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/* ----------------------------------------------------------------------

 * Project:      CMSIS DSP Library

 * Title:        arm_float_to_q31.c

 * Description:  Converts the elements of the floating-point vector to Q31 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

 */

/**

 * @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        */

#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 * 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 /* #if defined (ARM_MATH_DSP) */

}

/**

 * @} end of float_to_x group

 */