arm_mat_mult_fast_q15.c
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CLexer
r71 | /* ---------------------------------------------------------------------- | |||
* Copyright (C) 2010 ARM Limited. All rights reserved. | ||||
* | ||||
* $Date: 15. July 2011 | ||||
* $Revision: V1.0.10 | ||||
* | ||||
* Project: CMSIS DSP Library | ||||
* Title: arm_mat_mult_fast_q15.c | ||||
* | ||||
* Description: Q15 matrix multiplication (fast variant) | ||||
* | ||||
* Target Processor: Cortex-M4/Cortex-M3 | ||||
* | ||||
* Version 1.0.10 2011/7/15 | ||||
* Big Endian support added and Merged M0 and M3/M4 Source code. | ||||
* | ||||
* Version 1.0.3 2010/11/29 | ||||
* Re-organized the CMSIS folders and updated documentation. | ||||
* | ||||
* Version 1.0.2 2010/11/11 | ||||
* Documentation updated. | ||||
* | ||||
* Version 1.0.1 2010/10/05 | ||||
* Production release and review comments incorporated. | ||||
* | ||||
* Version 1.0.0 2010/09/20 | ||||
* Production release and review comments incorporated. | ||||
* -------------------------------------------------------------------- */ | ||||
#include "arm_math.h" | ||||
/** | ||||
* @ingroup groupMatrix | ||||
*/ | ||||
/** | ||||
* @addtogroup MatrixMult | ||||
* @{ | ||||
*/ | ||||
/** | ||||
* @brief Q15 matrix multiplication (fast variant) for Cortex-M3 and Cortex-M4 | ||||
* @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 | ||||
* @param[in] *pState points to the array for storing intermediate results | ||||
* @return The function returns either | ||||
* <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking. | ||||
* | ||||
* @details | ||||
* <b>Scaling and Overflow Behavior:</b> | ||||
* | ||||
* \par | ||||
* The difference between the function arm_mat_mult_q15() and this fast variant is that | ||||
* the fast variant use a 32-bit rather than a 64-bit accumulator. | ||||
* The result of each 1.15 x 1.15 multiplication is truncated to | ||||
* 2.30 format. These intermediate results are accumulated in a 32-bit register in 2.30 | ||||
* format. Finally, the accumulator is saturated and converted to a 1.15 result. | ||||
* | ||||
* \par | ||||
* The fast version has the same overflow behavior as the standard version but provides | ||||
* less precision since it discards the low 16 bits of each multiplication result. | ||||
* In order to avoid overflows completely the input signals must be scaled down. | ||||
* Scale down one of the input matrices by log2(numColsA) bits to | ||||
* avoid overflows, as a total of numColsA additions are computed internally for each | ||||
* output element. | ||||
* | ||||
* \par | ||||
* See <code>arm_mat_mult_q15()</code> for a slower implementation of this function | ||||
* which uses 64-bit accumulation to provide higher precision. | ||||
*/ | ||||
arm_status arm_mat_mult_fast_q15( | ||||
const arm_matrix_instance_q15 * pSrcA, | ||||
const arm_matrix_instance_q15 * pSrcB, | ||||
arm_matrix_instance_q15 * pDst, | ||||
q15_t * pState) | ||||
{ | ||||
q31_t sum; /* accumulator */ | ||||
q31_t in; /* Temporary variable to hold the input value */ | ||||
q15_t *pSrcBT = pState; /* input data matrix pointer for transpose */ | ||||
q15_t *pInA = pSrcA->pData; /* input data matrix pointer A of Q15 type */ | ||||
q15_t *pInB = pSrcB->pData; /* input data matrix pointer B of Q15 type */ | ||||
// q15_t *pDst = pDst->pData; /* output data matrix pointer */ | ||||
q15_t *px; /* Temporary output data matrix pointer */ | ||||
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 */ | ||||
uint16_t numRowsB = pSrcB->numRows; /* number of rows of input matrix A */ | ||||
uint16_t col, i = 0u, row = numRowsB, 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 */ | ||||
{ | ||||
/* Matrix transpose */ | ||||
do | ||||
{ | ||||
/* Apply loop unrolling and exchange the columns with row elements */ | ||||
col = numColsB >> 2; | ||||
