/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_cmplx_dot_prod_f16.c
* Description: Floating-point complex dot product
*
* $Date: 23 April 2021
* $Revision: V1.9.0
*
* Target Processor: Cortex-M and Cortex-A cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2021 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 "dsp/complex_math_functions_f16.h"
#if defined(ARM_FLOAT16_SUPPORTED)
/**
@ingroup groupCmplxMath
*/
/**
@defgroup cmplx_dot_prod Complex Dot Product
Computes the dot product of two complex vectors.
The vectors are multiplied element-by-element and then summed.
The pSrcA points to the first complex input vector and
pSrcB points to the second complex input vector.
numSamples specifies the number of complex samples
and the data in each array is stored in an interleaved fashion
(real, imag, real, imag, ...).
Each array has a total of 2*numSamples values.
The underlying algorithm is used:
realResult = 0;
imagResult = 0;
for (n = 0; n < numSamples; n++) {
realResult += pSrcA[(2*n)+0] * pSrcB[(2*n)+0] - pSrcA[(2*n)+1] * pSrcB[(2*n)+1];
imagResult += pSrcA[(2*n)+0] * pSrcB[(2*n)+1] + pSrcA[(2*n)+1] * pSrcB[(2*n)+0];
}
There are separate functions for floating-point, Q15, and Q31 data types.
*/
/**
@addtogroup cmplx_dot_prod
@{
*/
/**
@brief Floating-point complex dot product.
@param[in] pSrcA points to the first input vector
@param[in] pSrcB points to the second input vector
@param[in] numSamples number of samples in each vector
@param[out] realResult real part of the result returned here
@param[out] imagResult imaginary part of the result returned here
@return none
*/
#if defined(ARM_MATH_MVE_FLOAT16) && !defined(ARM_MATH_AUTOVECTORIZE)
#include "arm_helium_utils.h"
void arm_cmplx_dot_prod_f16(
const float16_t * pSrcA,
const float16_t * pSrcB,
uint32_t numSamples,
float16_t * realResult,
float16_t * imagResult)
{
int32_t blkCnt;
float16_t real_sum, imag_sum;
f16x8_t vecSrcA, vecSrcB;
f16x8_t vec_acc = vdupq_n_f16(0.0f16);
f16x8_t vecSrcC, vecSrcD;
blkCnt = (numSamples >> 3);
blkCnt -= 1;
if (blkCnt > 0) {
/* should give more freedom to generate stall free code */
vecSrcA = vld1q( pSrcA);
vecSrcB = vld1q( pSrcB);
pSrcA += 8;
pSrcB += 8;
while (blkCnt > 0) {
vec_acc = vcmlaq(vec_acc, vecSrcA, vecSrcB);
vecSrcC = vld1q(pSrcA);
pSrcA += 8;
vec_acc = vcmlaq_rot90(vec_acc, vecSrcA, vecSrcB);
vecSrcD = vld1q(pSrcB);
pSrcB += 8;
vec_acc = vcmlaq(vec_acc, vecSrcC, vecSrcD);
vecSrcA = vld1q(pSrcA);
pSrcA += 8;
vec_acc = vcmlaq_rot90(vec_acc, vecSrcC, vecSrcD);
vecSrcB = vld1q(pSrcB);
pSrcB += 8;
/*
* Decrement the blockSize loop counter
*/
blkCnt--;
}
/* process last elements out of the loop avoid the armclang breaking the SW pipeline */
vec_acc = vcmlaq(vec_acc, vecSrcA, vecSrcB);
