/* ---------------------------------------------------------------------- * Copyright (C) 2010-2013 ARM Limited. All rights reserved. * * $Date: 17. January 2013 * $Revision: V1.4.1 * * Project: CMSIS DSP Library * Title: arm_mat_mult_fast_q15.c * * Description: Q15 matrix multiplication (fast variant) * * Target Processor: Cortex-M4/Cortex-M3 * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * - Neither the name of ARM LIMITED nor the names of its contributors * may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * -------------------------------------------------------------------- */ #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 * ARM_MATH_SIZE_MISMATCH or ARM_MATH_SUCCESS based on the outcome of size checking. * * @details * Scaling and Overflow Behavior: * * \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 arm_mat_mult_q15() 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 */ 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 *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 */ #ifndef UNALIGNED_SUPPORT_DISABLE q31_t in; /* Temporary variable to hold the input value */ q31_t inA1, inA2, inB1, inB2; #else q15_t in; /* Temporary variable to hold the input value */ q15_t inA1, inA2, inB1, inB2; #endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */ #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 { /* 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) { #ifndef UNALIGNED_SUPPORT_DISABLE /* 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 */ #else /* Read one element from the row */ in = *pInB++; /* Store one element in the destination */ *px = in; /* Update the pointer px to point to the next row of the transposed matrix */ px += numRowsB; /* Read one element from the row */ in = *pInB++; /* Store one element in the destination */ *px = in; /* Update the pointer px to point to the next row of the transposed matrix */ px += numRowsB; /* Read one element from the row */ in = *pInB++; /* Store one element in the destination */ *px = in; /* Update the pointer px to point to the next row of the transposed matrix */ px += numRowsB; /* Read one element from the row */ in = *pInB++; /* Store one element in the destination */ *px = in; #endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */ /* 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 >> 2; /* 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) */ #ifndef UNALIGNED_SUPPORT_DISABLE inA1 = *__SIMD32(pInA)++; inB1 = *__SIMD32(pInB)++; inA2 = *__SIMD32(pInA)++; inB2 = *__SIMD32(pInB)++; sum = __SMLAD(inA1, inB1, sum); sum = __SMLAD(inA2, inB2, sum); #else inA1 = *pInA++; inB1 = *pInB++; inA2 = *pInA++; sum += inA1 * inB1; inB2 = *pInB++; inA1 = *pInA++; inB1 = *pInB++; sum += inA2 * inB2; inA2 = *pInA++; inB2 = *pInB++; sum += inA1 * inB1; sum += inA2 * inB2; #endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */ /* Decrement the loop counter */ colCnt--; } /* process odd column samples */ 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) */ sum += (q31_t) (*pInA++) * (*pInB++); colCnt--; } /* 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 */