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 | THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
47 | file, README, in this same directory. !! 47 | The copyright notice above does not evidence any
>> 48 | actual or intended publication of such source code.
48 49
49 |satan idnt 2,1 | Motorola 040 Floating Po 50 |satan idnt 2,1 | Motorola 040 Floating Point Software Package
50 51
51 |section 8 52 |section 8
52 53
53 #include "fpsp.h" 54 #include "fpsp.h"
54 !! 55
55 BOUNDS1: .long 0x3FFB8000,0x4002FFFF 56 BOUNDS1: .long 0x3FFB8000,0x4002FFFF
56 57
57 ONE: .long 0x3F800000 58 ONE: .long 0x3F800000
58 59
59 .long 0x00000000 60 .long 0x00000000
60 61
61 ATANA3: .long 0xBFF6687E,0x314987D8 62 ATANA3: .long 0xBFF6687E,0x314987D8
62 ATANA2: .long 0x4002AC69,0x34A26DB3 63 ATANA2: .long 0x4002AC69,0x34A26DB3
63 64
64 ATANA1: .long 0xBFC2476F,0x4E1DA28E 65 ATANA1: .long 0xBFC2476F,0x4E1DA28E
65 ATANB6: .long 0x3FB34444,0x7F876989 66 ATANB6: .long 0x3FB34444,0x7F876989
66 67
67 ATANB5: .long 0xBFB744EE,0x7FAF45DB 68 ATANB5: .long 0xBFB744EE,0x7FAF45DB
68 ATANB4: .long 0x3FBC71C6,0x46940220 69 ATANB4: .long 0x3FBC71C6,0x46940220
69 70
70 ATANB3: .long 0xBFC24924,0x921872F9 71 ATANB3: .long 0xBFC24924,0x921872F9
71 ATANB2: .long 0x3FC99999,0x99998FA9 72 ATANB2: .long 0x3FC99999,0x99998FA9
72 73
73 ATANB1: .long 0xBFD55555,0x55555555 74 ATANB1: .long 0xBFD55555,0x55555555
74 ATANC5: .long 0xBFB70BF3,0x98539E6A 75 ATANC5: .long 0xBFB70BF3,0x98539E6A
75 76
76 ATANC4: .long 0x3FBC7187,0x962D1D7D 77 ATANC4: .long 0x3FBC7187,0x962D1D7D
77 ATANC3: .long 0xBFC24924,0x827107B8 78 ATANC3: .long 0xBFC24924,0x827107B8
78 79
79 ATANC2: .long 0x3FC99999,0x9996263E 80 ATANC2: .long 0x3FC99999,0x9996263E
80 ATANC1: .long 0xBFD55555,0x55555536 81 ATANC1: .long 0xBFD55555,0x55555536
81 82
82 PPIBY2: .long 0x3FFF0000,0xC90FDAA2,0x2168C235 83 PPIBY2: .long 0x3FFF0000,0xC90FDAA2,0x2168C235,0x00000000
83 NPIBY2: .long 0xBFFF0000,0xC90FDAA2,0x2168C235 84 NPIBY2: .long 0xBFFF0000,0xC90FDAA2,0x2168C235,0x00000000
84 PTINY: .long 0x00010000,0x80000000,0x00000000 85 PTINY: .long 0x00010000,0x80000000,0x00000000,0x00000000
85 NTINY: .long 0x80010000,0x80000000,0x00000000 86 NTINY: .long 0x80010000,0x80000000,0x00000000,0x00000000
86 87
87 ATANTBL: 88 ATANTBL:
88 .long 0x3FFB0000,0x83D152C5,0x060B7A 89 .long 0x3FFB0000,0x83D152C5,0x060B7A51,0x00000000
89 .long 0x3FFB0000,0x8BC85445,0x65498B 90 .long 0x3FFB0000,0x8BC85445,0x65498B8B,0x00000000
90 .long 0x3FFB0000,0x93BE4060,0x17626B 91 .long 0x3FFB0000,0x93BE4060,0x17626B0D,0x00000000
91 .long 0x3FFB0000,0x9BB3078D,0x35AEC2 92 .long 0x3FFB0000,0x9BB3078D,0x35AEC202,0x00000000
92 .long 0x3FFB0000,0xA3A69A52,0x5DDCE7 93 .long 0x3FFB0000,0xA3A69A52,0x5DDCE7DE,0x00000000
93 .long 0x3FFB0000,0xAB98E943,0x627656 94 .long 0x3FFB0000,0xAB98E943,0x62765619,0x00000000
94 .long 0x3FFB0000,0xB389E502,0xF9C598 95 .long 0x3FFB0000,0xB389E502,0xF9C59862,0x00000000
95 .long 0x3FFB0000,0xBB797E43,0x6B09E6 96 .long 0x3FFB0000,0xBB797E43,0x6B09E6FB,0x00000000
96 .long 0x3FFB0000,0xC367A5C7,0x39E5F4 97 .long 0x3FFB0000,0xC367A5C7,0x39E5F446,0x00000000
97 .long 0x3FFB0000,0xCB544C61,0xCFF7D5 98 .long 0x3FFB0000,0xCB544C61,0xCFF7D5C6,0x00000000
98 .long 0x3FFB0000,0xD33F62F8,0x248853 99 .long 0x3FFB0000,0xD33F62F8,0x2488533E,0x00000000
99 .long 0x3FFB0000,0xDB28DA81,0x62404C 100 .long 0x3FFB0000,0xDB28DA81,0x62404C77,0x00000000
