81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
/**************************************************************************
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*
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* Copyright 2008 VMware, Inc.
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* All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sub license, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice (including the
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* next paragraph) shall be included in all copies or substantial portions
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* of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
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* IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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**************************************************************************/
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#include "bitscan.h"
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#ifdef HAVE___BUILTIN_FFS
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#elif defined(_MSC_VER) && (_M_IX86 || _M_ARM || _M_AMD64 || _M_IA64)
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#else
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int
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ffs(int i)
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{
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int bit = 0;
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if (!i)
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return bit;
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if (!(i & 0xffff)) {
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bit += 16;
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i >>= 16;
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}
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if (!(i & 0xff)) {
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bit += 8;
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i >>= 8;
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}
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if (!(i & 0xf)) {
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bit += 4;
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i >>= 4;
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}
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if (!(i & 0x3)) {
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bit += 2;
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i >>= 2;
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}
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if (!(i & 0x1))
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bit += 1;
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return bit + 1;
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}
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#endif
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#ifdef HAVE___BUILTIN_FFSLL
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#elif defined(_MSC_VER) && (_M_AMD64 || _M_ARM64 || _M_IA64)
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#else
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int
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ffsll(long long int val)
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{
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int bit;
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bit = ffs((unsigned) (val & 0xffffffff));
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if (bit != 0)
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return bit;
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bit = ffs((unsigned) (val >> 32));
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if (bit != 0)
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return 32 + bit;
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return 0;
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}
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#endif
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