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61 lines
1.0 KiB
61 lines
1.0 KiB
/*
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* Copyright (c) Hisilicon Technologies Co., Ltd. 2014-2020. All rights reserved.
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* Description: bits.c
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* Author: SmartMedia_BSP
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* Create: 2014-06-04
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*/
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#include <stddef.h>
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int bits_count(uint32 nn)
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{
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int count = 0;
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while (nn) {
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if (nn & 1) {
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count++;
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}
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nn >>= 1;
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}
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return count;
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}
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int ffs(int nn)
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{
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int pos = 1;
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unsigned int mask = 0xFFFF;
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unsigned int shift = 16; /* 16:number */
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if (!nn) {
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return 0;
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}
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while (shift) {
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if (!((unsigned int)nn & mask)) {
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nn = (unsigned int)nn >> shift;
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pos += shift;
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}
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shift >>= 1;
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mask >>= shift;
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}
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return pos;
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}
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int ffs64(uint64 nn)
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{
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int pos = 1;
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uint32 mask = 0xFFFFFFFF;
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uint32 shift = 32; /* 32:number */
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if (!nn) {
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return 0;
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}
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while (shift) {
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if (!(nn & mask)) {
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nn >>= shift;
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pos += shift;
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}
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shift >>= 1;
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mask >>= shift;
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}
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return pos;
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}
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