100 .long 0x3FFB0000,0xE310A407,0x8AD34F 101 .long 0x3FFB0000,0xE310A407,0x8AD34F18,0x00000000
101 .long 0x3FFB0000,0xEAF6B0A8,0x188EE1 102 .long 0x3FFB0000,0xEAF6B0A8,0x188EE1EB,0x00000000
102 .long 0x3FFB0000,0xF2DAF194,0x9DBE79 103 .long 0x3FFB0000,0xF2DAF194,0x9DBE79D5,0x00000000
103 .long 0x3FFB0000,0xFABD5813,0x61D47E 104 .long 0x3FFB0000,0xFABD5813,0x61D47E3E,0x00000000
104 .long 0x3FFC0000,0x8346AC21,0x0959EC 105 .long 0x3FFC0000,0x8346AC21,0x0959ECC4,0x00000000
105 .long 0x3FFC0000,0x8B232A08,0x304282 106 .long 0x3FFC0000,0x8B232A08,0x304282D8,0x00000000
106 .long 0x3FFC0000,0x92FB70B8,0xD29AE2 107 .long 0x3FFC0000,0x92FB70B8,0xD29AE2F9,0x00000000
107 .long 0x3FFC0000,0x9ACF476F,0x5CCD1C 108 .long 0x3FFC0000,0x9ACF476F,0x5CCD1CB4,0x00000000
108 .long 0x3FFC0000,0xA29E7630,0x4954F2 109 .long 0x3FFC0000,0xA29E7630,0x4954F23F,0x00000000
109 .long 0x3FFC0000,0xAA68C5D0,0x8AB852 110 .long 0x3FFC0000,0xAA68C5D0,0x8AB85230,0x00000000
110 .long 0x3FFC0000,0xB22DFFFD,0x9D539F 111 .long 0x3FFC0000,0xB22DFFFD,0x9D539F83,0x00000000
111 .long 0x3FFC0000,0xB9EDEF45,0x3E900E 112 .long 0x3FFC0000,0xB9EDEF45,0x3E900EA5,0x00000000
112 .long 0x3FFC0000,0xC1A85F1C,0xC75E3E 113 .long 0x3FFC0000,0xC1A85F1C,0xC75E3EA5,0x00000000
113 .long 0x3FFC0000,0xC95D1BE8,0x28138D 114 .long 0x3FFC0000,0xC95D1BE8,0x28138DE6,0x00000000
114 .long 0x3FFC0000,0xD10BF300,0x840D2D 115 .long 0x3FFC0000,0xD10BF300,0x840D2DE4,0x00000000
115 .long 0x3FFC0000,0xD8B4B2BA,0x6BC05E 116 .long 0x3FFC0000,0xD8B4B2BA,0x6BC05E7A,0x00000000
116 .long 0x3FFC0000,0xE0572A6B,0xB42335 117 .long 0x3FFC0000,0xE0572A6B,0xB42335F6,0x00000000
117 .long 0x3FFC0000,0xE7F32A70,0xEA9CAA 118 .long 0x3FFC0000,0xE7F32A70,0xEA9CAA8F,0x00000000
118 .long 0x3FFC0000,0xEF888432,0x64ECEF 119 .long 0x3FFC0000,0xEF888432,0x64ECEFAA,0x00000000
119 .long 0x3FFC0000,0xF7170A28,0xECC066 120 .long 0x3FFC0000,0xF7170A28,0xECC06666,0x00000000
120 .long 0x3FFD0000,0x812FD288,0x332DAD 121 .long 0x3FFD0000,0x812FD288,0x332DAD32,0x00000000
121 .long 0x3FFD0000,0x88A8D1B1,0x218E4D 122 .long 0x3FFD0000,0x88A8D1B1,0x218E4D64,0x00000000
122 .long 0x3FFD0000,0x9012AB3F,0x23E4AE 123 .long 0x3FFD0000,0x9012AB3F,0x23E4AEE8,0x00000000
123 .long 0x3FFD0000,0x976CC3D4,0x11E7F1 124 .long 0x3FFD0000,0x976CC3D4,0x11E7F1B9,0x00000000
124 .long 0x3FFD0000,0x9EB68949,0x3889A2 125 .long 0x3FFD0000,0x9EB68949,0x3889A227,0x00000000
125 .long 0x3FFD0000,0xA5EF72C3,0x448736 126 .long 0x3FFD0000,0xA5EF72C3,0x4487361B,0x00000000
126 .long 0x3FFD0000,0xAD1700BA,0xF07A72 127 .long 0x3FFD0000,0xAD1700BA,0xF07A7227,0x00000000
127 .long 0x3FFD0000,0xB42CBCFA,0xFD37EF 128 .long 0x3FFD0000,0xB42CBCFA,0xFD37EFB7,0x00000000
128 .long 0x3FFD0000,0xBB303A94,0x0BA80F 129 .long 0x3FFD0000,0xBB303A94,0x0BA80F89,0x00000000
129 .long 0x3FFD0000,0xC22115C6,0xFCAEBB 130 .long 0x3FFD0000,0xC22115C6,0xFCAEBBAF,0x00000000
130 .long 0x3FFD0000,0xC8FEF3E6,0x863312 131 .long 0x3FFD0000,0xC8FEF3E6,0x86331221,0x00000000
131 .long 0x3FFD0000,0xCFC98330,0xB4000C 132 .long 0x3FFD0000,0xCFC98330,0xB4000C70,0x00000000
132 .long 0x3FFD0000,0xD6807AA1,0x102C5B 133 .long 0x3FFD0000,0xD6807AA1,0x102C5BF9,0x00000000
133 .long 0x3FFD0000,0xDD2399BC,0x31252A 134 .long 0x3FFD0000,0xDD2399BC,0x31252AA3,0x00000000
134 .long 0x3FFD0000,0xE3B2A855,0x6B8FC5 135 .long 0x3FFD0000,0xE3B2A855,0x6B8FC517,0x00000000
135 .long 0x3FFD0000,0xEA2D764F,0x643159 136 .long 0x3FFD0000,0xEA2D764F,0x64315989,0x00000000
136 .long 0x3FFD0000,0xF3BF5BF8,0xBAD1A2 137 .long 0x3FFD0000,0xF3BF5BF8,0xBAD1A21D,0x00000000
