forked from OSchip/llvm-project
42 lines
1.2 KiB
C
42 lines
1.2 KiB
C
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//===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------===//
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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 __ashrdi3 for the compiler_rt library.
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//
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//===----------------------------------------------------------------------===//
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#include "int_lib.h"
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// Returns: arithmetic a >> b
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// Precondition: 0 <= b < bits_in_dword
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di_int
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__ashrdi3(di_int a, si_int b)
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{
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const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
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dwords input;
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dwords result;
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input.all = a;
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if (b & bits_in_word) // bits_in_word <= b < bits_in_dword
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{
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// result.high = input.high < 0 ? -1 : 0
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result.high = input.high >> (bits_in_word - 1);
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result.low = input.high >> (b - bits_in_word);
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}
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else // 0 <= b < bits_in_word
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{
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if (b == 0)
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return a;
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result.high = input.high >> b;
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result.low = (input.high << (bits_in_word - b)) | (input.low >> b);
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}
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return result.all;
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}
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