OLD | NEW |
1 /* origin: FreeBSD /usr/src/lib/msun/src/e_j1.c */ | 1 /* origin: FreeBSD /usr/src/lib/msun/src/e_j1.c */ |
2 /* | 2 /* |
3 * ==================================================== | 3 * ==================================================== |
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. | 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
5 * | 5 * |
6 * Developed at SunSoft, a Sun Microsystems, Inc. business. | 6 * Developed at SunSoft, a Sun Microsystems, Inc. business. |
7 * Permission to use, copy, modify, and distribute this | 7 * Permission to use, copy, modify, and distribute this |
8 * software is freely granted, provided that this notice | 8 * software is freely granted, provided that this notice |
9 * is preserved. | 9 * is preserved. |
10 * ==================================================== | 10 * ==================================================== |
(...skipping 40 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
51 * 3. For x>=2. | 51 * 3. For x>=2. |
52 * y1(x) = sqrt(2/(pi*x))*(p1(x)*sin(x1)+q1(x)*cos(x1)) | 52 * y1(x) = sqrt(2/(pi*x))*(p1(x)*sin(x1)+q1(x)*cos(x1)) |
53 * where x1 = x-3*pi/4. It is better to compute sin(x1),cos(x1) | 53 * where x1 = x-3*pi/4. It is better to compute sin(x1),cos(x1) |
54 * by method mentioned above. | 54 * by method mentioned above. |
55 */ | 55 */ |
56 | 56 |
57 #include "libm.h" | 57 #include "libm.h" |
58 | 58 |
59 static double pone(double), qone(double); | 59 static double pone(double), qone(double); |
60 | 60 |
61 static const double | 61 static const double invsqrtpi = |
62 invsqrtpi = 5.64189583547756279280e-01, /* 0x3FE20DD7, 0x50429B6D */ | 62 5.64189583547756279280e-01, /* 0x3FE20DD7, 0x50429B6D */ |
63 tpi = 6.36619772367581382433e-01; /* 0x3FE45F30, 0x6DC9C883 */ | 63 tpi = 6.36619772367581382433e-01; /* 0x3FE45F30, 0x6DC9C883 */ |
64 | 64 |
65 static double common(uint32_t ix, double x, int y1, int sign) | 65 static double common(uint32_t ix, double x, int y1, int sign) { |
66 { | 66 double z, s, c, ss, cc; |
67 » double z,s,c,ss,cc; | |
68 | 67 |
69 » /* | 68 /* |
70 » * j1(x) = sqrt(2/(pi*x))*(p1(x)*cos(x-3pi/4)-q1(x)*sin(x-3pi/4)) | 69 * j1(x) = sqrt(2/(pi*x))*(p1(x)*cos(x-3pi/4)-q1(x)*sin(x-3pi/4)) |
71 » * y1(x) = sqrt(2/(pi*x))*(p1(x)*sin(x-3pi/4)+q1(x)*cos(x-3pi/4)) | 70 * y1(x) = sqrt(2/(pi*x))*(p1(x)*sin(x-3pi/4)+q1(x)*cos(x-3pi/4)) |
72 » * | 71 * |
73 » * sin(x-3pi/4) = -(sin(x) + cos(x))/sqrt(2) | 72 * sin(x-3pi/4) = -(sin(x) + cos(x))/sqrt(2) |
74 » * cos(x-3pi/4) = (sin(x) - cos(x))/sqrt(2) | 73 * cos(x-3pi/4) = (sin(x) - cos(x))/sqrt(2) |
75 » * sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x)) | 74 * sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x)) |
76 » */ | 75 */ |
77 » s = sin(x); | 76 s = sin(x); |
78 » if (y1) | 77 if (y1) |
79 » » s = -s; | 78 s = -s; |
80 » c = cos(x); | 79 c = cos(x); |
81 » cc = s-c; | 80 cc = s - c; |
82 » if (ix < 0x7fe00000) { | 81 if (ix < 0x7fe00000) { |
83 » » /* avoid overflow in 2*x */ | 82 /* avoid overflow in 2*x */ |
84 » » ss = -s-c; | 83 ss = -s - c; |
85 » » z = cos(2*x); | 84 z = cos(2 * x); |
86 » » if (s*c > 0) | 85 if (s * c > 0) |
87 » » » cc = z/ss; | 86 cc = z / ss; |
88 » » else | 87 else |
89 » » » ss = z/cc; | 88 ss = z / cc; |
90 » » if (ix < 0x48000000) { | 89 if (ix < 0x48000000) { |
91 » » » if (y1) | 90 if (y1) |
