arm_negate_f32.c
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00001 /* ---------------------------------------------------------------------- 00002 * Copyright (C) 2011 ARM Limited. All rights reserved. 00003 * 00004 * $Date: 15. December 2011 00005 * $Revision: V2.0.0 00006 * 00007 * Project: Cortex-R DSP Library 00008 * Title: arm_negate_f32.c 00009 * 00010 * Description: Negates floating-point vectors. 00011 * 00012 * Target Processor: Cortex-R4/R5 00013 * 00014 * Version 1.0.0 2011/03/08 00015 * Alpha release. 00016 * 00017 * Version 1.0.1 2011/09/30 00018 * Beta release. 00019 * 00020 * Version 2.0.0 2011/12/15 00021 * Final release. 00022 * 00023 * ---------------------------------------------------------------------------- */ 00024 #include "arm_math.h" 00025 00053 void arm_negate_f32( 00054 float32_t * pSrc, 00055 float32_t * pDst, 00056 uint32_t blockSize) 00057 { 00058 uint32_t blkCnt; /* loop counter */ 00059 float32_t in1, in2, in3, in4; /* temporary variables */ 00060 00061 /*loop Unrolling */ 00062 blkCnt = blockSize >> 3u; 00063 00064 /* First part of the processing with loop unrolling. Compute 4 outputs at a time. 00065 ** a second loop below computes the remaining 1 to 7 samples. */ 00066 while(blkCnt > 0u) 00067 { 00068 /* read inputs from source */ 00069 in1 = *pSrc; 00070 in2 = *(pSrc + 1); 00071 in3 = *(pSrc + 2); 00072 in4 = *(pSrc + 3); 00073 00074 /* negate the input */ 00075 in1 = -in1; 00076 in2 = -in2; 00077 in3 = -in3; 00078 in4 = -in4; 00079 00080 /* store the result to destination */ 00081 *pDst = in1; 00082 *(pDst + 1) = in2; 00083 *(pDst + 2) = in3; 00084 *(pDst + 3) = in4; 00085 00086 /* read inputs from source */ 00087 in1 = *(pSrc + 4); 00088 in2 = *(pSrc + 5); 00089 in3 = *(pSrc + 6); 00090 in4 = *(pSrc + 7); 00091 00092 /* negate the input */ 00093 in1 = -in1; 00094 in2 = -in2; 00095 in3 = -in3; 00096 in4 = -in4; 00097 00098 /* store the result to destination */ 00099 *(pDst + 4) = in1; 00100 *(pDst + 5) = in2; 00101 *(pDst + 6) = in3; 00102 *(pDst + 7) = in4; 00103 00104 /* increment sourec by 8 to process next samples */ 00105 pSrc += 8u; 00106 /* increment destination by 8 to process next samples */ 00107 pDst += 8u; 00108 00109 /* Decrement the loop counter */ 00110 blkCnt--; 00111 } 00112 00113 /* If the blockSize is not a multiple of 8, compute any remaining output samples here. 00114 ** No loop unrolling is used. */ 00115 blkCnt = blockSize % 0x8u; 00116 00117 while(blkCnt > 0u) 00118 { 00119 /* C = -A */ 00120 /* Negate and then store the results in the destination buffer. */ 00121 *pDst++ = -*pSrc++; 00122 00123 /* Decrement the loop counter */ 00124 blkCnt--; 00125 } 00126 } 00127