vecSrcC = vld1q(pSrcA);
vec_acc = vcmlaq_rot90(vec_acc, vecSrcA, vecSrcB);
vecSrcD = vld1q(pSrcB);
vec_acc = vcmlaq(vec_acc, vecSrcC, vecSrcD);
vec_acc = vcmlaq_rot90(vec_acc, vecSrcC, vecSrcD);
/*
* tail
*/
blkCnt = CMPLX_DIM * (numSamples & 7);
while (blkCnt > 0) {
mve_pred16_t p = vctp16q(blkCnt);
pSrcA += 8;
pSrcB += 8;
vecSrcA = vldrhq_z_f16(pSrcA, p);
vecSrcB = vldrhq_z_f16(pSrcB, p);
vec_acc = vcmlaq_m(vec_acc, vecSrcA, vecSrcB, p);
vec_acc = vcmlaq_rot90_m(vec_acc, vecSrcA, vecSrcB, p);
blkCnt -= 8;
}
} else {
/* small vector */
blkCnt = numSamples * CMPLX_DIM;
vec_acc = vdupq_n_f16(0.0f16);
do {
mve_pred16_t p = vctp16q(blkCnt);
vecSrcA = vldrhq_z_f16(pSrcA, p);
vecSrcB = vldrhq_z_f16(pSrcB, p);
vec_acc = vcmlaq_m(vec_acc, vecSrcA, vecSrcB, p);
vec_acc = vcmlaq_rot90_m(vec_acc, vecSrcA, vecSrcB, p);
/*
* Decrement the blkCnt loop counter
* Advance vector source and destination pointers
*/
pSrcA += 8;
pSrcB += 8;
blkCnt -= 8;
}
while (blkCnt > 0);
}
/* Sum the partial parts */
mve_cmplx_sum_intra_r_i_f16(vec_acc, real_sum, imag_sum);
/*
* Store the real and imaginary results in the destination buffers
*/
*realResult = real_sum;
*imagResult = imag_sum;
}
#else
void arm_cmplx_dot_prod_f16(
const float16_t * pSrcA,
const float16_t * pSrcB,
uint32_t numSamples,
float16_t * realResult,
float16_t * imagResult)
{
uint32_t blkCnt; /* Loop counter */
_Float16 real_sum = 0.0f, imag_sum = 0.0f; /* Temporary result variables */
_Float16 a0,b0,c0,d0;
#if defined (ARM_MATH_LOOPUNROLL) && !defined(ARM_MATH_AUTOVECTORIZE)
/* Loop unrolling: Compute 4 outputs at a time */
blkCnt = numSamples >> 2U;
while (blkCnt > 0U)
{
a0 = *pSrcA++;
b0 = *pSrcA++;
c0 = *pSrcB++;
d0 = *pSrcB++;
real_sum += a0 * c0;
imag_sum += a0 * d0;
real_sum -= b0 * d0;
imag_sum += b0 * c0;
a0 = *pSrcA++;
b0 = *pSrcA++;
c0 = *pSrcB++;
d0 = *pSrcB++;
real_sum += a0 * c0;
imag_sum += a0 * d0;
real_sum -= b0 * d0;
imag_sum += b0 * c0;
a0 = *pSrcA++;
b0 = *pSrcA++;
c0 = *pSrcB++;
d0 = *pSrcB++;
real_sum += a0 * c0;
imag_sum += a0 * d0;
real_sum -= b0 * d0;
imag_sum += b0 * c0;
a0 = *pSrcA++;
b0 = *pSrcA++;
c0 = *pSrcB++;
d0 = *pSrcB++;
real_sum += a0 * c0;
imag_sum += a0 * d0;
real_sum -= b0 * d0;
imag_sum += b0 * c0;
/* 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)
{
a0 = *pSrcA++;
b0 = *pSrcA++;
c0 = *pSrcB++;
d0 = *pSrcB++;
real_sum += a0 * c0;
imag_sum += a0 * d0;
real_sum -= b0 * d0;
imag_sum += b0 * c0;
/* Decrement loop counter */
blkCnt--;
}
/* Store real and imaginary result in destination buffer. */
*realResult = real_sum;
*imagResult = imag_sum;
}
#endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */
/**
@} end of cmplx_dot_prod group
*/
#endif /* #if defined(ARM_FLOAT16_SUPPORTED) */