895DC,0xFBE318 180 .long 0x3FFF0000,0xA60895DC,0xFBE3187E,0x00000000
181 .long 0x3FFF0000,0xA72A51DC,0x7367BE 181 .long 0x3FFF0000,0xA72A51DC,0x7367BEAC,0x00000000
182 .long 0x3FFF0000,0xA83A5153,0x095616 182 .long 0x3FFF0000,0xA83A5153,0x0956168F,0x00000000
183 .long 0x3FFF0000,0xA93A2007,0x753954 183 .long 0x3FFF0000,0xA93A2007,0x7539546E,0x00000000
184 .long 0x3FFF0000,0xAA9E7245,0x023B26 184 .long 0x3FFF0000,0xAA9E7245,0x023B2605,0x00000000
185 .long 0x3FFF0000,0xAC4C84BA,0x6FE4D5 185 .long 0x3FFF0000,0xAC4C84BA,0x6FE4D58F,0x00000000
186 .long 0x3FFF0000,0xADCE4A4A,0x606B97 186 .long 0x3FFF0000,0xADCE4A4A,0x606B9712,0x00000000
187 .long 0x3FFF0000,0xAF2A2DCD,0x8D263C 187 .long 0x3FFF0000,0xAF2A2DCD,0x8D263C9C,0x00000000
188 .long 0x3FFF0000,0xB0656F81,0xF22265 188 .long 0x3FFF0000,0xB0656F81,0xF22265C7,0x00000000
189 .long 0x3FFF0000,0xB1846515,0x0F7149 189 .long 0x3FFF0000,0xB1846515,0x0F71496A,0x00000000
190 .long 0x3FFF0000,0xB28AAA15,0x6F9ADA 190 .long 0x3FFF0000,0xB28AAA15,0x6F9ADA35,0x00000000
191 .long 0x3FFF0000,0xB37B44FF,0x3766B8 191 .long 0x3FFF0000,0xB37B44FF,0x3766B895,0x00000000
192 .long 0x3FFF0000,0xB458C3DC,0xE96304 192 .long 0x3FFF0000,0xB458C3DC,0xE9630433,0x00000000
193 .long 0x3FFF0000,0xB525529D,0x562246 193 .long 0x3FFF0000,0xB525529D,0x562246BD,0x00000000
194 .long 0x3FFF0000,0xB5E2CCA9,0x5F9D88 194 .long 0x3FFF0000,0xB5E2CCA9,0x5F9D88CC,0x00000000
195 .long 0x3FFF0000,0xB692CADA,0x7ACA1A 195 .long 0x3FFF0000,0xB692CADA,0x7ACA1ADA,0x00000000
196 .long 0x3FFF0000,0xB736AEA7,0xA69258 196 .long 0x3FFF0000,0xB736AEA7,0xA6925838,0x00000000
197 .long 0x3FFF0000,0xB7CFAB28,0x7E9F7B 197 .long 0x3FFF0000,0xB7CFAB28,0x7E9F7B36,0x00000000
198 .long 0x3FFF0000,0xB85ECC66,0xCB2198 198 .long 0x3FFF0000,0xB85ECC66,0xCB219835,0x00000000
199 .long 0x3FFF0000,0xB8E4FD5A,0x20A593 199 .long 0x3FFF0000,0xB8E4FD5A,0x20A593DA,0x00000000
200 .long 0x3FFF0000,0xB99F41F6,0x4AFF9B 200 .long 0x3FFF0000,0xB99F41F6,0x4AFF9BB5,0x00000000
201 .long 0x3FFF0000,0xBA7F1E17,0x842BBE 201 .long 0x3FFF0000,0xBA7F1E17,0x842BBE7B,0x00000000
202 .long 0x3FFF0000,0xBB471285,0x7637E1 202 .long 0x3FFF0000,0xBB471285,0x7637E17D,0x00000000
203 .long 0x3FFF0000,0xBBFABE8A,0x4788DF 203 .long 0x3FFF0000,0xBBFABE8A,0x4788DF6F,0x00000000
204 .long 0x3FFF0000,0xBC9D0FAD,0x2B689D 204 .long 0x3FFF0000,0xBC9D0FAD,0x2B689D79,0x00000000
205 .long 0x3FFF0000,0xBD306A39,0x471ECD 205 .long 0x3FFF0000,0xBD306A39,0x471ECD86,0x00000000
206 .long 0x3FFF0000,0xBDB6C731,0x856AF1 206 .long 0x3FFF0000,0xBDB6C731,0x856AF18A,0x00000000
