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/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_float_to_q7.c
* Description: Converts the elements of the floating-point vector to Q7 vector
*
* $Date: 27. January 2017
* $Revision: V.1.5.1
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "arm_math.h"
/**
* @ingroup groupSupport
*/
/**
* @addtogroup float_to_x
* @{
*/
/**
* @brief Converts the elements of the floating-point vector to Q7 vector.
* @param[in] *pSrc points to the floating-point input vector
* @param[out] *pDst points to the Q7 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] = (q7_t)(pSrc[n] * 128); 0 <= n < blockSize.
* </pre>
* \par Scaling and Overflow Behavior:
* \par
* The function uses saturating arithmetic.
* Results outside of the allowable Q7 range [0x80 0x7F] 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_q7(
float32_t * pSrc,
q7_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 */
#if defined (ARM_MATH_DSP)
/* 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 * 128 */
/* convert from float to q7 and then store the results in the destination buffer */
in = *pIn++;
in = (in * 128);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
in = *pIn++;
in = (in * 128);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
in = *pIn++;
in = (in * 128);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
in = *pIn++;
in = (in * 128);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
#else
/* C = A * 128 */
/* convert from float to q7 and then store the results in the destination buffer */
*pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
*pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
*pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
*pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
#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 * 128 */
/* convert from float to q7 and then store the results in the destination buffer */
in = *pIn++;
in = (in * 128);
in += in > 0.0f ? 0.5f : -0.5f;
*pDst++ = (q7_t) (__SSAT((q15_t) (in), 8));
#else
/* C = A * 128 */
/* convert from float to q7 and then store the results in the destination buffer */
*pDst++ = __SSAT((q31_t) (*pIn++ * 128.0f), 8);
#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 * 128 */
/* convert from float to q7 and then store the results in the destination buffer */
in = *pIn++;
in = (in * 128.0f);
in += in > 0 ? 0.5f : -0.5f;
*pDst++ = (q7_t) (__SSAT((q31_t) (in), 8));
#else
/* C = A * 128 */
/* convert from float to q7 and then store the results in the destination buffer */
*pDst++ = (q7_t) __SSAT((q31_t) (*pIn++ * 128.0f), 8);
#endif /* #ifdef ARM_MATH_ROUNDING */
/* Decrement the loop counter */
blkCnt--;
}
#endif /* #if defined (ARM_MATH_DSP) */
}
/**
* @} end of float_to_x group
*/
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