| /* ---------------------------------------------------------------------- |
| * Project: CMSIS DSP Library |
| * Title: arm_mat_sub_q15.c |
| * Description: Q15 Matrix subtraction |
| * |
| * $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 MatrixSub |
| * @{ |
| */ |
| |
| /** |
| * @brief Q15 matrix subtraction. |
| * @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. |
| * |
| * <b>Scaling and Overflow Behavior:</b> |
| * \par |
| * The function uses saturating arithmetic. |
| * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated. |
| */ |
| |
| arm_status arm_mat_sub_q15( |
| const arm_matrix_instance_q15 * pSrcA, |
| const arm_matrix_instance_q15 * pSrcB, |
| arm_matrix_instance_q15 * pDst) |
| { |
| q15_t *pInA = pSrcA->pData; /* input data matrix pointer A */ |
| q15_t *pInB = pSrcB->pData; /* input data matrix pointer B */ |
| q15_t *pOut = pDst->pData; /* output data matrix pointer */ |
| uint32_t numSamples; /* total number of elements in the matrix */ |
| uint32_t blkCnt; /* loop counters */ |
| arm_status status; /* status of matrix subtraction */ |
| |
| |
| #ifdef ARM_MATH_MATRIX_CHECK |
| |
| |
| /* Check for matrix mismatch condition */ |
| if ((pSrcA->numRows != pSrcB->numRows) || |
| (pSrcA->numCols != pSrcB->numCols) || |
| (pSrcA->numRows != pDst->numRows) || (pSrcA->numCols != pDst->numCols)) |
| { |
| /* Set status as ARM_MATH_SIZE_MISMATCH */ |
| status = ARM_MATH_SIZE_MISMATCH; |
| } |
| else |
| #endif /* #ifdef ARM_MATH_MATRIX_CHECK */ |
| |
| { |
| /* Total number of samples in the input matrix */ |
| numSamples = (uint32_t) pSrcA->numRows * pSrcA->numCols; |
| |
| #if defined (ARM_MATH_DSP) |
| |
| /* Run the below code for Cortex-M4 and Cortex-M3 */ |
| |
| /* Apply loop unrolling */ |
| blkCnt = numSamples >> 2U; |
| |
| /* 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 (blkCnt > 0U) |
| { |
| /* C(m,n) = A(m,n) - B(m,n) */ |
| /* Subtract, Saturate and then store the results in the destination buffer. */ |
| *__SIMD32(pOut)++ = __QSUB16(*__SIMD32(pInA)++, *__SIMD32(pInB)++); |
| *__SIMD32(pOut)++ = __QSUB16(*__SIMD32(pInA)++, *__SIMD32(pInB)++); |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| /* If the blockSize is not a multiple of 4, compute any remaining output samples here. |
| ** No loop unrolling is used. */ |
| blkCnt = numSamples % 0x4U; |
| |
| while (blkCnt > 0U) |
| { |
| /* C(m,n) = A(m,n) - B(m,n) */ |
| /* Subtract and then store the results in the destination buffer. */ |
| *pOut++ = (q15_t) __QSUB16(*pInA++, *pInB++); |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| #else |
| |
| /* Run the below code for Cortex-M0 */ |
| |
| /* Initialize blkCnt with number of samples */ |
| blkCnt = numSamples; |
| |
| while (blkCnt > 0U) |
| { |
| /* C(m,n) = A(m,n) - B(m,n) */ |
| /* Subtract and then store the results in the destination buffer. */ |
| *pOut++ = (q15_t) __SSAT(((q31_t) * pInA++ - *pInB++), 16); |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| #endif /* #if defined (ARM_MATH_DSP) */ |
| |
| /* Set status as ARM_MATH_SUCCESS */ |
| status = ARM_MATH_SUCCESS; |
| } |
| |
| /* Return to application */ |
| return (status); |
| } |
| |
| /** |
| * @} end of MatrixSub group |
| */ |