/* ---------------------------------------------------------------------- * Copyright (C) 2010-2014 ARM Limited. All rights reserved. * * $Date: 12. March 2014 * $Revision: V1.4.4 * * Project: CMSIS DSP Library * Title: arm_cmplx_conj_f32.c * * Description: Floating-point complex conjugate. * * 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 */ /** * @defgroup cmplx_conj Complex Conjugate * * Conjugates the elements of a complex data vector. * * The pSrc points to the source data and * pDst points to the where the result should be written. * numSamples specifies the number of complex samples * and the data in each array is stored in an interleaved fashion * (real, imag, real, imag, ...). * Each array has a total of 2*numSamples values. * The underlying algorithm is used: * *
        
 * for(n=0; n        
 *        
 * There are separate functions for floating-point, Q15, and Q31 data types.        
 */

/**        
 * @addtogroup cmplx_conj        
 * @{        
 */

/**        
 * @brief  Floating-point complex conjugate.        
 * @param  *pSrc points to the input vector        
 * @param  *pDst points to the output vector        
 * @param  numSamples number of complex samples in each vector        
 * @return none.        
 */

void arm_cmplx_conj_f32(
  float32_t * pSrc,
  float32_t * pDst,
  uint32_t numSamples)
{
  uint32_t blkCnt;                               /* loop counter */

#ifndef ARM_MATH_CM0_FAMILY

  /* Run the below code for Cortex-M4 and Cortex-M3 */
  float32_t inR1, inR2, inR3, inR4;
  float32_t inI1, inI2, inI3, inI4;

  /*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[0]+jC[1] = A[0]+ j (-1) A[1] */
    /* Calculate Complex Conjugate and then store the results in the destination buffer. */
    /* read real input samples */
    inR1 = pSrc[0];
    /* store real samples to destination */
    pDst[0] = inR1;
    inR2 = pSrc[2];
    pDst[2] = inR2;
    inR3 = pSrc[4];
    pDst[4] = inR3;
    inR4 = pSrc[6];
    pDst[6] = inR4;

    /* read imaginary input samples */
    inI1 = pSrc[1];
    inI2 = pSrc[3];

    /* conjugate input */
    inI1 = -inI1;

    /* read imaginary input samples */
    inI3 = pSrc[5];

    /* conjugate input */
    inI2 = -inI2;

    /* read imaginary input samples */
    inI4 = pSrc[7];

    /* conjugate input */
    inI3 = -inI3;

    /* store imaginary samples to destination */
    pDst[1] = inI1;
    pDst[3] = inI2;

    /* conjugate input */
    inI4 = -inI4;

    /* store imaginary samples to destination */
    pDst[5] = inI3;

    /* increment source pointer by 8 to process next sampels */
    pSrc += 8u;

    /* store imaginary sample to destination */
    pDst[7] = inI4;

    /* increment destination pointer by 8 to store next samples */
    pDst += 8u;

    /* Decrement the 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;

#else

  /* Run the below code for Cortex-M0 */
  blkCnt = numSamples;

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

  while(blkCnt > 0u)
  {
    /* realOut + j (imagOut) = realIn + j (-1) imagIn */
    /* Calculate Complex Conjugate and then store the results in the destination buffer. */
    *pDst++ = *pSrc++;
    *pDst++ = -*pSrc++;

    /* Decrement the loop counter */
    blkCnt--;
  }
}

/**        
 * @} end of cmplx_conj group        
 */