Revert "VM: Simplify lowering of is-tests."

runtime/vm/flow_graph_compiler_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 538 matching lines @@
 // - Class equality (only if class is not parameterized).
 // Inputs:
 // - RAX: object.
 // - RDX: instantiator type arguments or raw_null.
 // Clobbers RDX.
 // Returns:
 // - true or false in RAX.
 void FlowGraphCompiler::GenerateInstanceOf(TokenPosition token_pos,
                                            intptr_t deopt_id,
                                            const AbstractType& type,
+                                           bool negate_result,
                                            LocationSummary* locs) {
   ASSERT(type.IsFinalized() && !type.IsMalformedOrMalbounded());
   ASSERT(!type.IsObjectType() && !type.IsDynamicType());
 
   Label is_instance, is_not_instance;
   __ pushq(RDX);  // Store instantiator type arguments.
   // If type is instantiated and non-parameterized, we can inline code
   // checking whether the tested instance is a Smi.
   if (type.IsInstantiated()) {
     // A null object is only an instance of Null, Object, and dynamic.
@@ skipping 20 matching lines @@
     __ PushObject(Object::null_object());  // Make room for the result.
     __ pushq(RAX);                         // Push the instance.
     __ PushObject(type);                   // Push the type.
     __ pushq(RDX);                         // Instantiator type arguments.
     __ LoadUniqueObject(RAX, test_cache);
     __ pushq(RAX);
     GenerateRuntimeCall(token_pos, deopt_id, kInstanceofRuntimeEntry, 4, locs);
     // Pop the parameters supplied to the runtime entry. The result of the
     // instanceof runtime call will be left as the result of the operation.
     __ Drop(4);
-    __ popq(RAX);
+    if (negate_result) {
+      __ popq(RDX);
+      __ LoadObject(RAX, Bool::True());
+      __ cmpq(RDX, RAX);
+      __ j(NOT_EQUAL, &done, Assembler::kNearJump);
+      __ LoadObject(RAX, Bool::False());
+    } else {
+      __ popq(RAX);
+    }
     __ jmp(&done, Assembler::kNearJump);
   }
   __ Bind(&is_not_instance);
-  __ LoadObject(RAX, Bool::Get(false));
+  __ LoadObject(RAX, Bool::Get(negate_result));
   __ jmp(&done, Assembler::kNearJump);
 
   __ Bind(&is_instance);
-  __ LoadObject(RAX, Bool::Get(true));
+  __ LoadObject(RAX, Bool::Get(!negate_result));
   __ Bind(&done);
   __ popq(RDX);  // Remove pushed instantiator type arguments.
 }
 
 
 // Optimize assignable type check by adding inlined tests for:
 // - NULL -> return NULL.
 // - Smi -> compile time subtype check (only if dst class is not parameterized).
 // - Class equality (only if class is not parameterized).
 // Inputs:
@@ skipping 1141 matching lines @@
   __ movups(reg, Address(RSP, 0));
   __ AddImmediate(RSP, Immediate(kFpuRegisterSize));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64