nuttx/libs/libc/math/lib_copysignf.c
Alin Jerpelea abf8a72ef0 LICENSE: add libs/libc/math/ to license file
Add Sun Microsystems license for libs/libc/math/__sin.c
and libs/libc/math/__cos.c

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-09-02 21:56:05 +08:00

102 lines
3.4 KiB
C

/****************************************************************************
* libs/libc/math/lib_copysignf.c
*
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
*
* 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. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <math.h>
#include <stdint.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Get a 32 bit int from a float. */
#define GET_FLOAT_WORD(i,d) \
do \
{ \
ieee_float_shape_type gf_u; \
gf_u.value = (d); \
(i) = gf_u.word; \
} while (0)
/* Set a float from a 32 bit int. */
#define SET_FLOAT_WORD(d,i) \
do \
{ \
ieee_float_shape_type sf_u; \
sf_u.word = (i); \
(d) = sf_u.value; \
} while (0)
/****************************************************************************
* Private Types
****************************************************************************/
/* union which permits us to convert between a float and a 32 bit int. */
typedef union
{
float value;
uint32_t word;
}
ieee_float_shape_type;
/****************************************************************************
* Public Functions
****************************************************************************/
float copysignf(float x, float y)
{
uint32_t ix;
uint32_t iy;
GET_FLOAT_WORD(ix, x);
GET_FLOAT_WORD(iy, y);
SET_FLOAT_WORD(x, (ix & 0x7fffffff) | (iy & 0x80000000));
return x;
}