137 .long 0x3FFE0000,0x801CE39E,0x0D205C 138 .long 0x3FFE0000,0x801CE39E,0x0D205C9A,0x00000000
138 .long 0x3FFE0000,0x8630A2DA,0xDA1ED0 139 .long 0x3FFE0000,0x8630A2DA,0xDA1ED066,0x00000000
139 .long 0x3FFE0000,0x8C1AD445,0xF3E09B 140 .long 0x3FFE0000,0x8C1AD445,0xF3E09B8C,0x00000000
140 .long 0x3FFE0000,0x91DB8F16,0x64F350 141 .long 0x3FFE0000,0x91DB8F16,0x64F350E2,0x00000000
141 .long 0x3FFE0000,0x97731420,0x365E53 142 .long 0x3FFE0000,0x97731420,0x365E538C,0x00000000
142 .long 0x3FFE0000,0x9CE1C8E6,0xA0B8CD 143 .long 0x3FFE0000,0x9CE1C8E6,0xA0B8CDBA,0x00000000
143 .long 0x3FFE0000,0xA22832DB,0xCADAAE 144 .long 0x3FFE0000,0xA22832DB,0xCADAAE09,0x00000000
144 .long 0x3FFE0000,0xA746F2DD,0xB76022 145 .long 0x3FFE0000,0xA746F2DD,0xB7602294,0x00000000
145 .long 0x3FFE0000,0xAC3EC0FB,0x997DD6 146 .long 0x3FFE0000,0xAC3EC0FB,0x997DD6A2,0x00000000
146 .long 0x3FFE0000,0xB110688A,0xEBDC6F 147 .long 0x3FFE0000,0xB110688A,0xEBDC6F6A,0x00000000
147 .long 0x3FFE0000,0xB5BCC490,0x59ECC4 148 .long 0x3FFE0000,0xB5BCC490,0x59ECC4B0,0x00000000
148 .long 0x3FFE0000,0xBA44BC7D,0xD47078 149 .long 0x3FFE0000,0xBA44BC7D,0xD470782F,0x00000000
149 .long 0x3FFE0000,0xBEA94144,0xFD049A 150 .long 0x3FFE0000,0xBEA94144,0xFD049AAC,0x00000000
150 .long 0x3FFE0000,0xC2EB4ABB,0x661628 151 .long 0x3FFE0000,0xC2EB4ABB,0x661628B6,0x00000000
151 .long 0x3FFE0000,0xC70BD54C,0xE602EE 152 .long 0x3FFE0000,0xC70BD54C,0xE602EE14,0x00000000
152 .long 0x3FFE0000,0xCD000549,0xADEC71 153 .long 0x3FFE0000,0xCD000549,0xADEC7159,0x00000000
153 .long 0x3FFE0000,0xD48457D2,0xD8EA4E 154 .long 0x3FFE0000,0xD48457D2,0xD8EA4EA3,0x00000000
154 .long 0x3FFE0000,0xDB948DA7,0x12DECE 155 .long 0x3FFE0000,0xDB948DA7,0x12DECE3B,0x00000000
155 .long 0x3FFE0000,0xE23855F9,0x69E809 156 .long 0x3FFE0000,0xE23855F9,0x69E8096A,0x00000000
156 .long 0x3FFE0000,0xE8771129,0xC43532 157 .long 0x3FFE0000,0xE8771129,0xC4353259,0x00000000
157 .long 0x3FFE0000,0xEE57C16E,0x0D379C 158 .long 0x3FFE0000,0xEE57C16E,0x0D379C0D,0x00000000
158 .long 0x3FFE0000,0xF3E10211,0xA87C37 159 .long 0x3FFE0000,0xF3E10211,0xA87C3779,0x00000000
159 .long 0x3FFE0000,0xF919039D,0x758B8D 160 .long 0x3FFE0000,0xF919039D,0x758B8D41,0x00000000
160 .long 0x3FFE0000,0xFE058B8F,0x64935F 161 .long 0x3FFE0000,0xFE058B8F,0x64935FB3,0x00000000
161 .long 0x3FFF0000,0x8155FB49,0x7B685D 162 .long 0x3FFF0000,0x8155FB49,0x7B685D04,0x00000000
162 .long 0x3FFF0000,0x83889E35,0x49D108 163 .long 0x3FFF0000,0x83889E35,0x49D108E1,0x00000000
163 .long 0x3FFF0000,0x859CFA76,0x511D72 164 .long 0x3FFF0000,0x859CFA76,0x511D724B,0x00000000
164 .long 0x3FFF0000,0x87952ECF,0xFF8131 165 .long 0x3FFF0000,0x87952ECF,0xFF8131E7,0x00000000
165 .long 0x3FFF0000,0x89732FD1,0x955764 166 .long 0x3FFF0000,0x89732FD1,0x9557641B,0x00000000
166 .long 0x3FFF0000,0x8B38CAD1,0x01932A 167 .long 0x3FFF0000,0x8B38CAD1,0x01932A35,0x00000000
167 .long 0x3FFF0000,0x8CE7A8D8,0x301EE6 168 .long 0x3FFF0000,0x8CE7A8D8,0x301EE6B5,0x00000000
168 .long 0x3FFF0000,0x8F46A39E,0x2EAE52 169 .long 0x3FFF0000,0x8F46A39E,0x2EAE5281,0x00000000
169 .long 0x3FFF0000,0x922DA7D7,0x918884 170 .long 0x3FFF0000,0x922DA7D7,0x91888487,0x00000000
170 .long 0x3FFF0000,0x94D19FCB,0xDEDF52 171 .long 0x3FFF0000,0x94D19FCB,0xDEDF5241,0x00000000
171 .long 0x3FFF0000,0x973AB944,0x19D2A0 172 .long 0x3FFF0000,0x973AB944,0x19D2A08B,0x00000000
172 .long 0x3FFF0000,0x996FF00E,0x08E10B 173 .long 0x3FFF0000,0x996FF00E,0x08E10B96,0x00000000
