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

1 files changed, 2 insertions, 3 deletions

diff --git a/llvm/utils/TableGen/AsmWriterEmitter.cpp b/llvm/utils/TableGen/AsmWriterEmitter.cpp
index 389889ab80f..8163f681d88 100644
--- a/llvm/utils/TableGen/AsmWriterEmitter.cpp
+++ b/llvm/utils/TableGen/AsmWriterEmitter.cpp
@@ -1105,9 +1105,8 @@ AsmWriterEmitter::AsmWriterEmitter(RecordKeeper &R) : Records(R), Target(R) {
   Record *AsmWriter = Target.getAsmWriter();
   for (const CodeGenInstruction *I : Target.instructions())
     if (!I->AsmString.empty() && I->TheDef->getName() != "PHI")
-      Instructions.push_back(
-          AsmWriterInst(*I, AsmWriter->getValueAsInt("Variant"),
-                        AsmWriter->getValueAsInt("PassSubtarget")));
+      Instructions.emplace_back(*I, AsmWriter->getValueAsInt("Variant"),
+                                AsmWriter->getValueAsInt("PassSubtarget"));
 
   // Get the instruction numbering.
   NumberedInstructions = &Target.getInstructionsByEnumValue();