207 .long 0x3FFF0000,0xBE31CAC5,0x02E80D 207 .long 0x3FFF0000,0xBE31CAC5,0x02E80D70,0x00000000
208 .long 0x3FFF0000,0xBEA2D55C,0xE33194 208 .long 0x3FFF0000,0xBEA2D55C,0xE33194E2,0x00000000
209 .long 0x3FFF0000,0xBF0B10B7,0xC03128 209 .long 0x3FFF0000,0xBF0B10B7,0xC03128F0,0x00000000
210 .long 0x3FFF0000,0xBF6B7A18,0xDACB77 210 .long 0x3FFF0000,0xBF6B7A18,0xDACB778D,0x00000000
211 .long 0x3FFF0000,0xBFC4EA46,0x63FA18 211 .long 0x3FFF0000,0xBFC4EA46,0x63FA18F6,0x00000000
212 .long 0x3FFF0000,0xC0181BDE,0x8B89A4 212 .long 0x3FFF0000,0xC0181BDE,0x8B89A454,0x00000000
213 .long 0x3FFF0000,0xC065B066,0xCFBF64 213 .long 0x3FFF0000,0xC065B066,0xCFBF6439,0x00000000
214 .long 0x3FFF0000,0xC0AE345F,0x56340A 214 .long 0x3FFF0000,0xC0AE345F,0x56340AE6,0x00000000
215 .long 0x3FFF0000,0xC0F22291,0x9CB9E6 215 .long 0x3FFF0000,0xC0F22291,0x9CB9E6A7,0x00000000
216 216
217 .set X,FP_SCR1 217 .set X,FP_SCR1
218 .set XDCARE,X+2 218 .set XDCARE,X+2
219 .set XFRAC,X+4 219 .set XFRAC,X+4
220 .set XFRACLO,X+8 220 .set XFRACLO,X+8
221 221
222 .set ATANF,FP_SCR2 222 .set ATANF,FP_SCR2
223 .set ATANFHI,ATANF+4 223 .set ATANFHI,ATANF+4
224 .set ATANFLO,ATANF+8 224 .set ATANFLO,ATANF+8
225 225
226 226
227 | xref t_frcinx 227 | xref t_frcinx
228 |xref t_extdnrm 228 |xref t_extdnrm
229 229
230 .global satand 230 .global satand
231 satand: 231 satand:
232 |--ENTRY POINT FOR ATAN(X) FOR DENORMALIZED AR 232 |--ENTRY POINT FOR ATAN(X) FOR DENORMALIZED ARGUMENT
233 233
234 bra t_extdnrm 234 bra t_extdnrm
235 235
236 .global satan 236 .global satan
237 satan: 237 satan:
238 |--ENTRY POINT FOR ATAN(X), HERE X IS FINITE, 238 |--ENTRY POINT FOR ATAN(X), HERE X IS FINITE, NON-ZERO, AND NOT NAN'S
239 239
240 fmovex (%a0),%fp0 | ...L 240 fmovex (%a0),%fp0 | ...LOAD INPUT
241 241
242 movel (%a0),%d0 242 movel (%a0),%d0
243 movew 4(%a0),%d0 243 movew 4(%a0),%d0
244 fmovex %fp0,X(%a6) 244 fmovex %fp0,X(%a6)
245 andil #0x7FFFFFFF,%d0 245 andil #0x7FFFFFFF,%d0
246 246
247 cmpil #0x3FFB8000,%d0 247 cmpil #0x3FFB8000,%d0 | ...|X| >= 1/16?
248 bges ATANOK1 248 bges ATANOK1
249 bra ATANSM 249 bra ATANSM
250 250
251 ATANOK1: 251 ATANOK1:
252 cmpil #0x4002FFFF,%d0 252 cmpil #0x4002FFFF,%d0 | ...|X| < 16 ?
253 bles ATANMAIN 253 bles ATANMAIN
254 bra ATANBIG 254 bra ATANBIG
255 255
256 256
257 |--THE MOST LIKELY CASE, |X| IN [1/16, 16). WE 257 |--THE MOST LIKELY CASE, |X| IN [1/16, 16). WE USE TABLE TECHNIQUE
258 |--THE IDEA IS ATAN(X) = ATAN(F) + ATAN( [X-F] 258 |--THE IDEA IS ATAN(X) = ATAN(F) + ATAN( [X-F] / [1+XF] ).
