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  1. /* ----------------------------------------------------------------------
  2.  * Project:      CMSIS DSP Library
  3.  * Title:        arm_cmplx_mult_cmplx_q31.c
  4.  * Description:  Q31 complex-by-complex multiplication
  5.  *
  6.  * $Date:        27. January 2017
  7.  * $Revision:    V.1.5.1
  8.  *
  9.  * Target Processor: Cortex-M cores
  10.  * -------------------------------------------------------------------- */
  11. /*
  12.  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
  13.  *
  14.  * SPDX-License-Identifier: Apache-2.0
  15.  *
  16.  * Licensed under the Apache License, Version 2.0 (the License); you may
  17.  * not use this file except in compliance with the License.
  18.  * You may obtain a copy of the License at
  19.  *
  20.  * www.apache.org/licenses/LICENSE-2.0
  21.  *
  22.  * Unless required by applicable law or agreed to in writing, software
  23.  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
  24.  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  25.  * See the License for the specific language governing permissions and
  26.  * limitations under the License.
  27.  */
  28.  
  29. #include "arm_math.h"
  30.  
  31. /**
  32.  * @ingroup groupCmplxMath
  33.  */
  34.  
  35. /**
  36.  * @addtogroup CmplxByCmplxMult
  37.  * @{
  38.  */
  39.  
  40.  
  41. /**
  42.  * @brief  Q31 complex-by-complex multiplication
  43.  * @param[in]  *pSrcA points to the first input vector
  44.  * @param[in]  *pSrcB points to the second input vector
  45.  * @param[out]  *pDst  points to the output vector
  46.  * @param[in]  numSamples number of complex samples in each vector
  47.  * @return none.
  48.  *
  49.  * <b>Scaling and Overflow Behavior:</b>
  50.  * \par
  51.  * The function implements 1.31 by 1.31 multiplications and finally output is converted into 3.29 format.
  52.  * Input down scaling is not required.
  53.  */
  54.  
  55. void arm_cmplx_mult_cmplx_q31(
  56.   q31_t * pSrcA,
  57.   q31_t * pSrcB,
  58.   q31_t * pDst,
  59.   uint32_t numSamples)
  60. {
  61.   q31_t a, b, c, d;                              /* Temporary variables to store real and imaginary values */
  62.   uint32_t blkCnt;                               /* loop counters */
  63.   q31_t mul1, mul2, mul3, mul4;
  64.   q31_t out1, out2;
  65.  
  66. #if defined (ARM_MATH_DSP)
  67.  
  68.   /* Run the below code for Cortex-M4 and Cortex-M3 */
  69.  
  70.   /* loop Unrolling */
  71.   blkCnt = numSamples >> 2U;
  72.  
  73.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  74.    ** a second loop below computes the remaining 1 to 3 samples. */
  75.   while (blkCnt > 0U)
  76.   {
  77.     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
  78.     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
  79.     a = *pSrcA++;
  80.     b = *pSrcA++;
  81.     c = *pSrcB++;
  82.     d = *pSrcB++;
  83.  
  84.     mul1 = (q31_t) (((q63_t) a * c) >> 32);
  85.     mul2 = (q31_t) (((q63_t) b * d) >> 32);
  86.     mul3 = (q31_t) (((q63_t) a * d) >> 32);
  87.     mul4 = (q31_t) (((q63_t) b * c) >> 32);
  88.  
  89.     mul1 = (mul1 >> 1);
  90.     mul2 = (mul2 >> 1);
  91.     mul3 = (mul3 >> 1);
  92.     mul4 = (mul4 >> 1);
  93.  
  94.     out1 = mul1 - mul2;
  95.     out2 = mul3 + mul4;
  96.  
  97.     /* store the real result in 3.29 format in the destination buffer. */
  98.     *pDst++ = out1;
  99.     /* store the imag result in 3.29 format in the destination buffer. */
  100.     *pDst++ = out2;
  101.  
  102.     a = *pSrcA++;
  103.     b = *pSrcA++;
  104.     c = *pSrcB++;
  105.     d = *pSrcB++;
  106.  
  107.     mul1 = (q31_t) (((q63_t) a * c) >> 32);
  108.     mul2 = (q31_t) (((q63_t) b * d) >> 32);
  109.     mul3 = (q31_t) (((q63_t) a * d) >> 32);
  110.     mul4 = (q31_t) (((q63_t) b * c) >> 32);
  111.  
