Tests for GuardField length check along with bug fixes

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 a57cc42eb1d75fab24d5145edad3d6b3996f84fa..765b4ff13f6bcde22e9ab18774ca67eb4109f9bf 100644
--- a/runtime/vm/intermediate_language_ia32.cc
+++ b/runtime/vm/intermediate_language_ia32.cc
@@ -1612,7 +1612,6 @@ void GuardFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     ASSERT(!compiler->is_optimizing());
     return;  // Nothing to emit.
   }
-
   const intptr_t value_cid = value()->Type()->ToCid();
 
   Register value_reg = locs()->in(0).reg();
@@ -1658,7 +1657,6 @@ void GuardFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
       }
 
       LoadValueCid(compiler, value_cid_reg, value_reg);
-
       Label skip_length_check;
       __ cmpl(value_cid_reg, field_cid_operand);
       // Value CID != Field guard CID, skip length check.
@@ -1679,7 +1677,38 @@ void GuardFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
           __ popl(value_cid_reg);
         } else {
           ASSERT(field_cid == kIllegalCid);
-          // Following jump cannot not occur, fall through.
+          Label check_array, local_exit, local_fail;
+          // Check field guard.
+          __ cmpl(value_cid_reg, Immediate(kNullCid));
+          __ j(EQUAL, &local_fail);
+          // Check for typed data array.
+          __ cmpl(value_cid_reg, Immediate(kTypedDataFloat32x4ArrayCid));
+          __ j(GREATER, &local_fail);  // Not a typed array or a regular array.
+          __ cmpl(value_cid_reg, Immediate(kTypedDataInt8ArrayCid));
+          __ j(LESS, &check_array);  // Could still be a regular array.
+          __ pushl(value_cid_reg);
+          __ movl(value_cid_reg,
+                  FieldAddress(value_reg, TypedData::length_offset()));
+          __ cmpl(field_length_operand, value_cid_reg);
+          __ popl(value_cid_reg);
+          __ jmp(&local_exit);
+          // Check for regular array.
+          __ Bind(&check_array);
+          __ cmpl(value_cid_reg, Immediate(kImmutableArrayCid));
+          __ j(GREATER, &local_fail);
+          __ cmpl(value_cid_reg, Immediate(kArrayCid));
+          __ j(LESS, &local_fail);
+          __ pushl(value_cid_reg);
+          __ movl(value_cid_reg,
+                  FieldAddress(value_reg, Array::length_offset()));
+          __ cmpl(field_length_operand, value_cid_reg);
+          __ popl(value_cid_reg);
+          __ jmp(&local_exit);
+
+          __ Bind(&local_fail);
+          __ movl(field_length_operand, Immediate(Field::kNoFixedLength));
+
+          __ Bind(&local_exit);
         }
         __ j(NOT_EQUAL, fail);
       }
@@ -1720,6 +1749,7 @@ void GuardFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
           ASSERT(field_cid == kIllegalCid);
           // Following jump cannot not occur, fall through.
         }
+        __ j(NOT_EQUAL, fail);
       }
       // Not identical, possibly null.
       __ Bind(&skip_length_check);
@@ -1727,7 +1757,6 @@ void GuardFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     // Jump when class id guard and list length guard are okay.
     __ j(EQUAL, &ok);
 
-
     // Check if guard field is uninitialized.
     __ cmpl(field_cid_operand, Immediate(kIllegalCid));
     // Jump to failure path when guard field has been initialized and
@@ -1780,18 +1809,20 @@ void GuardFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
       ASSERT(field_reg != kNoRegister);
       __ movl(field_cid_operand, Immediate(value_cid));
       __ movl(field_nullability_operand, Immediate(value_cid));
-      if ((value_cid == kArrayCid) || (value_cid == kImmutableArrayCid)) {
-        // Destroy value_cid_reg (safe because we are finished with it).
-        __ movl(value_cid_reg,
-                FieldAddress(value_reg, Array::length_offset()));
-        __ movl(field_length_operand, value_cid_reg);
-      } else if (RawObject::IsTypedDataClassId(value_cid)) {
-        // Destroy value_cid_reg (safe because we are finished with it).
-        __ movl(value_cid_reg,
-                FieldAddress(value_reg, TypedData::length_offset()));
-        __ movl(field_length_operand, value_cid_reg);
-      } else {
-        __ movl(field_length_operand, Immediate(Field::kNoFixedLength));
+      if (field_has_length) {
+        if ((value_cid == kArrayCid) || (value_cid == kImmutableArrayCid)) {
+          // Destroy value_cid_reg (safe because we are finished with it).
+          __ movl(value_cid_reg,
+                  FieldAddress(value_reg, Array::length_offset()));
+          __ movl(field_length_operand, value_cid_reg);
+        } else if (RawObject::IsTypedDataClassId(value_cid)) {
+          // Destroy value_cid_reg (safe because we are finished with it).
+          __ movl(value_cid_reg,
+                  FieldAddress(value_reg, TypedData::length_offset()));
+          __ movl(field_length_operand, value_cid_reg);
+        } else {
+          __ movl(field_length_operand, Immediate(Field::kNoFixedLength));
+        }
       }
     }
 
@@ -1800,7 +1831,6 @@ void GuardFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
     }
   } else {
     // Field guard class has been initialized and is known.
-
     if (field_reg != kNoRegister) {
       __ LoadObject(field_reg, Field::ZoneHandle(field().raw()));
     }