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, 5 insertions, 7 deletions

diff --git a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
index fd02bbdc6b4..40ebdd99a7e 100644
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -3798,13 +3798,11 @@ void CodeGenDAGPatterns::GenerateVariants() {
       if (AlreadyExists) continue;
 
       // Otherwise, add it to the list of patterns we have.
-      PatternsToMatch.
-        push_back(PatternToMatch(PatternsToMatch[i].getSrcRecord(),
-                                 PatternsToMatch[i].getPredicates(),
-                                 Variant, PatternsToMatch[i].getDstPattern(),
-                                 PatternsToMatch[i].getDstRegs(),
-                                 PatternsToMatch[i].getAddedComplexity(),
-                                 Record::getNewUID()));
+      PatternsToMatch.emplace_back(
+          PatternsToMatch[i].getSrcRecord(), PatternsToMatch[i].getPredicates(),
+          Variant, PatternsToMatch[i].getDstPattern(),
+          PatternsToMatch[i].getDstRegs(),
+          PatternsToMatch[i].getAddedComplexity(), Record::getNewUID());
     }
 
     DEBUG(errs() << "\n");