MC: Shave a pointer off of MCSymbol::Name
Shave a pointer off of `MCSymbolName` by storing `StringMapEntry<bool>*`
instead of `StringRef`. This brings `sizeof(MCSymbol)` down to 64 on
64-bit platforms, a nice round number. My profile showed memory
dropping from 914 MB down to 908 MB, roughly 0.7%. Other than memory
usage, no functionality change here.
(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)
llvm-svn: 238005
diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index f3ea3cc..968fd26 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -125,7 +125,7 @@
}
auto NameIter = UsedNames.insert(std::make_pair(Name, true)).first;
- Sym = new (*this) MCSymbol(NameIter->getKey(), /*isTemporary*/ false);
+ Sym = new (*this) MCSymbol(&*NameIter, /*isTemporary*/ false);
if (!OldSym)
OldSym = Sym;
@@ -156,7 +156,7 @@
IsTemporary = Name.startswith(MAI->getPrivateGlobalPrefix());
if (IsTemporary && AlwaysAddSuffix && !UseNamesOnTempLabels)
- return new (*this) MCSymbol("", true);
+ return new (*this) MCSymbol(nullptr, true);
SmallString<128> NewName = Name;
bool AddSuffix = AlwaysAddSuffix;
@@ -170,8 +170,7 @@
if (NameEntry.second) {
// Ok, we found a name. Have the MCSymbol object itself refer to the copy
// of the string that is embedded in the UsedNames entry.
- MCSymbol *Result =
- new (*this) MCSymbol(NameEntry.first->getKey(), IsTemporary);
+ MCSymbol *Result = new (*this) MCSymbol(&*NameEntry.first, IsTemporary);
return Result;
}
assert(IsTemporary && "Cannot rename non-temporary symbols");