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_negate_q31.c 00009 * 00010 * Description: Negates Q31 vectors. 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 00057 void arm_negate_q31( 00058 q31_t * pSrc, 00059 q31_t * pDst, 00060 uint32_t blockSize) 00061 { 00062 q31_t in; /* Temporary variable */ 00063 uint32_t blkCnt; /* loop counter */ 00064 00065 #ifndef ARM_MATH_CM0 00066 00067 /* Run the below code for Cortex-M4 and Cortex-M3 */ 00068 00069 /*loop Unrolling */ 00070 blkCnt = blockSize >> 2u; 00071 00072 /* First part of the processing with loop unrolling. Compute 4 outputs at a time. 00073 ** a second loop below computes the remaining 1 to 3 samples. */ 00074 while(blkCnt > 0u) 00075 { 00076 /* C = -A */ 00077 /* Negate and then store the results in the destination buffer. */ 00078 in = *pSrc++; 00079 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00080 in = *pSrc++; 00081 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00082 in = *pSrc++; 00083 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00084 in = *pSrc++; 00085 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00086 00087 /* Decrement the loop counter */ 00088 blkCnt--; 00089 } 00090 00091 /* If the blockSize is not a multiple of 4, compute any remaining output samples here. 00092 ** No loop unrolling is used. */ 00093 blkCnt = blockSize % 0x4u; 00094 00095 #else 00096 00097 /* Run the below code for Cortex-M0 */ 00098 00099 /* Initialize blkCnt with number of samples */ 00100 blkCnt = blockSize; 00101 00102 #endif /* #ifndef ARM_MATH_CM0 */ 00103 00104 00105 while(blkCnt > 0u) 00106 { 00107 /* C = -A */ 00108 /* Negate and then store the result in the destination buffer. */ 00109 in = *pSrc++; 00110 *pDst++ = (in == 0x80000000) ? 0x7fffffff : -in; 00111 00112 /* Decrement the loop counter */ 00113 blkCnt--; 00114 } 00115 } 00116