Fix a bug in block reordering/block compaction.

runtime/vm/intermediate_language_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/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 4512 matching lines @@
   compiler->SetNeedsStacktrace(catch_try_index());
   compiler->GenerateCallRuntime(token_pos(),
                                 deopt_id(),
                                 kReThrowRuntimeEntry,
                                 2,
                                 locs());
   __ int3();
 }
 
 
+void GraphEntryInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  if (!compiler->CanFallThroughTo(normal_entry())) {
+    __ jmp(compiler->GetJumpLabel(normal_entry()));
+  }
+}
+
+
 void TargetEntryInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ Bind(compiler->GetJumpLabel(this));
   if (!compiler->is_optimizing()) {
     compiler->AddCurrentDescriptor(PcDescriptors::kDeopt,
                                    deopt_id_,
                                    Scanner::kDummyTokenIndex);
     // Add an edge counter.
     const Array& counter = Array::ZoneHandle(Array::New(1, Heap::kOld));
     counter.SetAt(0, Smi::Handle(Smi::New(0)));
     Label done;
@@ skipping 55 matching lines @@
     __ jmp(compiler->GetJumpLabel(true_successor()));
   } else if (!value && !compiler->CanFallThroughTo(false_successor())) {
     __ jmp(compiler->GetJumpLabel(false_successor()));
   }
 }
 
 
 void ControlInstruction::EmitBranchOnCondition(FlowGraphCompiler* compiler,
                                                Condition true_condition) {
   if (compiler->CanFallThroughTo(false_successor())) {
-    // If the next block is the false successor we will fall through to it.
+    // If the next block is the false successor, fall through to it.
     __ j(true_condition, compiler->GetJumpLabel(true_successor()));
   } else {
-    // If the next block is the true successor we negate comparison and fall
-    // through to it.
+    // If the next block is not the false successor, branch to it.
     Condition false_condition = NegateCondition(true_condition);
     __ j(false_condition, compiler->GetJumpLabel(false_successor()));
 
     // Fall through or jump to the true successor.
     if (!compiler->CanFallThroughTo(true_successor())) {
       __ jmp(compiler->GetJumpLabel(true_successor()));
     }
   }
 }
 
@@ skipping 207 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64