/* The pointer px is set to starting address of the column being processed */ | ||||
px = pSrcBT + i; | ||||
/* First part of the processing with loop unrolling. Compute 4 outputs at a time. | ||||
** a second loop below computes the remaining 1 to 3 samples. */ | ||||
while(col > 0u) | ||||
{ | ||||
/* Read two elements from the row */ | ||||
in = *__SIMD32(pInB)++; | ||||
/* Unpack and store one element in the destination */ | ||||
#ifndef ARM_MATH_BIG_ENDIAN | ||||
*px = (q15_t) in; | ||||
#else | ||||
*px = (q15_t) ((in & (q31_t) 0xffff0000) >> 16); | ||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ | ||||
/* Update the pointer px to point to the next row of the transposed matrix */ | ||||
px += numRowsB; | ||||
/* Unpack and store the second element in the destination */ | ||||
#ifndef ARM_MATH_BIG_ENDIAN | ||||
*px = (q15_t) ((in & (q31_t) 0xffff0000) >> 16); | ||||
#else | ||||
*px = (q15_t) in; | ||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ | ||||
/* Update the pointer px to point to the next row of the transposed matrix */ | ||||
px += numRowsB; | ||||
/* Read two elements from the row */ | ||||
in = *__SIMD32(pInB)++; | ||||
/* Unpack and store one element in the destination */ | ||||
#ifndef ARM_MATH_BIG_ENDIAN | ||||
*px = (q15_t) in; | ||||
#else | ||||
*px = (q15_t) ((in & (q31_t) 0xffff0000) >> 16); | ||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ | ||||
/* Update the pointer px to point to the next row of the transposed matrix */ | ||||
px += numRowsB; | ||||
/* Unpack and store the second element in the destination */ | ||||
#ifndef ARM_MATH_BIG_ENDIAN | ||||
*px = (q15_t) ((in & (q31_t) 0xffff0000) >> 16); | ||||
#else | ||||
*px = (q15_t) in; | ||||
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ | ||||
/* Update the pointer px to point to the next row of the transposed matrix */ | ||||
px += numRowsB; | ||||
/* Decrement the column loop counter */ | ||||
col--; | ||||
} | ||||
/* If the columns of pSrcB is not a multiple of 4, compute any remaining output samples here. | ||||
** No loop unrolling is used. */ | ||||
col = numColsB % 0x4u; | ||||
while(col > 0u) | ||||
{ | ||||
/* Read and store the input element in the destination */ | ||||
*px = *pInB++; | ||||
/* Update the pointer px to point to the next row of the transposed matrix */ | ||||
px += numRowsB; | ||||
/* Decrement the column loop counter */ | ||||
col--; | ||||
} | ||||
i++; | ||||
/* Decrement the row loop counter */ | ||||
row--; | ||||
} while(row > 0u); | ||||
/* Reset the variables for the usage in the following multiplication process */ | ||||
row = numRowsA; | ||||
i = 0u; | ||||
px = pDst->pData; | ||||
/* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */ | ||||
/* row loop */ | ||||
do | ||||
{ | ||||
/* 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 transposed pSrcB data */ | ||||
pInB = pSrcBT; | ||||
/* column loop */ | ||||
do | ||||
{ | ||||
/* Set the variable sum, that acts as accumulator, to zero */ | ||||
sum = 0; | ||||
/* Apply loop unrolling and compute 2 MACs simultaneously. */ | ||||
colCnt = numColsA >> 1; | ||||
/* Initiate the pointer pIn1 to point to the starting address of the column being processed */ | ||||
pInA = pSrcA->pData + i; | ||||
/* 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) */ | ||||
sum = __SMLAD(*__SIMD32(pInA)++, *__SIMD32(pInB)++, sum); | ||||
/* Decrement the loop counter */ | ||||
colCnt--; | ||||
} | ||||
/* process odd column samples */ | ||||
if((numColsA & 0x1u) > 0u) | ||||
{ | ||||
/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */ | ||||
sum += ((q31_t) * pInA * (*pInB++)); | ||||
} | ||||
/* Saturate and store the result in the destination buffer */ | ||||
*px = (q15_t) (sum >> 15); | ||||
px++; | ||||
/* Decrement the column loop counter */ | ||||
col--; | ||||
} while(col > 0u); | ||||
i = i + 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 | ||||
*/ | ||||