259 |--SO IF F IS CHOSEN TO BE CLOSE TO X AND ATAN 259 |--SO IF F IS CHOSEN TO BE CLOSE TO X AND ATAN(F) IS STORED IN
260 |--A TABLE, ALL WE NEED IS TO APPROXIMATE ATAN 260 |--A TABLE, ALL WE NEED IS TO APPROXIMATE ATAN(U) WHERE
261 |--U = (X-F)/(1+XF) IS SMALL (REMEMBER F IS CL 261 |--U = (X-F)/(1+XF) IS SMALL (REMEMBER F IS CLOSE TO X). IT IS
262 |--TRUE THAT A DIVIDE IS NOW NEEDED, BUT THE A 262 |--TRUE THAT A DIVIDE IS NOW NEEDED, BUT THE APPROXIMATION FOR
263 |--ATAN(U) IS A VERY SHORT POLYNOMIAL AND THE 263 |--ATAN(U) IS A VERY SHORT POLYNOMIAL AND THE INDEXING TO
264 |--FETCH F AND SAVING OF REGISTERS CAN BE ALL 264 |--FETCH F AND SAVING OF REGISTERS CAN BE ALL HIDED UNDER THE
265 |--DIVIDE. IN THE END THIS METHOD IS MUCH FAST 265 |--DIVIDE. IN THE END THIS METHOD IS MUCH FASTER THAN A TRADITIONAL
266 |--ONE. NOTE ALSO THAT THE TRADITIONAL SCHEME 266 |--ONE. NOTE ALSO THAT THE TRADITIONAL SCHEME THAT APPROXIMATE
267 |--ATAN(X) DIRECTLY WILL NEED TO USE A RATIONA 267 |--ATAN(X) DIRECTLY WILL NEED TO USE A RATIONAL APPROXIMATION
268 |--(DIVISION NEEDED) ANYWAY BECAUSE A POLYNOMI 268 |--(DIVISION NEEDED) ANYWAY BECAUSE A POLYNOMIAL APPROXIMATION
269 |--WILL INVOLVE A VERY LONG POLYNOMIAL. 269 |--WILL INVOLVE A VERY LONG POLYNOMIAL.
270 270
271 |--NOW WE SEE X AS +-2^K * 1.BBBBBBB....B <- 1 271 |--NOW WE SEE X AS +-2^K * 1.BBBBBBB....B <- 1. + 63 BITS
272 |--WE CHOSE F TO BE +-2^K * 1.BBBB1 272 |--WE CHOSE F TO BE +-2^K * 1.BBBB1
273 |--THAT IS IT MATCHES THE EXPONENT AND FIRST 5 273 |--THAT IS IT MATCHES THE EXPONENT AND FIRST 5 BITS OF X, THE
274 |--SIXTH BITS IS SET TO BE 1. SINCE K = -4, -3 274 |--SIXTH BITS IS SET TO BE 1. SINCE K = -4, -3, ..., 3, THERE
275 |--ARE ONLY 8 TIMES 16 = 2^7 = 128 |F|'S. SINC 275 |--ARE ONLY 8 TIMES 16 = 2^7 = 128 |F|'S. SINCE ATAN(-|F|) IS
276 |-- -ATAN(|F|), WE NEED TO STORE ONLY ATAN(|F| 276 |-- -ATAN(|F|), WE NEED TO STORE ONLY ATAN(|F|).
