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Diffstat (limited to 'contrib/llvm/lib/Support/LEB128.cpp')
-rw-r--r-- | contrib/llvm/lib/Support/LEB128.cpp | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/LEB128.cpp b/contrib/llvm/lib/Support/LEB128.cpp new file mode 100644 index 000000000000..449626f2d451 --- /dev/null +++ b/contrib/llvm/lib/Support/LEB128.cpp @@ -0,0 +1,44 @@ +//===- LEB128.cpp - LEB128 utility functions implementation -----*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// 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 |