Pattern match on generated code to find edge counters.

runtime/vm/intermediate_language_mips.cc

Index: runtime/vm/intermediate_language_mips.cc
diff --git a/runtime/vm/intermediate_language_mips.cc b/runtime/vm/intermediate_language_mips.cc
index a1d5b188cc92b3fbf160f3efae9974d4b1db8c92..39311217845e3c036af8ef4c1cb4e197a700cd80 100644
--- a/runtime/vm/intermediate_language_mips.cc
+++ b/runtime/vm/intermediate_language_mips.cc
@@ -3868,6 +3868,26 @@ LocationSummary* GotoInstr::MakeLocationSummary() const {
 
 void GotoInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("GotoInstr");
+  if (!compiler->is_optimizing()) {
+    // Add deoptimization descriptor for deoptimizing instructions that may
+    // be inserted before this instruction.
+    compiler->AddCurrentDescriptor(PcDescriptors::kDeopt,
+                                   GetDeoptId(),
+                                   0);  // No token position.
+    // Add an edge counter.
+    const Array& counter = Array::ZoneHandle(Array::New(1, Heap::kOld));
+    counter.SetAt(0, Smi::Handle(Smi::New(0)));
+    Label done;
+    __ Comment("Edge counter");
+    __ LoadObject(T0, counter);
+    __ lw(T1, FieldAddress(T0, Array::element_offset(0)));
+    __ AddImmediateDetectOverflow(T1, T1, Smi::RawValue(1), CMPRES, T2);
+    __ bgez(CMPRES, &done);
+    __ delay_slot()->sw(T1, FieldAddress(T0, Array::element_offset(0)));
+    __ LoadImmediate(TMP1, Smi::RawValue(Smi::kMaxValue));
+    __ sw(TMP1, FieldAddress(T0, Array::element_offset(0)));  // If overflow.
+    __ Bind(&done);
+  }
   if (HasParallelMove()) {
     compiler->parallel_move_resolver()->EmitNativeCode(parallel_move());
   }