CMSIS DSP Library from CMSIS 2.0. See http://www.onarm.com/cmsis/ for full details
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arm_cmplx_conj_q31.c
00001 /* ---------------------------------------------------------------------- 00002 * Copyright (C) 2010 ARM Limited. All rights reserved. 00003 * 00004 * $Date: 29. November 2010 00005 * $Revision: V1.0.3 00006 * 00007 * Project: CMSIS DSP Library 00008 * Title: arm_cmplx_conj_q31.c 00009 * 00010 * Description: Q31 complex conjugate. 00011 * 00012 * Target Processor: Cortex-M4/Cortex-M3 00013 * 00014 * Version 1.0.3 2010/11/29 00015 * Re-organized the CMSIS folders and updated documentation. 00016 * 00017 * Version 1.0.2 2010/11/11 00018 * Documentation updated. 00019 * 00020 * Version 1.0.1 2010/10/05 00021 * Production release and review comments incorporated. 00022 * 00023 * Version 1.0.0 2010/09/20 00024 * Production release and review comments incorporated. 00025 * ---------------------------------------------------------------------------- */ 00026 00027 #include "arm_math.h" 00028 00029 /** 00030 * @ingroup groupCmplxMath 00031 */ 00032 00033 /** 00034 * @addtogroup cmplx_conj 00035 * @{ 00036 */ 00037 00038 /** 00039 * @brief Q31 complex conjugate. 00040 * @param *pSrc points to the input vector 00041 * @param *pDst points to the output vector 00042 * @param numSamples number of complex samples in each vector 00043 * @return none. 00044 * 00045 * <b>Scaling and Overflow Behavior:</b> 00046 * \par 00047 * The function uses saturating arithmetic. 00048 * The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF. 00049 */ 00050 00051 void arm_cmplx_conj_q31( 00052 q31_t * pSrc, 00053 q31_t * pDst, 00054 uint32_t numSamples) 00055 { 00056 uint32_t blkCnt; /* loop counter */ 00057 q31_t in; /* Input value */ 00058 00059 /*loop Unrolling */ 00060 blkCnt = numSamples >> 2u; 00061 00062 /* First part of the processing with loop unrolling. Compute 4 outputs at a time. 00063 ** a second loop below computes the remaining 1 to 3 samples. */ 00064 while(blkCnt > 0u) 00065 { 00066 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */ 00067 /* Calculate Complex Conjugate and then store the results in the destination buffer. */ 00068 /* Saturated to 0x7fffffff if the input is -1(0x80000000)*/ 00069 *pDst++ = *pSrc++; 00070 in = *pSrc++; 00071 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00072 *pDst++ = *pSrc++; 00073 in = *pSrc++; 00074 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00075 *pDst++ = *pSrc++; 00076 in = *pSrc++; 00077 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00078 *pDst++ = *pSrc++; 00079 in = *pSrc++; 00080 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00081 00082 /* Decrement the loop counter */ 00083 blkCnt--; 00084 } 00085 00086 /* If the numSamples is not a multiple of 4, compute any remaining output samples here. 00087 ** No loop unrolling is used. */ 00088 blkCnt = numSamples % 0x4u; 00089 00090 while(blkCnt > 0u) 00091 { 00092 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */ 00093 /* Calculate Complex Conjugate and then store the results in the destination buffer. */ 00094 /* Saturated to 0x7fffffff if the input is -1(0x80000000)*/ 00095 *pDst++ = *pSrc++; 00096 in = *pSrc++; 00097 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00098 00099 /* Decrement the loop counter */ 00100 blkCnt--; 00101 } 00102 } 00103 00104 /** 00105 * @} end of cmplx_conj group 00106 */
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