34 lines
939 B
C
34 lines
939 B
C
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/* ===-- ffsdi2.c - Implement __ffsdi2 -------------------------------------===
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*
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* The LLVM Compiler Infrastructure
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*
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* This file is dual licensed under the MIT and the University of Illinois Open
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* Source Licenses. See LICENSE.TXT for details.
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*
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* ===----------------------------------------------------------------------===
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*
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* This file implements __ffsdi2 for the compiler_rt library.
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*
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* ===----------------------------------------------------------------------===
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*/
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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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COMPILER_RT_ABI si_int
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__ffsdi2(di_int a)
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{
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dwords 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_ctz(x.s.high) + (1 + sizeof(si_int) * CHAR_BIT);
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}
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return __builtin_ctz(x.s.low) + 1;
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}
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