tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/ComplexMathFunctions/arm_cmplx_mult_real_q31.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_real_q31.c
   9 *
  10 * Description:  Q31 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  Q31 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 Q31 range[0x80000000 0x7FFFFFFF] will be saturated.
  65  */
  66
  67 void arm_cmplx_mult_real_q31(
  68   q31_t * pSrcCmplx,
  69   q31_t * pSrcReal,
  70   q31_t * pCmplxDst,
  71   uint32_t numSamples)
  72 {
  73   q31_t inA1;                                    /* 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 inA2, inA3, inA4;                        /* Temporary variables to hold input data */
  80   q31_t inB1, inB2;                              /* Temporary variabels to hold input data */
  81   q31_t out1, out2, out3, out4;                  /* Temporary variables to hold output data */
  82
  83   /* loop Unrolling */
  84   blkCnt = numSamples >> 2u;
  85
  86   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  87    ** a second loop below computes the remaining 1 to 3 samples. */
  88   while(blkCnt > 0u)
  89   {
  90     /* C[2 * i] = A[2 * i] * B[i].            */
  91     /* C[2 * i + 1] = A[2 * i + 1] * B[i].        */
  92     /* read real input from complex input buffer */
  93     inA1 = *pSrcCmplx++;
  94     inA2 = *pSrcCmplx++;
  95     /* read input from real input bufer */
  96     inB1 = *pSrcReal++;
  97     inB2 = *pSrcReal++;
  98     /* read imaginary input from complex input buffer */
  99     inA3 = *pSrcCmplx++;
 100     inA4 = *pSrcCmplx++;
 101
 102     /* multiply complex input with real input */
 103     out1 = ((q63_t) inA1 * inB1) >> 32;
 104     out2 = ((q63_t) inA2 * inB1) >> 32;
 105     out3 = ((q63_t) inA3 * inB2) >> 32;
 106     out4 = ((q63_t) inA4 * inB2) >> 32;
 107
 108     /* sature the result */
 109     out1 = __SSAT(out1, 31);
 110     out2 = __SSAT(out2, 31);
 111     out3 = __SSAT(out3, 31);
 112     out4 = __SSAT(out4, 31);
 113
 114     /* get result in 1.31 format */
 115     out1 = out1 << 1;
 116     out2 = out2 << 1;
 117     out3 = out3 << 1;
 118     out4 = out4 << 1;
 119
 120     /* store the result to destination buffer */
 121     *pCmplxDst++ = out1;
 122     *pCmplxDst++ = out2;
 123     *pCmplxDst++ = out3;
 124     *pCmplxDst++ = out4;
 125
 126     /* read real input from complex input buffer */
 127     inA1 = *pSrcCmplx++;
 128     inA2 = *pSrcCmplx++;
 129     /* read input from real input bufer */
 130     inB1 = *pSrcReal++;
 131     inB2 = *pSrcReal++;
 132     /* read imaginary input from complex input buffer */
 133     inA3 = *pSrcCmplx++;
 134     inA4 = *pSrcCmplx++;
 135
 136     /* multiply complex input with real input */
 137     out1 = ((q63_t) inA1 * inB1) >> 32;
 138     out2 = ((q63_t) inA2 * inB1) >> 32;
 139     out3 = ((q63_t) inA3 * inB2) >> 32;
 140     out4 = ((q63_t) inA4 * inB2) >> 32;
 141
 142     /* sature the result */
 143     out1 = __SSAT(out1, 31);
 144     out2 = __SSAT(out2, 31);
 145     out3 = __SSAT(out3, 31);
 146     out4 = __SSAT(out4, 31);
 147
 148     /* get result in 1.31 format */
 149     out1 = out1 << 1;
 150     out2 = out2 << 1;
 151     out3 = out3 << 1;
 152     out4 = out4 << 1;
 153
 154     /* store the result to destination buffer */
 155     *pCmplxDst++ = out1;
 156     *pCmplxDst++ = out2;
 157     *pCmplxDst++ = out3;
 158     *pCmplxDst++ = out4;
 159
 160     /* Decrement the numSamples loop counter */
 161     blkCnt--;
 162   }
 163
 164   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
 165    ** No loop unrolling is used. */
 166   blkCnt = numSamples % 0x4u;
 167
 168   while(blkCnt > 0u)
 169   {
 170     /* C[2 * i] = A[2 * i] * B[i].            */
 171     /* C[2 * i + 1] = A[2 * i + 1] * B[i].        */
 172     /* read real input from complex input buffer */
 173     inA1 = *pSrcCmplx++;
 174     inA2 = *pSrcCmplx++;
 175     /* read input from real input bufer */
 176     inB1 = *pSrcReal++;
 177
 178     /* multiply complex input with real input */
 179     out1 = ((q63_t) inA1 * inB1) >> 32;
 180     out2 = ((q63_t) inA2 * inB1) >> 32;
 181
 182     /* sature the result */
 183     out1 = __SSAT(out1, 31);
 184     out2 = __SSAT(out2, 31);
 185
 186     /* get result in 1.31 format */
 187     out1 = out1 << 1;
 188     out2 = out2 << 1;
 189
 190     /* store the result to destination buffer */
 191     *pCmplxDst++ = out1;
 192     *pCmplxDst++ = out2;
 193
 194     /* Decrement the numSamples loop counter */
 195     blkCnt--;
 196   }
 197
 198 #else
 199
 200   /* Run the below code for Cortex-M0 */
 201
 202   while(numSamples > 0u)
 203   {
 204     /* realOut = realA * realB.            */
 205     /* imagReal = imagA * realB.               */
 206     inA1 = *pSrcReal++;
 207     /* store the result in the destination buffer. */
 208     *pCmplxDst++ =
 209       (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * inA1) >> 31);
 210     *pCmplxDst++ =
 211       (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * inA1) >> 31);
 212
 213     /* Decrement the numSamples loop counter */
 214     numSamples--;
 215   }
 216
 217 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
 218
 219 }
 220
 221 /**
 222  * @} end of CmplxByRealMult group
 223  */