Fixup redefinitions before doing code motion

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index fae6a677ded1d9d3f0458006dd78f5b924861b16..8c6eb050f51d5b973c3da63394d3402234eed3f2 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -891,6 +891,8 @@ bool CompileParsedFunctionHelper::Compile(CompilationPipeline* pipeline) {
         // Optimistically convert loop phis that have a single non-smi input
         // coming from the loop pre-header into smi-phis.
         if (FLAG_loop_invariant_code_motion) {
+          flow_graph->FixupRedefinitions();
+          DEBUG_ASSERT(flow_graph->VerifyRedefinitions());
           LICM licm(flow_graph);
           licm.OptimisticallySpecializeSmiPhis();

[Vyacheslav Egorov (Google), 2017/02/23 13:47:27]

I think we don't need to fixup redefinitions here - this pass only hoists
CheckSmi instructions.

[Florian Schneider, 2017/02/23 19:26:35]

Done.

           DEBUG_ASSERT(flow_graph->VerifyUseLists());