6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-26 21:32:10 +00:00
Code Issues Projects Releases Wiki Activity

Reuse constants for COFF string table entry offsets

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202130 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nico Rieck 2014-02-25 09:50:40 +00:00
parent 64d5fd932b
commit 6c35c95c73
1 changed files with 9 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
lib/MC/WinCOFFObjectWriter.cpp
View File

@ -468,11 +468,16 @@ void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
} }
} }
// Maximum offsets for different string table entry encodings.
static const unsigned Max6DecimalOffset = 999999;
static const unsigned Max7DecimalOffset = 9999999;
static const uint64_t MaxBase64Offset = 0xFFFFFFFFFULL; // 64^6, including 0
// Encode a string table entry offset in base 64, padded to 6 chars, and // Encode a string table entry offset in base 64, padded to 6 chars, and
// prefixed with a double slash: '//AAAAAA', '//AAAAAB', ... // prefixed with a double slash: '//AAAAAA', '//AAAAAB', ...
// Buffer must be at least 8 bytes large. No terminating null appended. // Buffer must be at least 8 bytes large. No terminating null appended.
static void encodeBase64StringEntry(char* Buffer, uint64_t Value) { static void encodeBase64StringEntry(char* Buffer, uint64_t Value) {
assert(Value > 9999999 && Value <= 0xFFFFFFFFF && assert(Value > Max7DecimalOffset && Value <= MaxBase64Offset &&
"Illegal section name encoding for value"); "Illegal section name encoding for value");
static const char Alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" static const char Alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@ -494,20 +499,17 @@ static void encodeBase64StringEntry(char* Buffer, uint64_t Value) {
/// name into the string table if needed /// name into the string table if needed
void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) { void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) {
if (S.Name.size() > COFF::NameSize) { if (S.Name.size() > COFF::NameSize) {
const unsigned Max6DecimalSize = 999999;
const unsigned Max7DecimalSize = 9999999;
const uint64_t MaxBase64Size = 0xFFFFFFFFF; // 64^6, including 0
uint64_t StringTableEntry = Strings.insert(S.Name.c_str()); uint64_t StringTableEntry = Strings.insert(S.Name.c_str());
if (StringTableEntry <= Max6DecimalSize) { if (StringTableEntry <= Max6DecimalOffset) {
std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry)); std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
} else if (StringTableEntry <= Max7DecimalSize) { } else if (StringTableEntry <= Max7DecimalOffset) {
// With seven digits, we have to skip the terminating null. Because // With seven digits, we have to skip the terminating null. Because
// sprintf always appends it, we use a larger temporary buffer. // sprintf always appends it, we use a larger temporary buffer.
char buffer[9] = { }; char buffer[9] = { };
std::sprintf(buffer, "/%d", unsigned(StringTableEntry)); std::sprintf(buffer, "/%d", unsigned(StringTableEntry));
std::memcpy(S.Header.Name, buffer, 8); std::memcpy(S.Header.Name, buffer, 8);
} else if (StringTableEntry <= MaxBase64Size) { } else if (StringTableEntry <= MaxBase64Offset) {
// Starting with 10,000,000, offsets are encoded as base64. // Starting with 10,000,000, offsets are encoded as base64.
encodeBase64StringEntry(S.Header.Name, StringTableEntry); encodeBase64StringEntry(S.Header.Name, StringTableEntry);
} else { } else {