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Diffstat (limited to 'platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q31.c')
| -rw-r--r-- | platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q31.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q31.c b/platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q31.c new file mode 100644 index 0000000..ed6b09f --- /dev/null +++ b/platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_scale_q31.c @@ -0,0 +1,239 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 12. March 2014 +* $Revision: V1.4.4 +* +* 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 + */ |