/* ----------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date: 16/10/14 6:01p $Revision:  V.1.4.5
*
* Project:      CMSIS DSP Library
* Title:        arm_cmplx_mag_q15.c
*
* Description:  Q15 complex magnitude.
*
* 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 groupCmplxMath
 */

/**
 * @addtogroup cmplx_mag
 * @{
 */


/**
 * @brief  Q15 complex magnitude
 * @param  *pSrc points to the complex input vector
 * @param  *pDst points to the real output vector
 * @param  numSamples number of complex samples in the input vector
 * @return none.
 *
 * <b>Scaling and Overflow Behavior:</b>
 * \par
 * The function implements 1.15 by 1.15 multiplications and finally output is converted into 2.14 format.
 */

void arm_cmplx_mag_q15(
    q15_t * pSrc,
    q15_t * pDst,
    uint32_t numSamples)
{
    q31_t acc0, acc1;                              /* Accumulators */

#ifndef ARM_MATH_CM0_FAMILY

    /* Run the below code for Cortex-M4 and Cortex-M3 */
    uint32_t blkCnt;                               /* loop counter */
    q31_t in1, in2, in3, in4;
    q31_t acc2, acc3;


    /*loop Unrolling */
    blkCnt = numSamples >> 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)
    {

        /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
        in1 = *__SIMD32(pSrc)++;
        in2 = *__SIMD32(pSrc)++;
        in3 = *__SIMD32(pSrc)++;
        in4 = *__SIMD32(pSrc)++;

        acc0 = __SMUAD(in1, in1);
        acc1 = __SMUAD(in2, in2);
        acc2 = __SMUAD(in3, in3);
        acc3 = __SMUAD(in4, in4);

        /* store the result in 2.14 format in the destination buffer. */
        arm_sqrt_q15((q15_t)((acc0) >> 17), pDst++);
        arm_sqrt_q15((q15_t)((acc1) >> 17), pDst++);
        arm_sqrt_q15((q15_t)((acc2) >> 17), pDst++);
        arm_sqrt_q15((q15_t)((acc3) >> 17), pDst++);

        /* Decrement the loop counter */
        blkCnt--;
    }

    /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
     ** No loop unrolling is used. */
    blkCnt = numSamples % 0x4u;

    while(blkCnt > 0u)
    {
        /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
        in1 = *__SIMD32(pSrc)++;
        acc0 = __SMUAD(in1, in1);

        /* store the result in 2.14 format in the destination buffer. */
        arm_sqrt_q15((q15_t)(acc0 >> 17), pDst++);

        /* Decrement the loop counter */
        blkCnt--;
    }

#else

    /* Run the below code for Cortex-M0 */
    q15_t real, imag;                              /* Temporary variables to hold input values */

    while(numSamples > 0u)
    {
        /* out = sqrt(real * real + imag * imag) */
        real = *pSrc++;
        imag = *pSrc++;

        acc0 = (real * real);
        acc1 = (imag * imag);

        /* store the result in 2.14 format in the destination buffer. */
        arm_sqrt_q15((q15_t)(((q63_t) acc0 + acc1) >> 17), pDst++);

        /* Decrement the loop counter */
        numSamples--;
    }

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

}

/**
 * @} end of cmplx_mag group
 */
