Improve type checking, remove unused stub (removed also in x64 in preparation of porting the better…

runtime/vm/stub_code_x64.cc

Index: runtime/vm/stub_code_x64.cc
===================================================================
--- runtime/vm/stub_code_x64.cc	(revision 7391)
+++ runtime/vm/stub_code_x64.cc	(working copy)
@@ -1724,86 +1724,6 @@
 }
 
 
-// Check if an instance class is a subtype of class/interface using simple
-// superchain and interface array traversal. Does not take type parameters into
-// account.
-// RAX: instance (preserved)
-// RCX: class/interface to test against (is class of instance a subtype of it).
-//      (preserved).
-// Result in RBX: 1 is subtype, 0 maybe not.
-// Must preserve RDX.
-// Destroys RBX, R13, R10.
-void StubCode::GenerateIsRawSubTypeStub(Assembler* assembler) {
-  const Immediate raw_null =
-      Immediate(reinterpret_cast<intptr_t>(Object::null()));
-  Label test_class, not_found, found, class_loaded_in_R10, smi_value;
-  __ EnterFrame(0);
-  __ testq(RAX, Immediate(kSmiTagMask));
-  __ j(ZERO, &smi_value, Assembler::kNearJump);
-  __ movq(R10, FieldAddress(RAX, Object::class_offset()));
-  __ jmp(&class_loaded_in_R10, Assembler::kNearJump);
-  __ Bind(&smi_value);
-  __ movq(R10, FieldAddress(CTX, Context::isolate_offset()));
-  __ movq(R10, Address(R10, Isolate::object_store_offset()));
-  __ movq(R10, Address(R10, ObjectStore::smi_class_offset()));
-  __ Bind(&class_loaded_in_R10);
-
-  __ movzxb(RBX, FieldAddress(RCX, Class::is_interface_offset()));
-  // Check if we are comparing against class or interface.
-  __ cmpq(RBX, Immediate(0));
-  __ j(EQUAL, &test_class, Assembler::kNearJump);
-
-  // Get interfaces array from instance class.
-  __ movq(RBX, FieldAddress(R10, Class::interfaces_offset()));
-  __ cmpq(RBX, raw_null);
-  __ j(EQUAL, &not_found, Assembler::kNearJump);
-  __ movq(R13, FieldAddress(RBX, Array::length_offset()));
-  // R13: array index.
-  // RBX: interface array.
-  // RCX: interface searched
-  Label array_loop;
-  __ Bind(&array_loop);
-  __ subq(R13, Immediate(Smi::RawValue(1)));
-  // __ cmpq(R13, Immediate(0));
-  __ j(LESS, &not_found, Assembler::kNearJump);
-  // R13 is Smi therefore TIMES_4 instead of TIMES_8.
-  // Get type from array.
-  __ movq(R10, FieldAddress(RBX, R13, TIMES_4, Array::data_offset()));
-  __ movq(R10, FieldAddress(R10, Type::type_class_offset()));
-  __ cmpq(R10, RCX);
-  __ j(EQUAL, &found, Assembler::kNearJump);
-  __ jmp(&array_loop, Assembler::kNearJump);
-
-  __ Bind(&not_found);
-  __ xorq(RBX, RBX);
-  __ LeaveFrame();
-  __ ret();
-
-  __ Bind(&found);
-  __ movq(RBX, Immediate(1));
-  __ LeaveFrame();
-  __ ret();
-
-  __ Bind(&test_class);
-  // RCX: test class.
-  __ cmpq(R10, RCX);
-  __ j(EQUAL, &found, Assembler::kNearJump);
-
-  // Check superclasses using a loop (faster than runtime call).
-  Label super_loop;
-  __ Bind(&super_loop);
-  // R10: class -> super.
-  __ movq(R10, FieldAddress(R10, Class::super_type_offset()));
-  // The supertype of Object is a null object.
-  __ cmpq(R10, raw_null);
-  __ j(EQUAL, &not_found, Assembler::kNearJump);
-  __ movq(R10, FieldAddress(R10, Type::type_class_offset()));
-  __ cmpq(RCX, R10);
-  __ j(NOT_EQUAL, &super_loop, Assembler::kNearJump);
-  __ jmp(&found, Assembler::kNearJump);
-}
-
-
 void StubCode::GenerateSubtype1TestCacheStub(Assembler* assembler) {
   __ Unimplemented("Subtype1TestCache Stub");
 }