/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_cmplx_mult_real_q15.c * Description: Q15 complex by real multiplication * * $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 CmplxByRealMult @{ */ /** @brief Q15 complex-by-real multiplication. @param[in] pSrcCmplx points to complex input vector @param[in] pSrcReal points to real input vector @param[out] pCmplxDst points to complex output vector @param[in] numSamples number of samples in each vector @return none @par Scaling and Overflow Behavior The function uses saturating arithmetic. Results outside of the allowable Q15 range [0x8000 0x7FFF] are saturated. */ void arm_cmplx_mult_real_q15( const q15_t * pSrcCmplx, const q15_t * pSrcReal, q15_t * pCmplxDst, uint32_t numSamples) { uint32_t blkCnt; /* Loop counter */ q15_t in; /* Temporary variable */ #if defined (ARM_MATH_LOOPUNROLL) #if defined (ARM_MATH_DSP) q31_t inA1, inA2; /* Temporary variables to hold input data */ q31_t inB1; /* Temporary variables to hold input data */ q15_t out1, out2, out3, out4; /* Temporary variables to hold output data */ q31_t mul1, mul2, mul3, mul4; /* Temporary variables to hold intermediate data */ #endif /* Loop unrolling: Compute 4 outputs at a time */ blkCnt = numSamples >> 2U; while (blkCnt > 0U) { /* C[2 * i ] = A[2 * i ] * B[i]. */ /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */ #if defined (ARM_MATH_DSP) /* read 2 complex numbers both real and imaginary from complex input buffer */ inA1 = read_q15x2_ia ((q15_t **) &pSrcCmplx); inA2 = read_q15x2_ia ((q15_t **) &pSrcCmplx); /* read 2 real values at a time from real input buffer */ inB1 = read_q15x2_ia ((q15_t **) &pSrcReal); /* multiply complex number with real numbers */ #ifndef ARM_MATH_BIG_ENDIAN mul1 = (q31_t) ((q15_t) (inA1) * (q15_t) (inB1)); mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1)); mul3 = (q31_t) ((q15_t) (inA2) * (q15_t) (inB1 >> 16)); mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB1 >> 16)); #else mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16)); mul1 = (q31_t) ((q15_t) inA1 * (q15_t) (inB1 >> 16)); mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) inB1); mul3 = (q31_t) ((q15_t) inA2 * (q15_t) inB1); #endif /* #ifndef ARM_MATH_BIG_ENDIAN */ /* saturate the result */ out1 = (q15_t) __SSAT(mul1 >> 15U, 16); out2 = (q15_t) __SSAT(mul2 >> 15U, 16); out3 = (q15_t) __SSAT(mul3 >> 15U, 16); out4 = (q15_t) __SSAT(mul4 >> 15U, 16); /* pack real and imaginary outputs and store them to destination */ write_q15x2_ia (&pCmplxDst, __PKHBT(out1, out2, 16)); write_q15x2_ia (&pCmplxDst, __PKHBT(out3, out4, 16)); inA1 = read_q15x2_ia ((q15_t **) &pSrcCmplx); inA2 = read_q15x2_ia ((q15_t **) &pSrcCmplx); inB1 = read_q15x2_ia ((q15_t **) &pSrcReal); #ifndef ARM_MATH_BIG_ENDIAN mul1 = (q31_t) ((q15_t) (inA1) * (q15_t) (inB1)); mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1)); mul3 = (q31_t) ((q15_t) (inA2) * (q15_t) (inB1 >> 16)); mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB1 >> 16)); #else mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16)); mul1 = (q31_t) ((q15_t) inA1 * (q15_t) (inB1 >> 16)); mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) inB1); mul3 = (q31_t) ((q15_t) inA2 * (q15_t) inB1); #endif /* #ifndef ARM_MATH_BIG_ENDIAN */ out1 = (q15_t) __SSAT(mul1 >> 15U, 16); out2 = (q15_t) __SSAT(mul2 >> 15U, 16); out3 = (q15_t) __SSAT(mul3 >> 15U, 16); out4 = (q15_t) __SSAT(mul4 >> 15U, 16); write_q15x2_ia (&pCmplxDst, __PKHBT(out1, out2, 16)); write_q15x2_ia (&pCmplxDst, __PKHBT(out3, out4, 16)); #else in = *pSrcReal++; *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); in = *pSrcReal++; *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); in = *pSrcReal++; *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); in = *pSrcReal++; *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); #endif /* 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[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++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16); /* Decrement loop counter */ blkCnt--; } } /** @} end of CmplxByRealMult group */