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CMSIS DSP library

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cmsis_dsp/ComplexMathFunctions/arm_cmplx_mag_squared_f32.c@1:fdd22bb7aa52, 2012-11-28 (annotated)

Committer:
emilmont
Date:
Wed Nov 28 12:30:09 2012 +0000
Revision:
1:fdd22bb7aa52
Child:
2:da51fb522205
DSP library code

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------
emilmont 1:fdd22bb7aa52 2 * Copyright (C) 2010 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
emilmont 1:fdd22bb7aa52 4 * $Date: 15. February 2012
emilmont 1:fdd22bb7aa52 5 * $Revision: V1.1.0
emilmont 1:fdd22bb7aa52 6 *
emilmont 1:fdd22bb7aa52 7 * Project: CMSIS DSP Library
emilmont 1:fdd22bb7aa52 8 * Title: arm_cmplx_mag_squared_f32.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 1:fdd22bb7aa52 10 * Description: Floating-point complex magnitude squared.
emilmont 1:fdd22bb7aa52 11 *
emilmont 1:fdd22bb7aa52 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emilmont 1:fdd22bb7aa52 13 *
emilmont 1:fdd22bb7aa52 14 * Version 1.1.0 2012/02/15
emilmont 1:fdd22bb7aa52 15 * Updated with more optimizations, bug fixes and minor API changes.
emilmont 1:fdd22bb7aa52 16 *
emilmont 1:fdd22bb7aa52 17 * Version 1.0.10 2011/7/15
emilmont 1:fdd22bb7aa52 18 * Big Endian support added and Merged M0 and M3/M4 Source code.
emilmont 1:fdd22bb7aa52 19 *
emilmont 1:fdd22bb7aa52 20 * Version 1.0.3 2010/11/29
emilmont 1:fdd22bb7aa52 21 * Re-organized the CMSIS folders and updated documentation.
emilmont 1:fdd22bb7aa52 22 *
emilmont 1:fdd22bb7aa52 23 * Version 1.0.2 2010/11/11
emilmont 1:fdd22bb7aa52 24 * Documentation updated.
emilmont 1:fdd22bb7aa52 25 *
emilmont 1:fdd22bb7aa52 26 * Version 1.0.1 2010/10/05
emilmont 1:fdd22bb7aa52 27 * Production release and review comments incorporated.
emilmont 1:fdd22bb7aa52 28 *
emilmont 1:fdd22bb7aa52 29 * Version 1.0.0 2010/09/20
emilmont 1:fdd22bb7aa52 30 * Production release and review comments incorporated.
emilmont 1:fdd22bb7aa52 31 * ---------------------------------------------------------------------------- */
emilmont 1:fdd22bb7aa52 32 #include "arm_math.h"
emilmont 1:fdd22bb7aa52 33
emilmont 1:fdd22bb7aa52 34 /**
emilmont 1:fdd22bb7aa52 35 * @ingroup groupCmplxMath
emilmont 1:fdd22bb7aa52 36 */
emilmont 1:fdd22bb7aa52 37
emilmont 1:fdd22bb7aa52 38 /**
emilmont 1:fdd22bb7aa52 39 * @defgroup cmplx_mag_squared Complex Magnitude Squared
emilmont 1:fdd22bb7aa52 40 *
emilmont 1:fdd22bb7aa52 41 * Computes the magnitude squared of the elements of a complex data vector.
emilmont 1:fdd22bb7aa52 42 *
emilmont 1:fdd22bb7aa52 43 * The <code>pSrc</code> points to the source data and
emilmont 1:fdd22bb7aa52 44 * <code>pDst</code> points to the where the result should be written.
emilmont 1:fdd22bb7aa52 45 * <code>numSamples</code> specifies the number of complex samples
emilmont 1:fdd22bb7aa52 46 * in the input array and the data is stored in an interleaved fashion
emilmont 1:fdd22bb7aa52 47 * (real, imag, real, imag, ...).
emilmont 1:fdd22bb7aa52 48 * The input array has a total of <code>2*numSamples</code> values;
emilmont 1:fdd22bb7aa52 49 * the output array has a total of <code>numSamples</code> values.
emilmont 1:fdd22bb7aa52 50 *
emilmont 1:fdd22bb7aa52 51 * The underlying algorithm is used:
emilmont 1:fdd22bb7aa52 52 *
emilmont 1:fdd22bb7aa52 53 * <pre>
emilmont 1:fdd22bb7aa52 54 * for(n=0; n<numSamples; n++) {
emilmont 1:fdd22bb7aa52 55 * pDst[n] = pSrc[(2*n)+0]^2 + pSrc[(2*n)+1]^2;
emilmont 1:fdd22bb7aa52 56 * }
emilmont 1:fdd22bb7aa52 57 * </pre>
emilmont 1:fdd22bb7aa52 58 *
emilmont 1:fdd22bb7aa52 59 * There are separate functions for floating-point, Q15, and Q31 data types.
