Fix a stack state error in checked mode.

runtime/vm/flow_graph_compiler_x64.cc

 // Copyright (c) 2012, 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 "lib/error.h"
@@ skipping 580 matching lines @@
     __ PushObject(dst_name);  // Push the name of the destination.
     __ PushObject(error_message);
     GenerateCallRuntime(deopt_id,
                         token_pos,
                         try_index,
                         kMalformedTypeErrorRuntimeEntry);
     // We should never return here.
     __ int3();
 
     __ Bind(&is_assignable);  // For a null object.
+    __ popq(RDX);  // Remove pushed instantiator type arguments.
+    __ popq(RCX);  // Remove pushed instantiator.
     return;
   }
 
   // Generate inline type check, linking to runtime call if not assignable.
   SubtypeTestCache& test_cache = SubtypeTestCache::ZoneHandle();
   test_cache = GenerateInlineInstanceof(token_pos, dst_type,
                                         &is_assignable, &runtime_call);
 
   __ Bind(&runtime_call);
   __ movq(RDX, Address(RSP, 0));  // Get instantiator type arguments.
   __ movq(RCX, Address(RSP, kWordSize));  // Get instantiator.
   __ PushObject(Object::ZoneHandle());  // Make room for the result.
   __ pushq(RAX);  // Push the source object.
   __ PushObject(dst_type);  // Push the type of the destination.
   __ pushq(RCX);  // Instantiator.
   __ pushq(RDX);  // Instantiator type arguments.
   __ PushObject(dst_name);  // Push the name of the destination.
   __ LoadObject(RAX, test_cache);
   __ pushq(RAX);
   GenerateCallRuntime(deopt_id,
                       token_pos,
                       try_index,
                       kTypeCheckRuntimeEntry);
   // Pop the parameters supplied to the runtime entry. The result of the
   // type check runtime call is the checked value.
   __ Drop(6);
   __ popq(RAX);
 
   __ Bind(&is_assignable);
-  __ popq(RDX);  // Remove pushed instantiator type arguments..
+  __ popq(RDX);  // Remove pushed instantiator type arguments.
   __ popq(RCX);  // Remove pushed instantiator.
 }
 
 
 void FlowGraphCompiler::EmitInstructionPrologue(Instruction* instr) {
   LocationSummary* locs = instr->locs();
   ASSERT(locs != NULL);
 
   frame_register_allocator()->AllocateRegisters(instr);
 
@@ skipping 572 matching lines @@
 void ParallelMoveResolver::Exchange(const Address& mem1, const Address& mem2) {
   __ Exchange(mem1, mem2);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64