2 * Copyright (c) 2017-2021 Steven G. Kargl
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28 * See ../src/s_cospi.c for implementation details.
32 #include "math_private.h"
35 * pi_hi contains the leading 56 bits of a 169 bit approximation for pi.
37 static const long double
38 pi_hi = 3.14159265358979322702026593105983920e+00L,
39 pi_lo = 1.14423774522196636802434264184180742e-17L;
44 volatile static const double vzero = 0;
49 long double ax, c, xf;
60 return (__kernel_cospil(ax));
64 c = __kernel_sinpil(0.5 - ax);
68 c = -__kernel_sinpil(ax - 0.5);
70 c = -__kernel_cospil(1 - ax);
75 /* Split x = n + r with 0 <= r < 1. */
76 xf = (ax + 0x1p112L) - 0x1p112L; /* Integer part */
77 ax -= xf; /* Remainder */
85 c = ax == 0 ? 1 : __kernel_cospil(ax);
87 c = __kernel_sinpil(0.5 - ax);
92 c = -__kernel_sinpil(ax - 0.5);
94 c = -__kernel_cospil(1 - ax);
102 return (ix & 1 ? -c : c);
105 if (isinf(x) || isnan(x))
106 return (vzero / vzero);
109 * |x| >= 0x1p112 is always an even integer, so return 1.