173 .long 0x3FFF0000,0x9B773F95,0x12321D 174 .long 0x3FFF0000,0x9B773F95,0x12321DA7,0x00000000
174 .long 0x3FFF0000,0x9D55CC32,0x0F9356 175 .long 0x3FFF0000,0x9D55CC32,0x0F935624,0x00000000
175 .long 0x3FFF0000,0x9F100575,0x006CC5 176 .long 0x3FFF0000,0x9F100575,0x006CC571,0x00000000
176 .long 0x3FFF0000,0xA0A9C290,0xD97CC0 177 .long 0x3FFF0000,0xA0A9C290,0xD97CC06C,0x00000000
177 .long 0x3FFF0000,0xA22659EB,0xEBC063 178 .long 0x3FFF0000,0xA22659EB,0xEBC0630A,0x00000000
178 .long 0x3FFF0000,0xA388B4AF,0xF6EF0E 179 .long 0x3FFF0000,0xA388B4AF,0xF6EF0EC9,0x00000000
179 .long 0x3FFF0000,0xA4D35F10,0x61D292 180 .long 0x3FFF0000,0xA4D35F10,0x61D292C4,0x00000000
180 .long 0x3FFF0000,0xA60895DC,0xFBE318 181 .long 0x3FFF0000,0xA60895DC,0xFBE3187E,0x00000000
181 .long 0x3FFF0000,0xA72A51DC,0x7367BE 182 .long 0x3FFF0000,0xA72A51DC,0x7367BEAC,0x00000000
182 .long 0x3FFF0000,0xA83A5153,0x095616 183 .long 0x3FFF0000,0xA83A5153,0x0956168F,0x00000000
183 .long 0x3FFF0000,0xA93A2007,0x753954 184 .long 0x3FFF0000,0xA93A2007,0x7539546E,0x00000000
184 .long 0x3FFF0000,0xAA9E7245,0x023B26 185 .long 0x3FFF0000,0xAA9E7245,0x023B2605,0x00000000
185 .long 0x3FFF0000,0xAC4C84BA,0x6FE4D5 186 .long 0x3FFF0000,0xAC4C84BA,0x6FE4D58F,0x00000000
186 .long 0x3FFF0000,0xADCE4A4A,0x606B97 187 .long 0x3FFF0000,0xADCE4A4A,0x606B9712,0x00000000
187 .long 0x3FFF0000,0xAF2A2DCD,0x8D263C 188 .long 0x3FFF0000,0xAF2A2DCD,0x8D263C9C,0x00000000
188 .long 0x3FFF0000,0xB0656F81,0xF22265 189 .long 0x3FFF0000,0xB0656F81,0xF22265C7,0x00000000
189 .long 0x3FFF0000,0xB1846515,0x0F7149 190 .long 0x3FFF0000,0xB1846515,0x0F71496A,0x00000000
190 .long 0x3FFF0000,0xB28AAA15,0x6F9ADA 191 .long 0x3FFF0000,0xB28AAA15,0x6F9ADA35,0x00000000
191 .long 0x3FFF0000,0xB37B44FF,0x3766B8 192 .long 0x3FFF0000,0xB37B44FF,0x3766B895,0x00000000
192 .long 0x3FFF0000,0xB458C3DC,0xE96304 193 .long 0x3FFF0000,0xB458C3DC,0xE9630433,0x00000000
193 .long 0x3FFF0000,0xB525529D,0x562246 194 .long 0x3FFF0000,0xB525529D,0x562246BD,0x00000000
194 .long 0x3FFF0000,0xB5E2CCA9,0x5F9D88 195 .long 0x3FFF0000,0xB5E2CCA9,0x5F9D88CC,0x00000000
195 .long 0x3FFF0000,0xB692CADA,0x7ACA1A 196 .long 0x3FFF0000,0xB692CADA,0x7ACA1ADA,0x00000000
196 .long 0x3FFF0000,0xB736AEA7,0xA69258 197 .long 0x3FFF0000,0xB736AEA7,0xA6925838,0x00000000
197 .long 0x3FFF0000,0xB7CFAB28,0x7E9F7B 198 .long 0x3FFF0000,0xB7CFAB28,0x7E9F7B36,0x00000000
198 .long 0x3FFF0000,0xB85ECC66,0xCB2198 199 .long 0x3FFF0000,0xB85ECC66,0xCB219835,0x00000000
199 .long 0x3FFF0000,0xB8E4FD5A,0x20A593 200 .long 0x3FFF0000,0xB8E4FD5A,0x20A593DA,0x00000000
200 .long 0x3FFF0000,0xB99F41F6,0x4AFF9B 201 .long 0x3FFF0000,0xB99F41F6,0x4AFF9BB5,0x00000000
201 .long 0x3FFF0000,0xBA7F1E17,0x842BBE 202 .long 0x3FFF0000,0xBA7F1E17,0x842BBE7B,0x00000000
202 .long 0x3FFF0000,0xBB471285,0x7637E1 203 .long 0x3FFF0000,0xBB471285,0x7637E17D,0x00000000
203 .long 0x3FFF0000,0xBBFABE8A,0x4788DF 204 .long 0x3FFF0000,0xBBFABE8A,0x4788DF6F,0x00000000
204 .long 0x3FFF0000,0xBC9D0FAD,0x2B689D 205 .long 0x3FFF0000,0xBC9D0FAD,0x2B689D79,0x00000000
205 .long 0x3FFF0000,0xBD306A39,0x471ECD 206 .long 0x3FFF0000,0xBD306A39,0x471ECD86,0x00000000
206 .long 0x3FFF0000,0xBDB6C731,0x856AF1 207 .long 0x3FFF0000,0xBDB6C731,0x856AF18A,0x00000000
207 .long 0x3FFF0000,0xBE31CAC5,0x02E80D 208 .long 0x3FFF0000,0xBE31CAC5,0x02E80D70,0x00000000
208 .long 0x3FFF0000,0xBEA2D55C,0xE33194 209 .long 0x3FFF0000,0xBEA2D55C,0xE33194E2,0x00000000
