149 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			149 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* ----------------------------------------------------------------------
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|  * Project:      CMSIS DSP Library
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|  * Title:        arm_mult_q31.c
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|  * Description:  Q31 vector multiplication
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|  *
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|  * $Date:        27. January 2017
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|  * $Revision:    V.1.5.1
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|  *
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|  * Target Processor: Cortex-M cores
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|  * -------------------------------------------------------------------- */
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| /*
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|  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
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|  *
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|  * SPDX-License-Identifier: Apache-2.0
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|  *
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|  * Licensed under the Apache License, Version 2.0 (the License); you may
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|  * not use this file except in compliance with the License.
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|  * You may obtain a copy of the License at
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|  *
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|  * www.apache.org/licenses/LICENSE-2.0
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|  *
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|  * Unless required by applicable law or agreed to in writing, software
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|  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
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|  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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|  * See the License for the specific language governing permissions and
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|  * limitations under the License.
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|  */
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| 
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| #include "arm_math.h"
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| 
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| /**
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|  * @ingroup groupMath
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|  */
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| 
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| /**
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|  * @addtogroup BasicMult
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|  * @{
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|  */
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| 
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| /**
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|  * @brief Q31 vector multiplication.
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|  * @param[in]       *pSrcA points to the first input vector
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|  * @param[in]       *pSrcB points to the second input vector
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|  * @param[out]      *pDst points to the output vector
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|  * @param[in]       blockSize number of samples in each vector
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|  * @return none.
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|  *
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|  * <b>Scaling and Overflow Behavior:</b>
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|  * \par
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|  * The function uses saturating arithmetic.
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|  * Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] will be saturated.
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|  */
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| 
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| void arm_mult_q31(
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|   q31_t * pSrcA,
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|   q31_t * pSrcB,
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|   q31_t * pDst,
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|   uint32_t blockSize)
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| {
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|   uint32_t blkCnt;                               /* loop counters */
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| 
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| #if defined (ARM_MATH_DSP)
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| 
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| /* Run the below code for Cortex-M4 and Cortex-M3 */
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|   q31_t inA1, inA2, inA3, inA4;                  /* temporary input variables */
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|   q31_t inB1, inB2, inB3, inB4;                  /* temporary input variables */
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|   q31_t out1, out2, out3, out4;                  /* temporary output variables */
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| 
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|   /* loop Unrolling */
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|   blkCnt = blockSize >> 2U;
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| 
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|   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
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|    ** a second loop below computes the remaining 1 to 3 samples. */
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|   while (blkCnt > 0U)
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|   {
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|     /* C = A * B */
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|     /* Multiply the inputs and then store the results in the destination buffer. */
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|     inA1 = *pSrcA++;
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|     inA2 = *pSrcA++;
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|     inA3 = *pSrcA++;
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|     inA4 = *pSrcA++;
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|     inB1 = *pSrcB++;
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|     inB2 = *pSrcB++;
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|     inB3 = *pSrcB++;
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|     inB4 = *pSrcB++;
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| 
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|     out1 = ((q63_t) inA1 * inB1) >> 32;
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|     out2 = ((q63_t) inA2 * inB2) >> 32;
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|     out3 = ((q63_t) inA3 * inB3) >> 32;
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|     out4 = ((q63_t) inA4 * inB4) >> 32;
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| 
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|     out1 = __SSAT(out1, 31);
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|     out2 = __SSAT(out2, 31);
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|     out3 = __SSAT(out3, 31);
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|     out4 = __SSAT(out4, 31);
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| 
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|     *pDst++ = out1 << 1U;
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|     *pDst++ = out2 << 1U;
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|     *pDst++ = out3 << 1U;
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|     *pDst++ = out4 << 1U;
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| 
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|     /* Decrement the blockSize loop counter */
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|     blkCnt--;
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|   }
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| 
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|   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
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|    ** No loop unrolling is used. */
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|   blkCnt = blockSize % 0x4U;
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| 
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|   while (blkCnt > 0U)
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|   {
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|     /* C = A * B */
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|     /* Multiply the inputs and then store the results in the destination buffer. */
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|     inA1 = *pSrcA++;
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|     inB1 = *pSrcB++;
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|     out1 = ((q63_t) inA1 * inB1) >> 32;
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|     out1 = __SSAT(out1, 31);
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|     *pDst++ = out1 << 1U;
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| 
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|     /* Decrement the blockSize loop counter */
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|     blkCnt--;
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|   }
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| 
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| #else
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| 
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|   /* Run the below code for Cortex-M0 */
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| 
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|   /* Initialize blkCnt with number of samples */
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|   blkCnt = blockSize;
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| 
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| 
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|   while (blkCnt > 0U)
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|   {
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|     /* C = A * B */
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|     /* Multiply the inputs and then store the results in the destination buffer. */
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|     *pDst++ =
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|       (q31_t) clip_q63_to_q31(((q63_t) (*pSrcA++) * (*pSrcB++)) >> 31);
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| 
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|     /* Decrement the blockSize loop counter */
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|     blkCnt--;
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|   }
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| 
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| #endif /* #if defined (ARM_MATH_DSP) */
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| }
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| 
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| /**
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|  * @} end of BasicMult group
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|  */
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