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_abs_q31.c 00009 * 00010 * Description: Q31 vector absolute value. 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 0.0.7 2010/06/10 00030 * Misra-C changes done 00031 * -------------------------------------------------------------------- */ 00032 00033 #include "arm_math.h" 00034 00058 void arm_abs_q31( 00059 q31_t * pSrc, 00060 q31_t * pDst, 00061 uint32_t blockSize) 00062 { 00063 uint32_t blkCnt; /* loop counter */ 00064 q31_t in; /* Input value */ 00065 00066 #ifndef ARM_MATH_CM0 00067 00068 /* Run the below code for Cortex-M4 and Cortex-M3 */ 00069 00070 /*loop Unrolling */ 00071 blkCnt = blockSize >> 2u; 00072 00073 /* First part of the processing with loop unrolling. Compute 4 outputs at a time. 00074 ** a second loop below computes the remaining 1 to 3 samples. */ 00075 while(blkCnt > 0u) 00076 { 00077 /* C = |A| */ 00078 /* Calculate absolute of input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */ 00079 in = *pSrc++; 00080 *pDst++ = (in > 0) ? in : ((in == 0x80000000) ? 0x7fffffff : -in); 00081 in = *pSrc++; 00082 *pDst++ = (in > 0) ? in : ((in == 0x80000000) ? 0x7fffffff : -in); 00083 in = *pSrc++; 00084 *pDst++ = (in > 0) ? in : ((in == 0x80000000) ? 0x7fffffff : -in); 00085 in = *pSrc++; 00086 *pDst++ = (in > 0) ? in : ((in == 0x80000000) ? 0x7fffffff : -in); 00087 00088 /* Decrement the 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 while(blkCnt > 0u) 00106 { 00107 /* C = |A| */ 00108 /* Calculate absolute value of the input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */ 00109 in = *pSrc++; 00110 *pDst++ = (in > 0) ? in : ((in == 0x80000000) ? 0x7fffffff : -in); 00111 00112 /* Decrement the loop counter */ 00113 blkCnt--; 00114 } 00115 00116 } 00117