| /* ---------------------------------------------------------------------- |
| * Project: CMSIS DSP Library |
| * Title: arm_cmplx_conj_q15.c |
| * Description: Q15 complex conjugate |
| * |
| * $Date: 18. March 2019 |
| * $Revision: V1.6.0 |
| * |
| * Target Processor: Cortex-M cores |
| * -------------------------------------------------------------------- */ |
| /* |
| * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the License); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an AS IS BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "arm_math.h" |
| |
| /** |
| @ingroup groupCmplxMath |
| */ |
| |
| /** |
| @addtogroup cmplx_conj |
| @{ |
| */ |
| |
| /** |
| @brief Q15 complex conjugate. |
| @param[in] pSrc points to the input vector |
| @param[out] pDst points to the output vector |
| @param[in] numSamples number of samples in each vector |
| @return none |
| |
| @par Scaling and Overflow Behavior |
| The function uses saturating arithmetic. |
| The Q15 value -1 (0x8000) is saturated to the maximum allowable positive value 0x7FFF. |
| */ |
| |
| void arm_cmplx_conj_q15( |
| const q15_t * pSrc, |
| q15_t * pDst, |
| uint32_t numSamples) |
| { |
| uint32_t blkCnt; /* Loop counter */ |
| q31_t in1; /* Temporary input variable */ |
| |
| #if defined (ARM_MATH_LOOPUNROLL) && defined (ARM_MATH_DSP) |
| q31_t in2, in3, in4; /* Temporary input variables */ |
| #endif |
| |
| |
| #if defined (ARM_MATH_LOOPUNROLL) |
| |
| /* Loop unrolling: Compute 4 outputs at a time */ |
| blkCnt = numSamples >> 2U; |
| |
| while (blkCnt > 0U) |
| { |
| /* C[0] + jC[1] = A[0]+ j(-1)A[1] */ |
| |
| /* Calculate Complex Conjugate and store result in destination buffer. */ |
| |
| #if defined (ARM_MATH_DSP) |
| in1 = read_q15x2_ia ((q15_t **) &pSrc); |
| in2 = read_q15x2_ia ((q15_t **) &pSrc); |
| in3 = read_q15x2_ia ((q15_t **) &pSrc); |
| in4 = read_q15x2_ia ((q15_t **) &pSrc); |
| |
| #ifndef ARM_MATH_BIG_ENDIAN |
| in1 = __QASX(0, in1); |
| in2 = __QASX(0, in2); |
| in3 = __QASX(0, in3); |
| in4 = __QASX(0, in4); |
| #else |
| in1 = __QSAX(0, in1); |
| in2 = __QSAX(0, in2); |
| in3 = __QSAX(0, in3); |
| in4 = __QSAX(0, in4); |
| #endif /* #ifndef ARM_MATH_BIG_ENDIAN */ |
| |
| in1 = ((uint32_t) in1 >> 16) | ((uint32_t) in1 << 16); |
| in2 = ((uint32_t) in2 >> 16) | ((uint32_t) in2 << 16); |
| in3 = ((uint32_t) in3 >> 16) | ((uint32_t) in3 << 16); |
| in4 = ((uint32_t) in4 >> 16) | ((uint32_t) in4 << 16); |
| |
| write_q15x2_ia (&pDst, in1); |
| write_q15x2_ia (&pDst, in2); |
| write_q15x2_ia (&pDst, in3); |
| write_q15x2_ia (&pDst, in4); |
| #else |
| *pDst++ = *pSrc++; |
| in1 = *pSrc++; |
| *pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1; |
| |
| *pDst++ = *pSrc++; |
| in1 = *pSrc++; |
| *pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1; |
| |
| *pDst++ = *pSrc++; |
| in1 = *pSrc++; |
| *pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1; |
| |
| *pDst++ = *pSrc++; |
| in1 = *pSrc++; |
| *pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1; |
| |
| #endif /* #if defined (ARM_MATH_DSP) */ |
| |
| /* Decrement loop counter */ |
| blkCnt--; |
| } |
| |
| /* Loop unrolling: Compute remaining outputs */ |
| blkCnt = numSamples % 0x4U; |
| |
| #else |
| |
| /* Initialize blkCnt with number of samples */ |
| blkCnt = numSamples; |
| |
| #endif /* #if defined (ARM_MATH_LOOPUNROLL) */ |
| |
| while (blkCnt > 0U) |
| { |
| /* C[0] + jC[1] = A[0]+ j(-1)A[1] */ |
| |
| /* Calculate Complex Conjugate and store result in destination buffer. */ |
| *pDst++ = *pSrc++; |
| in1 = *pSrc++; |
| #if defined (ARM_MATH_DSP) |
| *pDst++ = __SSAT(-in1, 16); |
| #else |
| *pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1; |
| #endif |
| |
| /* Decrement loop counter */ |
| blkCnt--; |
| } |
| |
| } |
| |
| /** |
| @} end of cmplx_conj group |
| */ |