arm_fill_q15.c

00001 /* ----------------------------------------------------------------------    
00002 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.    
00003 *    
00004 * $Date:        17. January 2013 
00005 * $Revision:    V1.4.1  
00006 *    
00007 * Project:      CMSIS DSP Library    
00008 * Title:        arm_fill_q15.c    
00009 *    
00010 * Description:  Fills a constant value into a Q15 vector.   
00011 *    
00012 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
00013 *  
00014 * Redistribution and use in source and binary forms, with or without 
00015 * modification, are permitted provided that the following conditions
00016 * are met:
00017 *   - Redistributions of source code must retain the above copyright
00018 *     notice, this list of conditions and the following disclaimer.
00019 *   - Redistributions in binary form must reproduce the above copyright
00020 *     notice, this list of conditions and the following disclaimer in
00021 *     the documentation and/or other materials provided with the 
00022 *     distribution.
00023 *   - Neither the name of ARM LIMITED nor the names of its contributors
00024 *     may be used to endorse or promote products derived from this
00025 *     software without specific prior written permission.
00026 *
00027 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00028 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00029 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00030 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
00031 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00032 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00033 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00034 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00035 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00036 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
00037 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00038 * POSSIBILITY OF SUCH DAMAGE.    
00039 * -------------------------------------------------------------------- */
00040 
00041 #include "arm_math.h"
00042 
00043 /**    
00044  * @ingroup groupSupport    
00045  */
00046 
00047 /**    
00048  * @addtogroup Fill    
00049  * @{    
00050  */
00051 
00052 /**    
00053  * @brief Fills a constant value into a Q15 vector.    
00054  * @param[in]       value input value to be filled   
00055  * @param[out]      *pDst points to output vector    
00056  * @param[in]       blockSize length of the output vector   
00057  * @return none.    
00058  *    
00059  */
00060 
00061 void arm_fill_q15(
00062   q15_t value,
00063   q15_t * pDst,
00064   uint32_t blockSize)
00065 {
00066   uint32_t blkCnt;                               /* loop counter */
00067 
00068 #ifndef ARM_MATH_CM0_FAMILY
00069 
00070   /* Run the below code for Cortex-M4 and Cortex-M3 */
00071 
00072   q31_t packedValue;                             /* value packed to 32 bits */
00073 
00074 
00075   /*loop Unrolling */
00076   blkCnt = blockSize >> 2u;
00077 
00078   /* Packing two 16 bit values to 32 bit value in order to use SIMD */
00079   packedValue = __PKHBT(value, value, 16u);
00080 
00081   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
00082    ** a second loop below computes the remaining 1 to 3 samples. */
00083   while(blkCnt > 0u)
00084   {
00085     /* C = value */
00086     /* Fill the value in the destination buffer */
00087     *__SIMD32(pDst)++ = packedValue;
00088     *__SIMD32(pDst)++ = packedValue;
00089 
00090     /* Decrement the loop counter */
00091     blkCnt--;
00092   }
00093 
00094   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.    
00095    ** No loop unrolling is used. */
00096   blkCnt = blockSize % 0x4u;
00097 
00098 #else
00099 
00100   /* Run the below code for Cortex-M0 */
00101 
00102   /* Loop over blockSize number of values */
00103   blkCnt = blockSize;
00104 
00105 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
00106 
00107   while(blkCnt > 0u)
00108   {
00109     /* C = value */
00110     /* Fill the value in the destination buffer */
00111     *pDst++ = value;
00112 
00113     /* Decrement the loop counter */
00114     blkCnt--;
00115   }
00116 }
00117 
00118 /**    
00119  * @} end of Fill group    
00120  */