45 lines
1.2 KiB
C++
45 lines
1.2 KiB
C++
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//===- LEB128.cpp - LEB128 utility functions implementation -----*- C++ -*-===//
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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 some utility functions for encoding SLEB128 and
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// ULEB128 values.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Support/LEB128.h"
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namespace llvm {
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/// Utility function to get the size of the ULEB128-encoded value.
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unsigned getULEB128Size(uint64_t Value) {
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unsigned Size = 0;
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do {
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Value >>= 7;
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Size += sizeof(int8_t);
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} while (Value);
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return Size;
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}
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/// Utility function to get the size of the SLEB128-encoded value.
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unsigned getSLEB128Size(int64_t Value) {
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unsigned Size = 0;
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int Sign = Value >> (8 * sizeof(Value) - 1);
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bool IsMore;
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do {
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unsigned Byte = Value & 0x7f;
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Value >>= 7;
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IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
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Size += sizeof(int8_t);
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} while (IsMore);
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return Size;
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}
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} // namespace llvm
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