| /* ---------------------------------------------------------------------- |
| * 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 |
| */ |