MachObjectWriter: optimize the string table for common suffices
This is a follow-up to r207670 (ELF) and r218636 (COFF).
Differential Revision: http://reviews.llvm.org/D5622
llvm-svn: 219126
diff --git a/llvm/lib/MC/StringTableBuilder.cpp b/llvm/lib/MC/StringTableBuilder.cpp
index 34e7e6f..9de9363 100644
--- a/llvm/lib/MC/StringTableBuilder.cpp
+++ b/llvm/lib/MC/StringTableBuilder.cpp
@@ -36,12 +36,16 @@
std::sort(Strings.begin(), Strings.end(), compareBySuffix);
- if (kind == ELF) {
+ switch (kind) {
+ case ELF:
+ case MachO:
// Start the table with a NUL byte.
StringTable += '\x00';
- } else if (kind == WinCOFF) {
+ break;
+ case WinCOFF:
// Make room to write the table size later.
StringTable.append(4, '\x00');
+ break;
}
StringRef Previous;
@@ -60,11 +64,21 @@
Previous = s;
}
- if (kind == WinCOFF) {
+ switch (kind) {
+ case ELF:
+ break;
+ case MachO:
+ // Pad to multiple of 4.
+ while (StringTable.size() % 4)
+ StringTable += '\x00';
+ break;
+ case WinCOFF:
+ // Write the table size in the first word.
assert(StringTable.size() <= std::numeric_limits<uint32_t>::max());
uint32_t size = static_cast<uint32_t>(StringTable.size());
support::endian::write<uint32_t, support::little, support::unaligned>(
StringTable.data(), size);
+ break;
}
}