  112.     mul1 = (mul1 >> 1);
  113.     mul2 = (mul2 >> 1);
  114.     mul3 = (mul3 >> 1);
  115.     mul4 = (mul4 >> 1);
  116.  
  117.     out1 = mul1 - mul2;
  118.     out2 = mul3 + mul4;
  119.  
  120.     /* store the real result in 3.29 format in the destination buffer. */
  121.     *pDst++ = out1;
  122.     /* store the imag result in 3.29 format in the destination buffer. */
  123.     *pDst++ = out2;
  124.  
  125.     a = *pSrcA++;
  126.     b = *pSrcA++;
  127.     c = *pSrcB++;
  128.     d = *pSrcB++;
  129.  
  130.     mul1 = (q31_t) (((q63_t) a * c) >> 32);
  131.     mul2 = (q31_t) (((q63_t) b * d) >> 32);
  132.     mul3 = (q31_t) (((q63_t) a * d) >> 32);
  133.     mul4 = (q31_t) (((q63_t) b * c) >> 32);
  134.  
  135.     mul1 = (mul1 >> 1);
  136.     mul2 = (mul2 >> 1);
  137.     mul3 = (mul3 >> 1);
  138.     mul4 = (mul4 >> 1);
  139.  
  140.     out1 = mul1 - mul2;
  141.     out2 = mul3 + mul4;
  142.  
  143.     /* store the real result in 3.29 format in the destination buffer. */
  144.     *pDst++ = out1;
  145.     /* store the imag result in 3.29 format in the destination buffer. */
  146.     *pDst++ = out2;
  147.  
  148.     a = *pSrcA++;
  149.     b = *pSrcA++;
  150.     c = *pSrcB++;
  151.     d = *pSrcB++;
  152.  
  153.     mul1 = (q31_t) (((q63_t) a * c) >> 32);
  154.     mul2 = (q31_t) (((q63_t) b * d) >> 32);
  155.     mul3 = (q31_t) (((q63_t) a * d) >> 32);
  156.     mul4 = (q31_t) (((q63_t) b * c) >> 32);
  157.  
  158.     mul1 = (mul1 >> 1);
  159.     mul2 = (mul2 >> 1);
  160.     mul3 = (mul3 >> 1);
  161.     mul4 = (mul4 >> 1);
  162.  
  163.     out1 = mul1 - mul2;
  164.     out2 = mul3 + mul4;
  165.  
  166.     /* store the real result in 3.29 format in the destination buffer. */
  167.     *pDst++ = out1;
  168.     /* store the imag result in 3.29 format in the destination buffer. */
  169.     *pDst++ = out2;
  170.  
  171.     /* Decrement the blockSize loop counter */
  172.     blkCnt--;
  173.   }
  174.  
  175.   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
  176.    ** No loop unrolling is used. */
  177.   blkCnt = numSamples % 0x4U;
  178.  
  179.   while (blkCnt > 0U)
  180.   {
  181.     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
  182.     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
  183.     a = *pSrcA++;
  184.     b = *pSrcA++;
  185.     c = *pSrcB++;
  186.     d = *pSrcB++;
  187.  
  188.     mul1 = (q31_t) (((q63_t) a * c) >> 32);
  189.     mul2 = (q31_t) (((q63_t) b * d) >> 32);
  190.     mul3 = (q31_t) (((q63_t) a * d) >> 32);
  191.     mul4 = (q31_t) (((q63_t) b * c) >> 32);
  192.  
  193.     mul1 = (mul1 >> 1);
  194.     mul2 = (mul2 >> 1);
  195.     mul3 = (mul3 >> 1);
  196.     mul4 = (mul4 >> 1);
  197.  
  198.     out1 = mul1 - mul2;
  199.     out2 = mul3 + mul4;
  200.  
  201.     /* store the real result in 3.29 format in the destination buffer. */
  202.     *pDst++ = out1;
  203.     /* store the imag result in 3.29 format in the destination buffer. */
  204.     *pDst++ = out2;
  205.  
  206.     /* Decrement the blockSize loop counter */
  207.     blkCnt--;
  208.   }
  209.  
