VM: Array bounds checks that don't deoptimize for precompiled code.

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
diff --git a/runtime/vm/intermediate_language_ia32.cc b/runtime/vm/intermediate_language_ia32.cc
index 34555dc6410020d71ea407e3828af4c95d13ddbe..3ccb078f787cb6b9f0abd67d2ebcabf6395e1c20 100644
--- a/runtime/vm/intermediate_language_ia32.cc
+++ b/runtime/vm/intermediate_language_ia32.cc
@@ -5847,8 +5847,7 @@ void CheckSmiInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Label* deopt = compiler->AddDeoptStub(deopt_id(),
                                         ICData::kDeoptCheckSmi,
                                         licm_hoisted_ ? ICData::kHoisted : 0);
-  __ testl(value, Immediate(kSmiTagMask));
-  __ j(NOT_ZERO, deopt);
+  __ BranchIfNotSmi(value, deopt);
 }
 
 
@@ -5871,6 +5870,20 @@ void CheckClassIdInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 }
 
 
+LocationSummary* GenericCheckBoundInstr::MakeLocationSummary(Zone* zone,
+                                                             bool opt) const {
+  // Only needed for AOT.
+  UNIMPLEMENTED();
+  return NULL;
+}
+
+
+void GenericCheckBoundInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  // Only needed for AOT.
+  UNIMPLEMENTED();
+}
+
+
 // Length: register or constant.
 // Index: register, constant or stack slot.
 LocationSummary* CheckArrayBoundInstr::MakeLocationSummary(Zone* zone,
@@ -5910,8 +5923,12 @@ void CheckArrayBoundInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     return;
   }
 
+  const intptr_t index_cid = index()->Type()->ToCid();
   if (length_loc.IsConstant()) {
     Register index = index_loc.reg();
+    if (index_cid != kSmiCid) {
+      __ BranchIfNotSmi(index, deopt);
+    }
     const Smi& length = Smi::Cast(length_loc.constant());
     if (length.Value() == Smi::kMaxValue) {
       __ testl(index, index);
@@ -5933,11 +5950,17 @@ void CheckArrayBoundInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   } else if (length_loc.IsStackSlot()) {
     Register index = index_loc.reg();
     const Address& length = length_loc.ToStackSlotAddress();
+    if (index_cid != kSmiCid) {
+      __ BranchIfNotSmi(index, deopt);
+    }
     __ cmpl(index, length);
     __ j(ABOVE_EQUAL, deopt);
   } else {
     Register index = index_loc.reg();
     Register length = length_loc.reg();
+    if (index_cid != kSmiCid) {
+      __ BranchIfNotSmi(index, deopt);
+    }
     __ cmpl(length, index);
     __ j(BELOW_EQUAL, deopt);
   }