Use UnboxedInt32 and UnboxedUint32 representation for LoadIndexedInstr

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
diff --git a/runtime/vm/flow_graph_optimizer.cc b/runtime/vm/flow_graph_optimizer.cc
index cb7eb2b67e0ca37ba79a0537ea09790b66f88099..611280b0158bda0d60fb814dd569b0f9c72edecd 100644
--- a/runtime/vm/flow_graph_optimizer.cc
+++ b/runtime/vm/flow_graph_optimizer.cc
@@ -75,6 +75,7 @@ static bool CanConvertUnboxedMintToDouble() {
 #endif
 }
 
+
 // Optimize instance calls using ICData.
 void FlowGraphOptimizer::ApplyICData() {
   VisitBlocks();
@@ -628,6 +629,8 @@ void FlowGraphOptimizer::InsertConversion(Representation from,
     converted = new(I) UnboxIntegerInstr(use->CopyWithType(), deopt_id);
   } else if ((from == kUnboxedMint) && (to == kTagged)) {
     converted = new(I) BoxIntegerInstr(use->CopyWithType());
+  } else if ((from == kUnboxedUint32) && (to == kTagged)) {
+    converted = new(I) BoxUint32Instr(use->CopyWithType());
   } else if (IsUnboxedInteger(from) && IsUnboxedInteger(to)) {
     const intptr_t deopt_id = (to == kUnboxedInt32) && (deopt_target != NULL) ?
         deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
@@ -1355,7 +1358,12 @@ bool FlowGraphOptimizer::InlineSetIndexed(
        RawObject::IsTypedDataViewClassId(array_cid) ||
        RawObject::IsExternalTypedDataClassId(array_cid)) ? kNoStoreBarrier
                                                          : kEmitStoreBarrier;
-  if (!value_check.IsNull()) {
+
+  // No need to class check stores to Int32 and Uint32 arrays because
+  // we insert unboxing instructions below which include a class check.
+  if ((array_cid != kTypedDataUint32ArrayCid) &&
+      (array_cid != kTypedDataInt32ArrayCid) &&
+      !value_check.IsNull()) {
     // No store barrier needed because checked value is a smi, an unboxed mint,
     // an unboxed double, an unboxed Float32x4, or unboxed Int32x4.
     needs_store_barrier = kNoStoreBarrier;