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, 4 insertions, 8 deletions

diff --git a/llvm/tools/bugpoint/Miscompilation.cpp b/llvm/tools/bugpoint/Miscompilation.cpp
index 53631d25c39..fad16368698 100644
--- a/llvm/tools/bugpoint/Miscompilation.cpp
+++ b/llvm/tools/bugpoint/Miscompilation.cpp
@@ -386,10 +386,8 @@ static bool ExtractLoops(BugDriver &BD,
       // that masked the error.  Stop loop extraction now.
 
       std::vector<std::pair<std::string, FunctionType*> > MisCompFunctions;
-      for (unsigned i = 0, e = MiscompiledFunctions.size(); i != e; ++i) {
-        Function *F = MiscompiledFunctions[i];
-        MisCompFunctions.push_back(std::make_pair(F->getName(),
-                                                  F->getFunctionType()));
+      for (Function *F : MiscompiledFunctions) {
+        MisCompFunctions.emplace_back(F->getName(), F->getFunctionType());
       }
 
       if (Linker::LinkModules(ToNotOptimize, ToOptimizeLoopExtracted))
@@ -414,8 +412,7 @@ static bool ExtractLoops(BugDriver &BD,
     for (Module::iterator I = ToOptimizeLoopExtracted->begin(),
            E = ToOptimizeLoopExtracted->end(); I != E; ++I)
       if (!I->isDeclaration())
-        MisCompFunctions.push_back(std::make_pair(I->getName(),
-                                                  I->getFunctionType()));
+        MisCompFunctions.emplace_back(I->getName(), I->getFunctionType());
 
     // Okay, great!  Now we know that we extracted a loop and that loop
     // extraction both didn't break the program, and didn't mask the problem.
@@ -596,8 +593,7 @@ static bool ExtractBlocks(BugDriver &BD,
   for (Module::iterator I = Extracted->begin(), E = Extracted->end();
        I != E; ++I)
     if (!I->isDeclaration())
-      MisCompFunctions.push_back(std::make_pair(I->getName(),
-                                                I->getFunctionType()));
+      MisCompFunctions.emplace_back(I->getName(), I->getFunctionType());
 
   if (Linker::LinkModules(ProgClone, Extracted.get()))
     exit(1);