diff options
Diffstat (limited to 'libc-top-half/musl/src/math/asinl.c')
-rw-r--r-- | libc-top-half/musl/src/math/asinl.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/math/asinl.c b/libc-top-half/musl/src/math/asinl.c new file mode 100644 index 0000000..347c535 --- /dev/null +++ b/libc-top-half/musl/src/math/asinl.c @@ -0,0 +1,71 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/e_asinl.c */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunSoft, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ +/* + * See comments in asin.c. + * Converted to long double by David Schultz <das@FreeBSD.ORG>. + */ + +#include "libm.h" + +#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 +long double asinl(long double x) +{ + return asin(x); +} +#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 +#include "__invtrigl.h" +#if LDBL_MANT_DIG == 64 +#define CLOSETO1(u) (u.i.m>>56 >= 0xf7) +#define CLEARBOTTOM(u) (u.i.m &= -1ULL << 32) +#elif LDBL_MANT_DIG == 113 +#define CLOSETO1(u) (u.i.top >= 0xee00) +#define CLEARBOTTOM(u) (u.i.lo = 0) +#endif + +long double asinl(long double x) +{ + union ldshape u = {x}; + long double z, r, s; + uint16_t e = u.i.se & 0x7fff; + int sign = u.i.se >> 15; + + if (e >= 0x3fff) { /* |x| >= 1 or nan */ + /* asin(+-1)=+-pi/2 with inexact */ + if (x == 1 || x == -1) + return x*pio2_hi + 0x1p-120f; + return 0/(x-x); + } + if (e < 0x3fff - 1) { /* |x| < 0.5 */ + if (e < 0x3fff - (LDBL_MANT_DIG+1)/2) { + /* return x with inexact if x!=0 */ + FORCE_EVAL(x + 0x1p120f); + return x; + } + return x + x*__invtrigl_R(x*x); + } + /* 1 > |x| >= 0.5 */ + z = (1.0 - fabsl(x))*0.5; + s = sqrtl(z); + r = __invtrigl_R(z); + if (CLOSETO1(u)) { + x = pio2_hi - (2*(s+s*r)-pio2_lo); + } else { + long double f, c; + u.f = s; + CLEARBOTTOM(u); + f = u.f; + c = (z - f*f)/(s + f); + x = 0.5*pio2_hi-(2*s*r - (pio2_lo-2*c) - (0.5*pio2_hi-2*f)); + } + return sign ? -x : x; +} +#endif |