| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
| * |
| * $Date: 19. March 2015 |
| * $Revision: V.1.4.5 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_cmplx_conj_q31.c |
| * |
| * Description: Q31 complex conjugate. |
| * |
| * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * - Neither the name of ARM LIMITED nor the names of its contributors |
| * may be used to endorse or promote products derived from this |
| * software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| * ---------------------------------------------------------------------------- */ |
| #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_FAMILY |
| |
| /* 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_FAMILY */ |
| |
| 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 == INT32_MIN) ? INT32_MAX : -in; |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| } |
| |
| /** |
| * @} end of cmplx_conj group |
| */ |