92 » » » » ss = -ss; | 91 ss = -ss; |
93 » » » cc = pone(x)*cc-qone(x)*ss; | 92 cc = pone(x) * cc - qone(x) * ss; |
94 » » } | 93 } |
95 » } | 94 } |
96 » if (sign) | 95 if (sign) |
97 » » cc = -cc; | 96 cc = -cc; |
98 » return invsqrtpi*cc/sqrt(x); | 97 return invsqrtpi * cc / sqrt(x); |
99 } | 98 } |
100 | 99 |
101 /* R0/S0 on [0,2] */ | 100 /* R0/S0 on [0,2] */ |
102 static const double | 101 static const double |
103 r00 = -6.25000000000000000000e-02, /* 0xBFB00000, 0x00000000 */ | 102 r00 = -6.25000000000000000000e-02, /* 0xBFB00000, 0x00000000 */ |
104 r01 = 1.40705666955189706048e-03, /* 0x3F570D9F, 0x98472C61 */ | 103 r01 = 1.40705666955189706048e-03, /* 0x3F570D9F, 0x98472C61 */ |
105 r02 = -1.59955631084035597520e-05, /* 0xBEF0C5C6, 0xBA169668 */ | 104 r02 = -1.59955631084035597520e-05, /* 0xBEF0C5C6, 0xBA169668 */ |
106 r03 = 4.96727999609584448412e-08, /* 0x3E6AAAFA, 0x46CA0BD9 */ | 105 r03 = 4.96727999609584448412e-08, /* 0x3E6AAAFA, 0x46CA0BD9 */ |
107 s01 = 1.91537599538363460805e-02, /* 0x3F939D0B, 0x12637E53 */ | 106 s01 = 1.91537599538363460805e-02, /* 0x3F939D0B, 0x12637E53 */ |
108 s02 = 1.85946785588630915560e-04, /* 0x3F285F56, 0xB9CDF664 */ | 107 s02 = 1.85946785588630915560e-04, /* 0x3F285F56, 0xB9CDF664 */ |
109 s03 = 1.17718464042623683263e-06, /* 0x3EB3BFF8, 0x333F8498 */ | 108 s03 = 1.17718464042623683263e-06, /* 0x3EB3BFF8, 0x333F8498 */ |
110 s04 = 5.04636257076217042715e-09, /* 0x3E35AC88, 0xC97DFF2C */ | 109 s04 = 5.04636257076217042715e-09, /* 0x3E35AC88, 0xC97DFF2C */ |
111 s05 = 1.23542274426137913908e-11; /* 0x3DAB2ACF, 0xCFB97ED8 */ | 110 s05 = 1.23542274426137913908e-11; /* 0x3DAB2ACF, 0xCFB97ED8 */ |
112 | 111 |
113 double j1(double x) | 112 double j1(double x) { |
114 { | 113 double z, r, s; |
115 » double z,r,s; | 114 uint32_t ix; |
116 » uint32_t ix; | 115 int sign; |
117 » int sign; | |
118 | 116 |
119 » GET_HIGH_WORD(ix, x); | 117 GET_HIGH_WORD(ix, x); |
120 » sign = ix>>31; | 118 sign = ix >> 31; |
121 » ix &= 0x7fffffff; | 119 ix &= 0x7fffffff; |
122 » if (ix >= 0x7ff00000) | 120 if (ix >= 0x7ff00000) |
123 » » return 1/(x*x); | 121 return 1 / (x * x); |
124 » if (ix >= 0x40000000) /* |x| >= 2 */ | 122 if (ix >= 0x40000000) /* |x| >= 2 */ |
125 » » return common(ix, fabs(x), 0, sign); | 123 return common(ix, fabs(x), 0, sign); |
126 » if (ix >= 0x38000000) { /* |x| >= 2**-127 */ | 124 if (ix >= 0x38000000) { /* |x| >= 2**-127 */ |
127 » » z = x*x; | 125 z = x * x; |
128 » » r = z*(r00+z*(r01+z*(r02+z*r03))); | 126 r = z * (r00 + z * (r01 + z * (r02 + z * r03))); |
129 » » s = 1+z*(s01+z*(s02+z*(s03+z*(s04+z*s05)))); | 127 s = 1 + z * (s01 + z * (s02 + z * (s03 + z * (s04 + z * s05)))); |
130 » » z = r/s; | 128 z = r / s; |
131 » } else | 129 } else |
132 » » /* avoid underflow, raise inexact if x!=0 */ | 130 /* avoid underflow, raise inexact if x!=0 */ |
133 » » z = x; | 131 z = x; |
134 » return (0.5 + z)*x; | 132 return (0.5 + z) * x; |
135 } | 133 } |
136 | 134 |
137 static const double U0[5] = { | 135 static const double U0[5] = { |
138 -1.96057090646238940668e-01, /* 0xBFC91866, 0x143CBC8A */ | 136 -1.96057090646238940668e-01, /* 0xBFC91866, 0x143CBC8A */ |
139 5.04438716639811282616e-02, /* 0x3FA9D3C7, 0x76292CD1 */ | 137 5.04438716639811282616e-02, /* 0x3FA9D3C7, 0x76292CD1 */ |
140 -1.91256895875763547298e-03, /* 0xBF5F55E5, 0x4844F50F */ | 138 -1.91256895875763547298e-03, /* 0xBF5F55E5, 0x4844F50F */ |
