| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010 ARM Limited. All rights reserved. |
| * |
| * $Date: 15. July 2011 |
| * $Revision: V1.0.10 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_cmplx_mult_real_q31.c |
| * |
| * Description: Q31 complex by real multiplication |
| * |
| * 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 CmplxByRealMult |
| * @{ |
| */ |
| |
| |
| /** |
| * @brief Q31 complex-by-real multiplication |
| * @param[in] *pSrcCmplx points to the complex input vector |
| * @param[in] *pSrcReal points to the real input vector |
| * @param[out] *pCmplxDst points to the complex output vector |
| * @param[in] numSamples number of samples in each vector |
| * @return none. |
| * |
| * <b>Scaling and Overflow Behavior:</b> |
| * \par |
| * The function uses saturating arithmetic. |
| * Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] will be saturated. |
| */ |
| |
| void arm_cmplx_mult_real_q31( |
| q31_t * pSrcCmplx, |
| q31_t * pSrcReal, |
| q31_t * pCmplxDst, |
| uint32_t numSamples) |
| { |
| q31_t in; /* Temporary variable to store input value */ |
| |
| #ifndef ARM_MATH_CM0 |
| |
| /* Run the below code for Cortex-M4 and Cortex-M3 */ |
| uint32_t blkCnt; /* loop counters */ |
| |
| /* 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[2 * i] = A[2 * i] * B[i]. */ |
| /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */ |
| in = *pSrcReal++; |
| /* store the result in the destination buffer. */ |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| |
| in = *pSrcReal++; |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| |
| in = *pSrcReal++; |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| |
| in = *pSrcReal++; |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| |
| /* Decrement the numSamples 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[2 * i] = A[2 * i] * B[i]. */ |
| /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */ |
| in = *pSrcReal++; |
| /* store the result in the destination buffer. */ |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| |
| /* Decrement the numSamples loop counter */ |
| blkCnt--; |
| } |
| |
| #else |
| |
| /* Run the below code for Cortex-M0 */ |
| |
| while(numSamples > 0u) |
| { |
| /* realOut = realA * realB. */ |
| /* imagReal = imagA * realB. */ |
| in = *pSrcReal++; |
| /* store the result in the destination buffer. */ |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| *pCmplxDst++ = |
| (q31_t) clip_q63_to_q31(((q63_t) * pSrcCmplx++ * in) >> 31); |
| |
| /* Decrement the numSamples loop counter */ |
| numSamples--; |
| } |
| |
| #endif /* #ifndef ARM_MATH_CM0 */ |
| |
| } |
| |
| /** |
| * @} end of CmplxByRealMult group |
| */ |