209 .long 0x3FFF0000,0xBF0B10B7,0xC03128 210 .long 0x3FFF0000,0xBF0B10B7,0xC03128F0,0x00000000
210 .long 0x3FFF0000,0xBF6B7A18,0xDACB77 211 .long 0x3FFF0000,0xBF6B7A18,0xDACB778D,0x00000000
211 .long 0x3FFF0000,0xBFC4EA46,0x63FA18 212 .long 0x3FFF0000,0xBFC4EA46,0x63FA18F6,0x00000000
212 .long 0x3FFF0000,0xC0181BDE,0x8B89A4 213 .long 0x3FFF0000,0xC0181BDE,0x8B89A454,0x00000000
213 .long 0x3FFF0000,0xC065B066,0xCFBF64 214 .long 0x3FFF0000,0xC065B066,0xCFBF6439,0x00000000
214 .long 0x3FFF0000,0xC0AE345F,0x56340A 215 .long 0x3FFF0000,0xC0AE345F,0x56340AE6,0x00000000
215 .long 0x3FFF0000,0xC0F22291,0x9CB9E6 216 .long 0x3FFF0000,0xC0F22291,0x9CB9E6A7,0x00000000
216 217
217 .set X,FP_SCR1 218 .set X,FP_SCR1
218 .set XDCARE,X+2 219 .set XDCARE,X+2
219 .set XFRAC,X+4 220 .set XFRAC,X+4
220 .set XFRACLO,X+8 221 .set XFRACLO,X+8
221 222
222 .set ATANF,FP_SCR2 223 .set ATANF,FP_SCR2
223 .set ATANFHI,ATANF+4 224 .set ATANFHI,ATANF+4
224 .set ATANFLO,ATANF+8 225 .set ATANFLO,ATANF+8
225 226
226 227
227 | xref t_frcinx 228 | xref t_frcinx
228 |xref t_extdnrm 229 |xref t_extdnrm
229 230
230 .global satand 231 .global satand
231 satand: 232 satand:
232 |--ENTRY POINT FOR ATAN(X) FOR DENORMALIZED AR 233 |--ENTRY POINT FOR ATAN(X) FOR DENORMALIZED ARGUMENT
233 234
234 bra t_extdnrm 235 bra t_extdnrm
235 236
236 .global satan 237 .global satan
237 satan: 238 satan:
238 |--ENTRY POINT FOR ATAN(X), HERE X IS FINITE, 239 |--ENTRY POINT FOR ATAN(X), HERE X IS FINITE, NON-ZERO, AND NOT NAN'S
239 240
240 fmovex (%a0),%fp0 | ...L 241 fmovex (%a0),%fp0 | ...LOAD INPUT
241 242
242 movel (%a0),%d0 243 movel (%a0),%d0
243 movew 4(%a0),%d0 244 movew 4(%a0),%d0
244 fmovex %fp0,X(%a6) 245 fmovex %fp0,X(%a6)
245 andil #0x7FFFFFFF,%d0 246 andil #0x7FFFFFFF,%d0
246 247
247 cmpil #0x3FFB8000,%d0 248 cmpil #0x3FFB8000,%d0 | ...|X| >= 1/16?
248 bges ATANOK1 249 bges ATANOK1
249 bra ATANSM 250 bra ATANSM
250 251
251 ATANOK1: 252 ATANOK1:
252 cmpil #0x4002FFFF,%d0 253 cmpil #0x4002FFFF,%d0 | ...|X| < 16 ?
253 bles ATANMAIN 254 bles ATANMAIN
254 bra ATANBIG 255 bra ATANBIG
255 256
256 257
257 |--THE MOST LIKELY CASE, |X| IN [1/16, 16). WE 258 |--THE MOST LIKELY CASE, |X| IN [1/16, 16). WE USE TABLE TECHNIQUE
258 |--THE IDEA IS ATAN(X) = ATAN(F) + ATAN( [X-F] 259 |--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 260 |--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 261 |--A TABLE, ALL WE NEED IS TO APPROXIMATE ATAN(U) WHERE
261 |--U = (X-F)/(1+XF) IS SMALL (REMEMBER F IS CL 262 |--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 263 |--TRUE THAT A DIVIDE IS NOW NEEDED, BUT THE APPROXIMATION FOR
263 |--ATAN(U) IS A VERY SHORT POLYNOMIAL AND THE 264 |--ATAN(U) IS A VERY SHORT POLYNOMIAL AND THE INDEXING TO
264 |--FETCH F AND SAVING OF REGISTERS CAN BE ALL 265 |--FETCH F AND SAVING OF REGISTERS CAN BE ALL HIDED UNDER THE
265 |--DIVIDE. IN THE END THIS METHOD IS MUCH FAST 266 |--DIVIDE. IN THE END THIS METHOD IS MUCH FASTER THAN A TRADITIONAL
266 |--ONE. NOTE ALSO THAT THE TRADITIONAL SCHEME 267 |--ONE. NOTE ALSO THAT THE TRADITIONAL SCHEME THAT APPROXIMATE
267 |--ATAN(X) DIRECTLY WILL NEED TO USE A RATIONA 268 |--ATAN(X) DIRECTLY WILL NEED TO USE A RATIONAL APPROXIMATION
268 |--(DIVISION NEEDED) ANYWAY BECAUSE A POLYNOMI 269 |--(DIVISION NEEDED) ANYWAY BECAUSE A POLYNOMIAL APPROXIMATION
269 |--WILL INVOLVE A VERY LONG POLYNOMIAL. 270 |--WILL INVOLVE A VERY LONG POLYNOMIAL.
