+++ /dev/null
-/* ----------------------------------------------------------------------
-* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
-*
-* $Date: 17. January 2013
-* $Revision: V1.4.1
-*
-* Project: CMSIS DSP Library
-* Title: arm_scale_q31.c
-*
-* Description: Multiplies a Q31 vector by a scalar.
-*
-* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
-*
-* 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 groupMath
- */
-
-/**
- * @addtogroup scale
- * @{
- */
-
-/**
- * @brief Multiplies a Q31 vector by a scalar.
- * @param[in] *pSrc points to the input vector
- * @param[in] scaleFract fractional portion of the scale value
- * @param[in] shift number of bits to shift the result by
- * @param[out] *pDst points to the output vector
- * @param[in] blockSize number of samples in the vector
- * @return none.
- *
- * <b>Scaling and Overflow Behavior:</b>
- * \par
- * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.31 format.
- * These are multiplied to yield a 2.62 intermediate result and this is shifted with saturation to 1.31 format.
- */
-
-void arm_scale_q31(
- q31_t * pSrc,
- q31_t scaleFract,
- int8_t shift,
- q31_t * pDst,
- uint32_t blockSize)
-{
- int8_t kShift = shift + 1; /* Shift to apply after scaling */
- int8_t sign = (kShift & 0x80);
- uint32_t blkCnt; /* loop counter */
- q31_t in, out;
-
-#ifndef ARM_MATH_CM0_FAMILY
-
-/* Run the below code for Cortex-M4 and Cortex-M3 */
-
- q31_t in1, in2, in3, in4; /* temporary input variables */
- q31_t out1, out2, out3, out4; /* temporary output variabels */
-
-
- /*loop Unrolling */
- blkCnt = blockSize >> 2u;
-
- if(sign == 0u)
- {
- /* 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)
- {
- /* read four inputs from source */
- in1 = *pSrc;
- in2 = *(pSrc + 1);
- in3 = *(pSrc + 2);
- in4 = *(pSrc + 3);
-
- /* multiply input with scaler value */
- in1 = ((q63_t) in1 * scaleFract) >> 32;
- in2 = ((q63_t) in2 * scaleFract) >> 32;
- in3 = ((q63_t) in3 * scaleFract) >> 32;
- in4 = ((q63_t) in4 * scaleFract) >> 32;
-
- /* apply shifting */
- out1 = in1 << kShift;
- out2 = in2 << kShift;
-
- /* saturate the results. */
- if(in1 != (out1 >> kShift))
- out1 = 0x7FFFFFFF ^ (in1 >> 31);
-
- if(in2 != (out2 >> kShift))
- out2 = 0x7FFFFFFF ^ (in2 >> 31);
-
- out3 = in3 << kShift;
- out4 = in4 << kShift;
-
- *pDst = out1;
- *(pDst + 1) = out2;
-
- if(in3 != (out3 >> kShift))
- out3 = 0x7FFFFFFF ^ (in3 >> 31);
-
- if(in4 != (out4 >> kShift))
- out4 = 0x7FFFFFFF ^ (in4 >> 31);
-
- /* Store result destination */
- *(pDst + 2) = out3;
- *(pDst + 3) = out4;
-
- /* Update pointers to process next sampels */
- pSrc += 4u;
- pDst += 4u;
-
- /* Decrement the loop counter */
- blkCnt--;
- }
-
- }
- else
- {
- /* 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)
- {
- /* read four inputs from source */
- in1 = *pSrc;
- in2 = *(pSrc + 1);
- in3 = *(pSrc + 2);
- in4 = *(pSrc + 3);
-
- /* multiply input with scaler value */
- in1 = ((q63_t) in1 * scaleFract) >> 32;
- in2 = ((q63_t) in2 * scaleFract) >> 32;
- in3 = ((q63_t) in3 * scaleFract) >> 32;
- in4 = ((q63_t) in4 * scaleFract) >> 32;
-
- /* apply shifting */
- out1 = in1 >> -kShift;
- out2 = in2 >> -kShift;
-
- out3 = in3 >> -kShift;
- out4 = in4 >> -kShift;
-
- /* Store result destination */
- *pDst = out1;
- *(pDst + 1) = out2;
-
- *(pDst + 2) = out3;
- *(pDst + 3) = out4;
-
- /* Update pointers to process next sampels */
- pSrc += 4u;
- pDst += 4u;
-
- /* 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 = blockSize % 0x4u;
-
-#else
-
- /* Run the below code for Cortex-M0 */
-
- /* Initialize blkCnt with number of samples */
- blkCnt = blockSize;
-
-#endif /* #ifndef ARM_MATH_CM0_FAMILY */
-
- if(sign == 0)
- {
- while(blkCnt > 0u)
- {
- /* C = A * scale */
- /* Scale the input and then store the result in the destination buffer. */
- in = *pSrc++;
- in = ((q63_t) in * scaleFract) >> 32;
-
- out = in << kShift;
-
- if(in != (out >> kShift))
- out = 0x7FFFFFFF ^ (in >> 31);
-
- *pDst++ = out;
-
- /* Decrement the loop counter */
- blkCnt--;
- }
- }
- else
- {
- while(blkCnt > 0u)
- {
- /* C = A * scale */
- /* Scale the input and then store the result in the destination buffer. */
- in = *pSrc++;
- in = ((q63_t) in * scaleFract) >> 32;
-
- out = in >> -kShift;
-
- *pDst++ = out;
-
- /* Decrement the loop counter */
- blkCnt--;
- }
-
- }
-}
-
-/**
- * @} end of scale group
- */
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