Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types

If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.


Call sites were found with the ASTMatcher + some semi-automated cleanup.

memberCallExpr(
    argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
    on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
    hasArgument(0, bindTemporaryExpr(
                       hasType(recordDecl(hasNonTrivialDestructor())),
                       has(constructExpr()))),
    unless(isInTemplateInstantiation()))

No functional change intended.

llvm-svn: 238602

llvm/lib/CodeGen/MachineModuleInfo.cpp

@@ -114,7 +114,7 @@ MCSymbol *MMIAddrLabelMap::getAddrLabelSymbol(BasicBlock *BB) {
 
   // Otherwise, this is a new entry, create a new symbol for it and add an
   // entry to BBCallbacks so we can be notified if the BB is deleted or RAUWd.
-  BBCallbacks.push_back(BB);
+  BBCallbacks.emplace_back(BB);
   BBCallbacks.back().setMap(this);
   Entry.Index = BBCallbacks.size()-1;
   Entry.Fn = BB->getParent();