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//===- llvm/Support/BCD.h - Binary-Coded Decimal utility functions -*- 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 declares some utility functions for encoding/decoding BCD values.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_BCD_H
#define LLVM_SUPPORT_BCD_H
#include <assert.h>
#include <cstddef>
#include <cstdint>
namespace llvm {
// Decode a packed BCD value.
// Maximum value of int64_t is 9,223,372,036,854,775,807. These are 18 usable
// decimal digits. Thus BCD numbers of up to 9 bytes can be converted.
// Please note that s390 supports BCD numbers up to a length of 16 bytes.
inline int64_t decodePackedBCD(const uint8_t *Ptr, size_t ByteLen,
bool IsSigned = true) {
assert(ByteLen >= 1 && ByteLen <= 9 && "Invalid BCD number");
int64_t Value = 0;
size_t RunLen = ByteLen - static_cast<unsigned>(IsSigned);
for (size_t I = 0; I < RunLen; ++I) {
uint8_t DecodedByteValue = ((Ptr[I] >> 4) & 0x0f) * 10 + (Ptr[I] & 0x0f);
Value = (Value * 100) + DecodedByteValue;
}
if (IsSigned) {
uint8_t DecodedByteValue = (Ptr[ByteLen - 1] >> 4) & 0x0f;
uint8_t Sign = Ptr[ByteLen - 1] & 0x0f;
Value = (Value * 10) + DecodedByteValue;
if (Sign == 0x0d || Sign == 0x0b)
Value *= -1;
}
return Value;
}
template <typename ResultT, typename ValT>
inline ResultT decodePackedBCD(const ValT Val, bool IsSigned = true) {
return static_cast<ResultT>(decodePackedBCD(
reinterpret_cast<const uint8_t *>(&Val), sizeof(ValT), IsSigned));
}
} // namespace llvm
#endif // LLVM_SUPPORT_BCD_H
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