tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/ComplexMathFunctions/arm_cmplx_mult_cmplx_f32.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_f32.c
   9 *
  10 * Description:  Floating-point 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 #include "arm_math.h"
  41
  42 /**
  43  * @ingroup groupCmplxMath
  44  */
  45
  46 /**
  47  * @defgroup CmplxByCmplxMult Complex-by-Complex Multiplication
  48  *
  49  * Multiplies a complex vector by another complex vector and generates a complex result.
  50  * The data in the complex arrays is stored in an interleaved fashion
  51  * (real, imag, real, imag, ...).
  52  * The parameter <code>numSamples</code> represents the number of complex
  53  * samples processed.  The complex arrays have a total of <code>2*numSamples</code>
  54  * real values.
  55  *
  56  * The underlying algorithm is used:
  57  *
  58  * <pre>
  59  * for(n=0; n<numSamples; n++) {
  60  *     pDst[(2*n)+0] = pSrcA[(2*n)+0] * pSrcB[(2*n)+0] - pSrcA[(2*n)+1] * pSrcB[(2*n)+1];
  61  *     pDst[(2*n)+1] = pSrcA[(2*n)+0] * pSrcB[(2*n)+1] + pSrcA[(2*n)+1] * pSrcB[(2*n)+0];
  62  * }
  63  * </pre>
  64  *
  65  * There are separate functions for floating-point, Q15, and Q31 data types.
  66  */
  67
  68 /**
  69  * @addtogroup CmplxByCmplxMult
  70  * @{
  71  */
  72
  73
  74 /**
  75  * @brief  Floating-point complex-by-complex multiplication
  76  * @param[in]  *pSrcA points to the first input vector
  77  * @param[in]  *pSrcB points to the second input vector
  78  * @param[out]  *pDst  points to the output vector
  79  * @param[in]  numSamples number of complex samples in each vector
  80  * @return none.
  81  */
  82
  83 void arm_cmplx_mult_cmplx_f32(
  84   float32_t * pSrcA,
  85   float32_t * pSrcB,
  86   float32_t * pDst,
  87   uint32_t numSamples)
  88 {
  89   float32_t a1, b1, c1, d1;                      /* Temporary variables to store real and imaginary values */
  90   uint32_t blkCnt;                               /* loop counters */
  91
  92 #ifndef ARM_MATH_CM0_FAMILY
  93
  94   /* Run the below code for Cortex-M4 and Cortex-M3 */
  95   float32_t a2, b2, c2, d2;                      /* Temporary variables to store real and imaginary values */
  96   float32_t acc1, acc2, acc3, acc4;
  97
  98
  99   /* loop Unrolling */
 100   blkCnt = numSamples >> 2u;
 101
 102   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
 103    ** a second loop below computes the remaining 1 to 3 samples. */
 104   while(blkCnt > 0u)
 105   {
 106     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
 107     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
 108     a1 = *pSrcA;                /* A[2 * i] */
 109     c1 = *pSrcB;                /* B[2 * i] */
 110
 111     b1 = *(pSrcA + 1);          /* A[2 * i + 1] */
 112     acc1 = a1 * c1;             /* acc1 = A[2 * i] * B[2 * i] */
 113
 114     a2 = *(pSrcA + 2);          /* A[2 * i + 2] */
 115     acc2 = (b1 * c1);           /* acc2 = A[2 * i + 1] * B[2 * i] */
 116
 117     d1 = *(pSrcB + 1);          /* B[2 * i + 1] */
 118     c2 = *(pSrcB + 2);          /* B[2 * i + 2] */
 119     acc1 -= b1 * d1;            /* acc1 =      A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1] */
 120
 121     d2 = *(pSrcB + 3);          /* B[2 * i + 3] */
 122     acc3 = a2 * c2;             /* acc3 =       A[2 * i + 2] * B[2 * i + 2] */
 123
 124     b2 = *(pSrcA + 3);          /* A[2 * i + 3] */
 125     acc2 += (a1 * d1);          /* acc2 =      A[2 * i + 1] * B[2 * i] + A[2 * i] * B[2 * i + 1] */
 126
 127     a1 = *(pSrcA + 4);          /* A[2 * i + 4] */
 128     acc4 = (a2 * d2);           /* acc4 =   A[2 * i + 2] * B[2 * i + 3] */
 129
 130     c1 = *(pSrcB + 4);          /* B[2 * i + 4] */
 131     acc3 -= (b2 * d2);          /* acc3 =       A[2 * i + 2] * B[2 * i + 2] - A[2 * i + 3] * B[2 * i + 3] */
 132     *pDst = acc1;               /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1] */
 133
 134     b1 = *(pSrcA + 5);          /* A[2 * i + 5] */
 135     acc4 += b2 * c2;            /* acc4 =   A[2 * i + 2] * B[2 * i + 3] + A[2 * i + 3] * B[2 * i + 2] */
 136
 137     *(pDst + 1) = acc2;         /* C[2 * i + 1] = A[2 * i + 1] * B[2 * i] + A[2 * i] * B[2 * i + 1]  */
 138     acc1 = (a1 * c1);
 139
 140     d1 = *(pSrcB + 5);
 141     acc2 = (b1 * c1);
 142
 143     *(pDst + 2) = acc3;
 144     *(pDst + 3) = acc4;
 145
 146     a2 = *(pSrcA + 6);
 147     acc1 -= (b1 * d1);
 148
 149     c2 = *(pSrcB + 6);
 150     acc2 += (a1 * d1);
 151
 152     b2 = *(pSrcA + 7);
 153     acc3 = (a2 * c2);
 154
 155     d2 = *(pSrcB + 7);
 156     acc4 = (b2 * c2);
 157
 158     *(pDst + 4) = acc1;
 159     pSrcA += 8u;
 160
 161     acc3 -= (b2 * d2);
 162     acc4 += (a2 * d2);
 163
 164     *(pDst + 5) = acc2;
 165     pSrcB += 8u;
 166
 167     *(pDst + 6) = acc3;
 168     *(pDst + 7) = acc4;
 169
 170     pDst += 8u;
 171
 172     /* Decrement the numSamples loop counter */
 173     blkCnt--;
 174   }
 175
 176   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
 177    ** No loop unrolling is used. */
 178   blkCnt = numSamples % 0x4u;
 179
 180 #else
 181
 182   /* Run the below code for Cortex-M0 */
 183   blkCnt = numSamples;
 184
 185 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
 186
 187   while(blkCnt > 0u)
 188   {
 189     /* C[2 * i] = A[2 * i] * B[2 * i] - A[2 * i + 1] * B[2 * i + 1].  */
 190     /* C[2 * i + 1] = A[2 * i] * B[2 * i + 1] + A[2 * i + 1] * B[2 * i].  */
 191     a1 = *pSrcA++;
 192     b1 = *pSrcA++;
 193     c1 = *pSrcB++;
 194     d1 = *pSrcB++;
 195
 196     /* store the result in the destination buffer. */
 197     *pDst++ = (a1 * c1) - (b1 * d1);
 198     *pDst++ = (a1 * d1) + (b1 * c1);
 199
 200     /* Decrement the numSamples loop counter */
 201     blkCnt--;
 202   }
 203 }
 204
 205 /**
 206  * @} end of CmplxByCmplxMult group
 207  */