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_mean_f32.c 00009 * 00010 * Description: Mean value of a floating-point vector. 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 00030 #include "arm_math.h" 00031 00064 void arm_mean_f32( 00065 float32_t * pSrc, 00066 uint32_t blockSize, 00067 float32_t * pResult) 00068 { 00069 float32_t sum = 0.0f; /* Temporary result storage */ 00070 uint32_t blkCnt; /* loop counter */ 00071 00072 #ifndef ARM_MATH_CM0 00073 00074 /* Run the below code for Cortex-M4 and Cortex-M3 */ 00075 00076 /*loop Unrolling */ 00077 blkCnt = blockSize >> 2u; 00078 00079 /* First part of the processing with loop unrolling. Compute 4 outputs at a time. 00080 ** a second loop below computes the remaining 1 to 3 samples. */ 00081 while(blkCnt > 0u) 00082 { 00083 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ 00084 sum += *pSrc++; 00085 sum += *pSrc++; 00086 sum += *pSrc++; 00087 sum += *pSrc++; 00088 00089 /* Decrement the loop counter */ 00090 blkCnt--; 00091 } 00092 00093 /* If the blockSize is not a multiple of 4, compute any remaining output samples here. 00094 ** No loop unrolling is used. */ 00095 blkCnt = blockSize % 0x4u; 00096 00097 #else 00098 00099 /* Run the below code for Cortex-M0 */ 00100 00101 /* Loop over blockSize number of values */ 00102 blkCnt = blockSize; 00103 00104 #endif /* #ifndef ARM_MATH_CM0 */ 00105 00106 while(blkCnt > 0u) 00107 { 00108 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ 00109 sum += *pSrc++; 00110 00111 /* Decrement the loop counter */ 00112 blkCnt--; 00113 } 00114 00115 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */ 00116 /* Store the result to the destination */ 00117 *pResult = sum / (float32_t) blockSize; 00118 } 00119