arm_fill_q15.c

00001 /* ----------------------------------------------------------------------
00002  * Project:      CMSIS DSP Library
00003  * Title:        arm_fill_q15.c
00004  * Description:  Fills a constant value into a Q15 vector
00005  *
00006  * $Date:        27. January 2017
00007  * $Revision:    V.1.5.1
00008  *
00009  * Target Processor: Cortex-M cores
00010  * -------------------------------------------------------------------- */
00011 /*
00012  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
00013  *
00014  * SPDX-License-Identifier: Apache-2.0
00015  *
00016  * Licensed under the Apache License, Version 2.0 (the License); you may
00017  * not use this file except in compliance with the License.
00018  * You may obtain a copy of the License at
00019  *
00020  * www.apache.org/licenses/LICENSE-2.0
00021  *
00022  * Unless required by applicable law or agreed to in writing, software
00023  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00024  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00025  * See the License for the specific language governing permissions and
00026  * limitations under the License.
00027  */
00028 
00029 #include "arm_math.h"
00030 
00031 /**
00032  * @ingroup groupSupport
00033  */
00034 
00035 /**
00036  * @addtogroup Fill
00037  * @{
00038  */
00039 
00040 /**
00041  * @brief Fills a constant value into a Q15 vector.
00042  * @param[in]       value input value to be filled
00043  * @param[out]      *pDst points to output vector
00044  * @param[in]       blockSize length of the output vector
00045  * @return none.
00046  *
00047  */
00048 
00049 void arm_fill_q15(
00050   q15_t value,
00051   q15_t * pDst,
00052   uint32_t blockSize)
00053 {
00054   uint32_t blkCnt;                               /* loop counter */
00055 
00056 #if defined (ARM_MATH_DSP)
00057 
00058   /* Run the below code for Cortex-M4 and Cortex-M3 */
00059 
00060   q31_t packedValue;                             /* value packed to 32 bits */
00061 
00062 
00063   /*loop Unrolling */
00064   blkCnt = blockSize >> 2U;
00065 
00066   /* Packing two 16 bit values to 32 bit value in order to use SIMD */
00067   packedValue = __PKHBT(value, value, 16U);
00068 
00069   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
00070    ** a second loop below computes the remaining 1 to 3 samples. */
00071   while (blkCnt > 0U)
00072   {
00073     /* C = value */
00074     /* Fill the value in the destination buffer */
00075     *__SIMD32(pDst)++ = packedValue;
00076     *__SIMD32(pDst)++ = packedValue;
00077 
00078     /* Decrement the loop counter */
00079     blkCnt--;
00080   }
00081 
00082   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
00083    ** No loop unrolling is used. */
00084   blkCnt = blockSize % 0x4U;
00085 
00086 #else
00087 
00088   /* Run the below code for Cortex-M0 */
00089 
00090   /* Loop over blockSize number of values */
00091   blkCnt = blockSize;
00092 
00093 #endif /* #if defined (ARM_MATH_DSP) */
00094 
00095   while (blkCnt > 0U)
00096   {
00097     /* C = value */
00098     /* Fill the value in the destination buffer */
00099     *pDst++ = value;
00100 
00101     /* Decrement the loop counter */
00102     blkCnt--;
00103   }
00104 }
00105 
00106 /**
00107  * @} end of Fill group
00108  */