277 277
278 ATANMAIN: 278 ATANMAIN:
279 279
280 movew #0x0000,XDCARE(%a6) 280 movew #0x0000,XDCARE(%a6) | ...CLEAN UP X JUST IN CASE
281 andil #0xF8000000,XFRAC(%a6) 281 andil #0xF8000000,XFRAC(%a6) | ...FIRST 5 BITS
282 oril #0x04000000,XFRAC(%a6) 282 oril #0x04000000,XFRAC(%a6) | ...SET 6-TH BIT TO 1
283 movel #0x00000000,XFRACLO(%a 283 movel #0x00000000,XFRACLO(%a6) | ...LOCATION OF X IS NOW F
284 284
285 fmovex %fp0,%fp1 285 fmovex %fp0,%fp1 | ...FP1 IS X
286 fmulx X(%a6),%fp1 286 fmulx X(%a6),%fp1 | ...FP1 IS X*F, NOTE THAT X*F > 0
287 fsubx X(%a6),%fp0 287 fsubx X(%a6),%fp0 | ...FP0 IS X-F
288 fadds #0x3F800000,%fp1 288 fadds #0x3F800000,%fp1 | ...FP1 IS 1 + X*F
289 fdivx %fp1,%fp0 289 fdivx %fp1,%fp0 | ...FP0 IS U = (X-F)/(1+X*F)
290 290
291 |--WHILE THE DIVISION IS TAKING ITS TIME, WE F 291 |--WHILE THE DIVISION IS TAKING ITS TIME, WE FETCH ATAN(|F|)
292 |--CREATE ATAN(F) AND STORE IT IN ATANF, AND 292 |--CREATE ATAN(F) AND STORE IT IN ATANF, AND
293 |--SAVE REGISTERS FP2. 293 |--SAVE REGISTERS FP2.
294 294
295 movel %d2,-(%a7) | ...S 295 movel %d2,-(%a7) | ...SAVE d2 TEMPORARILY
296 movel %d0,%d2 | ...T 296 movel %d0,%d2 | ...THE EXPO AND 16 BITS OF X
297 andil #0x00007800,%d0 | ...4 297 andil #0x00007800,%d0 | ...4 VARYING BITS OF F'S FRACTION
298 andil #0x7FFF0000,%d2 | ...E 298 andil #0x7FFF0000,%d2 | ...EXPONENT OF F
299 subil #0x3FFB0000,%d2 | ...K 299 subil #0x3FFB0000,%d2 | ...K+4
300 asrl #1,%d2 300 asrl #1,%d2
301 addl %d2,%d0 | ...T 301 addl %d2,%d0 | ...THE 7 BITS IDENTIFYING F
302 asrl #7,%d0 | ...I 302 asrl #7,%d0 | ...INDEX INTO TBL OF ATAN(|F|)
303 lea ATANTBL,%a1 303 lea ATANTBL,%a1
304 addal %d0,%a1 | ...A 304 addal %d0,%a1 | ...ADDRESS OF ATAN(|F|)
305 movel (%a1)+,ATANF(%a6) 305 movel (%a1)+,ATANF(%a6)
306 movel (%a1)+,ATANFHI(%a6) 306 movel (%a1)+,ATANFHI(%a6)
307 movel (%a1)+,ATANFLO(%a6) 307 movel (%a1)+,ATANFLO(%a6) | ...ATANF IS NOW ATAN(|F|)
308 movel X(%a6),%d0 308 movel X(%a6),%d0 | ...LOAD SIGN AND EXPO. AGAIN
309 andil #0x80000000,%d0 | ...S 309 andil #0x80000000,%d0 | ...SIGN(F)
310 orl %d0,ATANF(%a6) | ...A 310 orl %d0,ATANF(%a6) | ...ATANF IS NOW SIGN(F)*ATAN(|F|)
311 movel (%a7)+,%d2 | ...R 311 movel (%a7)+,%d2 | ...RESTORE d2
312 312
313 |--THAT'S ALL I HAVE TO DO FOR NOW, 313 |--THAT'S ALL I HAVE TO DO FOR NOW,
314 |--BUT ALAS, THE DIVIDE IS STILL CRANKING! 314 |--BUT ALAS, THE DIVIDE IS STILL CRANKING!
315 315
316 |--U IN FP0, WE ARE NOW READY TO COMPUTE ATAN( 316 |--U IN FP0, WE ARE NOW READY TO COMPUTE ATAN(U) AS
317 |--U + A1*U*V*(A2 + V*(A3 + V)), V = U*U 317 |--U + A1*U*V*(A2 + V*(A3 + V)), V = U*U
318 |--THE POLYNOMIAL MAY LOOK STRANGE, BUT IS NEV 318 |--THE POLYNOMIAL MAY LOOK STRANGE, BUT IS NEVERTHELESS CORRECT.
319 |--THE NATURAL FORM IS U + U*V*(A1 + V*(A2 + V 319 |--THE NATURAL FORM IS U + U*V*(A1 + V*(A2 + V*A3))
320 |--WHAT WE HAVE HERE IS MERELY A1 = A3, A2 = 320 |--WHAT WE HAVE HERE IS MERELY A1 = A3, A2 = A1/A3, A3 = A2/A3.
