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CMSIS DSP library

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cmsis_dsp/ComplexMathFunctions/arm_cmplx_conj_q31.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_conj_q31.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 1:fdd22bb7aa52 10 * Description: Q31 complex conjugate.
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 * @addtogroup cmplx_conj
emilmont 1:fdd22bb7aa52 40 * @{
emilmont 1:fdd22bb7aa52 41 */
emilmont 1:fdd22bb7aa52 42
emilmont 1:fdd22bb7aa52 43 /**
emilmont 1:fdd22bb7aa52 44 * @brief Q31 complex conjugate.
emilmont 1:fdd22bb7aa52 45 * @param *pSrc points to the input vector
emilmont 1:fdd22bb7aa52 46 * @param *pDst points to the output vector
emilmont 1:fdd22bb7aa52 47 * @param numSamples number of complex samples in each vector
emilmont 1:fdd22bb7aa52 48 * @return none.
emilmont 1:fdd22bb7aa52 49 *
emilmont 1:fdd22bb7aa52 50 * <b>Scaling and Overflow Behavior:</b>
emilmont 1:fdd22bb7aa52 51 * \par
emilmont 1:fdd22bb7aa52 52 * The function uses saturating arithmetic.
emilmont 1:fdd22bb7aa52 53 * The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.
emilmont 1:fdd22bb7aa52 54 */
emilmont 1:fdd22bb7aa52 55
emilmont 1:fdd22bb7aa52 56 void arm_cmplx_conj_q31(
emilmont 1:fdd22bb7aa52 57 q31_t * pSrc,
emilmont 1:fdd22bb7aa52 58 q31_t * pDst,
emilmont 1:fdd22bb7aa52 59 uint32_t numSamples)
emilmont 1:fdd22bb7aa52 60 {
emilmont 1:fdd22bb7aa52 61 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 62 q31_t in; /* Input value */
emilmont 1:fdd22bb7aa52 63
emilmont 1:fdd22bb7aa52 64 #ifndef ARM_MATH_CM0
emilmont 1:fdd22bb7aa52 65
emilmont 1:fdd22bb7aa52 66 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 67 q31_t inR1, inR2, inR3, inR4; /* Temporary real variables */
emilmont 1:fdd22bb7aa52 68 q31_t inI1, inI2, inI3, inI4; /* Temporary imaginary variables */
emilmont 1:fdd22bb7aa52 69
emilmont 1:fdd22bb7aa52 70 /*loop Unrolling */
emilmont 1:fdd22bb7aa52 71 blkCnt = numSamples >> 2u;
emilmont 1:fdd22bb7aa52 72
emilmont 1:fdd22bb7aa52 73 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 74 ** a second loop below computes the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 75 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 76 {
emilmont 1:fdd22bb7aa52 77 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
emilmont 1:fdd22bb7aa52 78 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
emilmont 1:fdd22bb7aa52 79 /* Saturated to 0x7fffffff if the input is -1(0x80000000) */
emilmont 1:fdd22bb7aa52 80 /* read real input sample */
emilmont 1:fdd22bb7aa52 81 inR1 = pSrc[0];
emilmont 1:fdd22bb7aa52 82 /* store real input sample */
emilmont 1:fdd22bb7aa52 83 pDst[0] = inR1;
emilmont 1:fdd22bb7aa52 84
emilmont 1:fdd22bb7aa52 85 /* read imaginary input sample */
emilmont 1:fdd22bb7aa52 86 inI1 = pSrc[1];
emilmont 1:fdd22bb7aa52 87
emilmont 1:fdd22bb7aa52 88 /* read real input sample */
emilmont 1:fdd22bb7aa52 89 inR2 = pSrc[2];
emilmont 1:fdd22bb7aa52 90 /* store real input sample */
emilmont 1:fdd22bb7aa52 91 pDst[2] = inR2;
emilmont 1:fdd22bb7aa52 92
emilmont 1:fdd22bb7aa52 93 /* read imaginary input sample */
emilmont 1:fdd22bb7aa52 94 inI2 = pSrc[3];
emilmont 1:fdd22bb7aa52 95
emilmont 1:fdd22bb7aa52 96 /* negate imaginary input sample */
emilmont 1:fdd22bb7aa52 97 inI1 = __QSUB(0, inI1);
emilmont 1:fdd22bb7aa52 98
emilmont 1:fdd22bb7aa52 99 /* read real input sample */
