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/*-
* 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.
*/
#define INLINE_KERNEL_TANDF
#include "math.h"
#include "math_private.h"
#include "k_tanf.c"
static const float
pi_hi = 3.14160156e+00F, /* 0x40491000 */
pi_lo = -8.90890988e-06F; /* 0xb715777a */
static inline float
__kernel_tanpif(float x)
{
float t;
if (x < 0.25F)
t = __kernel_tandf(M_PI * x, 1);
else if (x > 0.25F)
t = -__kernel_tandf(M_PI * (0.5 - x), -1);
else
t = 1;
return (t);
}
volatile static const float vzero = 0;
float
tanpif(float x)
{
float ax, hi, lo, odd, t;
uint32_t hx, ix, j0;
GET_FLOAT_WORD(hx, x);
ix = hx & 0x7fffffff;
SET_FLOAT_WORD(ax, ix);
if (ix < 0x3f800000) { /* |x| < 1 */
if (ix < 0x3f000000) { /* |x| < 0.5 */
if (ix < 0x38800000) { /* |x| < 0x1p-14 */
if (ix == 0)
return (x);
SET_FLOAT_WORD(hi, hx & 0xffff0000);
hi *= 0x1p23F;
lo = x * 0x1p23F - hi;
t = (pi_lo + pi_hi) * lo + pi_lo * hi +
pi_hi * hi;
return (t * 0x1p-23F);
}
t = __kernel_tanpif(ax);
} else if (ix == 0x3f000000)
t = 1 / vzero;
else
t = - __kernel_tanpif(1 - ax);
return ((hx & 0x80000000) ? -t : t);
}
if (ix < 0x4b000000) { /* 1 <= |x| < 0x1p23 */
FFLOORF(x, j0, ix); /* Integer part of ax. */
odd = (uint32_t)x & 1 ? -1 : 1;
ax -= x;
GET_FLOAT_WORD(ix, ax);
if (ix < 0x3f000000) /* |x| < 0.5 */
t = ix == 0 ? copysignf(0, odd) : __kernel_tanpif(ax);
else if (ix == 0x3f000000)
t = odd / vzero;
else
t = - __kernel_tanpif(1 - ax);
return ((hx & 0x80000000) ? -t : t);
}
/* x = +-inf or nan. */
if (ix >= 0x7f800000)
return (vzero / vzero);
/*
* For 0x1p23 <= |x| < 0x1p24 need to determine if x is an even
* or odd integer to set t = +0 or -0.
* For |x| >= 0x1p24, it is always an even integer, so t = 0.
*/
t = ix >= 0x4b800000 ? 0 : (copysignf(0, (ix & 1) ? -1 : 1));
return ((hx & 0x80000000) ? -t : t);
}
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