00001 /* ---------------------------------------------------------------------- 00002 * Copyright (C) 2010 ARM Limited. All rights reserved. 00003 * 00004 * $Date: 15. July 2011 00005 * $Revision: V1.0.10 00006 * 00007 * Project: CMSIS DSP Library 00008 * Title: arm_mult_q15.c 00009 * 00010 * Description: Q15 vector multiplication. 00011 * 00012 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 00013 * 00014 * Version 1.0.10 2011/7/15 00015 * Big Endian support added and Merged M0 and M3/M4 Source code. 00016 * 00017 * Version 1.0.3 2010/11/29 00018 * Re-organized the CMSIS folders and updated documentation. 00019 * 00020 * Version 1.0.2 2010/11/11 00021 * Documentation updated. 00022 * 00023 * Version 1.0.1 2010/10/05 00024 * Production release and review comments incorporated. 00025 * 00026 * Version 1.0.0 2010/09/20 00027 * Production release and review comments incorporated. 00028 * 00029 * Version 0.0.5 2010/04/26 00030 * incorporated review comments and updated with latest CMSIS layer 00031 * 00032 * Version 0.0.3 2010/03/10 00033 * Initial version 00034 * -------------------------------------------------------------------- */ 00035 00036 #include "arm_math.h" 00037 00062 void arm_mult_q15( 00063 q15_t * pSrcA, 00064 q15_t * pSrcB, 00065 q15_t * pDst, 00066 uint32_t blockSize) 00067 { 00068 uint32_t blkCnt; /* loop counters */ 00069 00070 #ifndef ARM_MATH_CM0 00071 00072 /* Run the below code for Cortex-M4 and Cortex-M3 */ 00073 00074 /* loop Unrolling */ 00075 blkCnt = blockSize >> 2u; 00076 00077 /* First part of the processing with loop unrolling. Compute 4 outputs at a time. 00078 ** a second loop below computes the remaining 1 to 3 samples. */ 00079 while(blkCnt > 0u) 00080 { 00081 /* C = A * B */ 00082 /* Multiply the inputs and store the result in the destination buffer */ 00083 *pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16); 00084 *pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16); 00085 *pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16); 00086 *pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16); 00087 00088 /* Decrement the blockSize loop counter */ 00089 blkCnt--; 00090 } 00091 00092 /* If the blockSize is not a multiple of 4, compute any remaining output samples here. 00093 ** No loop unrolling is used. */ 00094 blkCnt = blockSize % 0x4u; 00095 00096 #else 00097 00098 /* Run the below code for Cortex-M0 */ 00099 00100 /* Initialize blkCnt with number of samples */ 00101 blkCnt = blockSize; 00102 00103 #endif /* #ifndef ARM_MATH_CM0 */ 00104 00105 00106 while(blkCnt > 0u) 00107 { 00108 /* C = A * B */ 00109 /* Multiply the inputs and store the result in the destination buffer */ 00110 *pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16); 00111 00112 /* Decrement the blockSize loop counter */ 00113 blkCnt--; 00114 } 00115 } 00116