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# arm_cmplx_mag_q31.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_mag_q31.c
    00009 *
    00010 * Description:  Q31 complex magnitude
    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
    00051 void arm_cmplx_mag_q31(
    00052   q31_t * pSrc,
    00053   q31_t * pDst,
    00054   uint32_t numSamples)
    00055 {
    00056   q31_t real, imag;                              /* Temporary variables to hold input values */
    00057   q31_t acc0, acc1;                              /* Accumulators */
    00058   uint32_t blkCnt;                               /* loop counter */
    00059
    00060
    00061   /*loop Unrolling */
    00062   blkCnt = numSamples >> 2u;
    00063
    00064   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00065    ** a second loop below computes the remaining 1 to 3 samples. */
    00066   while(blkCnt > 0u)
    00067   {
    00068
    00069     /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
    00070     real = *pSrc++;
    00071     imag = *pSrc++;
    00072     acc0 = (q31_t) (((q63_t) real * real) >> 33);
    00073     acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
    00074     /* store the result in 2.30 format in the destination buffer. */
    00075     arm_sqrt_q31(acc0 + acc1, pDst++);
    00076
    00077     real = *pSrc++;
    00078     imag = *pSrc++;
    00079     acc0 = (q31_t) (((q63_t) real * real) >> 33);
    00080     acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
    00081     /* store the result in 2.30 format in the destination buffer. */
    00082     arm_sqrt_q31(acc0 + acc1, pDst++);
    00083
    00084     real = *pSrc++;
    00085     imag = *pSrc++;
    00086     acc0 = (q31_t) (((q63_t) real * real) >> 33);
    00087     acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
    00088     /* store the result in 2.30 format in the destination buffer. */
    00089     arm_sqrt_q31(acc0 + acc1, pDst++);
    00090
    00091     real = *pSrc++;
    00092     imag = *pSrc++;
    00093     acc0 = (q31_t) (((q63_t) real * real) >> 33);
    00094     acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
    00095     /* store the result in 2.30 format in the destination buffer. */
    00096     arm_sqrt_q31(acc0 + acc1, pDst++);
    00097
    00098     /* Decrement the loop counter */
    00099     blkCnt--;
    00100   }
    00101
    00102   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
    00103    ** No loop unrolling is used. */
    00104   blkCnt = numSamples % 0x4u;
    00105
    00106   while(blkCnt > 0u)
    00107   {
    00108     /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
    00109     real = *pSrc++;
    00110     imag = *pSrc++;
    00111     acc0 = (q31_t) (((q63_t) real * real) >> 33);
    00112     acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
    00113     /* store the result in 2.30 format in the destination buffer. */
    00114     arm_sqrt_q31(acc0 + acc1, pDst++);
    00115
    00116     /* Decrement the loop counter */
    00117     blkCnt--;
    00118   }
    00119 }
    00120

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