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

* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    

*    

* $Date:        19. March 2015

* $Revision:    V.1.4.5

*    

* Project:          CMSIS DSP Library    

* Title:            arm_cmplx_mult_cmplx_q31.c    

*    

* Description:  Q31 complex-by-complex multiplication    

*    

* 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 CmplxByCmplxMult    

 * @{    

 */

/**    

 * @brief  Q31 complex-by-complex multiplication    

 * @param[in]  *pSrcA points to the first input vector    

 * @param[in]  *pSrcB points to the second input vector    

 * @param[out]  *pDst  points to the output vector    

 * @param[in]  numSamples number of complex samples in each vector    

 * @return none.    

 *    

 * <b>Scaling and Overflow Behavior:</b>    

 * \par    

 * The function implements 1.31 by 1.31 multiplications and finally output is converted into 3.29 format.    

 * Input down scaling is not required.    

 */

void arm_cmplx_mult_cmplx_q31(

  q31_t * pSrcA,

  q31_t * pSrcB,

  q31_t * pDst,

  uint32_t numSamples)

{

  q31_t a, b, c, d;                              /* Temporary variables to store real and imaginary values */

  uint32_t blkCnt;                               /* loop counters */

  q31_t mul1, mul2, mul3, mul4;

  q31_t out1, out2;

#ifndef ARM_MATH_CM0_FAMILY

  /* Run the below code for Cortex-M4 and Cortex-M3 */

  /* 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[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */

    /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */

    a = *pSrcA++;

    b = *pSrcA++;

    c = *pSrcB++;

    d = *pSrcB++;

    mul1 = (q31_t) (((q63_t) a * c) >> 32);

    mul2 = (q31_t) (((q63_t) b * d) >> 32);

    mul3 = (q31_t) (((q63_t) a * d) >> 32);

    mul4 = (q31_t) (((q63_t) b * c) >> 32);

    mul1 = (mul1 >> 1);

    mul2 = (mul2 >> 1);

    mul3 = (mul3 >> 1);

    mul4 = (mul4 >> 1);

    out1 = mul1 - mul2;

    out2 = mul3 + mul4;

    /* store the real result in 3.29 format in the destination buffer. */

    *pDst++ = out1;

    /* store the imag result in 3.29 format in the destination buffer. */

    *pDst++ = out2;

    a = *pSrcA++;

    b = *pSrcA++;

    c = *pSrcB++;

    d = *pSrcB++;

    mul1 = (q31_t) (((q63_t) a * c) >> 32);

    mul2 = (q31_t) (((q63_t) b * d) >> 32);

    mul3 = (q31_t) (((q63_t) a * d) >> 32);

    mul4 = (q31_t) (((q63_t) b * c) >> 32);

    mul1 = (mul1 >> 1);

    mul2 = (mul2 >> 1);

    mul3 = (mul3 >> 1);

    mul4 = (mul4 >> 1);

    out1 = mul1 - mul2;

    out2 = mul3 + mul4;

    /* store the real result in 3.29 format in the destination buffer. */

    *pDst++ = out1;

    /* store the imag result in 3.29 format in the destination buffer. */

    *pDst++ = out2;

    a = *pSrcA++;

    b = *pSrcA++;

    c = *pSrcB++;

    d = *pSrcB++;

    mul1 = (q31_t) (((q63_t) a * c) >> 32);

    mul2 = (q31_t) (((q63_t) b * d) >> 32);

    mul3 = (q31_t) (((q63_t) a * d) >> 32);

    mul4 = (q31_t) (((q63_t) b * c) >> 32);

    mul1 = (mul1 >> 1);

    mul2 = (mul2 >> 1);

    mul3 = (mul3 >> 1);

    mul4 = (mul4 >> 1);

    out1 = mul1 - mul2;

    out2 = mul3 + mul4;

    /* store the real result in 3.29 format in the destination buffer. */

    *pDst++ = out1;

    /* store the imag result in 3.29 format in the destination buffer. */

    *pDst++ = out2;

    a = *pSrcA++;

    b = *pSrcA++;

    c = *pSrcB++;

    d = *pSrcB++;

    mul1 = (q31_t) (((q63_t) a * c) >> 32);

    mul2 = (q31_t) (((q63_t) b * d) >> 32);

    mul3 = (q31_t) (((q63_t) a * d) >> 32);

    mul4 = (q31_t) (((q63_t) b * c) >> 32);

    mul1 = (mul1 >> 1);

    mul2 = (mul2 >> 1);

    mul3 = (mul3 >> 1);

    mul4 = (mul4 >> 1);

    out1 = mul1 - mul2;

    out2 = mul3 + mul4;

    /* store the real result in 3.29 format in the destination buffer. */

    *pDst++ = out1;

    /* store the imag result in 3.29 format in the destination buffer. */

    *pDst++ = out2;

    /* Decrement the blockSize loop counter */

    blkCnt--;

  }

  /* If the blockSize is not a multiple of 4, compute any remaining output samples here.    

