diff options
Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/__tanl.c')
| -rw-r--r-- | lib/mlibc/options/ansi/musl-generic-math/__tanl.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/__tanl.c b/lib/mlibc/options/ansi/musl-generic-math/__tanl.c new file mode 100644 index 0000000..54abc3d --- /dev/null +++ b/lib/mlibc/options/ansi/musl-generic-math/__tanl.c @@ -0,0 +1,143 @@ +/* origin: FreeBSD /usr/src/lib/msun/ld80/k_tanl.c */ +/* origin: FreeBSD /usr/src/lib/msun/ld128/k_tanl.c */ +/* + * ==================================================== + * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved. + * Copyright (c) 2008 Steven G. Kargl, David Schultz, Bruce D. Evans. + * + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include "libm.h" + +#if (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 +#if LDBL_MANT_DIG == 64 +/* + * ld80 version of __tan.c. See __tan.c for most comments. + */ +/* + * Domain [-0.67434, 0.67434], range ~[-2.25e-22, 1.921e-22] + * |tan(x)/x - t(x)| < 2**-71.9 + * + * See __cosl.c for more details about the polynomial. + */ +static const long double +T3 = 0.333333333333333333180L, /* 0xaaaaaaaaaaaaaaa5.0p-65 */ +T5 = 0.133333333333333372290L, /* 0x88888888888893c3.0p-66 */ +T7 = 0.0539682539682504975744L, /* 0xdd0dd0dd0dc13ba2.0p-68 */ +pio4 = 0.785398163397448309628L, /* 0xc90fdaa22168c235.0p-64 */ +pio4lo = -1.25413940316708300586e-20L; /* -0xece675d1fc8f8cbb.0p-130 */ +static const double +T9 = 0.021869488536312216, /* 0x1664f4882cc1c2.0p-58 */ +T11 = 0.0088632355256619590, /* 0x1226e355c17612.0p-59 */ +T13 = 0.0035921281113786528, /* 0x1d6d3d185d7ff8.0p-61 */ +T15 = 0.0014558334756312418, /* 0x17da354aa3f96b.0p-62 */ +T17 = 0.00059003538700862256, /* 0x13559358685b83.0p-63 */ +T19 = 0.00023907843576635544, /* 0x1f56242026b5be.0p-65 */ +T21 = 0.000097154625656538905, /* 0x1977efc26806f4.0p-66 */ +T23 = 0.000038440165747303162, /* 0x14275a09b3ceac.0p-67 */ +T25 = 0.000018082171885432524, /* 0x12f5e563e5487e.0p-68 */ +T27 = 0.0000024196006108814377, /* 0x144c0d80cc6896.0p-71 */ +T29 = 0.0000078293456938132840, /* 0x106b59141a6cb3.0p-69 */ +T31 = -0.0000032609076735050182, /* -0x1b5abef3ba4b59.0p-71 */ +T33 = 0.0000023261313142559411; /* 0x13835436c0c87f.0p-71 */ +#define RPOLY(w) (T5 + w * (T9 + w * (T13 + w * (T17 + w * (T21 + \ + w * (T25 + w * (T29 + w * T33))))))) +#define VPOLY(w) (T7 + w * (T11 + w * (T15 + w * (T19 + w * (T23 + \ + w * (T27 + w * T31)))))) +#elif LDBL_MANT_DIG == 113 +/* + * ld128 version of __tan.c. See __tan.c for most comments. + */ +/* + * Domain [-0.67434, 0.67434], range ~[-3.37e-36, 1.982e-37] + * |tan(x)/x - t(x)| < 2**-117.8 (XXX should be ~1e-37) + * + * See __cosl.c for more details about the polynomial. + */ +static const long double +T3 = 