emilmont 1:fdd22bb7aa52 60 */
emilmont 1:fdd22bb7aa52 61
emilmont 1:fdd22bb7aa52 62 /**
emilmont 1:fdd22bb7aa52 63 * @addtogroup cmplx_mag_squared
emilmont 1:fdd22bb7aa52 64 * @{
emilmont 1:fdd22bb7aa52 65 */
emilmont 1:fdd22bb7aa52 66
emilmont 1:fdd22bb7aa52 67
emilmont 1:fdd22bb7aa52 68 /**
emilmont 1:fdd22bb7aa52 69 * @brief Floating-point complex magnitude squared
emilmont 1:fdd22bb7aa52 70 * @param[in] *pSrc points to the complex input vector
emilmont 1:fdd22bb7aa52 71 * @param[out] *pDst points to the real output vector
emilmont 1:fdd22bb7aa52 72 * @param[in] numSamples number of complex samples in the input vector
emilmont 1:fdd22bb7aa52 73 * @return none.
emilmont 1:fdd22bb7aa52 74 */
emilmont 1:fdd22bb7aa52 75
emilmont 1:fdd22bb7aa52 76 void arm_cmplx_mag_squared_f32(
emilmont 1:fdd22bb7aa52 77 float32_t * pSrc,
emilmont 1:fdd22bb7aa52 78 float32_t * pDst,
emilmont 1:fdd22bb7aa52 79 uint32_t numSamples)
emilmont 1:fdd22bb7aa52 80 {
emilmont 1:fdd22bb7aa52 81 float32_t real, imag; /* Temporary variables to store real and imaginary values */
emilmont 1:fdd22bb7aa52 82 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 83
emilmont 1:fdd22bb7aa52 84 #ifndef ARM_MATH_CM0
emilmont 1:fdd22bb7aa52 85 float32_t real1, real2, real3, real4; /* Temporary variables to hold real values */
emilmont 1:fdd22bb7aa52 86 float32_t imag1, imag2, imag3, imag4; /* Temporary variables to hold imaginary values */
emilmont 1:fdd22bb7aa52 87 float32_t mul1, mul2, mul3, mul4; /* Temporary variables */
emilmont 1:fdd22bb7aa52 88 float32_t mul5, mul6, mul7, mul8; /* Temporary variables */
emilmont 1:fdd22bb7aa52 89 float32_t out1, out2, out3, out4; /* Temporary variables to hold output values */
emilmont 1:fdd22bb7aa52 90
emilmont 1:fdd22bb7aa52 91 /*loop Unrolling */
emilmont 1:fdd22bb7aa52 92 blkCnt = numSamples >> 2u;
emilmont 1:fdd22bb7aa52 93
emilmont 1:fdd22bb7aa52 94 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 95 ** a second loop below computes the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 96 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 97 {
emilmont 1:fdd22bb7aa52 98 /* C[0] = (A[0] * A[0] + A[1] * A[1]) */
emilmont 1:fdd22bb7aa52 99 /* read real input sample from source buffer */
emilmont 1:fdd22bb7aa52 100 real1 = pSrc[0];
emilmont 1:fdd22bb7aa52 101 /* read imaginary input sample from source buffer */
emilmont 1:fdd22bb7aa52 102 imag1 = pSrc[1];
emilmont 1:fdd22bb7aa52 103
emilmont 1:fdd22bb7aa52 104 /* calculate power of real value */
emilmont 1:fdd22bb7aa52 105 mul1 = real1 * real1;
emilmont 1:fdd22bb7aa52 106
emilmont 1:fdd22bb7aa52 107 /* read real input sample from source buffer */
emilmont 1:fdd22bb7aa52 108 real2 = pSrc[2];
emilmont 1:fdd22bb7aa52 109
emilmont 1:fdd22bb7aa52 110 /* calculate power of imaginary value */
emilmont 1:fdd22bb7aa52 111 mul2 = imag1 * imag1;
emilmont 1:fdd22bb7aa52 112
emilmont 1:fdd22bb7aa52 113 /* read imaginary input sample from source buffer */
emilmont 1:fdd22bb7aa52 114 imag2 = pSrc[3];
emilmont 1:fdd22bb7aa52 115
emilmont 1:fdd22bb7aa52 116 /* calculate power of real value */
emilmont 1:fdd22bb7aa52 117 mul3 = real2 * real2;
emilmont 1:fdd22bb7aa52 118
emilmont 1:fdd22bb7aa52 119 /* read real input sample from source buffer */
emilmont 1:fdd22bb7aa52 120 real3 = pSrc[4];
emilmont 1:fdd22bb7aa52 121
emilmont 1:fdd22bb7aa52 122 /* calculate power of imaginary value */
emilmont 1:fdd22bb7aa52 123 mul4 = imag2 * imag2;
emilmont 1:fdd22bb7aa52 124
emilmont 1:fdd22bb7aa52 125 /* read imaginary input sample from source buffer */
emilmont 1:fdd22bb7aa52 126 imag3 = pSrc[5];
emilmont 1:fdd22bb7aa52 127
emilmont 1:fdd22bb7aa52 128 /* calculate power of real value */