321 |--THE REASON FOR THIS REARRANGEMENT IS TO MAK 321 |--THE REASON FOR THIS REARRANGEMENT IS TO MAKE THE INDEPENDENT
322 |--PARTS A1*U*V AND (A2 + ... STUFF) MORE LOAD 322 |--PARTS A1*U*V AND (A2 + ... STUFF) MORE LOAD-BALANCED
323 323
324 324
325 fmovex %fp0,%fp1 325 fmovex %fp0,%fp1
326 fmulx %fp1,%fp1 326 fmulx %fp1,%fp1
327 fmoved ATANA3,%fp2 327 fmoved ATANA3,%fp2
328 faddx %fp1,%fp2 328 faddx %fp1,%fp2 | ...A3+V
329 fmulx %fp1,%fp2 329 fmulx %fp1,%fp2 | ...V*(A3+V)
330 fmulx %fp0,%fp1 330 fmulx %fp0,%fp1 | ...U*V
331 faddd ATANA2,%fp2 | ...A 331 faddd ATANA2,%fp2 | ...A2+V*(A3+V)
332 fmuld ATANA1,%fp1 | ...A 332 fmuld ATANA1,%fp1 | ...A1*U*V
333 fmulx %fp2,%fp1 333 fmulx %fp2,%fp1 | ...A1*U*V*(A2+V*(A3+V))
334 334
335 faddx %fp1,%fp0 335 faddx %fp1,%fp0 | ...ATAN(U), FP1 RELEASED
336 fmovel %d1,%FPCR 336 fmovel %d1,%FPCR |restore users exceptions
337 faddx ATANF(%a6),%fp0 | ...A 337 faddx ATANF(%a6),%fp0 | ...ATAN(X)
338 bra t_frcinx 338 bra t_frcinx
339 339
340 ATANBORS: 340 ATANBORS:
341 |--|X| IS IN d0 IN COMPACT FORM. FP1, d0 SAVED 341 |--|X| IS IN d0 IN COMPACT FORM. FP1, d0 SAVED.
342 |--FP0 IS X AND |X| <= 1/16 OR |X| >= 16. 342 |--FP0 IS X AND |X| <= 1/16 OR |X| >= 16.
343 cmpil #0x3FFF8000,%d0 343 cmpil #0x3FFF8000,%d0
344 bgt ATANBIG | ...I.E. |X| 344 bgt ATANBIG | ...I.E. |X| >= 16
345 345
346 ATANSM: 346 ATANSM:
347 |--|X| <= 1/16 347 |--|X| <= 1/16
348 |--IF |X| < 2^(-40), RETURN X AS ANSWER. OTHER 348 |--IF |X| < 2^(-40), RETURN X AS ANSWER. OTHERWISE, APPROXIMATE
349 |--ATAN(X) BY X + X*Y*(B1+Y*(B2+Y*(B3+Y*(B4+Y* 349 |--ATAN(X) BY X + X*Y*(B1+Y*(B2+Y*(B3+Y*(B4+Y*(B5+Y*B6)))))
350 |--WHICH IS X + X*Y*( [B1+Z*(B3+Z*B5)] + [Y*(B 350 |--WHICH IS X + X*Y*( [B1+Z*(B3+Z*B5)] + [Y*(B2+Z*(B4+Z*B6)] )
351 |--WHERE Y = X*X, AND Z = Y*Y. 351 |--WHERE Y = X*X, AND Z = Y*Y.
