38 lines
949 B
C
38 lines
949 B
C
/* ===-- ffsti2.c - Implement __ffsti2 -------------------------------------===
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*
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* The LLVM Compiler Infrastructure
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*
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* This file is distributed under the University of Illinois Open Source
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* License. See LICENSE.TXT for details.
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*
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* ===----------------------------------------------------------------------===
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*
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* This file implements __ffsti2 for the compiler_rt library.
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*
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* ===----------------------------------------------------------------------===
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*/
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#if __x86_64
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#include "int_lib.h"
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/* Returns: the index of the least significant 1-bit in a, or
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* the value zero if a is zero. The least significant bit is index one.
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*/
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si_int
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__ffsti2(ti_int a)
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{
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twords x;
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x.all = a;
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if (x.s.low == 0)
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{
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if (x.s.high == 0)
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return 0;
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return __builtin_ctzll(x.s.high) + (1 + sizeof(di_int) * CHAR_BIT);
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}
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return __builtin_ctzll(x.s.low) + 1;
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}
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#endif /* __x86_64 */
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