arm_abs_q31.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_abs_q31.c 00009 * 00010 * Description: Q31 vector absolute value. 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 00049 void arm_abs_q31( 00050 q31_t * pSrc, 00051 q31_t * pDst, 00052 uint32_t blockSize) 00053 { 00054 uint32_t blkCnt; /* loop counter */ 00055 q31_t in1, in2, in3, in4; /* Input value */ 00056 q31_t out1, out2, out3, out4; /* Output value */ 00057 00058 /*loop Unrolling */ 00059 blkCnt = blockSize >> 3u; 00060 00061 /* First part of the processing with loop unrolling. Compute 8 outputs at a time. 00062 ** a second loop below computes the remaining 1 to 7 samples. */ 00063 while(blkCnt > 0u) 00064 { 00065 /* C = |A| */ 00066 /* Calculate absolute of input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */ 00067 /* Read inputs */ 00068 in1 = *pSrc; 00069 in2 = *(pSrc + 1); 00070 in3 = *(pSrc + 2); 00071 00072 /* find absolute value */ 00073 out1 = (in1 > 0) ? in1 : __QSUB(0, in1); 00074 00075 /* read input */ 00076 in4 = *(pSrc + 3); 00077 00078 /* find absolute value */ 00079 out2 = (in2 > 0) ? in2 : __QSUB(0, in2); 00080 00081 /* store result to destination */ 00082 *pDst = out1; 00083 00084 /* find absolute value */ 00085 out3 = (in3 > 0) ? in3 : __QSUB(0, in3); 00086 00087 /* read input */ 00088 in1 = *(pSrc + 4); 00089 00090 /* find absolute value */ 00091 out4 = (in4 > 0) ? in4 : __QSUB(0, in4); 00092 00093 /* store result to destination */ 00094 *(pDst + 1) = out2; 00095 00096 /* read input */ 00097 in2 = *(pSrc + 5); 00098 00099 /* find absolute value */ 00100 out1 = (in1 > 0) ? in1 : __QSUB(0, in1); 00101 00102 /* store result to destination */ 00103 *(pDst + 2) = out3; 00104 00105 /* find absolute value */ 00106 out2 = (in2 > 0) ? in2 : __QSUB(0, in2); 00107 00108 /* read input */ 00109 in3 = *(pSrc + 6); 00110 00111 /* store result to destination */ 00112 *(pDst + 3) = out4; 00113 00114 /* read input */ 00115 in4 = *(pSrc + 7); 00116 00117 /* find absolute value */ 00118 out3 = (in3 > 0) ? in3 : __QSUB(0, in3); 00119 00120 /* store result to destination */ 00121 *(pDst + 4) = out1; 00122 00123 /* find absolute value */ 00124 out4 = (in4 > 0) ? in4 : __QSUB(0, in4); 00125 00126 /* store result to destination */ 00127 *(pDst + 5) = out2; 00128 *(pDst + 6) = out3; 00129 00130 /* increment source pointer by 8 */ 00131 pSrc += 8u; 00132 00133 /* store result to destination */ 00134 *(pDst + 7) = out4; 00135 00136 /* increment destination pointer by 8 */ 00137 pDst += 8u; 00138 00139 /* Decrement the loop counter */ 00140 blkCnt--; 00141 } 00142 00143 /* If the blockSize is not a multiple of 8, compute any remaining output samples here. 00144 ** No loop unrolling is used. */ 00145 blkCnt = blockSize % 0x8u; 00146 00147 while(blkCnt > 0u) 00148 { 00149 /* C = |A| */ 00150 /* Calculate absolute value of the input (if -1 then saturated to 0x7fffffff) and then store the results in the destination buffer. */ 00151 in1 = *pSrc++; 00152 *pDst++ = (in1 > 0) ? in1 : __QSUB(0, in1); 00153 00154 /* Decrement the loop counter */ 00155 blkCnt--; 00156 } 00157 } 00158
