Subversion Repositories DashDisplay

Rev

Rev 2 | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  1. /* ----------------------------------------------------------------------    
  2. * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  3. *    
  4. * $Date:        19. March 2015
  5. * $Revision:    V.1.4.5
  6. *    
  7. * Project:          CMSIS DSP Library    
  8. * Title:                arm_cmplx_mag_q31.c    
  9. *    
  10. * Description:  Q31 complex magnitude    
  11. *    
  12. * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  13. *  
  14. * Redistribution and use in source and binary forms, with or without
  15. * modification, are permitted provided that the following conditions
  16. * are met:
  17. *   - Redistributions of source code must retain the above copyright
  18. *     notice, this list of conditions and the following disclaimer.
  19. *   - Redistributions in binary form must reproduce the above copyright
  20. *     notice, this list of conditions and the following disclaimer in
  21. *     the documentation and/or other materials provided with the
  22. *     distribution.
  23. *   - Neither the name of ARM LIMITED nor the names of its contributors
  24. *     may be used to endorse or promote products derived from this
  25. *     software without specific prior written permission.
  26. *
  27. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28. * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29. * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  30. * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  31. * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  32. * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  33. * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  34. * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  35. * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  37. * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38. * POSSIBILITY OF SUCH DAMAGE.  
  39. * ---------------------------------------------------------------------------- */
  40.  
  41. #include "arm_math.h"
  42.  
  43. /**        
  44.  * @ingroup groupCmplxMath        
  45.  */
  46.  
  47. /**        
  48.  * @addtogroup cmplx_mag        
  49.  * @{        
  50.  */
  51.  
  52. /**        
  53.  * @brief  Q31 complex magnitude        
  54.  * @param  *pSrc points to the complex input vector        
  55.  * @param  *pDst points to the real output vector        
  56.  * @param  numSamples number of complex samples in the input vector        
  57.  * @return none.        
  58.  *        
  59.  * <b>Scaling and Overflow Behavior:</b>        
  60.  * \par        
  61.  * The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format.        
  62.  * Input down scaling is not required.        
  63.  */
  64.  
  65. void arm_cmplx_mag_q31(
  66.   q31_t * pSrc,
  67.   q31_t * pDst,
  68.   uint32_t numSamples)
  69. {
  70.   q31_t real, imag;                              /* Temporary variables to hold input values */
  71.   q31_t acc0, acc1;                              /* Accumulators */
  72.   uint32_t blkCnt;                               /* loop counter */
  73.  
  74. #ifndef ARM_MATH_CM0_FAMILY
  75.  
  76.   /* Run the below code for Cortex-M4 and Cortex-M3 */
  77.   q31_t real1, real2, imag1, imag2;              /* Temporary variables to hold input values */
  78.   q31_t out1, out2, out3, out4;                  /* Accumulators */
  79.   q63_t mul1, mul2, mul3, mul4;                  /* Temporary variables */
  80.  
  81.  
  82.   /*loop Unrolling */
  83.   blkCnt = numSamples >> 2u;
  84.  
  85.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.        
  86.    ** a second loop below computes the remaining 1 to 3 samples. */
  87.   while(blkCnt > 0u)
  88.   {
  89.     /* read complex input from source buffer */
  90.     real1 = pSrc[0];
  91.     imag1 = pSrc[1];
  92.     real2 = pSrc[2];
  93.     imag2 = pSrc[3];
  94.  
  95.     /* calculate power of input values */
  96.     mul1 = (q63_t) real1 *real1;
  97.     mul2 = (q63_t) imag1 *imag1;
  98.     mul3 = (q63_t) real2 *real2;
  99.     mul4 = (q63_t) imag2 *imag2;
  100.  
  101.     /* get the result to 3.29 format */
  102.     out1 = (q31_t) (mul1 >> 33);
  103.     out2 = (q31_t) (mul2 >> 33);
  104.     out3 = (q31_t) (mul3 >> 33);
  105.     out4 = (q31_t) (mul4 >> 33);
  106.  
  107.     /* add real and imaginary accumulators */
  108.     out1 = out1 + out2;
  109.     out3 = out3 + out4;
  110.  
  111.     /* read complex input from source buffer */
  112.     real1 = pSrc[4];
  113.     imag1 = pSrc[5];
  114.     real2 = pSrc[6];
  115.     imag2 = pSrc[7];
  116.  
  117.     /* calculate square root */
  118.     arm_sqrt_q31(out1, &pDst[0]);
  119.  
  120.     /* calculate power of input values */
  121.     mul1 = (q63_t) real1 *real1;
  122.  
  123.     /* calculate square root */
  124.     arm_sqrt_q31(out3, &pDst[1]);
  125.  
  126.     /* calculate power of input values */
  127.     mul2 = (q63_t) imag1 *imag1;
  128.     mul3 = (q63_t) real2 *real2;
  129.     mul4 = (q63_t) imag2 *imag2;
  130.  
  131.     /* get the result to 3.29 format */
  132.     out1 = (q31_t) (mul1 >> 33);
  133.     out2 = (q31_t) (mul2 >> 33);
  134.     out3 = (q31_t) (mul3 >> 33);
  135.     out4 = (q31_t) (mul4 >> 33);
  136.  
  137.     /* add real and imaginary accumulators */
  138.     out1 = out1 + out2;
  139.     out3 = out3 + out4;
  140.  
  141.     /* calculate square root */
  142.     arm_sqrt_q31(out1, &pDst[2]);
  143.  
  144.     /* increment destination by 8 to process next samples */
  145.     pSrc += 8u;
  146.  
  147.     /* calculate square root */
  148.     arm_sqrt_q31(out3, &pDst[3]);
  149.  
  150.     /* increment destination by 4 to process next samples */
  151.     pDst += 4u;
  152.  
  153.     /* Decrement the loop counter */
  154.     blkCnt--;
  155.   }
  156.  
  157.   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.        
  158.    ** No loop unrolling is used. */
  159.   blkCnt = numSamples % 0x4u;
  160.  
  161. #else
  162.  
  163.   /* Run the below code for Cortex-M0 */
  164.   blkCnt = numSamples;
  165.  
  166. #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  167.  
  168.   while(blkCnt > 0u)
  169.   {
  170.     /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
  171.     real = *pSrc++;
  172.     imag = *pSrc++;
  173.     acc0 = (q31_t) (((q63_t) real * real) >> 33);
  174.     acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
  175.     /* store the result in 2.30 format in the destination buffer. */
  176.     arm_sqrt_q31(acc0 + acc1, pDst++);
  177.  
  178.     /* Decrement the loop counter */
  179.     blkCnt--;
  180.   }
  181. }
  182.  
  183. /**        
  184.  * @} end of cmplx_mag group        
  185.  */
  186.