270 271
271 |--NOW WE SEE X AS +-2^K * 1.BBBBBBB....B <- 1 272 |--NOW WE SEE X AS +-2^K * 1.BBBBBBB....B <- 1. + 63 BITS
272 |--WE CHOSE F TO BE +-2^K * 1.BBBB1 273 |--WE CHOSE F TO BE +-2^K * 1.BBBB1
273 |--THAT IS IT MATCHES THE EXPONENT AND FIRST 5 274 |--THAT IS IT MATCHES THE EXPONENT AND FIRST 5 BITS OF X, THE
274 |--SIXTH BITS IS SET TO BE 1. SINCE K = -4, -3 275 |--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 276 |--ARE ONLY 8 TIMES 16 = 2^7 = 128 |F|'S. SINCE ATAN(-|F|) IS
276 |-- -ATAN(|F|), WE NEED TO STORE ONLY ATAN(|F| 277 |-- -ATAN(|F|), WE NEED TO STORE ONLY ATAN(|F|).
277 278
278 ATANMAIN: 279 ATANMAIN:
279 280
280 movew #0x0000,XDCARE(%a6) 281 movew #0x0000,XDCARE(%a6) | ...CLEAN UP X JUST IN CASE
281 andil #0xF8000000,XFRAC(%a6) 282 andil #0xF8000000,XFRAC(%a6) | ...FIRST 5 BITS
282 oril #0x04000000,XFRAC(%a6) 283 oril #0x04000000,XFRAC(%a6) | ...SET 6-TH BIT TO 1
283 movel #0x00000000,XFRACLO(%a 284 movel #0x00000000,XFRACLO(%a6) | ...LOCATION OF X IS NOW F
284 285
285 fmovex %fp0,%fp1 286 fmovex %fp0,%fp1 | ...FP1 IS X
286 fmulx X(%a6),%fp1 287 fmulx X(%a6),%fp1 | ...FP1 IS X*F, NOTE THAT X*F > 0
287 fsubx X(%a6),%fp0 288 fsubx X(%a6),%fp0 | ...FP0 IS X-F
288 fadds #0x3F800000,%fp1 289 fadds #0x3F800000,%fp1 | ...FP1 IS 1 + X*F
289 fdivx %fp1,%fp0 290 fdivx %fp1,%fp0 | ...FP0 IS U = (X-F)/(1+X*F)
290 291
291 |--WHILE THE DIVISION IS TAKING ITS TIME, WE F 292 |--WHILE THE DIVISION IS TAKING ITS TIME, WE FETCH ATAN(|F|)
292 |--CREATE ATAN(F) AND STORE IT IN ATANF, AND 293 |--CREATE ATAN(F) AND STORE IT IN ATANF, AND
293 |--SAVE REGISTERS FP2. 294 |--SAVE REGISTERS FP2.
294 295
295 movel %d2,-(%a7) | ...S 296 movel %d2,-(%a7) | ...SAVE d2 TEMPORARILY
296 movel %d0,%d2 | ...T 297 movel %d0,%d2 | ...THE EXPO AND 16 BITS OF X
297 andil #0x00007800,%d0 | ...4 298 andil #0x00007800,%d0 | ...4 VARYING BITS OF F'S FRACTION
298 andil #0x7FFF0000,%d2 | ...E 299 andil #0x7FFF0000,%d2 | ...EXPONENT OF F
299 subil #0x3FFB0000,%d2 | ...K 300 subil #0x3FFB0000,%d2 | ...K+4
300 asrl #1,%d2 301 asrl #1,%d2
301 addl %d2,%d0 | ...T 302 addl %d2,%d0 | ...THE 7 BITS IDENTIFYING F
302 asrl #7,%d0 | ...I 303 asrl #7,%d0 | ...INDEX INTO TBL OF ATAN(|F|)
303 lea ATANTBL,%a1 304 lea ATANTBL,%a1
304 addal %d0,%a1 | ...A 305 addal %d0,%a1 | ...ADDRESS OF ATAN(|F|)
305 movel (%a1)+,ATANF(%a6) 306 movel (%a1)+,ATANF(%a6)
306 movel (%a1)+,ATANFHI(%a6) 307 movel (%a1)+,ATANFHI(%a6)
307 movel (%a1)+,ATANFLO(%a6) 308 movel (%a1)+,ATANFLO(%a6) | ...ATANF IS NOW ATAN(|F|)
308 movel X(%a6),%d0 309 movel X(%a6),%d0 | ...LOAD SIGN AND EXPO. AGAIN
309 andil #0x80000000,%d0 | ...S 310 andil #0x80000000,%d0 | ...SIGN(F)
310 orl %d0,ATANF(%a6) | ...A 311 orl %d0,ATANF(%a6) | ...ATANF IS NOW SIGN(F)*ATAN(|F|)
311 movel (%a7)+,%d2 | ...R 312 movel (%a7)+,%d2 | ...RESTORE d2
312 313
313 |--THAT'S ALL I HAVE TO DO FOR NOW, 314 |--THAT'S ALL I HAVE TO DO FOR NOW,
314 |--BUT ALAS, THE DIVIDE IS STILL CRANKING! 315 |--BUT ALAS, THE DIVIDE IS STILL CRANKING!
315 316
316 |--U IN FP0, WE ARE NOW READY TO COMPUTE ATAN( 317 |--U IN FP0, WE ARE NOW READY TO COMPUTE ATAN(U) AS
317 |--U + A1*U*V*(A2 + V*(A3 + V)), V = U*U 318 |--U + A1*U*V*(A2 + V*(A3 + V)), V = U*U
318 |--THE POLYNOMIAL MAY LOOK STRANGE, BUT IS NEV 319 |--THE POLYNOMIAL MAY LOOK STRANGE, BUT IS NEVERTHELESS CORRECT.
319 |--THE NATURAL FORM IS U + U*V*(A1 + V*(A2 + V 320 |--THE NATURAL FORM IS U + U*V*(A1 + V*(A2 + V*A3))
320 |--WHAT WE HAVE HERE IS MERELY A1 = A3, A2 = 321 |--WHAT WE HAVE HERE IS MERELY A1 = A3, A2 = A1/A3, A3 = A2/A3.
