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/* ===-- lshrti3.c - Implement __lshrti3 -----------------------------------=== |
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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 __lshrti3 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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#ifdef CRT_HAS_128BIT |
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/* Returns: logical a >> b */ |
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/* Precondition: 0 <= b < bits_in_tword */ |
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COMPILER_RT_ABI ti_int |
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__lshrti3(ti_int a, si_int b) |
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{ |
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const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); |
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utwords input; |
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utwords result; |
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input.all = a; |
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if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ |
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{ |
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result.s.high = 0; |
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result.s.low = input.s.high >> (b - bits_in_dword); |
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} |
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else /* 0 <= b < bits_in_dword */ |
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{ |
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if (b == 0) |
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return a; |
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result.s.high = input.s.high >> b; |
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result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b); |
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} |
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return result.all; |
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} |
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#endif /* CRT_HAS_128BIT */ |