forked from OSchip/llvm-project
44 lines
1.2 KiB
C++
44 lines
1.2 KiB
C++
//===- LEB128.cpp - LEB128 utility functions implementation -----*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements some utility functions for encoding SLEB128 and
|
|
// ULEB128 values.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Support/LEB128.h"
|
|
|
|
namespace llvm {
|
|
|
|
/// Utility function to get the size of the ULEB128-encoded value.
|
|
unsigned getULEB128Size(uint64_t Value) {
|
|
unsigned Size = 0;
|
|
do {
|
|
Value >>= 7;
|
|
Size += sizeof(int8_t);
|
|
} while (Value);
|
|
return Size;
|
|
}
|
|
|
|
/// Utility function to get the size of the SLEB128-encoded value.
|
|
unsigned getSLEB128Size(int64_t Value) {
|
|
unsigned Size = 0;
|
|
int Sign = Value >> (8 * sizeof(Value) - 1);
|
|
bool IsMore;
|
|
|
|
do {
|
|
unsigned Byte = Value & 0x7f;
|
|
Value >>= 7;
|
|
IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
|
|
Size += sizeof(int8_t);
|
|
} while (IsMore);
|
|
return Size;
|
|
}
|
|
|
|
} // namespace llvm
|