LLVM 17.0.0git
BCD.h
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1//===- llvm/Support/BCD.h - Binary-Coded Decimal utility functions -*- 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 declares some utility functions for encoding/decoding BCD values.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_BCD_H
14#define LLVM_SUPPORT_BCD_H
15
16#include <assert.h>
17#include <cstddef>
18#include <cstdint>
19
20namespace llvm {
21
22// Decode a packed BCD value.
23// Maximum value of int64_t is 9,223,372,036,854,775,807. These are 18 usable
24// decimal digits. Thus BCD numbers of up to 9 bytes can be converted.
25// Please note that s390 supports BCD numbers up to a length of 16 bytes.
26inline int64_t decodePackedBCD(const uint8_t *Ptr, size_t ByteLen,
27 bool IsSigned = true) {
28 assert(ByteLen >= 1 && ByteLen <= 9 && "Invalid BCD number");
29 int64_t Value = 0;
30 size_t RunLen = ByteLen - static_cast<unsigned>(IsSigned);
31 for (size_t I = 0; I < RunLen; ++I) {
32 uint8_t DecodedByteValue = ((Ptr[I] >> 4) & 0x0f) * 10 + (Ptr[I] & 0x0f);
33 Value = (Value * 100) + DecodedByteValue;
34 }
35 if (IsSigned) {
36 uint8_t DecodedByteValue = (Ptr[ByteLen - 1] >> 4) & 0x0f;
37 uint8_t Sign = Ptr[ByteLen - 1] & 0x0f;
38 Value = (Value * 10) + DecodedByteValue;
39 if (Sign == 0x0d || Sign == 0x0b)
40 Value *= -1;
41 }
42 return Value;
43}
44
45template <typename ResultT, typename ValT>
46inline ResultT decodePackedBCD(const ValT Val, bool IsSigned = true) {
47 return static_cast<ResultT>(decodePackedBCD(
48 reinterpret_cast<const uint8_t *>(&Val), sizeof(ValT), IsSigned));
49}
50
51} // namespace llvm
52
53#endif // LLVM_SUPPORT_BCD_H
#define I(x, y, z)
Definition: MD5.cpp:58
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
LLVM Value Representation.
Definition: Value.h:74
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
int64_t decodePackedBCD(const uint8_t *Ptr, size_t ByteLen, bool IsSigned=true)
Definition: BCD.h:26