90 lines
2.8 KiB
C
90 lines
2.8 KiB
C
/* Single-precision cos function.
|
|
Copyright (c) 2018 Arm Ltd. All rights reserved.
|
|
|
|
SPDX-License-Identifier: BSD-3-Clause
|
|
|
|
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, 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.
|
|
3. The name of the company may not be used to endorse or promote
|
|
products derived from this software without specific prior written
|
|
permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY ARM LTD ``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 ARM LTD 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. */
|
|
|
|
#include "fdlibm.h"
|
|
#if !__OBSOLETE_MATH
|
|
|
|
#include <stdint.h>
|
|
#include <math.h>
|
|
#include "math_config.h"
|
|
#include "sincosf.h"
|
|
|
|
/* Fast cosf implementation. Worst-case ULP is 0.5607, maximum relative
|
|
error is 0.5303 * 2^-23. A single-step range reduction is used for
|
|
small values. Large inputs have their range reduced using fast integer
|
|
arithmetic. */
|
|
float
|
|
cosf (float y)
|
|
{
|
|
double x = y;
|
|
double s;
|
|
int n;
|
|
const sincos_t *p = &__sincosf_table[0];
|
|
|
|
if (abstop12 (y) < abstop12 (pio4))
|
|
{
|
|
double x2 = x * x;
|
|
|
|
if (unlikely (abstop12 (y) < abstop12 (0x1p-12f)))
|
|
return 1.0f;
|
|
|
|
return sinf_poly (x, x2, p, 1);
|
|
}
|
|
else if (likely (abstop12 (y) < abstop12 (120.0f)))
|
|
{
|
|
x = reduce_fast (x, p, &n);
|
|
|
|
/* Setup the signs for sin and cos. */
|
|
s = p->sign[n & 3];
|
|
|
|
if (n & 2)
|
|
p = &__sincosf_table[1];
|
|
|
|
return sinf_poly (x * s, x * x, p, n ^ 1);
|
|
}
|
|
else if (abstop12 (y) < abstop12 (INFINITY))
|
|
{
|
|
uint32_t xi = asuint (y);
|
|
int sign = xi >> 31;
|
|
|
|
x = reduce_large (xi, &n);
|
|
|
|
/* Setup signs for sin and cos - include original sign. */
|
|
s = p->sign[(n + sign) & 3];
|
|
|
|
if ((n + sign) & 2)
|
|
p = &__sincosf_table[1];
|
|
|
|
return sinf_poly (x * s, x * x, p, n ^ 1);
|
|
}
|
|
else
|
|
return __math_invalidf (y);
|
|
}
|
|
|
|
#endif
|