141 2.35252600561610495928e-05, /* 0x3EF8AB03, 0x8FA6B88E */ | 139 2.35252600561610495928e-05, /* 0x3EF8AB03, 0x8FA6B88E */ |
142 -9.19099158039878874504e-08, /* 0xBE78AC00, 0x569105B8 */ | 140 -9.19099158039878874504e-08, /* 0xBE78AC00, 0x569105B8 */ |
143 }; | 141 }; |
144 static const double V0[5] = { | 142 static const double V0[5] = { |
145 1.99167318236649903973e-02, /* 0x3F94650D, 0x3F4DA9F0 */ | 143 1.99167318236649903973e-02, /* 0x3F94650D, 0x3F4DA9F0 */ |
146 2.02552581025135171496e-04, /* 0x3F2A8C89, 0x6C257764 */ | 144 2.02552581025135171496e-04, /* 0x3F2A8C89, 0x6C257764 */ |
147 1.35608801097516229404e-06, /* 0x3EB6C05A, 0x894E8CA6 */ | 145 1.35608801097516229404e-06, /* 0x3EB6C05A, 0x894E8CA6 */ |
148 6.22741452364621501295e-09, /* 0x3E3ABF1D, 0x5BA69A86 */ | 146 6.22741452364621501295e-09, /* 0x3E3ABF1D, 0x5BA69A86 */ |
149 1.66559246207992079114e-11, /* 0x3DB25039, 0xDACA772A */ | 147 1.66559246207992079114e-11, /* 0x3DB25039, 0xDACA772A */ |
150 }; | 148 }; |
151 | 149 |
152 double y1(double x) | 150 double y1(double x) { |
153 { | 151 double z, u, v; |
154 » double z,u,v; | 152 uint32_t ix, lx; |
155 » uint32_t ix,lx; | |
156 | 153 |
157 » EXTRACT_WORDS(ix, lx, x); | 154 EXTRACT_WORDS(ix, lx, x); |
158 » /* y1(nan)=nan, y1(<0)=nan, y1(0)=-inf, y1(inf)=0 */ | 155 /* y1(nan)=nan, y1(<0)=nan, y1(0)=-inf, y1(inf)=0 */ |
159 » if ((ix<<1 | lx) == 0) | 156 if ((ix << 1 | lx) == 0) |
160 » » return -1/0.0; | 157 return -1 / 0.0; |
161 » if (ix>>31) | 158 if (ix >> 31) |
162 » » return 0/0.0; | 159 return 0 / 0.0; |
163 » if (ix >= 0x7ff00000) | 160 if (ix >= 0x7ff00000) |
164 » » return 1/x; | 161 return 1 / x; |
165 | 162 |
166 » if (ix >= 0x40000000) /* x >= 2 */ | 163 if (ix >= 0x40000000) /* x >= 2 */ |
167 » » return common(ix, x, 1, 0); | 164 return common(ix, x, 1, 0); |
168 » if (ix < 0x3c900000) /* x < 2**-54 */ | 165 if (ix < 0x3c900000) /* x < 2**-54 */ |
169 » » return -tpi/x; | 166 return -tpi / x; |
170 » z = x*x; | 167 z = x * x; |
171 » u = U0[0]+z*(U0[1]+z*(U0[2]+z*(U0[3]+z*U0[4]))); | 168 u = U0[0] + z * (U0[1] + z * (U0[2] + z * (U0[3] + z * U0[4]))); |
172 » v = 1+z*(V0[0]+z*(V0[1]+z*(V0[2]+z*(V0[3]+z*V0[4])))); | 169 v = 1 + z * (V0[0] + z * (V0[1] + z * (V0[2] + z * (V0[3] + z * V0[4])))); |
173 » return x*(u/v) + tpi*(j1(x)*log(x)-1/x); | 170 return x * (u / v) + tpi * (j1(x) * log(x) - 1 / x); |
174 } | 171 } |
175 | 172 |
176 /* For x >= 8, the asymptotic expansions of pone is | 173 /* For x >= 8, the asymptotic expansions of pone is |
177 * 1 + 15/128 s^2 - 4725/2^15 s^4 - ..., where s = 1/x. | 174 * 1 + 15/128 s^2 - 4725/2^15 s^4 - ..., where s = 1/x. |
178 * We approximate pone by | 175 * We approximate pone by |
179 * pone(x) = 1 + (R/S) | 176 * pone(x) = 1 + (R/S) |
180 * where R = pr0 + pr1*s^2 + pr2*s^4 + ... + pr5*s^10 | 177 * where R = pr0 + pr1*s^2 + pr2*s^4 + ... + pr5*s^10 |
181 * S = 1 + ps0*s^2 + ... + ps4*s^10 | 178 * S = 1 + ps0*s^2 + ... + ps4*s^10 |
182 * and | 179 * and |
183 * | pone(x)-1-R/S | <= 2 ** ( -60.06) | 180 * | pone(x)-1-R/S | <= 2 ** ( -60.06) |
184 */ | 181 */ |
185 | 182 |
186 static const double pr8[6] = { /* for x in [inf, 8]=1/[0,0.125] */ | 183 static const double pr8[6] = { |
187 0.00000000000000000000e+00, /* 0x00000000, 0x00000000 */ | 184 /* for x in [inf, 8]=1/[0,0.125] */ |
