Optimize conditional branches that have same true/false targets.

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
===================================================================
--- runtime/vm/compiler.cc	(revision 27294)
+++ runtime/vm/compiler.cc	(working copy)
@@ -456,6 +456,8 @@
           // Constant propagation can use information from range analysis to
           // find unreachable branch targets.
           ConstantPropagator::OptimizeBranches(flow_graph);
+          // Eliminate branches that have the same true- and false-target.
+          ConstantPropagator::RemoveRedundantBranches(flow_graph);

[Kevin Millikin (Google), 2013/09/27 11:03:43]

Since Optimize and RemoveRedundant go together, I'd just move the redundant
branch elimination into OptimizeBranches.  (Plus, OptimizeBranches is too
generic if you have a separate, descriptively named RemoveRedundantBranches, and
it's confusing to have differently named public RemoveRedundant and private
EliminateRedundant that implements it.  You dodge all those issues by putting
EliminateRedundant inside Optimize).

[Florian Schneider, 2013/09/30 12:19:23]

Done.

           DEBUG_ASSERT(flow_graph->VerifyUseLists());
         }