tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/ComplexMathFunctions/arm_cmplx_mult_cmplx_q15.c

   1 /* ----------------------------------------------------------------------
   2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
   3 *
   4 * $Date:        17. January 2013
   5 * $Revision:    V1.4.1
   6 *
   7 * Project:          CMSIS DSP Library
   8 * Title:            arm_cmplx_mult_cmplx_q15.c
   9 *
  10 * Description:  Q15 complex-by-complex 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 CmplxByCmplxMult
  49  * @{
  50  */
  51
  52 /**
  53  * @brief  Q15 complex-by-complex multiplication
  54  * @param[in]  *pSrcA points to the first input vector
  55  * @param[in]  *pSrcB points to the second input vector
  56  * @param[out]  *pDst  points to the output vector
  57  * @param[in]  numSamples number of complex samples in each vector
  58  * @return none.
  59  *
  60  * <b>Scaling and Overflow Behavior:</b>
  61  * \par
  62  * The function implements 1.15 by 1.15 multiplications and finally output is converted into 3.13 format.
  63  */
  64
  65 void arm_cmplx_mult_cmplx_q15(
  66   q15_t * pSrcA,
  67   q15_t * pSrcB,
  68   q15_t * pDst,
  69   uint32_t numSamples)
  70 {
  71   q15_t a, b, c, d;                              /* Temporary variables to store real and imaginary values */
  72
  73 #ifndef ARM_MATH_CM0_FAMILY
  74
  75   /* Run the below code for Cortex-M4 and Cortex-M3 */
  76   uint32_t blkCnt;                               /* loop counters */
  77
  78   /* loop Unrolling */
  79   blkCnt = numSamples >> 2u;
  80
  81   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  82    ** a second loop below computes the remaining 1 to 3 samples. */
  83   while(blkCnt > 0u)
  84   {
  85     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
  86     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
  87     a = *pSrcA++;
  88     b = *pSrcA++;
  89     c = *pSrcB++;
  90     d = *pSrcB++;
  91
  92     /* store the result in 3.13 format in the destination buffer. */
  93     *pDst++ =
  94       (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17);
  95     /* store the result in 3.13 format in the destination buffer. */
  96     *pDst++ =
  97       (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17);
  98
  99     a = *pSrcA++;
 100     b = *pSrcA++;
 101     c = *pSrcB++;
 102     d = *pSrcB++;
 103
 104     /* store the result in 3.13 format in the destination buffer. */
 105     *pDst++ =
 106       (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17);
 107     /* store the result in 3.13 format in the destination buffer. */
 108     *pDst++ =
 109       (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17);
 110
 111     a = *pSrcA++;
 112     b = *pSrcA++;
 113     c = *pSrcB++;
 114     d = *pSrcB++;
 115
 116     /* store the result in 3.13 format in the destination buffer. */
 117     *pDst++ =
 118       (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17);
 119     /* store the result in 3.13 format in the destination buffer. */
 120     *pDst++ =
 121       (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17);
 122
 123     a = *pSrcA++;
 124     b = *pSrcA++;
 125     c = *pSrcB++;
 126     d = *pSrcB++;
 127
 128     /* store the result in 3.13 format in the destination buffer. */
 129     *pDst++ =
 130       (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17);
 131     /* store the result in 3.13 format in the destination buffer. */
 132     *pDst++ =
 133       (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17);
 134
 135     /* Decrement the blockSize loop counter */
 136     blkCnt--;
 137   }
 138
 139   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
 140    ** No loop unrolling is used. */
 141   blkCnt = numSamples % 0x4u;
 142
 143   while(blkCnt > 0u)
 144   {
 145     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
 146     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
 147     a = *pSrcA++;
 148     b = *pSrcA++;
 149     c = *pSrcB++;
 150     d = *pSrcB++;
 151
 152     /* store the result in 3.13 format in the destination buffer. */
 153     *pDst++ =
 154       (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17);
 155     /* store the result in 3.13 format in the destination buffer. */
 156     *pDst++ =
 157       (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17);
 158
 159     /* Decrement the blockSize loop counter */
 160     blkCnt--;
 161   }
 162
 163 #else
 164
 165   /* Run the below code for Cortex-M0 */
 166
 167   while(numSamples > 0u)
 168   {
 169     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
 170     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
 171     a = *pSrcA++;
 172     b = *pSrcA++;
 173     c = *pSrcB++;
 174     d = *pSrcB++;
 175
 176     /* store the result in 3.13 format in the destination buffer. */
 177     *pDst++ =
 178       (q15_t) (q31_t) (((q31_t) a * c) >> 17) - (((q31_t) b * d) >> 17);
 179     /* store the result in 3.13 format in the destination buffer. */
 180     *pDst++ =
 181       (q15_t) (q31_t) (((q31_t) a * d) >> 17) + (((q31_t) b * c) >> 17);
 182
 183     /* Decrement the blockSize loop counter */
 184     numSamples--;
 185   }
 186
 187 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
 188
 189 }
 190
 191 /**
 192  * @} end of CmplxByCmplxMult group
 193  */