| /* ---------------------------------------------------------------------- |
| * 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_q31.c |
| * |
| * Description: Q31 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 Q31 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 |
| * @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_q31() and this fast variant is that |
| * the fast variant use a 32-bit rather than a 64-bit accumulator. |
| * The result of each 1.31 x 1.31 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 1.31 result. |
| * |
| * \par |
| * The fast version has the same overflow behavior as the standard version but provides |
| * less precision since it discards the low 32 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_q31()</code> for a slower implementation of this function |
| * which uses 64-bit accumulation to provide higher precision. |
| */ |
| |
| arm_status arm_mat_mult_fast_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 *pSrcB = pSrcB->pData; /* input data matrix pointer B */ |
| q31_t *pOut = pDst->pData; /* output data matrix pointer */ |
| q31_t *px; /* Temporary output data matrix pointer */ |
| q31_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 */ |
| uint16_t col, i = 0u, j, 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; |
| |
| 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 */ |
| sum = (q31_t) ((((q63_t) sum << 32) + |
| ((q63_t) * pIn1++ * (*pIn2))) >> 32); |
| pIn2 += numColsB; |
| sum = (q31_t) ((((q63_t) sum << 32) + |
| ((q63_t) * pIn1++ * (*pIn2))) >> 32); |
| pIn2 += numColsB; |
| sum = (q31_t) ((((q63_t) sum << 32) + |
| ((q63_t) * pIn1++ * (*pIn2))) >> 32); |
| pIn2 += numColsB; |
| sum = (q31_t) ((((q63_t) sum << 32) + |
| ((q63_t) * pIn1++ * (*pIn2))) >> 32); |
| pIn2 += numColsB; |
| |
| /* 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 = (q31_t) ((((q63_t) sum << 32) + |
| ((q63_t) * pIn1++ * (*pIn2))) >> 32); |
| pIn2 += numColsB; |
| |
| /* Decrement the loop counter */ |
| colCnt--; |
| } |
| |
| /* Convert the result from 2.30 to 1.31 format and store in destination buffer */ |
| *px++ = sum << 1; |
| |
| /* 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); |
| |
| /* 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 |
| */ |
