MIPS: Track up to 5 stable maps as field type.

Port r20831 (f91f993)

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/240503008

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20847 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/stub-cache-mips.cc

@@ -415,13 +415,24 @@ void StoreStubCompiler::GenerateStoreTransition(MacroAssembler* masm,
   } else if (representation.IsSmi()) {
     __ JumpIfNotSmi(value_reg, miss_label);
   } else if (representation.IsHeapObject()) {
+    __ JumpIfSmi(value_reg, miss_label);
     HeapType* field_type = descriptors->GetFieldType(descriptor);
-    if (field_type->IsClass()) {
-      __ CheckMap(value_reg, scratch1, field_type->AsClass()->Map(),
-                  miss_label, DO_SMI_CHECK);
-    } else {
-      ASSERT(HeapType::Any()->Is(field_type));
-      __ JumpIfSmi(value_reg, miss_label);
+    HeapType::Iterator<Map> it = field_type->Classes();
+    Handle<Map> current;
+    if (!it.Done()) {
+      __ lw(scratch1, FieldMemOperand(value_reg, HeapObject::kMapOffset));
+      Label do_store;
+      while (true) {
+        // Do the CompareMap() directly within the Branch() functions.
+        current = it.Current();
+        it.Advance();
+        if (it.Done()) {
+          __ Branch(miss_label, ne, scratch1, Operand(current));
+          break;
+        }
+        __ Branch(&do_store, eq, scratch1, Operand(current));
+      }
+      __ bind(&do_store);
     }
   } else if (representation.IsDouble()) {
     Label do_store, heap_number;
@@ -585,13 +596,24 @@ void StoreStubCompiler::GenerateStoreField(MacroAssembler* masm,
   if (representation.IsSmi()) {
     __ JumpIfNotSmi(value_reg, miss_label);
   } else if (representation.IsHeapObject()) {
+    __ JumpIfSmi(value_reg, miss_label);
     HeapType* field_type = lookup->GetFieldType();
-    if (field_type->IsClass()) {
-      __ CheckMap(value_reg, scratch1, field_type->AsClass()->Map(),
-                  miss_label, DO_SMI_CHECK);
-    } else {
-      ASSERT(HeapType::Any()->Is(field_type));
-      __ JumpIfSmi(value_reg, miss_label);
+    HeapType::Iterator<Map> it = field_type->Classes();
+    if (!it.Done()) {
+      __ lw(scratch1, FieldMemOperand(value_reg, HeapObject::kMapOffset));
+      Label do_store;
+      Handle<Map> current;
+      while (true) {
+        // Do the CompareMap() directly within the Branch() functions.
+        current = it.Current();
+        it.Advance();
+        if (it.Done()) {
+          __ Branch(miss_label, ne, scratch1, Operand(current));
+          break;
+        }
+        __ Branch(&do_store, eq, scratch1, Operand(current));
+      }
+      __ bind(&do_store);
     }
   } else if (representation.IsDouble()) {
     // Load the double storage.