  210. #else
  211.  
  212.   /* Run the below code for Cortex-M0 */
  213.  
  214.   /* loop Unrolling */
  215.   blkCnt = numSamples >> 1U;
  216.  
  217.   /* First part of the processing with loop unrolling.  Compute 2 outputs at a time.
  218.    ** a second loop below computes the remaining 1 sample. */
  219.   while (blkCnt > 0U)
  220.   {
  221.     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
  222.     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
  223.     a = *pSrcA++;
  224.     b = *pSrcA++;
  225.     c = *pSrcB++;
  226.     d = *pSrcB++;
  227.  
  228.     mul1 = (q31_t) (((q63_t) a * c) >> 32);
  229.     mul2 = (q31_t) (((q63_t) b * d) >> 32);
  230.     mul3 = (q31_t) (((q63_t) a * d) >> 32);
  231.     mul4 = (q31_t) (((q63_t) b * c) >> 32);
  232.  
  233.     mul1 = (mul1 >> 1);
  234.     mul2 = (mul2 >> 1);
  235.     mul3 = (mul3 >> 1);
  236.     mul4 = (mul4 >> 1);
  237.  
  238.     out1 = mul1 - mul2;
  239.     out2 = mul3 + mul4;
  240.  
  241.     /* store the real result in 3.29 format in the destination buffer. */
  242.     *pDst++ = out1;
  243.     /* store the imag result in 3.29 format in the destination buffer. */
  244.     *pDst++ = out2;
  245.  
  246.     a = *pSrcA++;
  247.     b = *pSrcA++;
  248.     c = *pSrcB++;
  249.     d = *pSrcB++;
  250.  
  251.     mul1 = (q31_t) (((q63_t) a * c) >> 32);
  252.     mul2 = (q31_t) (((q63_t) b * d) >> 32);
  253.     mul3 = (q31_t) (((q63_t) a * d) >> 32);
  254.     mul4 = (q31_t) (((q63_t) b * c) >> 32);
  255.  
  256.     mul1 = (mul1 >> 1);
  257.     mul2 = (mul2 >> 1);
  258.     mul3 = (mul3 >> 1);
  259.     mul4 = (mul4 >> 1);
  260.  
  261.     out1 = mul1 - mul2;
  262.     out2 = mul3 + mul4;
  263.  
  264.     /* store the real result in 3.29 format in the destination buffer. */
  265.     *pDst++ = out1;
  266.     /* store the imag result in 3.29 format in the destination buffer. */
  267.     *pDst++ = out2;
  268.  
  269.     /* Decrement the blockSize loop counter */
  270.     blkCnt--;
  271.   }
  272.  
  273.   /* If the blockSize is not a multiple of 2, compute any remaining output samples here.
  274.    ** No loop unrolling is used. */
  275.   blkCnt = numSamples % 0x2U;
  276.  
  277.   while (blkCnt > 0U)
  278.   {
  279.     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
  280.     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
  281.     a = *pSrcA++;
  282.     b = *pSrcA++;
  283.     c = *pSrcB++;
  284.     d = *pSrcB++;
  285.  
  286.     mul1 = (q31_t) (((q63_t) a * c) >> 32);
  287.     mul2 = (q31_t) (((q63_t) b * d) >> 32);
  288.     mul3 = (q31_t) (((q63_t) a * d) >> 32);
  289.     mul4 = (q31_t) (((q63_t) b * c) >> 32);
  290.  
  291.     mul1 = (mul1 >> 1);
  292.     mul2 = (mul2 >> 1);
  293.     mul3 = (mul3 >> 1);
  294.     mul4 = (mul4 >> 1);
  295.  
  296.     out1 = mul1 - mul2;
  297.     out2 = mul3 + mul4;
  298.  
  299.     /* store the real result in 3.29 format in the destination buffer. */
  300.     *pDst++ = out1;
  301.     /* store the imag result in 3.29 format in the destination buffer. */
  302.     *pDst++ = out2;
  303.  
  304.     /* Decrement the blockSize loop counter */
  305.     blkCnt--;
  306.   }
  307.  
  308. #endif /* #if defined (ARM_MATH_DSP) */
  309.  
  310. }
  311.  
  312. /**
  313.  * @} end of CmplxByCmplxMult group
  314.  */
  315.