Generalize bounds checks.

runtime/vm/intermediate_language_arm.cc

Index: runtime/vm/intermediate_language_arm.cc
diff --git a/runtime/vm/intermediate_language_arm.cc b/runtime/vm/intermediate_language_arm.cc
index f3212d12ecfacd02bc187e2b5f28ae2dec5b98d2..352a6e1eb726992060628aaee8d2f56d8a2b5f22 100644
--- a/runtime/vm/intermediate_language_arm.cc
+++ b/runtime/vm/intermediate_language_arm.cc
@@ -5824,10 +5824,10 @@ LocationSummary* CheckClassInstr::MakeLocationSummary(Isolate* isolate,
 
 
 void CheckClassInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  const ICData::DeoptReasonId deopt_reason = licm_hoisted_ ?
-      ICData::kDeoptHoistedCheckClass : ICData::kDeoptCheckClass;
+  Label* deopt = compiler->AddDeoptStub(deopt_id(),
+                                        ICData::kDeoptCheckClass,
+                                        licm_hoisted_ ? ICData::kHoisted : 0);
   if (IsNullCheck()) {
-    Label* deopt = compiler->AddDeoptStub(deopt_id(), deopt_reason);
     __ CompareImmediate(locs()->in(0).reg(),
                         reinterpret_cast<intptr_t>(Object::null()));
     __ b(deopt, EQ);
@@ -5838,7 +5838,6 @@ void CheckClassInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
          (unary_checks().NumberOfChecks() > 1));
   const Register value = locs()->in(0).reg();
   const Register temp = locs()->temp(0).reg();
-  Label* deopt = compiler->AddDeoptStub(deopt_id(), deopt_reason);
   Label is_ok;
   intptr_t cix = 0;
   if (unary_checks().GetReceiverClassIdAt(cix) == kSmiCid) {
@@ -5934,8 +5933,10 @@ LocationSummary* CheckArrayBoundInstr::MakeLocationSummary(Isolate* isolate,
 
 
 void CheckArrayBoundInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  Label* deopt = compiler->AddDeoptStub(deopt_id(),
-                                        ICData::kDeoptCheckArrayBound);
+  Label* deopt = compiler->AddDeoptStub(
+      deopt_id(),
+      ICData::kDeoptCheckArrayBound,
+      generalized_ ? ICData::kGeneralized : 0);
 
   Location length_loc = locs()->in(kLengthPos);
   Location index_loc = locs()->in(kIndexPos);
@@ -5958,8 +5959,13 @@ void CheckArrayBoundInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   } else if (length_loc.IsConstant()) {
     const Smi& length = Smi::Cast(length_loc.constant());
     const Register index = index_loc.reg();
-    __ CompareImmediate(index, reinterpret_cast<int32_t>(length.raw()));
-    __ b(deopt, CS);
+    if (length.Value() == Smi::kMaxValue) {
+      __ tst(index, Operand(index));
+      __ b(deopt, MI);
+    } else {
+      __ CompareImmediate(index, reinterpret_cast<int32_t>(length.raw()));
+      __ b(deopt, CS);
+    }
   } else {
     const Register length = length_loc.reg();
     const Register index = index_loc.reg();