| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010 ARM Limited. All rights reserved. |
| * |
| * $Date: 15. July 2011 |
| * $Revision: V1.0.10 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_cmplx_conj_q31.c |
| * |
| * Description: Q31 complex conjugate. |
| * |
| * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
| * |
| * Version 1.0.10 2011/7/15 |
| * Big Endian support added and Merged M0 and M3/M4 Source code. |
| * |
| * Version 1.0.3 2010/11/29 |
| * Re-organized the CMSIS folders and updated documentation. |
| * |
| * Version 1.0.2 2010/11/11 |
| * Documentation updated. |
| * |
| * Version 1.0.1 2010/10/05 |
| * Production release and review comments incorporated. |
| * |
| * Version 1.0.0 2010/09/20 |
| * Production release and review comments incorporated. |
| * ---------------------------------------------------------------------------- */ |
| |
| #include "arm_math.h" |
| |
| /** |
| * @ingroup groupCmplxMath |
| */ |
| |
| /** |
| * @addtogroup cmplx_conj |
| * @{ |
| */ |
| |
| /** |
| * @brief Q31 complex conjugate. |
| * @param *pSrc points to the input vector |
| * @param *pDst points to the output vector |
| * @param numSamples number of complex samples in each vector |
| * @return none. |
| * |
| * <b>Scaling and Overflow Behavior:</b> |
| * \par |
| * The function uses saturating arithmetic. |
| * The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF. |
| */ |
| |
| void arm_cmplx_conj_q31( |
| q31_t * pSrc, |
| q31_t * pDst, |
| uint32_t numSamples) |
| { |
| |
| #ifndef ARM_MATH_CM0 |
| |
| /* Run the below code for Cortex-M4 and Cortex-M3 */ |
| uint32_t blkCnt; /* loop counter */ |
| q31_t in; /* Input value */ |
| |
| /*loop Unrolling */ |
| blkCnt = numSamples >> 2u; |
| |
| /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
| ** a second loop below computes the remaining 1 to 3 samples. */ |
| while(blkCnt > 0u) |
| { |
| /* C[0]+jC[1] = A[0]+ j (-1) A[1] */ |
| /* Calculate Complex Conjugate and then store the results in the destination buffer. */ |
| /* Saturated to 0x7fffffff if the input is -1(0x80000000) */ |
| *pDst++ = *pSrc++; |
| in = *pSrc++; |
| *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; |
| *pDst++ = *pSrc++; |
| in = *pSrc++; |
| *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; |
| *pDst++ = *pSrc++; |
| in = *pSrc++; |
| *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; |
| *pDst++ = *pSrc++; |
| in = *pSrc++; |
| *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| /* If the numSamples is not a multiple of 4, compute any remaining output samples here. |
| ** No loop unrolling is used. */ |
| blkCnt = numSamples % 0x4u; |
| |
| while(blkCnt > 0u) |
| { |
| /* C[0]+jC[1] = A[0]+ j (-1) A[1] */ |
| /* Calculate Complex Conjugate and then store the results in the destination buffer. */ |
| /* Saturated to 0x7fffffff if the input is -1(0x80000000) */ |
| *pDst++ = *pSrc++; |
| in = *pSrc++; |
| *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| #else |
| |
| /* Run the below code for Cortex-M0 */ |
| |
| while(numSamples > 0u) |
| { |
| /* realOut + j (imagOut) = realIn+ j (-1) imagIn */ |
| /* Calculate Complex Conjugate and then store the results in the destination buffer. */ |
| *pDst++ = *pSrc++; |
| *pDst++ = -*pSrc++; |
| |
| /* Decrement the loop counter */ |
| numSamples--; |
| } |
| |
| #endif /* #ifndef ARM_MATH_CM0 */ |
| |
| } |
| |
| /** |
| * @} end of cmplx_conj group |
| */ |