321 |--THE REASON FOR THIS REARRANGEMENT IS TO MAK 322 |--THE REASON FOR THIS REARRANGEMENT IS TO MAKE THE INDEPENDENT
322 |--PARTS A1*U*V AND (A2 + ... STUFF) MORE LOAD 323 |--PARTS A1*U*V AND (A2 + ... STUFF) MORE LOAD-BALANCED
323 324
324 !! 325
325 fmovex %fp0,%fp1 326 fmovex %fp0,%fp1
326 fmulx %fp1,%fp1 327 fmulx %fp1,%fp1
327 fmoved ATANA3,%fp2 328 fmoved ATANA3,%fp2
328 faddx %fp1,%fp2 329 faddx %fp1,%fp2 | ...A3+V
329 fmulx %fp1,%fp2 330 fmulx %fp1,%fp2 | ...V*(A3+V)
330 fmulx %fp0,%fp1 331 fmulx %fp0,%fp1 | ...U*V
331 faddd ATANA2,%fp2 | ...A 332 faddd ATANA2,%fp2 | ...A2+V*(A3+V)
332 fmuld ATANA1,%fp1 | ...A 333 fmuld ATANA1,%fp1 | ...A1*U*V
333 fmulx %fp2,%fp1 334 fmulx %fp2,%fp1 | ...A1*U*V*(A2+V*(A3+V))
334 !! 335
335 faddx %fp1,%fp0 336 faddx %fp1,%fp0 | ...ATAN(U), FP1 RELEASED
336 fmovel %d1,%FPCR 337 fmovel %d1,%FPCR |restore users exceptions
337 faddx ATANF(%a6),%fp0 | ...A 338 faddx ATANF(%a6),%fp0 | ...ATAN(X)
338 bra t_frcinx 339 bra t_frcinx
339 340
340 ATANBORS: 341 ATANBORS:
341 |--|X| IS IN d0 IN COMPACT FORM. FP1, d0 SAVED 342 |--|X| IS IN d0 IN COMPACT FORM. FP1, d0 SAVED.
342 |--FP0 IS X AND |X| <= 1/16 OR |X| >= 16. 343 |--FP0 IS X AND |X| <= 1/16 OR |X| >= 16.
343 cmpil #0x3FFF8000,%d0 344 cmpil #0x3FFF8000,%d0
344 bgt ATANBIG | ...I.E. |X| 345 bgt ATANBIG | ...I.E. |X| >= 16
345 346
346 ATANSM: 347 ATANSM:
347 |--|X| <= 1/16 348 |--|X| <= 1/16
348 |--IF |X| < 2^(-40), RETURN X AS ANSWER. OTHER 349 |--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* 350 |--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 351 |--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. 352 |--WHERE Y = X*X, AND Z = Y*Y.
352 353
353 cmpil #0x3FD78000,%d0 354 cmpil #0x3FD78000,%d0
354 blt ATANTINY 355 blt ATANTINY
355 |--COMPUTE POLYNOMIAL 356 |--COMPUTE POLYNOMIAL
356 fmulx %fp0,%fp0 | ...F 357 fmulx %fp0,%fp0 | ...FP0 IS Y = X*X
357 358
358 !! 359
359 movew #0x0000,XDCARE(%a6) 360 movew #0x0000,XDCARE(%a6)
360 361
361 fmovex %fp0,%fp1 362 fmovex %fp0,%fp1
362 fmulx %fp1,%fp1 363 fmulx %fp1,%fp1 | ...FP1 IS Z = Y*Y
363 364
364 fmoved ATANB6,%fp2 365 fmoved ATANB6,%fp2
365 fmoved ATANB5,%fp3 366 fmoved ATANB5,%fp3
366 367
367 fmulx %fp1,%fp2 368 fmulx %fp1,%fp2 | ...Z*B6
368 fmulx %fp1,%fp3 369 fmulx %fp1,%fp3 | ...Z*B5
369 370
370 faddd ATANB4,%fp2 | ...B 371 faddd ATANB4,%fp2 | ...B4+Z*B6
371 faddd ATANB3,%fp3 | ...B 372 faddd ATANB3,%fp3 | ...B3+Z*B5
372 373
373 fmulx %fp1,%fp2 374 fmulx %fp1,%fp2 | ...Z*(B4+Z*B6)
374 fmulx %fp3,%fp1 375 fmulx %fp3,%fp1 | ...Z*(B3+Z*B5)
375 376
376 faddd ATANB2,%fp2 | ...B 377 faddd ATANB2,%fp2 | ...B2+Z*(B4+Z*B6)
377 faddd ATANB1,%fp1 | ...B 378 faddd ATANB1,%fp1 | ...B1+Z*(B3+Z*B5)
378 379
379 fmulx %fp0,%fp2 380 fmulx %fp0,%fp2 | ...Y*(B2+Z*(B4+Z*B6))
380 fmulx X(%a6),%fp0 381 fmulx X(%a6),%fp0 | ...X*Y
381 382
382 faddx %fp2,%fp1 383 faddx %fp2,%fp1 | ...[B1+Z*(B3+Z*B5)]+[Y*(B2+Z*(B4+Z*B6))]
383 !! 384
384 385
385 fmulx %fp1,%fp0 | ...X 386 fmulx %fp1,%fp0 | ...X*Y*([B1+Z*(B3+Z*B5)]+[Y*(B2+Z*(B4+Z*B6))])
386 387
387 fmovel %d1,%FPCR 388 fmovel %d1,%FPCR |restore users exceptions
388 faddx X(%a6),%fp0 389 faddx X(%a6),%fp0
389 390
390 bra t_frcinx 391 bra t_frcinx
391 392
392 ATANTINY: 393 ATANTINY:
393 |--|X| < 2^(-40), ATAN(X) = X 394 |--|X| < 2^(-40), ATAN(X) = X
394 movew #0x0000,XDCARE(%a6) 395 movew #0x0000,XDCARE(%a6)
395 396
396 fmovel %d1,%FPCR 397 fmovel %d1,%FPCR |restore users exceptions
397 fmovex X(%a6),%fp0 |last 398 fmovex X(%a6),%fp0 |last inst - possible exception set
398 399
399 bra t_frcinx 400 bra t_frcinx
400 401
401 ATANBIG: 402 ATANBIG:
402 |--IF |X| > 2^(100), RETURN SIGN(X)*(PI/2 403 |--IF |X| > 2^(100), RETURN SIGN(X)*(PI/2 - TINY). OTHERWISE,
403 |--RETURN SIGN(X)*PI/2 + ATAN(-1/X). 404 |--RETURN SIGN(X)*PI/2 + ATAN(-1/X).
