arm_cmplx_mult_real_q31.c

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/* ----------------------------------------------------------------------      
* Copyright (C) 2011 ARM Limited. All rights reserved. 
*      
* $Date:        15. December 2011   
* $Revision:    V2.0.0  
*      
* Project:      Cortex-R DSP Library 
* Title:        arm_cmplx_mult_real_q31.c      
*      
* Description:  Q31 complex by real multiplication      
*      
* Target Processor:          Cortex-R4/R5
*
* Version 1.0.0 2011/03/08
*     Alpha release.
*
* Version 1.0.1 2011/09/30
*     Beta release.
*
* Version 2.0.0 2011/12/15
*     Final release. 
* 
* -------------------------------------------------------------------- */     
#include "arm_math.h"     
     
void arm_cmplx_mult_real_q31(     
  q31_t * pSrcCmplx,     
  q31_t * pSrcReal,     
  q31_t * pCmplxDst,     
  uint32_t numSamples)     
{     
  q31_t in;                                      /* Temporary variable to store input value */     
  uint32_t blkCnt;                               /* loop counters */     
  q31_t inA1, inA2, inA3, inA4;                  /* Temporary variables to hold input data */  
  q31_t inB1, inB2;                              /* Temporary variabels to hold input data */  
  q31_t out1, out2, out3, out4;                  /* Temporary variables to hold output data */  
     
  /* 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[i].            */     
    /* C[2 * i + 1] = A[2 * i + 1] * B[i].        */   
    /* read real input from complex input buffer */  
    inA1 = pSrcCmplx[0];  
    /* read input from real input bufer */  
    inB1 = pSrcReal[0];  
    /* read imaginary input from complex input buffer */  
    inA2 = pSrcCmplx[1];  
      
    /* multiply complex input with real input */  
    out1 = ((q63_t) inA1 * inB1) >> 32;  
    inA3 = pSrcCmplx[2];  
    out2 = ((q63_t) inA2 * inB1) >> 32;  
    inB2 = pSrcReal[1];  
    inA4 = pSrcCmplx[3];  
    out3 = ((q63_t) inA3 * inB2) >> 32;  
    out4 = ((q63_t) inA4 * inB2) >> 32;  
  
    /* sature the result */  
#if CCS  
  
    out1 = __SSATA(out1, 0, 31);  
    out2 = __SSATA(out2, 0, 31);  
    out3 = __SSATA(out3, 0, 31);  
    out4 = __SSATA(out4, 0, 31);  
  
#else  
  
    out1 = __SSAT(out1, 31);  
    out2 = __SSAT(out2, 31);  
    out3 = __SSAT(out3, 31);  
    out4 = __SSAT(out4, 31);  
  
#endif  //  #ifdef CCS  
  
    inA1 = pSrcCmplx[4];  
      
    /* get result in 1.31 format */  
      
    out1 = out1 << 1;  
    inB1 = pSrcReal[2];  
    out2 = out2 << 1;  
    pCmplxDst[0] = out1;  
    out3 = out3 << 1;  
    pCmplxDst[1] = out2;  
    out4 = out4 << 1;  
  
    pCmplxDst[2] = out3;  
    pCmplxDst[3] = out4;  
  
    inA2 = pSrcCmplx[5];  
    out1 = ((q63_t) inA1 * inB1) >> 32;  
    inA3 = pSrcCmplx[6];  
    out2 = ((q63_t) inA2 * inB1) >> 32;  
    inB2 = pSrcReal[3];  
    inA4 = pSrcCmplx[7];  
  
    out3 = ((q63_t) inA3 * inB2) >> 32;  
    out4 = ((q63_t) inA4 * inB2) >> 32;  
  
#if CCS  
  
    out1 = __SSATA(out1, 0, 31);  
    out2 = __SSATA(out2, 0, 31);  
    out3 = __SSATA(out3, 0, 31);  
    out4 = __SSATA(out4, 0, 31);  
  
#else  
  
    out1 = __SSAT(out1, 31);  
    out2 = __SSAT(out2, 31);  
    out3 = __SSAT(out3, 31);  
    out4 = __SSAT(out4, 31);  
  
#endif  //  #ifdef CCS  
  
    out1 = out1 << 1;  
    out2 = out2 << 1;  
    pCmplxDst[4] = out1;  
    out3 = out3 << 1;  
    pCmplxDst[5] = out2;  
    out4 = out4 << 1;  
  
    pCmplxDst[6] = out3;  
    pSrcCmplx += 8u;  
    pCmplxDst[7] = out4;  
  
    pSrcReal += 4u;  
    pCmplxDst += 8u;  
   
    /* Decrement the numSamples 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[2 * i] = A[2 * i] * B[i].            */     
    /* C[2 * i + 1] = A[2 * i + 1] * B[i].        */     
    in = *pSrcReal++;     
    /* store the result in the destination buffer. */     
    *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31);     
    *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31);     
     
    /* Decrement the numSamples loop counter */     
    blkCnt--;     
  }     
}