352 352
353 cmpil #0x3FD78000,%d0 353 cmpil #0x3FD78000,%d0
354 blt ATANTINY 354 blt ATANTINY
355 |--COMPUTE POLYNOMIAL 355 |--COMPUTE POLYNOMIAL
356 fmulx %fp0,%fp0 | ...F 356 fmulx %fp0,%fp0 | ...FP0 IS Y = X*X
357 357
358 358
359 movew #0x0000,XDCARE(%a6) 359 movew #0x0000,XDCARE(%a6)
360 360
361 fmovex %fp0,%fp1 361 fmovex %fp0,%fp1
362 fmulx %fp1,%fp1 362 fmulx %fp1,%fp1 | ...FP1 IS Z = Y*Y
363 363
364 fmoved ATANB6,%fp2 364 fmoved ATANB6,%fp2
365 fmoved ATANB5,%fp3 365 fmoved ATANB5,%fp3
366 366
367 fmulx %fp1,%fp2 367 fmulx %fp1,%fp2 | ...Z*B6
368 fmulx %fp1,%fp3 368 fmulx %fp1,%fp3 | ...Z*B5
369 369
370 faddd ATANB4,%fp2 | ...B 370 faddd ATANB4,%fp2 | ...B4+Z*B6
371 faddd ATANB3,%fp3 | ...B 371 faddd ATANB3,%fp3 | ...B3+Z*B5
372 372
373 fmulx %fp1,%fp2 373 fmulx %fp1,%fp2 | ...Z*(B4+Z*B6)
374 fmulx %fp3,%fp1 374 fmulx %fp3,%fp1 | ...Z*(B3+Z*B5)
375 375
376 faddd ATANB2,%fp2 | ...B 376 faddd ATANB2,%fp2 | ...B2+Z*(B4+Z*B6)
377 faddd ATANB1,%fp1 | ...B 377 faddd ATANB1,%fp1 | ...B1+Z*(B3+Z*B5)
378 378
379 fmulx %fp0,%fp2 379 fmulx %fp0,%fp2 | ...Y*(B2+Z*(B4+Z*B6))
380 fmulx X(%a6),%fp0 380 fmulx X(%a6),%fp0 | ...X*Y
381 381
382 faddx %fp2,%fp1 382 faddx %fp2,%fp1 | ...[B1+Z*(B3+Z*B5)]+[Y*(B2+Z*(B4+Z*B6))]
383 383
384 384
385 fmulx %fp1,%fp0 | ...X 385 fmulx %fp1,%fp0 | ...X*Y*([B1+Z*(B3+Z*B5)]+[Y*(B2+Z*(B4+Z*B6))])
386 386
387 fmovel %d1,%FPCR 387 fmovel %d1,%FPCR |restore users exceptions
388 faddx X(%a6),%fp0 388 faddx X(%a6),%fp0
389 389
390 bra t_frcinx 390 bra t_frcinx
391 391
392 ATANTINY: 392 ATANTINY:
393 |--|X| < 2^(-40), ATAN(X) = X 393 |--|X| < 2^(-40), ATAN(X) = X
394 movew #0x0000,XDCARE(%a6) 394 movew #0x0000,XDCARE(%a6)
395 395
396 fmovel %d1,%FPCR 396 fmovel %d1,%FPCR |restore users exceptions
397 fmovex X(%a6),%fp0 |last 397 fmovex X(%a6),%fp0 |last inst - possible exception set
398 398
399 bra t_frcinx 399 bra t_frcinx
400 400
401 ATANBIG: 401 ATANBIG:
402 |--IF |X| > 2^(100), RETURN SIGN(X)*(PI/2 402 |--IF |X| > 2^(100), RETURN SIGN(X)*(PI/2 - TINY). OTHERWISE,
403 |--RETURN SIGN(X)*PI/2 + ATAN(-1/X). 403 |--RETURN SIGN(X)*PI/2 + ATAN(-1/X).
404 cmpil #0x40638000,%d0 404 cmpil #0x40638000,%d0
405 bgt ATANHUGE 405 bgt ATANHUGE
406 406
407 |--APPROXIMATE ATAN(-1/X) BY 407 |--APPROXIMATE ATAN(-1/X) BY
408 |--X'+X'*Y*(C1+Y*(C2+Y*(C3+Y*(C4+Y*C5)))), X' 408 |--X'+X'*Y*(C1+Y*(C2+Y*(C3+Y*(C4+Y*C5)))), X' = -1/X, Y = X'*X'
409 |--THIS CAN BE RE-WRITTEN AS 409 |--THIS CAN BE RE-WRITTEN AS
410 |--X'+X'*Y*( [C1+Z*(C3+Z*C5)] + [Y*(C2+Z*C4)] 410 |--X'+X'*Y*( [C1+Z*(C3+Z*C5)] + [Y*(C2+Z*C4)] ), Z = Y*Y.