188 1.17187499999988647970e-01, /* 0x3FBDFFFF, 0xFFFFFCCE */ | 185 0.00000000000000000000e+00, /* 0x00000000, 0x00000000 */ |
189 1.32394806593073575129e+01, /* 0x402A7A9D, 0x357F7FCE */ | 186 1.17187499999988647970e-01, /* 0x3FBDFFFF, 0xFFFFFCCE */ |
190 4.12051854307378562225e+02, /* 0x4079C0D4, 0x652EA590 */ | 187 1.32394806593073575129e+01, /* 0x402A7A9D, 0x357F7FCE */ |
191 3.87474538913960532227e+03, /* 0x40AE457D, 0xA3A532CC */ | 188 4.12051854307378562225e+02, /* 0x4079C0D4, 0x652EA590 */ |
192 7.91447954031891731574e+03, /* 0x40BEEA7A, 0xC32782DD */ | 189 3.87474538913960532227e+03, /* 0x40AE457D, 0xA3A532CC */ |
| 190 7.91447954031891731574e+03, /* 0x40BEEA7A, 0xC32782DD */ |
193 }; | 191 }; |
194 static const double ps8[5] = { | 192 static const double ps8[5] = { |
195 1.14207370375678408436e+02, /* 0x405C8D45, 0x8E656CAC */ | 193 1.14207370375678408436e+02, /* 0x405C8D45, 0x8E656CAC */ |
196 3.65093083420853463394e+03, /* 0x40AC85DC, 0x964D274F */ | 194 3.65093083420853463394e+03, /* 0x40AC85DC, 0x964D274F */ |
197 3.69562060269033463555e+04, /* 0x40E20B86, 0x97C5BB7F */ | 195 3.69562060269033463555e+04, /* 0x40E20B86, 0x97C5BB7F */ |
198 9.76027935934950801311e+04, /* 0x40F7D42C, 0xB28F17BB */ | 196 9.76027935934950801311e+04, /* 0x40F7D42C, 0xB28F17BB */ |
199 3.08042720627888811578e+04, /* 0x40DE1511, 0x697A0B2D */ | 197 3.08042720627888811578e+04, /* 0x40DE1511, 0x697A0B2D */ |
200 }; | 198 }; |
201 | 199 |
202 static const double pr5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */ | 200 static const double pr5[6] = { |
203 1.31990519556243522749e-11, /* 0x3DAD0667, 0xDAE1CA7D */ | 201 /* for x in [8,4.5454]=1/[0.125,0.22001] */ |
204 1.17187493190614097638e-01, /* 0x3FBDFFFF, 0xE2C10043 */ | 202 1.31990519556243522749e-11, /* 0x3DAD0667, 0xDAE1CA7D */ |
205 6.80275127868432871736e+00, /* 0x401B3604, 0x6E6315E3 */ | 203 1.17187493190614097638e-01, /* 0x3FBDFFFF, 0xE2C10043 */ |
206 1.08308182990189109773e+02, /* 0x405B13B9, 0x452602ED */ | 204 6.80275127868432871736e+00, /* 0x401B3604, 0x6E6315E3 */ |
207 5.17636139533199752805e+02, /* 0x40802D16, 0xD052D649 */ | 205 1.08308182990189109773e+02, /* 0x405B13B9, 0x452602ED */ |
208 5.28715201363337541807e+02, /* 0x408085B8, 0xBB7E0CB7 */ | 206 5.17636139533199752805e+02, /* 0x40802D16, 0xD052D649 */ |
| 207 5.28715201363337541807e+02, /* 0x408085B8, 0xBB7E0CB7 */ |
209 }; | 208 }; |
210 static const double ps5[5] = { | 209 static const double ps5[5] = { |
211 5.92805987221131331921e+01, /* 0x404DA3EA, 0xA8AF633D */ | 210 5.92805987221131331921e+01, /* 0x404DA3EA, 0xA8AF633D */ |
212 9.91401418733614377743e+02, /* 0x408EFB36, 0x1B066701 */ | 211 9.91401418733614377743e+02, /* 0x408EFB36, 0x1B066701 */ |
213 5.35326695291487976647e+03, /* 0x40B4E944, 0x5706B6FB */ | 212 5.35326695291487976647e+03, /* 0x40B4E944, 0x5706B6FB */ |
214 7.84469031749551231769e+03, /* 0x40BEA4B0, 0xB8A5BB15 */ | 213 7.84469031749551231769e+03, /* 0x40BEA4B0, 0xB8A5BB15 */ |
215 1.50404688810361062679e+03, /* 0x40978030, 0x036F5E51 */ | 214 1.50404688810361062679e+03, /* 0x40978030, 0x036F5E51 */ |
216 }; | 215 }; |
217 | 216 |
218 static const double pr3[6] = { | 217 static const double pr3[6] = { |
219 3.02503916137373618024e-09, /* 0x3E29FC21, 0xA7AD9EDD */ | 218 3.02503916137373618024e-09, /* 0x3E29FC21, 0xA7AD9EDD */ |
