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/* ===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------=== |
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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 __ctzdi2 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 number of trailing 0-bits */ |
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/* Precondition: a != 0 */ |
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COMPILER_RT_ABI si_int |
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__ctzdi2(di_int a) |
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{ |
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dwords x; |
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x.all = a; |
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const si_int f = -(x.s.low == 0); |
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return __builtin_ctz((x.s.high & f) | (x.s.low & ~f)) + |
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(f & ((si_int)(sizeof(si_int) * CHAR_BIT))); |
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} |