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

source code of llvm/lib/Support/LEB128.cpp