220 1.17186865567253592491e-01, /* 0x3FBDFFF5, 0x5B21D17B */ | 219 1.17186865567253592491e-01, /* 0x3FBDFFF5, 0x5B21D17B */ |
221 3.93297750033315640650e+00, /* 0x400F76BC, 0xE85EAD8A */ | 220 3.93297750033315640650e+00, /* 0x400F76BC, 0xE85EAD8A */ |
222 3.51194035591636932736e+01, /* 0x40418F48, 0x9DA6D129 */ | 221 3.51194035591636932736e+01, /* 0x40418F48, 0x9DA6D129 */ |
223 9.10550110750781271918e+01, /* 0x4056C385, 0x4D2C1837 */ | 222 9.10550110750781271918e+01, /* 0x4056C385, 0x4D2C1837 */ |
224 4.85590685197364919645e+01, /* 0x4048478F, 0x8EA83EE5 */ | 223 4.85590685197364919645e+01, /* 0x4048478F, 0x8EA83EE5 */ |
225 }; | 224 }; |
226 static const double ps3[5] = { | 225 static const double ps3[5] = { |
227 3.47913095001251519989e+01, /* 0x40416549, 0xA134069C */ | 226 3.47913095001251519989e+01, /* 0x40416549, 0xA134069C */ |
228 3.36762458747825746741e+02, /* 0x40750C33, 0x07F1A75F */ | 227 3.36762458747825746741e+02, /* 0x40750C33, 0x07F1A75F */ |
229 1.04687139975775130551e+03, /* 0x40905B7C, 0x5037D523 */ | 228 1.04687139975775130551e+03, /* 0x40905B7C, 0x5037D523 */ |
230 8.90811346398256432622e+02, /* 0x408BD67D, 0xA32E31E9 */ | 229 8.90811346398256432622e+02, /* 0x408BD67D, 0xA32E31E9 */ |
231 1.03787932439639277504e+02, /* 0x4059F26D, 0x7C2EED53 */ | 230 1.03787932439639277504e+02, /* 0x4059F26D, 0x7C2EED53 */ |
232 }; | 231 }; |
233 | 232 |
234 static const double pr2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */ | 233 static const double pr2[6] = { |
235 1.07710830106873743082e-07, /* 0x3E7CE9D4, 0xF65544F4 */ | 234 /* for x in [2.8570,2]=1/[0.3499,0.5] */ |
236 1.17176219462683348094e-01, /* 0x3FBDFF42, 0xBE760D83 */ | 235 1.07710830106873743082e-07, /* 0x3E7CE9D4, 0xF65544F4 */ |
237 2.36851496667608785174e+00, /* 0x4002F2B7, 0xF98FAEC0 */ | 236 1.17176219462683348094e-01, /* 0x3FBDFF42, 0xBE760D83 */ |
238 1.22426109148261232917e+01, /* 0x40287C37, 0x7F71A964 */ | 237 2.36851496667608785174e+00, /* 0x4002F2B7, 0xF98FAEC0 */ |
239 1.76939711271687727390e+01, /* 0x4031B1A8, 0x177F8EE2 */ | 238 1.22426109148261232917e+01, /* 0x40287C37, 0x7F71A964 */ |
240 5.07352312588818499250e+00, /* 0x40144B49, 0xA574C1FE */ | 239 1.76939711271687727390e+01, /* 0x4031B1A8, 0x177F8EE2 */ |
| 240 5.07352312588818499250e+00, /* 0x40144B49, 0xA574C1FE */ |
241 }; | 241 }; |
242 static const double ps2[5] = { | 242 static const double ps2[5] = { |
243 2.14364859363821409488e+01, /* 0x40356FBD, 0x8AD5ECDC */ | 243 2.14364859363821409488e+01, /* 0x40356FBD, 0x8AD5ECDC */ |
244 1.25290227168402751090e+02, /* 0x405F5293, 0x14F92CD5 */ | 244 1.25290227168402751090e+02, /* 0x405F5293, 0x14F92CD5 */ |
245 2.32276469057162813669e+02, /* 0x406D08D8, 0xD5A2DBD9 */ | 245 2.32276469057162813669e+02, /* 0x406D08D8, 0xD5A2DBD9 */ |
246 1.17679373287147100768e+02, /* 0x405D6B7A, 0xDA1884A9 */ | 246 1.17679373287147100768e+02, /* 0x405D6B7A, 0xDA1884A9 */ |
247 8.36463893371618283368e+00, /* 0x4020BAB1, 0xF44E5192 */ | 247 8.36463893371618283368e+00, /* 0x4020BAB1, 0xF44E5192 */ |
248 }; | 248 }; |
249 | 249 |
250 static double pone(double x) | 250 static double pone(double x) { |
251 { | 251 const double *p, *q; |
252 » const double *p,*q; | 252 double_t z, r, s; |
253 » double_t z,r,s; | 253 uint32_t ix; |
254 » uint32_t ix; | |
255 | 254 |
256 » GET_HIGH_WORD(ix, x); | 255 GET_HIGH_WORD(ix, x); |
