steering-wheel/Drivers/CMSIS/DSP/Source/ComplexMathFunctions/arm_cmplx_mag_f32.c

189 lines
4.6 KiB
C

/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_cmplx_mag_f32.c
* Description: Floating-point complex magnitude
*
* $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
*/
/**
@defgroup cmplx_mag Complex Magnitude
Computes the magnitude of the elements of a complex data vector.
The <code>pSrc</code> points to the source data and
<code>pDst</code> points to the where the result should be written.
<code>numSamples</code> specifies the number of complex samples
in the input array and the data is stored in an interleaved fashion
(real, imag, real, imag, ...).
The input array has a total of <code>2*numSamples</code> values;
the output array has a total of <code>numSamples</code> values.
The underlying algorithm is used:
<pre>
for (n = 0; n < numSamples; n++) {
pDst[n] = sqrt(pSrc[(2*n)+0]^2 + pSrc[(2*n)+1]^2);
}
</pre>
There are separate functions for floating-point, Q15, and Q31 data types.
*/
/**
@addtogroup cmplx_mag
@{
*/
/**
@brief Floating-point complex magnitude.
@param[in] pSrc points to input vector
@param[out] pDst points to output vector
@param[in] numSamples number of samples in each vector
@return none
*/
void arm_cmplx_mag_f32(
const float32_t * pSrc,
float32_t * pDst,
uint32_t numSamples)
{
uint32_t blkCnt; /* loop counter */
float32_t real, imag; /* Temporary variables to hold input values */
#if defined(ARM_MATH_NEON)
float32x4x2_t vecA;
float32x4_t vRealA;
float32x4_t vImagA;
float32x4_t vMagSqA;
float32x4x2_t vecB;
float32x4_t vRealB;
float32x4_t vImagB;
float32x4_t vMagSqB;
/* Loop unrolling: Compute 8 outputs at a time */
blkCnt = numSamples >> 3;
while (blkCnt > 0U)
{
/* out = sqrt((real * real) + (imag * imag)) */
vecA = vld2q_f32(pSrc);
pSrc += 8;
vecB = vld2q_f32(pSrc);
pSrc += 8;
vRealA = vmulq_f32(vecA.val[0], vecA.val[0]);
vImagA = vmulq_f32(vecA.val[1], vecA.val[1]);
vMagSqA = vaddq_f32(vRealA, vImagA);
vRealB = vmulq_f32(vecB.val[0], vecB.val[0]);
vImagB = vmulq_f32(vecB.val[1], vecB.val[1]);
vMagSqB = vaddq_f32(vRealB, vImagB);
/* Store the result in the destination buffer. */
vst1q_f32(pDst, __arm_vec_sqrt_f32_neon(vMagSqA));
pDst += 4;
vst1q_f32(pDst, __arm_vec_sqrt_f32_neon(vMagSqB));
pDst += 4;
/* Decrement the loop counter */
blkCnt--;
}
blkCnt = numSamples & 7;
#else
#if defined (ARM_MATH_LOOPUNROLL)
/* Loop unrolling: Compute 4 outputs at a time */
blkCnt = numSamples >> 2U;
while (blkCnt > 0U)
{
/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
real = *pSrc++;
imag = *pSrc++;
/* store result in destination buffer. */
arm_sqrt_f32((real * real) + (imag * imag), pDst++);
real = *pSrc++;
imag = *pSrc++;
arm_sqrt_f32((real * real) + (imag * imag), pDst++);
real = *pSrc++;
imag = *pSrc++;
arm_sqrt_f32((real * real) + (imag * imag), pDst++);
real = *pSrc++;
imag = *pSrc++;
arm_sqrt_f32((real * real) + (imag * imag), pDst++);
/* 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) */
#endif /* #if defined(ARM_MATH_NEON) */
while (blkCnt > 0U)
{
/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
real = *pSrc++;
imag = *pSrc++;
/* store result in destination buffer. */
arm_sqrt_f32((real * real) + (imag * imag), pDst++);
/* Decrement loop counter */
blkCnt--;
}
}
/**
@} end of cmplx_mag group
*/