The CMSIS DSP 5 library
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functions/MatrixFunctions/arm_mat_scale_q15.c
- Committer:
- xorjoep
- Date:
- 2018-06-21
- Revision:
- 3:4098b9d3d571
- Parent:
- 1:24714b45cd1b
File content as of revision 3:4098b9d3d571:
/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_mat_scale_q15.c * Description: Multiplies a Q15 matrix by a scalar * * $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 MatrixScale * @{ */ /** * @brief Q15 matrix scaling. * @param[in] *pSrc points to input matrix * @param[in] scaleFract fractional portion of the scale factor * @param[in] shift number of bits to shift the result by * @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 input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format. * These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format. */ arm_status arm_mat_scale_q15( const arm_matrix_instance_q15 * pSrc, q15_t scaleFract, int32_t shift, arm_matrix_instance_q15 * pDst) { q15_t *pIn = pSrc->pData; /* input data matrix pointer */ q15_t *pOut = pDst->pData; /* output data matrix pointer */ uint32_t numSamples; /* total number of elements in the matrix */ int32_t totShift = 15 - shift; /* total shift to apply after scaling */ uint32_t blkCnt; /* loop counters */ arm_status status; /* status of matrix scaling */ #if defined (ARM_MATH_DSP) q15_t in1, in2, in3, in4; q31_t out1, out2, out3, out4; q31_t inA1, inA2; #endif // #if defined (ARM_MATH_DSP) #ifdef ARM_MATH_MATRIX_CHECK /* Check for matrix mismatch */ if ((pSrc->numRows != pDst->numRows) || (pSrc->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) pSrc->numRows * pSrc->numCols; #if defined (ARM_MATH_DSP) /* Run the below code for Cortex-M4 and Cortex-M3 */ /* Loop Unrolling */ blkCnt = numSamples >> 2; /* 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) * k */ /* Scale, saturate and then store the results in the destination buffer. */ /* Reading 2 inputs from memory */ inA1 = _SIMD32_OFFSET(pIn); inA2 = _SIMD32_OFFSET(pIn + 2); /* C = A * scale */ /* Scale the inputs and then store the 2 results in the destination buffer * in single cycle by packing the outputs */ out1 = (q31_t) ((q15_t) (inA1 >> 16) * scaleFract); out2 = (q31_t) ((q15_t) inA1 * scaleFract); out3 = (q31_t) ((q15_t) (inA2 >> 16) * scaleFract); out4 = (q31_t) ((q15_t) inA2 * scaleFract); out1 = out1 >> totShift; inA1 = _SIMD32_OFFSET(pIn + 4); out2 = out2 >> totShift; inA2 = _SIMD32_OFFSET(pIn + 6); out3 = out3 >> totShift; out4 = out4 >> totShift; in1 = (q15_t) (__SSAT(out1, 16)); in2 = (q15_t) (__SSAT(out2, 16)); in3 = (q15_t) (__SSAT(out3, 16)); in4 = (q15_t) (__SSAT(out4, 16)); _SIMD32_OFFSET(pOut) = __PKHBT(in2, in1, 16); _SIMD32_OFFSET(pOut + 2) = __PKHBT(in4, in3, 16); /* update pointers to process next sampels */ pIn += 4U; pOut += 4U; /* Decrement the numSamples loop counter */ blkCnt--; } /* If the numSamples is not a multiple of 4, compute any remaining output samples here. ** No loop unrolling is used. */ blkCnt = numSamples % 0x4U; #else /* Run the below code for Cortex-M0 */ /* Initialize blkCnt with number of samples */ blkCnt = numSamples; #endif /* #if defined (ARM_MATH_DSP) */ while (blkCnt > 0U) { /* C(m,n) = A(m,n) * k */ /* Scale, saturate and then store the results in the destination buffer. */ *pOut++ = (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16)); /* Decrement the numSamples loop counter */ blkCnt--; } /* Set status as ARM_MATH_SUCCESS */ status = ARM_MATH_SUCCESS; } /* Return to application */ return (status); } /** * @} end of MatrixScale group */