257 » ix &= 0x7fffffff; | 256 ix &= 0x7fffffff; |
258 » if (ix >= 0x40200000){p = pr8; q = ps8;} | 257 if (ix >= 0x40200000) { |
259 » else if (ix >= 0x40122E8B){p = pr5; q = ps5;} | 258 p = pr8; |
260 » else if (ix >= 0x4006DB6D){p = pr3; q = ps3;} | 259 q = ps8; |
261 » else /*ix >= 0x40000000*/ {p = pr2; q = ps2;} | 260 } else if (ix >= 0x40122E8B) { |
262 » z = 1.0/(x*x); | 261 p = pr5; |
263 » r = p[0]+z*(p[1]+z*(p[2]+z*(p[3]+z*(p[4]+z*p[5])))); | 262 q = ps5; |
264 » s = 1.0+z*(q[0]+z*(q[1]+z*(q[2]+z*(q[3]+z*q[4])))); | 263 } else if (ix >= 0x4006DB6D) { |
265 » return 1.0+ r/s; | 264 p = pr3; |
| 265 q = ps3; |
| 266 } else /*ix >= 0x40000000*/ { |
| 267 p = pr2; |
| 268 q = ps2; |
| 269 } |
| 270 z = 1.0 / (x * x); |
| 271 r = p[0] + z * (p[1] + z * (p[2] + z * (p[3] + z * (p[4] + z * p[5])))); |
| 272 s = 1.0 + z * (q[0] + z * (q[1] + z * (q[2] + z * (q[3] + z * q[4])))); |
| 273 return 1.0 + r / s; |
266 } | 274 } |
267 | 275 |
268 /* For x >= 8, the asymptotic expansions of qone is | 276 /* For x >= 8, the asymptotic expansions of qone is |
269 * 3/8 s - 105/1024 s^3 - ..., where s = 1/x. | 277 * 3/8 s - 105/1024 s^3 - ..., where s = 1/x. |
270 * We approximate pone by | 278 * We approximate pone by |
271 * qone(x) = s*(0.375 + (R/S)) | 279 * qone(x) = s*(0.375 + (R/S)) |
272 * where R = qr1*s^2 + qr2*s^4 + ... + qr5*s^10 | 280 * where R = qr1*s^2 + qr2*s^4 + ... + qr5*s^10 |
273 * S = 1 + qs1*s^2 + ... + qs6*s^12 | 281 * S = 1 + qs1*s^2 + ... + qs6*s^12 |
274 * and | 282 * and |
275 * | qone(x)/s -0.375-R/S | <= 2 ** ( -61.13) | 283 * | qone(x)/s -0.375-R/S | <= 2 ** ( -61.13) |
276 */ | 284 */ |
277 | 285 |
278 static const double qr8[6] = { /* for x in [inf, 8]=1/[0,0.125] */ | 286 static const double qr8[6] = { |
279 0.00000000000000000000e+00, /* 0x00000000, 0x00000000 */ | 287 /* for x in [inf, 8]=1/[0,0.125] */ |
280 -1.02539062499992714161e-01, /* 0xBFBA3FFF, 0xFFFFFDF3 */ | 288 0.00000000000000000000e+00, /* 0x00000000, 0x00000000 */ |
281 -1.62717534544589987888e+01, /* 0xC0304591, 0xA26779F7 */ | 289 -1.02539062499992714161e-01, /* 0xBFBA3FFF, 0xFFFFFDF3 */ |
282 -7.59601722513950107896e+02, /* 0xC087BCD0, 0x53E4B576 */ | 290 -1.62717534544589987888e+01, /* 0xC0304591, 0xA26779F7 */ |
283 -1.18498066702429587167e+04, /* 0xC0C724E7, 0x40F87415 */ | 291 -7.59601722513950107896e+02, /* 0xC087BCD0, 0x53E4B576 */ |
284 -4.84385124285750353010e+04, /* 0xC0E7A6D0, 0x65D09C6A */ | 292 -1.18498066702429587167e+04, /* 0xC0C724E7, 0x40F87415 */ |
| 293 -4.84385124285750353010e+04, /* 0xC0E7A6D0, 0x65D09C6A */ |
285 }; | 294 }; |
286 static const double qs8[6] = { | 295 static const double qs8[6] = { |
287 1.61395369700722909556e+02, /* 0x40642CA6, 0xDE5BCDE5 */ | 296 1.61395369700722909556e+02, /* 0x40642CA6, 0xDE5BCDE5 */ |
288 7.82538599923348465381e+03, /* 0x40BE9162, 0xD0D88419 */ | 297 7.82538599923348465381e+03, /* 0x40BE9162, 0xD0D88419 */ |
289 1.33875336287249578163e+05, /* 0x4100579A, 0xB0B75E98 */ | 298 1.33875336287249578163e+05, /* 0x4100579A, 0xB0B75E98 */ |
290 7.19657723683240939863e+05, /* 0x4125F653, 0x72869C19 */ | 299 7.19657723683240939863e+05, /* 0x4125F653, 0x72869C19 */ |
291 6.66601232617776375264e+05, /* 0x412457D2, 0x7719AD5C */ | 300 6.66601232617776375264e+05, /* 0x412457D2, 0x7719AD5C */ |
292 -2.94490264303834643215e+05, /* 0xC111F969, 0x0EA5AA18 */ | 301 -2.94490264303834643215e+05, /* 0xC111F969, 0x0EA5AA18 */ |