   ** No loop unrolling is used. */

  blkCnt = numSamples % 0x4u;

  while(blkCnt > 0u)

  {

    /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */

    /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */

    a = *pSrcA++;

    b = *pSrcA++;

    c = *pSrcB++;

    d = *pSrcB++;

    mul1 = (q31_t) (((q63_t) a * c) >> 32);

    mul2 = (q31_t) (((q63_t) b * d) >> 32);

    mul3 = (q31_t) (((q63_t) a * d) >> 32);

    mul4 = (q31_t) (((q63_t) b * c) >> 32);

    mul1 = (mul1 >> 1);

    mul2 = (mul2 >> 1);

    mul3 = (mul3 >> 1);

    mul4 = (mul4 >> 1);

    out1 = mul1 - mul2;

    out2 = mul3 + mul4;

    /* store the real result in 3.29 format in the destination buffer. */

    *pDst++ = out1;

    /* store the imag result in 3.29 format in the destination buffer. */

    *pDst++ = out2;

    /* Decrement the blockSize loop counter */

    blkCnt--;

  }

#else

  /* Run the below code for Cortex-M0 */

  /* loop Unrolling */

  blkCnt = numSamples >> 1u;

  /* First part of the processing with loop unrolling.  Compute 2 outputs at a time.    

   ** a second loop below computes the remaining 1 sample. */

  while(blkCnt > 0u)

  {

    /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */

    /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */

    a = *pSrcA++;

    b = *pSrcA++;

    c = *pSrcB++;

    d = *pSrcB++;

    mul1 = (q31_t) (((q63_t) a * c) >> 32);

    mul2 = (q31_t) (((q63_t) b * d) >> 32);

    mul3 = (q31_t) (((q63_t) a * d) >> 32);

    mul4 = (q31_t) (((q63_t) b * c) >> 32);

    mul1 = (mul1 >> 1);

    mul2 = (mul2 >> 1);

    mul3 = (mul3 >> 1);

    mul4 = (mul4 >> 1);

    out1 = mul1 - mul2;

    out2 = mul3 + mul4;

    /* store the real result in 3.29 format in the destination buffer. */

    *pDst++ = out1;

    /* store the imag result in 3.29 format in the destination buffer. */

    *pDst++ = out2;

    a = *pSrcA++;

    b = *pSrcA++;

    c = *pSrcB++;

    d = *pSrcB++;

    mul1 = (q31_t) (((q63_t) a * c) >> 32);

    mul2 = (q31_t) (((q63_t) b * d) >> 32);

    mul3 = (q31_t) (((q63_t) a * d) >> 32);

    mul4 = (q31_t) (((q63_t) b * c) >> 32);

    mul1 = (mul1 >> 1);

    mul2 = (mul2 >> 1);

    mul3 = (mul3 >> 1);

    mul4 = (mul4 >> 1);

    out1 = mul1 - mul2;

    out2 = mul3 + mul4;

    /* store the real result in 3.29 format in the destination buffer. */

    *pDst++ = out1;

    /* store the imag result in 3.29 format in the destination buffer. */

    *pDst++ = out2;

    /* Decrement the blockSize loop counter */

    blkCnt--;

  }

  /* If the blockSize is not a multiple of 2, compute any remaining output samples here.    

   ** No loop unrolling is used. */

  blkCnt = numSamples % 0x2u;

  while(blkCnt > 0u)

  {

    /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */

    /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */

    a = *pSrcA++;

    b = *pSrcA++;

    c = *pSrcB++;

    d = *pSrcB++;

    mul1 = (q31_t) (((q63_t) a * c) >> 32);

    mul2 = (q31_t) (((q63_t) b * d) >> 32);

    mul3 = (q31_t) (((q63_t) a * d) >> 32);

    mul4 = (q31_t) (((q63_t) b * c) >> 32);

    mul1 = (mul1 >> 1);

    mul2 = (mul2 >> 1);

    mul3 = (mul3 >> 1);

    mul4 = (mul4 >> 1);

    out1 = mul1 - mul2;

    out2 = mul3 + mul4;

    /* store the real result in 3.29 format in the destination buffer. */

    *pDst++ = out1;

    /* store the imag result in 3.29 format in the destination buffer. */

    *pDst++ = out2;

    /* Decrement the blockSize loop counter */

    blkCnt--;

  }

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

}

/**    

 * @} end of CmplxByCmplxMult group    

 */