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  1. /* ----------------------------------------------------------------------    
  2. * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  3. *    
  4. * $Date:        19. October 2015
  5. * $Revision:    V.1.4.5 a
  6. *    
  7. * Project:          CMSIS DSP Library    
  8. * Title:            arm_cmplx_mult_real_q15.c    
  9. *    
  10. * Description:  Q15 complex by real multiplication    
  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 CmplxByRealMult    
  49.  * @{    
  50.  */
  51.  
  52.  
  53. /**    
  54.  * @brief  Q15 complex-by-real multiplication    
  55.  * @param[in]  *pSrcCmplx points to the complex input vector    
  56.  * @param[in]  *pSrcReal points to the real input vector    
  57.  * @param[out]  *pCmplxDst points to the complex output vector    
  58.  * @param[in]  numSamples number of samples in each vector    
  59.  * @return none.    
  60.  *    
  61.  * <b>Scaling and Overflow Behavior:</b>    
  62.  * \par    
  63.  * The function uses saturating arithmetic.    
  64.  * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.    
  65.  */
  66.  
  67. void arm_cmplx_mult_real_q15(
  68.   q15_t * pSrcCmplx,
  69.   q15_t * pSrcReal,
  70.   q15_t * pCmplxDst,
  71.   uint32_t numSamples)
  72. {
  73.   q15_t in;                                      /* Temporary variable to store input value */
  74.  
  75. #ifndef ARM_MATH_CM0_FAMILY
  76.  
  77.   /* Run the below code for Cortex-M4 and Cortex-M3 */
  78.   uint32_t blkCnt;                               /* loop counters */
  79.   q31_t inA1, inA2;                              /* Temporary variables to hold input data */
  80.   q31_t inB1;                                    /* Temporary variables to hold input data */
  81.   q15_t out1, out2, out3, out4;                  /* Temporary variables to hold output data */
  82.   q31_t mul1, mul2, mul3, mul4;                  /* Temporary variables to hold intermediate data */
  83.  
  84.   /* loop Unrolling */
  85.   blkCnt = numSamples >> 2u;
  86.  
  87.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
  88.    ** a second loop below computes the remaining 1 to 3 samples. */
  89.   while(blkCnt > 0u)
  90.   {
  91.     /* C[2 * i] = A[2 * i] * B[i].            */
  92.     /* C[2 * i + 1] = A[2 * i + 1] * B[i].        */
  93.     /* read complex number both real and imaginary from complex input buffer */
  94.     inA1 = *__SIMD32(pSrcCmplx)++;
  95.     /* read two real values at a time from real input buffer */
  96.     inB1 = *__SIMD32(pSrcReal)++;
  97.     /* read complex number both real and imaginary from complex input buffer */
  98.     inA2 = *__SIMD32(pSrcCmplx)++;
  99.  
  100.     /* multiply complex number with real numbers */
  101. #ifndef ARM_MATH_BIG_ENDIAN
  102.  
  103.     mul1 = (q31_t) ((q15_t) (inA1) * (q15_t) (inB1));
  104.     mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1));
  105.     mul3 = (q31_t) ((q15_t) (inA2) * (q15_t) (inB1 >> 16));
  106.     mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB1 >> 16));
  107.  
  108. #else
  109.  
  110.     mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16));
  111.     mul1 = (q31_t) ((q15_t) inA1 * (q15_t) (inB1 >> 16));
  112.     mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) inB1);
  113.     mul3 = (q31_t) ((q15_t) inA2 * (q15_t) inB1);
  114.  
  115. #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
  116.  
  117.     /* saturate the result */
  118.     out1 = (q15_t) __SSAT(mul1 >> 15u, 16);
  119.     out2 = (q15_t) __SSAT(mul2 >> 15u, 16);
  120.     out3 = (q15_t) __SSAT(mul3 >> 15u, 16);
  121.     out4 = (q15_t) __SSAT(mul4 >> 15u, 16);
  122.  
  123.     /* pack real and imaginary outputs and store them to destination */
  124.     *__SIMD32(pCmplxDst)++ = __PKHBT(out1, out2, 16);
  125.     *__SIMD32(pCmplxDst)++ = __PKHBT(out3, out4, 16);
  126.  
  127.     inA1 = *__SIMD32(pSrcCmplx)++;
  128.     inB1 = *__SIMD32(pSrcReal)++;
  129.     inA2 = *__SIMD32(pSrcCmplx)++;
  130.  
  131. #ifndef ARM_MATH_BIG_ENDIAN
  132.  
  133.     mul1 = (q31_t) ((q15_t) (inA1) * (q15_t) (inB1));
  134.     mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1));
  135.     mul3 = (q31_t) ((q15_t) (inA2) * (q15_t) (inB1 >> 16));
  136.     mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB1 >> 16));
  137.  
  138. #else
  139.  
  140.     mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16));
  141.     mul1 = (q31_t) ((q15_t) inA1 * (q15_t) (inB1 >> 16));
  142.     mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) inB1);
  143.     mul3 = (q31_t) ((q15_t) inA2 * (q15_t) inB1);
  144.  
  145. #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
  146.  
  147.     out1 = (q15_t) __SSAT(mul1 >> 15u, 16);
  148.     out2 = (q15_t) __SSAT(mul2 >> 15u, 16);
  149.     out3 = (q15_t) __SSAT(mul3 >> 15u, 16);
  150.     out4 = (q15_t) __SSAT(mul4 >> 15u, 16);
  151.  
  152.     *__SIMD32(pCmplxDst)++ = __PKHBT(out1, out2, 16);
  153.     *__SIMD32(pCmplxDst)++ = __PKHBT(out3, out4, 16);
  154.  
  155.     /* Decrement the numSamples loop counter */
  156.     blkCnt--;
  157.   }
  158.  
  159.   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.    
  160.    ** No loop unrolling is used. */
  161.   blkCnt = numSamples % 0x4u;
  162.  
  163.   while(blkCnt > 0u)
  164.   {
  165.     /* C[2 * i] = A[2 * i] * B[i].            */
  166.     /* C[2 * i + 1] = A[2 * i + 1] * B[i].        */
  167.     in = *pSrcReal++;
  168.     /* store the result in the destination buffer. */
  169.     *pCmplxDst++ =
  170.       (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16);
  171.     *pCmplxDst++ =
  172.       (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16);
  173.  
  174.     /* Decrement the numSamples loop counter */
  175.     blkCnt--;
  176.   }
  177.  
  178. #else
  179.  
  180.   /* Run the below code for Cortex-M0 */
  181.  
  182.   while(numSamples > 0u)
  183.   {
  184.     /* realOut = realA * realB.            */
  185.     /* imagOut = imagA * realB.                */
  186.     in = *pSrcReal++;
  187.     /* store the result in the destination buffer. */
  188.     *pCmplxDst++ =
  189.       (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16);
  190.     *pCmplxDst++ =
  191.       (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16);
  192.  
  193.     /* Decrement the numSamples loop counter */
  194.     numSamples--;
  195.   }
  196.  
  197. #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  198.  
  199. }
  200.  
  201. /**    
  202.  * @} end of CmplxByRealMult group    
  203.  */
  204.