gmio/src/gmio_core/internal/numeric_utils.c
2016-07-05 12:46:22 +02:00

49 lines
2.2 KiB
C

/****************************************************************************
** Copyright (c) 2016, Fougue Ltd. <http://www.fougue.pro>
** 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, 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 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
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****************************************************************************/
#include "numeric_utils.h"
bool gmio_float32_ulp_equals(float a, float b, uint32_t max_ulp_diff)
{
const int32_t ia = gmio_convert_int32(a);
const int32_t ib = gmio_convert_int32(b);
const int32_t slp_diff = ia - ib;
const uint32_t ulp_diff = slp_diff > 0 ? slp_diff : -slp_diff;
/* Different signs, we could maybe get difference to 0, but so close to 0
* using epsilons is better */
if (gmio_int32_sign(ia) != gmio_int32_sign(ib)) {
/* Check for equality to make sure +0 == -0 */
return ia == ib;
}
/* Find the difference in ULPs */
return ulp_diff <= max_ulp_diff;
}