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/* ----------------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date: 31. July 2014
* $Revision: V1.4.4
*
* Project: CMSIS DSP Library
* Title: arm_float_to_q31.c
*
* Description: Converts the elements of the floating-point vector to Q31 vector.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - Neither the name of ARM LIMITED 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.
* ---------------------------------------------------------------------------- */
#include "arm_math.h"
/**
* @ingroup groupSupport
*/
/**
* @defgroup float_to_x Convert 32-bit floating point value
*/
/**
* @addtogroup float_to_x
* @{
*/
/**
* @brief Converts the elements of the floating-point vector to Q31 vector.
* @param[in] *pSrc points to the floating-point input vector
* @param[out] *pDst points to the Q31 output vector
* @param[in] blockSize length of the input vector
* @return none.
*
*\par Description:
* \par
* The equation used for the conversion process is:
*
* <pre>
* pDst[n] = (q31_t)(pSrc[n] * 2147483648); 0 <= n < blockSize.
* </pre>
* <b>Scaling and Overflow Behavior:</b>
* \par
* The function uses saturating arithmetic.
* Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] will be saturated.
*
* \note In order to apply rounding, the library should be rebuilt with the ROUNDING macro
* defined in the preprocessor section of project options.
*/
void arm_float_to_q31(
float32_t * pSrc,
q31_t * pDst,
uint32_t blockSize)
{
float32_t *pIn = pSrc; /* Src pointer */
uint32_t blkCnt; /* loop counter */
#ifdef ARM_MATH_ROUNDING
float32_t in;
#endif /* #ifdef ARM_MATH_ROUNDING */
#ifndef ARM_MATH_CM0_FAMILY
/* Run the below code for Cortex-M4 and Cortex-M3 */
/*loop Unrolling */
blkCnt = blockSize >> 2u;
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
** a second loop below computes the remaining 1 to 3 samples. */
while(blkCnt > 0u)
{
#ifdef ARM_MATH_ROUNDING
/* C = A * 32768 */
/* convert from float to Q31 and then store the results in the destination buffer */
in = *pIn++;
in = (in * 2147483648.0f);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = clip_q63_to_q31((q63_t) (in));
in = *pIn++;
in = (in * 2147483648.0f);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = clip_q63_to_q31((q63_t) (in));
in = *pIn++;
in = (in * 2147483648.0f);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = clip_q63_to_q31((q63_t) (in));
in = *pIn++;
in = (in * 2147483648.0f);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = clip_q63_to_q31((q63_t) (in));
#else
/* C = A * 2147483648 */
/* convert from float to Q31 and then store the results in the destination buffer */
*pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
*pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
*pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
*pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
#endif /* #ifdef ARM_MATH_ROUNDING */
/* Decrement the loop counter */
blkCnt--;
}
/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
** No loop unrolling is used. */
blkCnt = blockSize % 0x4u;
while(blkCnt > 0u)
{
#ifdef ARM_MATH_ROUNDING
/* C = A * 2147483648 */
/* convert from float to Q31 and then store the results in the destination buffer */
in = *pIn++;
in = (in * 2147483648.0f);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = clip_q63_to_q31((q63_t) (in));
#else
/* C = A * 2147483648 */
/* convert from float to Q31 and then store the results in the destination buffer */
*pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
#endif /* #ifdef ARM_MATH_ROUNDING */
/* Decrement the loop counter */
blkCnt--;
}
#else
/* Run the below code for Cortex-M0 */
/* Loop over blockSize number of values */
blkCnt = blockSize;
while(blkCnt > 0u)
{
#ifdef ARM_MATH_ROUNDING
/* C = A * 2147483648 */
/* convert from float to Q31 and then store the results in the destination buffer */
in = *pIn++;
in = (in * 2147483648.0f);
in += in > 0 ? 0.5f : -0.5f;
*pDst++ = clip_q63_to_q31((q63_t) (in));
#else
/* C = A * 2147483648 */
/* convert from float to Q31 and then store the results in the destination buffer */
*pDst++ = clip_q63_to_q31((q63_t) (*pIn++ * 2147483648.0f));
#endif /* #ifdef ARM_MATH_ROUNDING */
/* Decrement the loop counter */
blkCnt--;
}
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
}
/**
* @} end of float_to_x group
*/
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