arm_mat_scale_q15.c
150 lines
| 4.7 KiB
| text/x-c
|
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_scale_q15.c | ||||
* | ||||
* Description: Multiplies a Q15 matrix by a scalar. | ||||
* | ||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 | ||||
* | ||||
* 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. | ||||
* | ||||
* Version 0.0.5 2010/04/26 | ||||
* incorporated review comments and updated with latest CMSIS layer | ||||
* | ||||
* Version 0.0.3 2010/03/10 | ||||
* Initial version | ||||
* -------------------------------------------------------------------- */ | ||||
#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 */ | ||||
#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; | ||||
#ifndef ARM_MATH_CM0 | ||||
/* 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. */ | ||||
*pOut++ = | ||||
(q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16)); | ||||
*pOut++ = | ||||
(q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16)); | ||||
*pOut++ = | ||||
(q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16)); | ||||
*pOut++ = | ||||
(q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16)); | ||||
/* 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 /* #ifndef ARM_MATH_CM0 */ | ||||
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 | ||||
*/ | ||||