293 }; | 302 }; |
294 | 303 |
295 static const double qr5[6] = { /* for x in [8,4.5454]=1/[0.125,0.22001] */ | 304 static const double qr5[6] = { |
296 -2.08979931141764104297e-11, /* 0xBDB6FA43, 0x1AA1A098 */ | 305 /* for x in [8,4.5454]=1/[0.125,0.22001] */ |
297 -1.02539050241375426231e-01, /* 0xBFBA3FFF, 0xCB597FEF */ | 306 -2.08979931141764104297e-11, /* 0xBDB6FA43, 0x1AA1A098 */ |
298 -8.05644828123936029840e+00, /* 0xC0201CE6, 0xCA03AD4B */ | 307 -1.02539050241375426231e-01, /* 0xBFBA3FFF, 0xCB597FEF */ |
299 -1.83669607474888380239e+02, /* 0xC066F56D, 0x6CA7B9B0 */ | 308 -8.05644828123936029840e+00, /* 0xC0201CE6, 0xCA03AD4B */ |
300 -1.37319376065508163265e+03, /* 0xC09574C6, 0x6931734F */ | 309 -1.83669607474888380239e+02, /* 0xC066F56D, 0x6CA7B9B0 */ |
301 -2.61244440453215656817e+03, /* 0xC0A468E3, 0x88FDA79D */ | 310 -1.37319376065508163265e+03, /* 0xC09574C6, 0x6931734F */ |
| 311 -2.61244440453215656817e+03, /* 0xC0A468E3, 0x88FDA79D */ |
302 }; | 312 }; |
303 static const double qs5[6] = { | 313 static const double qs5[6] = { |
304 8.12765501384335777857e+01, /* 0x405451B2, 0xFF5A11B2 */ | 314 8.12765501384335777857e+01, /* 0x405451B2, 0xFF5A11B2 */ |
305 1.99179873460485964642e+03, /* 0x409F1F31, 0xE77BF839 */ | 315 1.99179873460485964642e+03, /* 0x409F1F31, 0xE77BF839 */ |
306 1.74684851924908907677e+04, /* 0x40D10F1F, 0x0D64CE29 */ | 316 1.74684851924908907677e+04, /* 0x40D10F1F, 0x0D64CE29 */ |
307 4.98514270910352279316e+04, /* 0x40E8576D, 0xAABAD197 */ | 317 4.98514270910352279316e+04, /* 0x40E8576D, 0xAABAD197 */ |
308 2.79480751638918118260e+04, /* 0x40DB4B04, 0xCF7C364B */ | 318 2.79480751638918118260e+04, /* 0x40DB4B04, 0xCF7C364B */ |
309 -4.71918354795128470869e+03, /* 0xC0B26F2E, 0xFCFFA004 */ | 319 -4.71918354795128470869e+03, /* 0xC0B26F2E, 0xFCFFA004 */ |
310 }; | 320 }; |
311 | 321 |
312 static const double qr3[6] = { | 322 static const double qr3[6] = { |
313 -5.07831226461766561369e-09, /* 0xBE35CFA9, 0xD38FC84F */ | 323 -5.07831226461766561369e-09, /* 0xBE35CFA9, 0xD38FC84F */ |
314 -1.02537829820837089745e-01, /* 0xBFBA3FEB, 0x51AEED54 */ | 324 -1.02537829820837089745e-01, /* 0xBFBA3FEB, 0x51AEED54 */ |
315 -4.61011581139473403113e+00, /* 0xC01270C2, 0x3302D9FF */ | 325 -4.61011581139473403113e+00, /* 0xC01270C2, 0x3302D9FF */ |
316 -5.78472216562783643212e+01, /* 0xC04CEC71, 0xC25D16DA */ | 326 -5.78472216562783643212e+01, /* 0xC04CEC71, 0xC25D16DA */ |
317 -2.28244540737631695038e+02, /* 0xC06C87D3, 0x4718D55F */ | 327 -2.28244540737631695038e+02, /* 0xC06C87D3, 0x4718D55F */ |
318 -2.19210128478909325622e+02, /* 0xC06B66B9, 0x5F5C1BF6 */ | 328 -2.19210128478909325622e+02, /* 0xC06B66B9, 0x5F5C1BF6 */ |
319 }; | 329 }; |
320 static const double qs3[6] = { | 330 static const double qs3[6] = { |
321 4.76651550323729509273e+01, /* 0x4047D523, 0xCCD367E4 */ | 331 4.76651550323729509273e+01, /* 0x4047D523, 0xCCD367E4 */ |
322 6.73865112676699709482e+02, /* 0x40850EEB, 0xC031EE3E */ | 332 6.73865112676699709482e+02, /* 0x40850EEB, 0xC031EE3E */ |
323 3.38015286679526343505e+03, /* 0x40AA684E, 0x448E7C9A */ | 333 3.38015286679526343505e+03, /* 0x40AA684E, 0x448E7C9A */ |
324 5.54772909720722782367e+03, /* 0x40B5ABBA, 0xA61D54A6 */ | 334 5.54772909720722782367e+03, /* 0x40B5ABBA, 0xA61D54A6 */ |
