Andrew Top | 286dd78 | 2018-10-02 16:52:45 -0700 | [diff] [blame] | 1 | #include <float.h> |
| 2 | #include "__invtrigl.h" |
| 3 | |
| 4 | #if LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 |
| 5 | static const long double |
| 6 | pS0 = 1.66666666666666666631e-01L, |
| 7 | pS1 = -4.16313987993683104320e-01L, |
| 8 | pS2 = 3.69068046323246813704e-01L, |
| 9 | pS3 = -1.36213932016738603108e-01L, |
| 10 | pS4 = 1.78324189708471965733e-02L, |
| 11 | pS5 = -2.19216428382605211588e-04L, |
| 12 | pS6 = -7.10526623669075243183e-06L, |
| 13 | qS1 = -2.94788392796209867269e+00L, |
| 14 | qS2 = 3.27309890266528636716e+00L, |
| 15 | qS3 = -1.68285799854822427013e+00L, |
| 16 | qS4 = 3.90699412641738801874e-01L, |
| 17 | qS5 = -3.14365703596053263322e-02L; |
| 18 | |
| 19 | const long double pio2_hi = 1.57079632679489661926L; |
| 20 | const long double pio2_lo = -2.50827880633416601173e-20L; |
| 21 | |
| 22 | /* used in asinl() and acosl() */ |
| 23 | /* R(x^2) is a rational approximation of (asin(x)-x)/x^3 with Remez algorithm */ |
| 24 | long double __invtrigl_R(long double z) |
| 25 | { |
| 26 | long double p, q; |
| 27 | p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*(pS5+z*pS6)))))); |
| 28 | q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*(qS4+z*qS5)))); |
| 29 | return p/q; |
| 30 | } |
| 31 | #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 |
| 32 | static const long double |
| 33 | pS0 = 1.66666666666666666666666666666700314e-01L, |
| 34 | pS1 = -7.32816946414566252574527475428622708e-01L, |
| 35 | pS2 = 1.34215708714992334609030036562143589e+00L, |
| 36 | pS3 = -1.32483151677116409805070261790752040e+00L, |
| 37 | pS4 = 7.61206183613632558824485341162121989e-01L, |
| 38 | pS5 = -2.56165783329023486777386833928147375e-01L, |
| 39 | pS6 = 4.80718586374448793411019434585413855e-02L, |
| 40 | pS7 = -4.42523267167024279410230886239774718e-03L, |
| 41 | pS8 = 1.44551535183911458253205638280410064e-04L, |
| 42 | pS9 = -2.10558957916600254061591040482706179e-07L, |
| 43 | qS1 = -4.84690167848739751544716485245697428e+00L, |
| 44 | qS2 = 9.96619113536172610135016921140206980e+00L, |
| 45 | qS3 = -1.13177895428973036660836798461641458e+01L, |
| 46 | qS4 = 7.74004374389488266169304117714658761e+00L, |
| 47 | qS5 = -3.25871986053534084709023539900339905e+00L, |
| 48 | qS6 = 8.27830318881232209752469022352928864e-01L, |
| 49 | qS7 = -1.18768052702942805423330715206348004e-01L, |
| 50 | qS8 = 8.32600764660522313269101537926539470e-03L, |
| 51 | qS9 = -1.99407384882605586705979504567947007e-04L; |
| 52 | |
| 53 | const long double pio2_hi = 1.57079632679489661923132169163975140L; |
| 54 | const long double pio2_lo = 4.33590506506189051239852201302167613e-35L; |
| 55 | |
| 56 | long double __invtrigl_R(long double z) |
| 57 | { |
| 58 | long double p, q; |
| 59 | p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*(pS5+z*(pS6+z*(pS7+z*(pS8+z*pS9))))))))); |
| 60 | q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*(qS4+z*(qS5+z*(qS6+z*(qS7+z*(qS8+z*qS9)))))))); |
| 61 | return p/q; |
| 62 | } |
| 63 | #endif |