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