CMSIS DSP library
Dependents: KL25Z_FFT_Demo Hat_Board_v5_1 KL25Z_FFT_Demo_tony KL25Z_FFT_Demo_tony ... more
Fork of mbed-dsp by
Diff: cmsis_dsp/ComplexMathFunctions/arm_cmplx_conj_q31.c
- Revision:
- 1:fdd22bb7aa52
- Child:
- 2:da51fb522205
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis_dsp/ComplexMathFunctions/arm_cmplx_conj_q31.c Wed Nov 28 12:30:09 2012 +0000 @@ -0,0 +1,172 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 15. February 2012 +* $Revision: V1.1.0 +* +* Project: CMSIS DSP Library +* Title: arm_cmplx_conj_q31.c +* +* Description: Q31 complex conjugate. +* +* 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_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) +{ + uint32_t blkCnt; /* loop counter */ + q31_t in; /* Input value */ + +#ifndef ARM_MATH_CM0 + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + q31_t inR1, inR2, inR3, inR4; /* Temporary real variables */ + q31_t inI1, inI2, inI3, inI4; /* Temporary imaginary variables */ + + /*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) */ + /* read real input sample */ + inR1 = pSrc[0]; + /* store real input sample */ + pDst[0] = inR1; + + /* read imaginary input sample */ + inI1 = pSrc[1]; + + /* read real input sample */ + inR2 = pSrc[2]; + /* store real input sample */ + pDst[2] = inR2; + + /* read imaginary input sample */ + inI2 = pSrc[3]; + + /* negate imaginary input sample */ + inI1 = __QSUB(0, inI1); + + /* read real input sample */ + inR3 = pSrc[4]; + /* store real input sample */ + pDst[4] = inR3; + + /* read imaginary input sample */ + inI3 = pSrc[5]; + + /* negate imaginary input sample */ + inI2 = __QSUB(0, inI2); + + /* read real input sample */ + inR4 = pSrc[6]; + /* store real input sample */ + pDst[6] = inR4; + + /* negate imaginary input sample */ + inI3 = __QSUB(0, inI3); + + /* store imaginary input sample */ + inI4 = pSrc[7]; + + /* store imaginary input samples */ + pDst[1] = inI1; + + /* negate imaginary input sample */ + inI4 = __QSUB(0, inI4); + + /* store imaginary input samples */ + pDst[3] = inI2; + + /* increment source pointer by 8 to proecess next samples */ + pSrc += 8u; + + /* store imaginary input samples */ + pDst[5] = inI3; + pDst[7] = inI4; + + /* increment destination pointer by 8 to process next samples */ + pDst += 8u; + + /* 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; + +#else + + /* Run the below code for Cortex-M0 */ + blkCnt = numSamples; + + +#endif /* #ifndef ARM_MATH_CM0 */ + + 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--; + } +} + +/** + * @} end of cmplx_conj group + */