0x1.5555555555555555555555555553p-2L, +T5 = 0x1.1111111111111111111111111eb5p-3L, +T7 = 0x1.ba1ba1ba1ba1ba1ba1ba1b694cd6p-5L, +T9 = 0x1.664f4882c10f9f32d6bbe09d8bcdp-6L, +T11 = 0x1.226e355e6c23c8f5b4f5762322eep-7L, +T13 = 0x1.d6d3d0e157ddfb5fed8e84e27b37p-9L, +T15 = 0x1.7da36452b75e2b5fce9ee7c2c92ep-10L, +T17 = 0x1.355824803674477dfcf726649efep-11L, +T19 = 0x1.f57d7734d1656e0aceb716f614c2p-13L, +T21 = 0x1.967e18afcb180ed942dfdc518d6cp-14L, +T23 = 0x1.497d8eea21e95bc7e2aa79b9f2cdp-15L, +T25 = 0x1.0b132d39f055c81be49eff7afd50p-16L, +T27 = 0x1.b0f72d33eff7bfa2fbc1059d90b6p-18L, +T29 = 0x1.5ef2daf21d1113df38d0fbc00267p-19L, +T31 = 0x1.1c77d6eac0234988cdaa04c96626p-20L, +T33 = 0x1.cd2a5a292b180e0bdd701057dfe3p-22L, +T35 = 0x1.75c7357d0298c01a31d0a6f7d518p-23L, +T37 = 0x1.2f3190f4718a9a520f98f50081fcp-24L, +pio4 = 0x1.921fb54442d18469898cc51701b8p-1L, +pio4lo = 0x1.cd129024e088a67cc74020bbea60p-116L; +static const double +T39 = 0.000000028443389121318352, /* 0x1e8a7592977938.0p-78 */ +T41 = 0.000000011981013102001973, /* 0x19baa1b1223219.0p-79 */ +T43 = 0.0000000038303578044958070, /* 0x107385dfb24529.0p-80 */ +T45 = 0.0000000034664378216909893, /* 0x1dc6c702a05262.0p-81 */ +T47 = -0.0000000015090641701997785, /* -0x19ecef3569ebb6.0p-82 */ +T49 = 0.0000000029449552300483952, /* 0x194c0668da786a.0p-81 */ +T51 = -0.0000000022006995706097711, /* -0x12e763b8845268.0p-81 */ +T53 = 0.0000000015468200913196612, /* 0x1a92fc98c29554.0p-82 */ +T55 = -0.00000000061311613386849674, /* -0x151106cbc779a9.0p-83 */ +T57 = 1.4912469681508012e-10; /* 0x147edbdba6f43a.0p-85 */ +#define RPOLY(w) (T5 + w * (T9 + w * (T13 + w * (T17 + w * (T21 + \ + w * (T25 + w * (T29 + w * (T33 + w * (T37 + w * (T41 + \ + w * (T45 + w * (T49 + w * (T53 + w * T57))))))))))))) +#define VPOLY(w) (T7 + w * (T11 + w * (T15 + w * (T19 + w * (T23 + \ + w * (T27 + w * (T31 + w * (T35 + w * (T39 + w * (T43 + \ + w * (T47 + w * (T51 + w * T55)))))))))))) +#endif + +long double __tanl(long double x, long double y, int odd) { + long double z, r, v, w, s, a, t; + int big, sign; + + big = fabsl(x) >= 0.67434; + if (big) { + sign = 0; + if (x < 0) { + sign = 1; + x = -x; + y = -y; + } + x = (pio4 - x) + (pio4lo - y); + y = 0.0; + } + z = x * x; + w = z * z; + r = RPOLY(w); + v = z * VPOLY(w); + s = z * x; + r = y + z * (s * (r + v) + y) + T3 * s; + w = x + r; + if (big) { + s = 1 - 2*odd; + v = s - 2.0 * (x + (r - w * w / (w + s))); + return sign ? -v : v; + } + if (!odd) + return w; + /* + * if allow error up to 2 ulp, simply return + * -1.0 / (x+r) here + */ + /* compute -1.0 / (x+r) accurately */ + z = w; + z = z + 0x1p32 - 0x1p32; + v = r - (z - x); /* z+v = r+x */ + t = a = -1.0 / w; /* a = -1.0/w */ + t = t + 0x1p32 - 0x1p32; + s = 1.0 + t * z; + return t + a * (s + t * v); +} +#endif |