CMSIS DSP library
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Diff: cmsis_dsp/ComplexMathFunctions/arm_cmplx_mag_squared_q31.c
- Revision:
- 1:fdd22bb7aa52
- Child:
- 2:da51fb522205
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis_dsp/ComplexMathFunctions/arm_cmplx_mag_squared_q31.c Wed Nov 28 12:30:09 2012 +0000 @@ -0,0 +1,153 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 15. February 2012 +* $Revision: V1.1.0 +* +* Project: CMSIS DSP Library +* Title: arm_cmplx_mag_squared_q31.c +* +* Description: Q31 complex magnitude squared. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Version 1.1.0 2012/02/15 +* Updated with more optimizations, bug fixes and minor API changes. +* +* 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_mag_squared + * @{ + */ + + +/** + * @brief Q31 complex magnitude squared + * @param *pSrc points to the complex input vector + * @param *pDst points to the real output vector + * @param numSamples number of complex samples in the input vector + * @return none. + * + * <b>Scaling and Overflow Behavior:</b> + * \par + * The function implements 1.31 by 1.31 multiplications and finally output is converted into 3.29 format. + * Input down scaling is not required. + */ + +void arm_cmplx_mag_squared_q31( + q31_t * pSrc, + q31_t * pDst, + uint32_t numSamples) +{ + q31_t real, imag; /* Temporary variables to store real and imaginary values */ + q31_t acc0, acc1; /* Accumulators */ + +#ifndef ARM_MATH_CM0 + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + uint32_t blkCnt; /* loop counter */ + + /* 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] = (A[0] * A[0] + A[1] * A[1]) */ + real = *pSrc++; + imag = *pSrc++; + acc0 = (q31_t) (((q63_t) real * real) >> 33); + acc1 = (q31_t) (((q63_t) imag * imag) >> 33); + /* store the result in 3.29 format in the destination buffer. */ + *pDst++ = acc0 + acc1; + + real = *pSrc++; + imag = *pSrc++; + acc0 = (q31_t) (((q63_t) real * real) >> 33); + acc1 = (q31_t) (((q63_t) imag * imag) >> 33); + /* store the result in 3.29 format in the destination buffer. */ + *pDst++ = acc0 + acc1; + + real = *pSrc++; + imag = *pSrc++; + acc0 = (q31_t) (((q63_t) real * real) >> 33); + acc1 = (q31_t) (((q63_t) imag * imag) >> 33); + /* store the result in 3.29 format in the destination buffer. */ + *pDst++ = acc0 + acc1; + + real = *pSrc++; + imag = *pSrc++; + acc0 = (q31_t) (((q63_t) real * real) >> 33); + acc1 = (q31_t) (((q63_t) imag * imag) >> 33); + /* store the result in 3.29 format in the destination buffer. */ + *pDst++ = acc0 + acc1; + + /* 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] = (A[0] * A[0] + A[1] * A[1]) */ + real = *pSrc++; + imag = *pSrc++; + acc0 = (q31_t) (((q63_t) real * real) >> 33); + acc1 = (q31_t) (((q63_t) imag * imag) >> 33); + /* store the result in 3.29 format in the destination buffer. */ + *pDst++ = acc0 + acc1; + + /* Decrement the loop counter */ + blkCnt--; + } + +#else + + /* Run the below code for Cortex-M0 */ + + while(numSamples > 0u) + { + /* out = ((real * real) + (imag * imag)) */ + real = *pSrc++; + imag = *pSrc++; + acc0 = (q31_t) (((q63_t) real * real) >> 33); + acc1 = (q31_t) (((q63_t) imag * imag) >> 33); + /* store the result in 3.29 format in the destination buffer. */ + *pDst++ = acc0 + acc1; + + /* Decrement the loop counter */ + numSamples--; + } + +#endif /* #ifndef ARM_MATH_CM0 */ + +} + +/** + * @} end of cmplx_mag_squared group + */