Don't require eliminating certain type checks in unoptimized compilation.

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"
 #include "vm/compiler.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
 #include "vm/deopt_instructions.h"
 #include "vm/il_printer.h"
 #include "vm/locations.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, trap_on_deoptimization, false, "Trap on deoptimization.");
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(int, reoptimization_counter_threshold);
-DECLARE_FLAG(bool, eliminate_type_checks);
 DECLARE_FLAG(bool, enable_simd_inline);
 
 
 FlowGraphCompiler::~FlowGraphCompiler() {
   // BlockInfos are zone-allocated, so their destructors are not called.
   // Verify the labels explicitly here.
   for (int i = 0; i < block_info_.length(); ++i) {
     ASSERT(!block_info_[i]->jump_label()->IsLinked());
   }
 }
@@ skipping 607 matching lines @@
   ASSERT(dst_type.IsMalformedOrMalbounded() ||
          (!dst_type.IsDynamicType() && !dst_type.IsObjectType()));
   // Preserve instantiator (R2) and its type arguments (R1).
   __ Push(R2);
   __ Push(R1);
   // A null object is always assignable and is returned as result.
   Label is_assignable, runtime_call;
   __ CompareObject(R0, Object::null_object(), PP);
   __ b(&is_assignable, EQ);
 
-  if (!FLAG_eliminate_type_checks || dst_type.IsMalformed()) {
-    // If type checks are not eliminated during the graph building then
-    // a transition sentinel can be seen here.
-    __ CompareObject(R0, Object::transition_sentinel(), PP);
-    __ b(&is_assignable, EQ);
-  }
-
   // Generate throw new TypeError() if the type is malformed or malbounded.
   if (dst_type.IsMalformedOrMalbounded()) {
     __ PushObject(Object::ZoneHandle(), PP);  // Make room for the result.
     __ Push(R0);  // Push the source object.
     __ PushObject(dst_name, PP);  // Push the name of the destination.
     __ PushObject(dst_type, PP);  // Push the type of the destination.
     GenerateRuntimeCall(token_pos,
                         deopt_id,
                         kBadTypeErrorRuntimeEntry,
                         3,
@@ skipping 1074 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   UNIMPLEMENTED();
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64