/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_mat_mult_q31.c
* Description: Q31 matrix multiplication
*
* $Date: 27. January 2017
* $Revision: V.1.5.1
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2017 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 groupMatrix
*/
/**
* @addtogroup MatrixMult
* @{
*/
/**
* @brief Q31 matrix multiplication
* @param[in] *pSrcA points to the first input matrix structure
* @param[in] *pSrcB points to the second input matrix structure
* @param[out] *pDst points to output matrix structure
* @return The function returns either
* ARM_MATH_SIZE_MISMATCH or ARM_MATH_SUCCESS based on the outcome of size checking.
*
* @details
* Scaling and Overflow Behavior:
*
* \par
* The function is implemented using an internal 64-bit accumulator.
* The accumulator has a 2.62 format and maintains full precision of the intermediate
* multiplication results but provides only a single guard bit. There is no saturation
* on intermediate additions. Thus, if the accumulator overflows it wraps around and
* distorts the result. The input signals should be scaled down to avoid intermediate
* overflows. The input is thus scaled down by log2(numColsA) bits
* to avoid overflows, as a total of numColsA additions are performed internally.
* The 2.62 accumulator is right shifted by 31 bits and saturated to 1.31 format to yield the final result.
*
* \par
* See arm_mat_mult_fast_q31() for a faster but less precise implementation of this function for Cortex-M3 and Cortex-M4.
*
*/
arm_status arm_mat_mult_q31(
const arm_matrix_instance_q31 * pSrcA,
const arm_matrix_instance_q31 * pSrcB,
arm_matrix_instance_q31 * pDst)
{
q31_t *pIn1 = pSrcA->pData; /* input data matrix pointer A */
q31_t *pIn2 = pSrcB->pData; /* input data matrix pointer B */
q31_t *pInA = pSrcA->pData; /* input data matrix pointer A */
q31_t *pOut = pDst->pData; /* output data matrix pointer */
q31_t *px; /* Temporary output data matrix pointer */
q63_t sum; /* Accumulator */
uint16_t numRowsA = pSrcA->numRows; /* number of rows of input matrix A */
uint16_t numColsB = pSrcB->numCols; /* number of columns of input matrix B */
uint16_t numColsA = pSrcA->numCols; /* number of columns of input matrix A */
#if defined (ARM_MATH_DSP)
/* Run the below code for Cortex-M4 and Cortex-M3 */
uint16_t col, i = 0u, j, row = numRowsA, colCnt; /* loop counters */
arm_status status; /* status of matrix multiplication */
q31_t a0, a1, a2, a3, b0, b1, b2, b3;
#ifdef ARM_MATH_MATRIX_CHECK
/* Check for matrix mismatch condition */
if ((pSrcA->numCols != pSrcB->numRows) ||
(pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols))
{
/* Set status as ARM_MATH_SIZE_MISMATCH */
status = ARM_MATH_SIZE_MISMATCH;
}
else
#endif /* #ifdef ARM_MATH_MATRIX_CHECK */
{
/* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
/* row loop */
do
{
/* Output pointer is set to starting address of the row being processed */
px = pOut + i;
/* For every row wise process, the column loop counter is to be initiated */
col = numColsB;
/* For every row wise process, the pIn2 pointer is set
** to the starting address of the pSrcB data */
pIn2 = pSrcB->pData;
j = 0u;
/* column loop */
do
{
/* Set the variable sum, that acts as accumulator, to zero */
sum = 0;
/* Initiate the pointer pIn1 to point to the starting address of pInA */
pIn1 = pInA;
/* Apply loop unrolling and compute 4 MACs simultaneously. */
colCnt = numColsA >> 2;
/* matrix multiplication */
while (colCnt > 0u)
{
/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
/* Perform the multiply-accumulates */
b0 = *pIn2;
pIn2 += numColsB;
a0 = *pIn1++;
a1 = *pIn1++;
b1 = *pIn2;
pIn2 += numColsB;
b2 = *pIn2;
pIn2 += numColsB;
sum += (q63_t) a0 *b0;
sum += (q63_t) a1 *b1;
a2 = *pIn1++;
a3 = *pIn1++;
b3 = *pIn2;
pIn2 += numColsB;
sum += (q63_t) a2 *b2;
sum += (q63_t) a3 *b3;
/* Decrement the loop counter */
colCnt--;
}
/* If the columns of pSrcA is not a multiple of 4, compute any remaining output samples here.
** No loop unrolling is used. */
colCnt = numColsA % 0x4u;
while (colCnt > 0u)
{
/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
/* Perform the multiply-accumulates */
sum += (q63_t) * pIn1++ * *pIn2;
pIn2 += numColsB;
/* Decrement the loop counter */
colCnt--;
}
/* Convert the result from 2.62 to 1.31 format and store in destination buffer */
*px++ = (q31_t) (sum >> 31);
/* Update the pointer pIn2 to point to the starting address of the next column */
j++;
pIn2 = (pSrcB->pData) + j;
/* Decrement the column loop counter */
col--;
} while (col > 0u);
#else
/* Run the below code for Cortex-M0 */
q31_t *pInB = pSrcB->pData; /* input data matrix pointer B */
uint16_t col, i = 0u, row = numRowsA, colCnt; /* loop counters */
arm_status status; /* status of matrix multiplication */
#ifdef ARM_MATH_MATRIX_CHECK
/* Check for matrix mismatch condition */
if ((pSrcA->numCols != pSrcB->numRows) ||
(pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols))
{
/* Set status as ARM_MATH_SIZE_MISMATCH */
status = ARM_MATH_SIZE_MISMATCH;
}
else
#endif /* #ifdef ARM_MATH_MATRIX_CHECK */
{
/* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
/* row loop */
do
{
/* Output pointer is set to starting address of the row being processed */
px = pOut + i;
/* For every row wise process, the column loop counter is to be initiated */
col = numColsB;
/* For every row wise process, the pIn2 pointer is set
** to the starting address of the pSrcB data */
pIn2 = pSrcB->pData;
/* column loop */
do
{
/* Set the variable sum, that acts as accumulator, to zero */
sum = 0;
/* Initiate the pointer pIn1 to point to the starting address of pInA */
pIn1 = pInA;
/* Matrix A columns number of MAC operations are to be performed */
colCnt = numColsA;
/* matrix multiplication */
while (colCnt > 0u)
{
/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
/* Perform the multiply-accumulates */
sum += (q63_t) * pIn1++ * *pIn2;
pIn2 += numColsB;
/* Decrement the loop counter */
colCnt--;
}
/* Convert the result from 2.62 to 1.31 format and store in destination buffer */
*px++ = (q31_t) clip_q63_to_q31(sum >> 31);
/* Decrement the column loop counter */
col--;
/* Update the pointer pIn2 to point to the starting address of the next column */
pIn2 = pInB + (numColsB - col);
} while (col > 0u);
#endif
/* Update the pointer pInA to point to the starting address of the next row */
i = i + numColsB;
pInA = pInA + numColsA;
/* Decrement the row loop counter */
row--;
} while (row > 0u);
/* set status as ARM_MATH_SUCCESS */
status = ARM_MATH_SUCCESS;
}
/* Return to application */
return (status);
}
/**
* @} end of MatrixMult group
*/