Implement array bounds checks explicitly in the optimized IL.

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
===================================================================
--- runtime/vm/intermediate_language_x64.cc	(revision 11394)
+++ runtime/vm/intermediate_language_x64.cc	(working copy)
@@ -826,19 +826,9 @@
   Register index = locs()->in(1).reg();
   Register result = locs()->out().reg();
 
-  const DeoptReasonId deopt_reason =
-      (receiver_type() == kGrowableObjectArrayCid) ?
-      kDeoptLoadIndexedGrowableArray : kDeoptLoadIndexedFixedArray;
-
-  Label* deopt = compiler->AddDeoptStub(original()->deopt_id(),
-                                        original()->try_index(),
-                                        deopt_reason);
-
   switch (receiver_type()) {
     case kArrayCid:
     case kImmutableArrayCid:
-      __ cmpq(index, FieldAddress(receiver, Array::length_offset()));
-      __ j(ABOVE_EQUAL, deopt);
       // Note that index is Smi, i.e, times 4.
       ASSERT(kSmiTagShift == 1);
       __ movq(result, FieldAddress(receiver, index, TIMES_4, sizeof(RawArray)));
@@ -846,10 +836,6 @@
 
     case kGrowableObjectArrayCid: {
       Register temp = locs()->temp(0).reg();
-
-      __ cmpq(index,
-              FieldAddress(receiver, GrowableObjectArray::length_offset()));
-      __ j(ABOVE_EQUAL, deopt);
       __ movq(temp, FieldAddress(receiver, GrowableObjectArray::data_offset()));
       // Note that index is Smi, i.e, times 4.
       ASSERT(kSmiTagShift == 1);
@@ -874,7 +860,6 @@
     locs->set_in(1, Location::RequiresRegister());
     locs->set_in(2, Location::RequiresRegister());
     locs->set_temp(0, Location::RequiresRegister());
-    locs->set_out(Location::NoLocation());
     return locs;
   } else  {
     ASSERT(receiver_type() == kArrayCid);
@@ -890,15 +875,9 @@
   Register index = locs()->in(1).reg();
   Register value = locs()->in(2).reg();
 
-  Label* deopt = compiler->AddDeoptStub(original()->deopt_id(),
-                                        original()->try_index(),
-                                        kDeoptStoreIndexed);
-
   switch (receiver_type()) {
     case kArrayCid:
     case kImmutableArrayCid:
-      __ cmpq(index, FieldAddress(receiver, Array::length_offset()));
-      __ j(ABOVE_EQUAL, deopt);
       // Note that index is Smi, i.e, times 4.
       ASSERT(kSmiTagShift == 1);
       if (this->value()->NeedsStoreBuffer()) {
@@ -914,9 +893,6 @@
 
     case kGrowableObjectArrayCid: {
       Register temp = locs()->temp(0).reg();
-      __ cmpq(index,
-              FieldAddress(receiver, GrowableObjectArray::length_offset()));
-      __ j(ABOVE_EQUAL, deopt);
       __ movq(temp, FieldAddress(receiver, GrowableObjectArray::data_offset()));
       // Note that index is Smi, i.e, times 4.
       ASSERT(kSmiTagShift == 1);
@@ -2378,6 +2354,37 @@
 }
 
 
+LocationSummary* CheckArrayBoundComp::MakeLocationSummary() const {
+  return LocationSummary::Make(2,
+                               Location::NoLocation(),
+                               LocationSummary::kNoCall);
+}
+
+
+void CheckArrayBoundComp::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register receiver = locs()->in(0).reg();
+  Register index = locs()->in(1).reg();
+
+  const DeoptReasonId deopt_reason =
+      (array_type() == kGrowableObjectArrayCid) ?
+      kDeoptLoadIndexedGrowableArray : kDeoptLoadIndexedFixedArray;
+  Label* deopt = compiler->AddDeoptStub(deopt_id(),
+                                        try_index(),
+                                        deopt_reason);
+  switch (array_type()) {
+    case kArrayCid:
+    case kImmutableArrayCid:
+      __ cmpq(index, FieldAddress(receiver, Array::length_offset()));
+      break;
+    case kGrowableObjectArrayCid:
+      __ cmpq(index,
+              FieldAddress(receiver, GrowableObjectArray::length_offset()));
+      break;
+  }
+  __ j(ABOVE_EQUAL, deopt);
+}
+
+
 }  // namespace dart
 
 #undef __