VM: Fix bug in the new edge counter code on ARM and MIPS.

The offset into the edge counter array may exceed the limit of what fits into an Address operand on ARM and MIPS. BUG= [email protected] Review URL: https://codereview.chromium.org//1373013002 .
dart-lang · Sep 28, 2015 · 66bc931 · 66bc931
1 parent da006ac
commit 66bc931
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Showing 2 changed files with 6 additions and 7 deletions.
diff --git a/runtime/vm/flow_graph_compiler_arm.cc b/runtime/vm/flow_graph_compiler_arm.cc
@@ -1188,17 +1188,16 @@ void FlowGraphCompiler::EmitEdgeCounter(intptr_t edge_id) {
   // optimization/deoptimization cycles we will attempt.
   ASSERT(!edge_counters_array_.IsNull());
   ASSERT(assembler_->constant_pool_allowed());
-  const Array& counter = Array::ZoneHandle(zone(), Array::New(1, Heap::kOld));
-  counter.SetAt(0, Smi::Handle(zone(), Smi::New(0)));
   __ Comment("Edge counter");
   __ LoadObject(R0, edge_counters_array_);
 #if defined(DEBUG)
   bool old_use_far_branches = assembler_->use_far_branches();
   assembler_->set_use_far_branches(true);
 #endif  // DEBUG
-  __ ldr(IP, FieldAddress(R0, Array::element_offset(edge_id)));
-  __ add(IP, IP, Operand(Smi::RawValue(1)));
-  __ StoreIntoSmiField(FieldAddress(R0, Array::element_offset(edge_id)), IP);
+  __ LoadFieldFromOffset(kWord, R1, R0, Array::element_offset(edge_id));
+  __ add(R1, R1, Operand(Smi::RawValue(1)));
+  __ StoreIntoObjectNoBarrierOffset(
+      R0, Array::element_offset(edge_id), R1, Assembler::kOnlySmi);
 #if defined(DEBUG)
   assembler_->set_use_far_branches(old_use_far_branches);
 #endif  // DEBUG

diff --git a/runtime/vm/flow_graph_compiler_mips.cc b/runtime/vm/flow_graph_compiler_mips.cc
@@ -1207,9 +1207,9 @@ void FlowGraphCompiler::EmitEdgeCounter(intptr_t edge_id) {
   ASSERT(!edge_counters_array_.IsNull());
   __ Comment("Edge counter");
   __ LoadObject(T0, edge_counters_array_);
-  __ lw(T1, FieldAddress(T0, Array::element_offset(edge_id)));
+  __ LoadFieldFromOffset(T1, T0, Array::element_offset(edge_id));
   __ AddImmediate(T1, T1, Smi::RawValue(1));
-  __ sw(T1, FieldAddress(T0, Array::element_offset(edge_id)));
+  __ StoreFieldToOffset(T1, T0, Array::element_offset(edge_id));
 }