404 cmpil #0x40638000,%d0 405 cmpil #0x40638000,%d0
405 bgt ATANHUGE 406 bgt ATANHUGE
406 407
407 |--APPROXIMATE ATAN(-1/X) BY 408 |--APPROXIMATE ATAN(-1/X) BY
408 |--X'+X'*Y*(C1+Y*(C2+Y*(C3+Y*(C4+Y*C5)))), X' 409 |--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 410 |--THIS CAN BE RE-WRITTEN AS
410 |--X'+X'*Y*( [C1+Z*(C3+Z*C5)] + [Y*(C2+Z*C4)] 411 |--X'+X'*Y*( [C1+Z*(C3+Z*C5)] + [Y*(C2+Z*C4)] ), Z = Y*Y.
411 412
412 fmoves #0xBF800000,%fp1 413 fmoves #0xBF800000,%fp1 | ...LOAD -1
413 fdivx %fp0,%fp1 414 fdivx %fp0,%fp1 | ...FP1 IS -1/X
414 415
415 !! 416
416 |--DIVIDE IS STILL CRANKING 417 |--DIVIDE IS STILL CRANKING
417 418
418 fmovex %fp1,%fp0 419 fmovex %fp1,%fp0 | ...FP0 IS X'
419 fmulx %fp0,%fp0 420 fmulx %fp0,%fp0 | ...FP0 IS Y = X'*X'
420 fmovex %fp1,X(%a6) 421 fmovex %fp1,X(%a6) | ...X IS REALLY X'
421 422
422 fmovex %fp0,%fp1 423 fmovex %fp0,%fp1
423 fmulx %fp1,%fp1 424 fmulx %fp1,%fp1 | ...FP1 IS Z = Y*Y
424 425
425 fmoved ATANC5,%fp3 426 fmoved ATANC5,%fp3
426 fmoved ATANC4,%fp2 427 fmoved ATANC4,%fp2
427 428
428 fmulx %fp1,%fp3 429 fmulx %fp1,%fp3 | ...Z*C5
429 fmulx %fp1,%fp2 430 fmulx %fp1,%fp2 | ...Z*B4
430 431
431 faddd ATANC3,%fp3 | ...C 432 faddd ATANC3,%fp3 | ...C3+Z*C5
432 faddd ATANC2,%fp2 | ...C 433 faddd ATANC2,%fp2 | ...C2+Z*C4
433 434
434 fmulx %fp3,%fp1 435 fmulx %fp3,%fp1 | ...Z*(C3+Z*C5), FP3 RELEASED
435 fmulx %fp0,%fp2 436 fmulx %fp0,%fp2 | ...Y*(C2+Z*C4)
436 437
437 faddd ATANC1,%fp1 | ...C 438 faddd ATANC1,%fp1 | ...C1+Z*(C3+Z*C5)
438 fmulx X(%a6),%fp0 439 fmulx X(%a6),%fp0 | ...X'*Y
439 440
440 faddx %fp2,%fp1 441 faddx %fp2,%fp1 | ...[Y*(C2+Z*C4)]+[C1+Z*(C3+Z*C5)]
441 !! 442
442 443
443 fmulx %fp1,%fp0 444 fmulx %fp1,%fp0 | ...X'*Y*([B1+Z*(B3+Z*B5)]
444 | ... 445 | ... +[Y*(B2+Z*(B4+Z*B6))])
445 faddx X(%a6),%fp0 446 faddx X(%a6),%fp0
446 447
447 fmovel %d1,%FPCR 448 fmovel %d1,%FPCR |restore users exceptions
448 !! 449
449 btstb #7,(%a0) 450 btstb #7,(%a0)
450 beqs pos_big 451 beqs pos_big
451 452
452 neg_big: 453 neg_big:
453 faddx NPIBY2,%fp0 454 faddx NPIBY2,%fp0
454 bra t_frcinx 455 bra t_frcinx
455 456
456 pos_big: 457 pos_big:
457 faddx PPIBY2,%fp0 458 faddx PPIBY2,%fp0
458 bra t_frcinx 459 bra t_frcinx
459 460
460 ATANHUGE: 461 ATANHUGE:
461 |--RETURN SIGN(X)*(PIBY2 - TINY) = SIGN(X)*PIB 462 |--RETURN SIGN(X)*(PIBY2 - TINY) = SIGN(X)*PIBY2 - SIGN(X)*TINY
462 btstb #7,(%a0) 463 btstb #7,(%a0)
463 beqs pos_huge 464 beqs pos_huge
464 465
465 neg_huge: 466 neg_huge:
466 fmovex NPIBY2,%fp0 467 fmovex NPIBY2,%fp0
467 fmovel %d1,%fpcr 468 fmovel %d1,%fpcr
468 fsubx NTINY,%fp0 469 fsubx NTINY,%fp0
469 bra t_frcinx 470 bra t_frcinx
470 471
471 pos_huge: 472 pos_huge:
472 fmovex PPIBY2,%fp0 473 fmovex PPIBY2,%fp0
473 fmovel %d1,%fpcr 474 fmovel %d1,%fpcr
474 fsubx PTINY,%fp0 475 fsubx PTINY,%fp0
475 bra t_frcinx 476 bra t_frcinx
476 !! 477
477 |end 478 |end
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