lib/main/CMSIS/DSP/Source/ComplexMathFunctions/arm_cmplx_mag_f32.c

   1 /* ----------------------------------------------------------------------
   2  * Project:      CMSIS DSP Library
   3  * Title:        arm_cmplx_mag_f32.c
   4  * Description:  Floating-point complex magnitude
   5  *
   6  * $Date:        27. January 2017
   7  * $Revision:    V.1.5.1
   8  *
   9  * Target Processor: Cortex-M cores
  10  * -------------------------------------------------------------------- */
  11 /*
  12  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
  13  *
  14  * SPDX-License-Identifier: Apache-2.0
  15  *
  16  * Licensed under the Apache License, Version 2.0 (the License); you may
  17  * not use this file except in compliance with the License.
  18  * You may obtain a copy of the License at
  19  *
  20  * www.apache.org/licenses/LICENSE-2.0
  21  *
  22  * Unless required by applicable law or agreed to in writing, software
  23  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
  24  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  25  * See the License for the specific language governing permissions and
  26  * limitations under the License.
  27  */
  28
  29 #include "arm_math.h"
  30
  31 /**
  32  * @ingroup groupCmplxMath
  33  */
  34
  35 /**
  36  * @defgroup cmplx_mag Complex Magnitude
  37  *
  38  * Computes the magnitude of the elements of a complex data vector.
  39  *
  40  * The <code>pSrc</code> points to the source data and
  41  * <code>pDst</code> points to the where the result should be written.
  42  * <code>numSamples</code> specifies the number of complex samples
  43  * in the input array and the data is stored in an interleaved fashion
  44  * (real, imag, real, imag, ...).
  45  * The input array has a total of <code>2*numSamples</code> values;
  46  * the output array has a total of <code>numSamples</code> values.
  47  * The underlying algorithm is used:
  48  *
  49  * <pre>
  50  * for(n=0; n<numSamples; n++) {
  51  *     pDst[n] = sqrt(pSrc[(2*n)+0]^2 + pSrc[(2*n)+1]^2);
  52  * }
  53  * </pre>
  54  *
  55  * There are separate functions for floating-point, Q15, and Q31 data types.
  56  */
  57
  58 /**
  59  * @addtogroup cmplx_mag
  60  * @{
  61  */
  62 /**
  63  * @brief Floating-point complex magnitude.
  64  * @param[in]       *pSrc points to complex input buffer
  65  * @param[out]      *pDst points to real output buffer
  66  * @param[in]       numSamples number of complex samples in the input vector
  67  * @return none.
  68  *
  69  */
  70
  71
  72 void arm_cmplx_mag_f32(
  73   float32_t * pSrc,
  74   float32_t * pDst,
  75   uint32_t numSamples)
  76 {
  77   float32_t realIn, imagIn;                      /* Temporary variables to hold input values */
  78
  79 #if defined (ARM_MATH_DSP)
  80
  81   /* Run the below code for Cortex-M4 and Cortex-M3 */
  82   uint32_t blkCnt;                               /* loop counter */
  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
  92     /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
  93     realIn = *pSrc++;
  94     imagIn = *pSrc++;
  95     /* store the result in the destination buffer. */
  96     arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
  97
  98     realIn = *pSrc++;
  99     imagIn = *pSrc++;
 100     arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
 101
 102     realIn = *pSrc++;
 103     imagIn = *pSrc++;
 104     arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
 105
 106     realIn = *pSrc++;
 107     imagIn = *pSrc++;
 108     arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
 109
 110
 111     /* Decrement the loop counter */
 112     blkCnt--;
 113   }
 114
 115   /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
 116    ** No loop unrolling is used. */
 117   blkCnt = numSamples % 0x4U;
 118
 119   while (blkCnt > 0U)
 120   {
 121     /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
 122     realIn = *pSrc++;
 123     imagIn = *pSrc++;
 124     /* store the result in the destination buffer. */
 125     arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
 126
 127     /* Decrement the loop counter */
 128     blkCnt--;
 129   }
 130
 131 #else
 132
 133   /* Run the below code for Cortex-M0 */
 134
 135   while (numSamples > 0U)
 136   {
 137     /* out = sqrt((real * real) + (imag * imag)) */
 138     realIn = *pSrc++;
 139     imagIn = *pSrc++;
 140     /* store the result in the destination buffer. */
 141     arm_sqrt_f32((realIn * realIn) + (imagIn * imagIn), pDst++);
 142
 143     /* Decrement the loop counter */
 144     numSamples--;
 145   }
 146
 147 #endif /* #if defined (ARM_MATH_DSP) */
 148
 149 }
 150
 151 /**
 152  * @} end of cmplx_mag group
 153  */