diff options
Diffstat (limited to 'lib/msun/ld80/s_tanpil.c')
| -rw-r--r-- | lib/msun/ld80/s_tanpil.c | 34 |
1 files changed, 14 insertions, 20 deletions
diff --git a/lib/msun/ld80/s_tanpil.c b/lib/msun/ld80/s_tanpil.c index 02451e562025..2d640413af6c 100644 --- a/lib/msun/ld80/s_tanpil.c +++ b/lib/msun/ld80/s_tanpil.c @@ -1,5 +1,5 @@ /*- - * Copyright (c) 2017 Steven G. Kargl + * Copyright (c) 2017, 2023 Steven G. Kargl * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -72,7 +72,7 @@ volatile static const double vzero = 0; long double tanpil(long double x) { - long double ax, hi, lo, t; + long double ax, hi, lo, odd, t; uint64_t lx, m; uint32_t j0; uint16_t hx, ix; @@ -98,31 +98,22 @@ tanpil(long double x) } t = __kernel_tanpil(ax); } else if (ax == 0.5) - RETURNI((ax - ax) / (ax - ax)); + t = 1 / vzero; else t = -__kernel_tanpil(1 - ax); RETURNI((hx & 0x8000) ? -t : t); } - if (ix < 0x403e) { /* 1 <= |x| < 0x1p63 */ - /* Determine integer part of ax. */ - j0 = ix - 0x3fff + 1; - if (j0 < 32) { - lx = (lx >> 32) << 32; - lx &= ~(((lx << 32)-1) >> j0); - } else { - m = (uint64_t)-1 >> (j0 + 1); - if (lx & m) lx &= ~m; - } - INSERT_LDBL80_WORDS(x, ix, lx); - + 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 = ax == 0 ? 0 : __kernel_tanpil(ax); - else if (ax == 0.5) - RETURNI((ax - ax) / (ax - ax)); + 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); @@ -133,7 +124,10 @@ tanpil(long double x) RETURNI(vzero / vzero); /* - * |x| >= 0x1p63 is always an integer, so return +-0. + * 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. */ - RETURNI(copysignl(0, x)); + t = ix >= 0x403f ? 0 : (copysignl(0, (lx & 1) ? -1 : 1)); + RETURNI((hx & 0x8000) ? -t : t); } |