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# arm_cmplx_mult_cmplx_f32.c

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    00001 /* ----------------------------------------------------------------------
    00002 * Copyright (C) 2010 ARM Limited. All rights reserved.
    00003 *
    00004 * $Date:        29. November 2010
    00005 * $Revision:    V1.0.3
    00006 *
    00007 * Project:      CMSIS DSP Library
    00008 * Title:        arm_cmplx_mult_cmplx_f32.c
    00009 *
    00010 * Description:  Floating-point complex-by-complex multiplication
    00011 *
    00012 * Target Processor: Cortex-M4/Cortex-M3
    00013 *
    00014 * Version 1.0.3 2010/11/29
    00015 *    Re-organized the CMSIS folders and updated documentation.
    00016 *
    00017 * Version 1.0.2 2010/11/11
    00018 *    Documentation updated.
    00019 *
    00020 * Version 1.0.1 2010/10/05
    00021 *    Production release and review comments incorporated.
    00022 *
    00023 * Version 1.0.0 2010/09/20
    00024 *    Production release and review comments incorporated.
    00025 * -------------------------------------------------------------------- */
    00026
    00027 #include "arm_math.h"
    00028
    00070 void arm_cmplx_mult_cmplx_f32(
    00071   float32_t * pSrcA,
    00072   float32_t * pSrcB,
    00073   float32_t * pDst,
    00074   uint32_t numSamples)
    00075 {
    00076   float32_t a, b, c, d;                          /* Temporary variables to store real and imaginary values */
    00077   uint32_t blkCnt;                               /* loop counters */
    00078
    00079   /* loop Unrolling */
    00080   blkCnt = numSamples >> 2u;
    00081
    00082   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00083    ** a second loop below computes the remaining 1 to 3 samples. */
    00084   while(blkCnt > 0u)
    00085   {
    00086     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
    00087     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
    00088     a = *pSrcA++;
    00089     b = *pSrcA++;
    00090     c = *pSrcB++;
    00091     d = *pSrcB++;
    00092
    00093     /* store the result in the destination buffer. */
    00094     *pDst++ = (a * c) - (b * d);
    00095     *pDst++ = (a * d) + (b * c);
    00096
    00097     a = *pSrcA++;
    00098     b = *pSrcA++;
    00099     c = *pSrcB++;
    00100     d = *pSrcB++;
    00101
    00102     *pDst++ = (a * c) - (b * d);
    00103     *pDst++ = (a * d) + (b * c);
    00104
    00105     a = *pSrcA++;
    00106     b = *pSrcA++;
    00107     c = *pSrcB++;
    00108     d = *pSrcB++;
    00109
    00110     *pDst++ = (a * c) - (b * d);
    00111     *pDst++ = (a * d) + (b * c);
    00112
    00113     a = *pSrcA++;
    00114     b = *pSrcA++;
    00115     c = *pSrcB++;
    00116     d = *pSrcB++;
    00117
    00118     *pDst++ = (a * c) - (b * d);
    00119     *pDst++ = (a * d) + (b * c);
    00120
    00121     /* Decrement the numSamples loop counter */
    00122     blkCnt--;
    00123   }
    00124
    00125   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
    00126    ** No loop unrolling is used. */
    00127   blkCnt = numSamples % 0x4u;
    00128
    00129   while(blkCnt > 0u)
    00130   {
    00131     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
    00132     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
    00133     a = *pSrcA++;
    00134     b = *pSrcA++;
    00135     c = *pSrcB++;
    00136     d = *pSrcB++;
    00137
    00138     /* store the result in the destination buffer. */
    00139     *pDst++ = (a * c) - (b * d);
    00140     *pDst++ = (a * d) + (b * c);
    00141
    00142     /* Decrement the numSamples loop counter */
    00143     blkCnt--;
    00144   }
    00145 }
    00146

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