411 411
412 fmoves #0xBF800000,%fp1 412 fmoves #0xBF800000,%fp1 | ...LOAD -1
413 fdivx %fp0,%fp1 413 fdivx %fp0,%fp1 | ...FP1 IS -1/X
414 414
415 415
416 |--DIVIDE IS STILL CRANKING 416 |--DIVIDE IS STILL CRANKING
417 417
418 fmovex %fp1,%fp0 418 fmovex %fp1,%fp0 | ...FP0 IS X'
419 fmulx %fp0,%fp0 419 fmulx %fp0,%fp0 | ...FP0 IS Y = X'*X'
420 fmovex %fp1,X(%a6) 420 fmovex %fp1,X(%a6) | ...X IS REALLY X'
421 421
422 fmovex %fp0,%fp1 422 fmovex %fp0,%fp1
423 fmulx %fp1,%fp1 423 fmulx %fp1,%fp1 | ...FP1 IS Z = Y*Y
424 424
425 fmoved ATANC5,%fp3 425 fmoved ATANC5,%fp3
426 fmoved ATANC4,%fp2 426 fmoved ATANC4,%fp2
427 427
428 fmulx %fp1,%fp3 428 fmulx %fp1,%fp3 | ...Z*C5
429 fmulx %fp1,%fp2 429 fmulx %fp1,%fp2 | ...Z*B4
430 430
431 faddd ATANC3,%fp3 | ...C 431 faddd ATANC3,%fp3 | ...C3+Z*C5
432 faddd ATANC2,%fp2 | ...C 432 faddd ATANC2,%fp2 | ...C2+Z*C4
433 433
434 fmulx %fp3,%fp1 434 fmulx %fp3,%fp1 | ...Z*(C3+Z*C5), FP3 RELEASED
435 fmulx %fp0,%fp2 435 fmulx %fp0,%fp2 | ...Y*(C2+Z*C4)
436 436
437 faddd ATANC1,%fp1 | ...C 437 faddd ATANC1,%fp1 | ...C1+Z*(C3+Z*C5)
438 fmulx X(%a6),%fp0 438 fmulx X(%a6),%fp0 | ...X'*Y
439 439
440 faddx %fp2,%fp1 440 faddx %fp2,%fp1 | ...[Y*(C2+Z*C4)]+[C1+Z*(C3+Z*C5)]
441 441
442 442
443 fmulx %fp1,%fp0 443 fmulx %fp1,%fp0 | ...X'*Y*([B1+Z*(B3+Z*B5)]
444 | ... 444 | ... +[Y*(B2+Z*(B4+Z*B6))])
445 faddx X(%a6),%fp0 445 faddx X(%a6),%fp0
446 446
447 fmovel %d1,%FPCR 447 fmovel %d1,%FPCR |restore users exceptions
448 448
449 btstb #7,(%a0) 449 btstb #7,(%a0)
450 beqs pos_big 450 beqs pos_big
451 451
452 neg_big: 452 neg_big:
453 faddx NPIBY2,%fp0 453 faddx NPIBY2,%fp0
454 bra t_frcinx 454 bra t_frcinx
455 455
456 pos_big: 456 pos_big:
457 faddx PPIBY2,%fp0 457 faddx PPIBY2,%fp0
458 bra t_frcinx 458 bra t_frcinx
459 459
460 ATANHUGE: 460 ATANHUGE:
461 |--RETURN SIGN(X)*(PIBY2 - TINY) = SIGN(X)*PIB 461 |--RETURN SIGN(X)*(PIBY2 - TINY) = SIGN(X)*PIBY2 - SIGN(X)*TINY
462 btstb #7,(%a0) 462 btstb #7,(%a0)
463 beqs pos_huge 463 beqs pos_huge
464 464
465 neg_huge: 465 neg_huge:
466 fmovex NPIBY2,%fp0 466 fmovex NPIBY2,%fp0
467 fmovel %d1,%fpcr 467 fmovel %d1,%fpcr
468 fsubx NTINY,%fp0 468 fsubx NTINY,%fp0
469 bra t_frcinx 469 bra t_frcinx
470 470
471 pos_huge: 471 pos_huge:
472 fmovex PPIBY2,%fp0 472 fmovex PPIBY2,%fp0
473 fmovel %d1,%fpcr 473 fmovel %d1,%fpcr
474 fsubx PTINY,%fp0 474 fsubx PTINY,%fp0
475 bra t_frcinx 475 bra t_frcinx
476 476
477 |end 477 |end
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