emilmont 1:fdd22bb7aa52 100 inR3 = pSrc[4];
emilmont 1:fdd22bb7aa52 101 /* store real input sample */
emilmont 1:fdd22bb7aa52 102 pDst[4] = inR3;
emilmont 1:fdd22bb7aa52 103
emilmont 1:fdd22bb7aa52 104 /* read imaginary input sample */
emilmont 1:fdd22bb7aa52 105 inI3 = pSrc[5];
emilmont 1:fdd22bb7aa52 106
emilmont 1:fdd22bb7aa52 107 /* negate imaginary input sample */
emilmont 1:fdd22bb7aa52 108 inI2 = __QSUB(0, inI2);
emilmont 1:fdd22bb7aa52 109
emilmont 1:fdd22bb7aa52 110 /* read real input sample */
emilmont 1:fdd22bb7aa52 111 inR4 = pSrc[6];
emilmont 1:fdd22bb7aa52 112 /* store real input sample */
emilmont 1:fdd22bb7aa52 113 pDst[6] = inR4;
emilmont 1:fdd22bb7aa52 114
emilmont 1:fdd22bb7aa52 115 /* negate imaginary input sample */
emilmont 1:fdd22bb7aa52 116 inI3 = __QSUB(0, inI3);
emilmont 1:fdd22bb7aa52 117
emilmont 1:fdd22bb7aa52 118 /* store imaginary input sample */
emilmont 1:fdd22bb7aa52 119 inI4 = pSrc[7];
emilmont 1:fdd22bb7aa52 120
emilmont 1:fdd22bb7aa52 121 /* store imaginary input samples */
emilmont 1:fdd22bb7aa52 122 pDst[1] = inI1;
emilmont 1:fdd22bb7aa52 123
emilmont 1:fdd22bb7aa52 124 /* negate imaginary input sample */
emilmont 1:fdd22bb7aa52 125 inI4 = __QSUB(0, inI4);
emilmont 1:fdd22bb7aa52 126
emilmont 1:fdd22bb7aa52 127 /* store imaginary input samples */
emilmont 1:fdd22bb7aa52 128 pDst[3] = inI2;
emilmont 1:fdd22bb7aa52 129
emilmont 1:fdd22bb7aa52 130 /* increment source pointer by 8 to proecess next samples */
emilmont 1:fdd22bb7aa52 131 pSrc += 8u;
emilmont 1:fdd22bb7aa52 132
emilmont 1:fdd22bb7aa52 133 /* store imaginary input samples */
emilmont 1:fdd22bb7aa52 134 pDst[5] = inI3;
emilmont 1:fdd22bb7aa52 135 pDst[7] = inI4;
emilmont 1:fdd22bb7aa52 136
emilmont 1:fdd22bb7aa52 137 /* increment destination pointer by 8 to process next samples */
emilmont 1:fdd22bb7aa52 138 pDst += 8u;
emilmont 1:fdd22bb7aa52 139
emilmont 1:fdd22bb7aa52 140 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 141 blkCnt--;
emilmont 1:fdd22bb7aa52 142 }
emilmont 1:fdd22bb7aa52 143
emilmont 1:fdd22bb7aa52 144 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 145 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 146 blkCnt = numSamples % 0x4u;
emilmont 1:fdd22bb7aa52 147
emilmont 1:fdd22bb7aa52 148 #else
emilmont 1:fdd22bb7aa52 149
emilmont 1:fdd22bb7aa52 150 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 151 blkCnt = numSamples;
emilmont 1:fdd22bb7aa52 152
emilmont 1:fdd22bb7aa52 153
emilmont 1:fdd22bb7aa52 154 #endif /* #ifndef ARM_MATH_CM0 */
emilmont 1:fdd22bb7aa52 155
emilmont 1:fdd22bb7aa52 156 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 157 {
emilmont 1:fdd22bb7aa52 158 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
emilmont 1:fdd22bb7aa52 159 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
emilmont 1:fdd22bb7aa52 160 /* Saturated to 0x7fffffff if the input is -1(0x80000000) */
emilmont 1:fdd22bb7aa52 161 *pDst++ = *pSrc++;
emilmont 1:fdd22bb7aa52 162 in = *pSrc++;
emilmont 1:fdd22bb7aa52 163 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in;
emilmont 1:fdd22bb7aa52 164
emilmont 1:fdd22bb7aa52 165 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 166 blkCnt--;
emilmont 1:fdd22bb7aa52 167 }
emilmont 1:fdd22bb7aa52 168 }
emilmont 1:fdd22bb7aa52 169
emilmont 1:fdd22bb7aa52 170 /**
emilmont 1:fdd22bb7aa52 171 * @} end of cmplx_conj group
emilmont 1:fdd22bb7aa52 172 */