Rewrite NRVO determination. Track NRVO candidates on the parser Scope and apply the NRVO candidate flag to all possible NRVO candidates here, and remove the flags in computeNRVO or upon template instantiation. A variable now has NRVO applied if and only if every return statement in that scope returns that variable. This is nearly optimal.
Performs NRVO roughly 7% more often in a bootstrap build of clang. Patch co-authored by Richard Smith.
llvm-svn: 207890
diff --git a/clang/lib/Parse/Parser.cpp b/clang/lib/Parse/Parser.cpp
index b096f1c..521ac9b 100644
--- a/clang/lib/Parse/Parser.cpp
+++ b/clang/lib/Parse/Parser.cpp
@@ -365,8 +365,7 @@
// Inform the actions module that this scope is going away if there are any
// decls in it.
- if (!getCurScope()->decl_empty())
- Actions.ActOnPopScope(Tok.getLocation(), getCurScope());
+ Actions.ActOnPopScope(Tok.getLocation(), getCurScope());
Scope *OldScope = getCurScope();
Actions.CurScope = OldScope->getParent();