diff options
Diffstat (limited to 'lib/msun/ld80/s_tanpil.c')
| -rw-r--r-- | lib/msun/ld80/s_tanpil.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/lib/msun/ld80/s_tanpil.c b/lib/msun/ld80/s_tanpil.c new file mode 100644 index 000000000000..2d640413af6c --- /dev/null +++ b/lib/msun/ld80/s_tanpil.c @@ -0,0 +1,133 @@ +/*- + * Copyright (c) 2017, 2023 Steven G. Kargl + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice unmodified, this list of conditions, and the following + * disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * See ../src/s_tanpi.c for implementation details. + */ + +#ifdef __i386__ +#include <ieeefp.h> +#endif +#include <stdint.h> + +#include "fpmath.h" +#include "math.h" +#include "math_private.h" + +static const double +pi_hi = 3.1415926814079285e+00, /* 0x400921fb 0x58000000 */ +pi_lo = -2.7818135228334233e-08; /* 0xbe5dde97 0x3dcb3b3a */ + +static inline long double +__kernel_tanpil(long double x) +{ + long double hi, lo, t; + + if (x < 0.25) { + hi = (float)x; + lo = x - hi; + lo = lo * (pi_lo + pi_hi) + hi * pi_lo; + hi *= pi_hi; + _2sumF(hi, lo); + t = __kernel_tanl(hi, lo, -1); + } else if (x > 0.25) { + x = 0.5 - x; + hi = (float)x; + lo = x - hi; + lo = lo * (pi_lo + pi_hi) + hi * pi_lo; + hi *= pi_hi; + _2sumF(hi, lo); + t = - __kernel_tanl(hi, lo, 1); + } else + t = 1; + + return (t); +} + +volatile static const double vzero = 0; + +long double +tanpil(long double x) +{ + long double ax, hi, lo, odd, t; + uint64_t lx, m; + uint32_t j0; + uint16_t hx, ix; + + EXTRACT_LDBL80_WORDS(hx, lx, x); + ix = hx & 0x7fff; + INSERT_LDBL80_WORDS(ax, ix, lx); + + ENTERI(); + + if (ix < 0x3fff) { /* |x| < 1 */ + if (ix < 0x3ffe) { /* |x| < 0.5 */ + if (ix < 0x3fdd) { /* |x| < 0x1p-34 */ + if (x == 0) + RETURNI(x); + INSERT_LDBL80_WORDS(hi, hx, + lx & 0xffffffff00000000ull); + hi *= 0x1p63L; + lo = x * 0x1p63L - hi; + t = (pi_lo + pi_hi) * lo + pi_lo * hi + + pi_hi * hi; + RETURNI(t * 0x1p-63L); + } + t = __kernel_tanpil(ax); + } else if (ax == 0.5) + t = 1 / vzero; + else + t = -__kernel_tanpil(1 - ax); + RETURNI((hx & 0x8000) ? -t : t); + } + + if (ix < 0x403e) { /* 1 <= |x| < 0x1p63 */ + FFLOORL80(x, j0, ix, lx); /* Integer part of ax. */ + odd = (uint64_t)x & 1 ? -1 : 1; + ax -= x; + EXTRACT_LDBL80_WORDS(ix, lx, ax); + + if (ix < 0x3ffe) /* |x| < 0.5 */ + t = ix == 0 ? copysignl(0, odd) : __kernel_tanpil(ax); + else if (ax == 0.5L) + t = odd / vzero; + else + t = -__kernel_tanpil(1 - ax); + RETURNI((hx & 0x8000) ? -t : t); + } + + /* x = +-inf or nan. */ + if (ix >= 0x7fff) + RETURNI(vzero / vzero); + + /* + * For 0x1p63 <= |x| < 0x1p64 need to determine if x is an even + * or odd integer to set t = +0 or -0. + * For |x| >= 0x1p64, it is always an even integer, so t = 0. + */ + t = ix >= 0x403f ? 0 : (copysignl(0, (lx & 1) ? -1 : 1)); + RETURNI((hx & 0x8000) ? -t : t); +} |