emilmont 1:fdd22bb7aa52 129 mul5 = real3 * real3;
emilmont 1:fdd22bb7aa52 130 /* calculate power of imaginary value */
emilmont 1:fdd22bb7aa52 131 mul6 = imag3 * imag3;
emilmont 1:fdd22bb7aa52 132
emilmont 1:fdd22bb7aa52 133 /* read real input sample from source buffer */
emilmont 1:fdd22bb7aa52 134 real4 = pSrc[6];
emilmont 1:fdd22bb7aa52 135
emilmont 1:fdd22bb7aa52 136 /* accumulate real and imaginary powers */
emilmont 1:fdd22bb7aa52 137 out1 = mul1 + mul2;
emilmont 1:fdd22bb7aa52 138
emilmont 1:fdd22bb7aa52 139 /* read imaginary input sample from source buffer */
emilmont 1:fdd22bb7aa52 140 imag4 = pSrc[7];
emilmont 1:fdd22bb7aa52 141
emilmont 1:fdd22bb7aa52 142 /* accumulate real and imaginary powers */
emilmont 1:fdd22bb7aa52 143 out2 = mul3 + mul4;
emilmont 1:fdd22bb7aa52 144
emilmont 1:fdd22bb7aa52 145 /* calculate power of real value */
emilmont 1:fdd22bb7aa52 146 mul7 = real4 * real4;
emilmont 1:fdd22bb7aa52 147 /* calculate power of imaginary value */
emilmont 1:fdd22bb7aa52 148 mul8 = imag4 * imag4;
emilmont 1:fdd22bb7aa52 149
emilmont 1:fdd22bb7aa52 150 /* store output to destination */
emilmont 1:fdd22bb7aa52 151 pDst[0] = out1;
emilmont 1:fdd22bb7aa52 152
emilmont 1:fdd22bb7aa52 153 /* accumulate real and imaginary powers */
emilmont 1:fdd22bb7aa52 154 out3 = mul5 + mul6;
emilmont 1:fdd22bb7aa52 155
emilmont 1:fdd22bb7aa52 156 /* store output to destination */
emilmont 1:fdd22bb7aa52 157 pDst[1] = out2;
emilmont 1:fdd22bb7aa52 158
emilmont 1:fdd22bb7aa52 159 /* accumulate real and imaginary powers */
emilmont 1:fdd22bb7aa52 160 out4 = mul7 + mul8;
emilmont 1:fdd22bb7aa52 161
emilmont 1:fdd22bb7aa52 162 /* store output to destination */
emilmont 1:fdd22bb7aa52 163 pDst[2] = out3;
emilmont 1:fdd22bb7aa52 164
emilmont 1:fdd22bb7aa52 165 /* increment destination pointer by 8 to process next samples */
emilmont 1:fdd22bb7aa52 166 pSrc += 8u;
emilmont 1:fdd22bb7aa52 167
emilmont 1:fdd22bb7aa52 168 /* store output to destination */
emilmont 1:fdd22bb7aa52 169 pDst[3] = out4;
emilmont 1:fdd22bb7aa52 170
emilmont 1:fdd22bb7aa52 171 /* increment destination pointer by 4 to process next samples */
emilmont 1:fdd22bb7aa52 172 pDst += 4u;
emilmont 1:fdd22bb7aa52 173
emilmont 1:fdd22bb7aa52 174 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 175 blkCnt--;
emilmont 1:fdd22bb7aa52 176 }
emilmont 1:fdd22bb7aa52 177
emilmont 1:fdd22bb7aa52 178 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 179 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 180 blkCnt = numSamples % 0x4u;
emilmont 1:fdd22bb7aa52 181
emilmont 1:fdd22bb7aa52 182 #else
emilmont 1:fdd22bb7aa52 183
emilmont 1:fdd22bb7aa52 184 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 185
emilmont 1:fdd22bb7aa52 186 blkCnt = numSamples;
emilmont 1:fdd22bb7aa52 187
emilmont 1:fdd22bb7aa52 188 #endif /* #ifndef ARM_MATH_CM0 */
emilmont 1:fdd22bb7aa52 189
emilmont 1:fdd22bb7aa52 190 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 191 {
emilmont 1:fdd22bb7aa52 192 /* C[0] = (A[0] * A[0] + A[1] * A[1]) */
emilmont 1:fdd22bb7aa52 193 real = *pSrc++;
emilmont 1:fdd22bb7aa52 194 imag = *pSrc++;
emilmont 1:fdd22bb7aa52 195
emilmont 1:fdd22bb7aa52 196 /* out = (real * real) + (imag * imag) */
emilmont 1:fdd22bb7aa52 197 /* store the result in the destination buffer. */
emilmont 1:fdd22bb7aa52 198 *pDst++ = (real * real) + (imag * imag);
emilmont 1:fdd22bb7aa52 199
emilmont 1:fdd22bb7aa52 200 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 201 blkCnt--;
emilmont 1:fdd22bb7aa52 202 }
emilmont 1:fdd22bb7aa52 203 }
emilmont 1:fdd22bb7aa52 204
emilmont 1:fdd22bb7aa52 205 /**
emilmont 1:fdd22bb7aa52 206 * @} end of cmplx_mag_squared group
emilmont 1:fdd22bb7aa52 207 */