325 1.90311919338810798763e+03, /* 0x409DBC7A, 0x0DD4DF4B */ | 335 1.90311919338810798763e+03, /* 0x409DBC7A, 0x0DD4DF4B */ |
326 -1.35201191444307340817e+02, /* 0xC060E670, 0x290A311F */ | 336 -1.35201191444307340817e+02, /* 0xC060E670, 0x290A311F */ |
327 }; | 337 }; |
328 | 338 |
329 static const double qr2[6] = {/* for x in [2.8570,2]=1/[0.3499,0.5] */ | 339 static const double qr2[6] = { |
330 -1.78381727510958865572e-07, /* 0xBE87F126, 0x44C626D2 */ | 340 /* for x in [2.8570,2]=1/[0.3499,0.5] */ |
331 -1.02517042607985553460e-01, /* 0xBFBA3E8E, 0x9148B010 */ | 341 -1.78381727510958865572e-07, /* 0xBE87F126, 0x44C626D2 */ |
332 -2.75220568278187460720e+00, /* 0xC0060484, 0x69BB4EDA */ | 342 -1.02517042607985553460e-01, /* 0xBFBA3E8E, 0x9148B010 */ |
333 -1.96636162643703720221e+01, /* 0xC033A9E2, 0xC168907F */ | 343 -2.75220568278187460720e+00, /* 0xC0060484, 0x69BB4EDA */ |
334 -4.23253133372830490089e+01, /* 0xC04529A3, 0xDE104AAA */ | 344 -1.96636162643703720221e+01, /* 0xC033A9E2, 0xC168907F */ |
335 -2.13719211703704061733e+01, /* 0xC0355F36, 0x39CF6E52 */ | 345 -4.23253133372830490089e+01, /* 0xC04529A3, 0xDE104AAA */ |
| 346 -2.13719211703704061733e+01, /* 0xC0355F36, 0x39CF6E52 */ |
336 }; | 347 }; |
337 static const double qs2[6] = { | 348 static const double qs2[6] = { |
338 2.95333629060523854548e+01, /* 0x403D888A, 0x78AE64FF */ | 349 2.95333629060523854548e+01, /* 0x403D888A, 0x78AE64FF */ |
339 2.52981549982190529136e+02, /* 0x406F9F68, 0xDB821CBA */ | 350 2.52981549982190529136e+02, /* 0x406F9F68, 0xDB821CBA */ |
340 7.57502834868645436472e+02, /* 0x4087AC05, 0xCE49A0F7 */ | 351 7.57502834868645436472e+02, /* 0x4087AC05, 0xCE49A0F7 */ |
341 7.39393205320467245656e+02, /* 0x40871B25, 0x48D4C029 */ | 352 7.39393205320467245656e+02, /* 0x40871B25, 0x48D4C029 */ |
342 1.55949003336666123687e+02, /* 0x40637E5E, 0x3C3ED8D4 */ | 353 1.55949003336666123687e+02, /* 0x40637E5E, 0x3C3ED8D4 */ |
343 -4.95949898822628210127e+00, /* 0xC013D686, 0xE71BE86B */ | 354 -4.95949898822628210127e+00, /* 0xC013D686, 0xE71BE86B */ |
344 }; | 355 }; |
345 | 356 |
346 static double qone(double x) | 357 static double qone(double x) { |
347 { | 358 const double *p, *q; |
348 » const double *p,*q; | 359 double_t s, r, z; |
349 » double_t s,r,z; | 360 uint32_t ix; |
350 » uint32_t ix; | |
351 | 361 |
352 » GET_HIGH_WORD(ix, x); | 362 GET_HIGH_WORD(ix, x); |
353 » ix &= 0x7fffffff; | 363 ix &= 0x7fffffff; |
354 » if (ix >= 0x40200000){p = qr8; q = qs8;} | 364 if (ix >= 0x40200000) { |
355 » else if (ix >= 0x40122E8B){p = qr5; q = qs5;} | 365 p = qr8; |
356 » else if (ix >= 0x4006DB6D){p = qr3; q = qs3;} | 366 q = qs8; |
357 » else /*ix >= 0x40000000*/ {p = qr2; q = qs2;} | 367 } else if (ix >= 0x40122E8B) { |
358 » z = 1.0/(x*x); | 368 p = qr5; |
359 » r = p[0]+z*(p[1]+z*(p[2]+z*(p[3]+z*(p[4]+z*p[5])))); | 369 q = qs5; |
360 » s = 1.0+z*(q[0]+z*(q[1]+z*(q[2]+z*(q[3]+z*(q[4]+z*q[5]))))); | 370 } else if (ix >= 0x4006DB6D) { |
361 » return (.375 + r/s)/x; | 371 p = qr3; |
| 372 q = qs3; |
| 373 } else /*ix >= 0x40000000*/ { |
| 374 p = qr2; |
| 375 q = qs2; |
| 376 } |
| 377 z = 1.0 / (x * x); |
| 378 r = p[0] + z * (p[1] + z * (p[2] + z * (p[3] + z * (p[4] + z * p[5])))); |
| 379 s = 1.0 + |
| 380 z * (q[0] + z * (q[1] + z * (q[2] + z * (q[3] + z * (q[4] + z * q[5]))))); |
| 381 return (.375 + r / s) / x; |
362 } | 382 } |
OLD | NEW |