1//===- LEB128.cpp - LEB128 utility functions implementation -----*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements some utility functions for encoding SLEB128 and
10// ULEB128 values.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Support/LEB128.h"
15
16namespace llvm {
17
18/// Utility function to get the size of the ULEB128-encoded value.
19unsigned getULEB128Size(uint64_t Value) {
20  unsigned Size = 0;
21  do {
22    Value >>= 7;
23    Size += sizeof(int8_t);
24  } while (Value);
25  return Size;
26}
27
28/// Utility function to get the size of the SLEB128-encoded value.
29unsigned getSLEB128Size(int64_t Value) {
30  unsigned Size = 0;
31  int Sign = Value >> (8 * sizeof(Value) - 1);
32  bool IsMore;
33
34  do {
35    unsigned Byte = Value & 0x7f;
36    Value >>= 7;
37    IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
38    Size += sizeof(int8_t);
39  } while (IsMore);
40  return Size;
41}
42
43}  // namespace llvm
44