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

runtime/vm/flow_graph_compiler_arm64.cc

 // Copyright (c) 2014, 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_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 531 matching lines @@
 // - Smi -> compile time subtype check (only if dst class is not parameterized).
 // - Class equality (only if class is not parameterized).
 // Inputs:
 // - R0: object.
 // - R1: instantiator type arguments or raw_null.
 // Returns:
 // - true or false in R0.
 void FlowGraphCompiler::GenerateInstanceOf(TokenPosition token_pos,
                                            intptr_t deopt_id,
                                            const AbstractType& type,
+                                           bool negate_result,
                                            LocationSummary* locs) {
   ASSERT(type.IsFinalized() && !type.IsMalformed() && !type.IsMalbounded());
   ASSERT(!type.IsObjectType() && !type.IsDynamicType());
 
   // Preserve instantiator type arguments (R1).
   __ Push(R1);
 
   Label is_instance, is_not_instance;
   // If type is instantiated and non-parameterized, we can inline code
   // checking whether the tested instance is a Smi.
@@ skipping 23 matching lines @@
     __ PushObject(Object::null_object());  // Make room for the result.
     __ Push(R0);                           // Push the instance.
     __ PushObject(type);                   // Push the type.
     __ Push(R1);  // Push instantiator type arguments (R1).
     __ LoadUniqueObject(R0, test_cache);
     __ Push(R0);
     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);
-    __ Pop(R0);
+    if (negate_result) {
+      __ Pop(R1);
+      __ LoadObject(R0, Bool::True());
+      __ CompareRegisters(R1, R0);
+      __ b(&done, NE);
+      __ LoadObject(R0, Bool::False());
+    } else {
+      __ Pop(R0);
+    }
     __ b(&done);
   }
   __ Bind(&is_not_instance);
-  __ LoadObject(R0, Bool::Get(false));
+  __ LoadObject(R0, Bool::Get(negate_result));
   __ b(&done);
 
   __ Bind(&is_instance);
-  __ LoadObject(R0, Bool::Get(true));
+  __ LoadObject(R0, Bool::Get(!negate_result));
   __ Bind(&done);
   // Remove instantiator type arguments (R1).
   __ Drop(1);
 }
 
 
 // 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).
@@ skipping 1222 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   __ PopDouble(reg);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64