Eliminate the type distinction between BindInstr and DoInstr.

runtime/vm/il_printer.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/il_printer.h"
 
 #include "vm/intermediate_language.h"
 #include "vm/os.h"
 
 namespace dart {
@@ skipping 349 matching lines @@
 void TargetEntryInstr::PrintTo(BufferFormatter* f) const {
   f->Print("%2d: [target", block_id());
   if (HasTryIndex()) {
     f->Print(" catch %d]", try_index());
   } else {
     f->Print("]");
   }
 }
 
 
-void DoInstr::PrintTo(BufferFormatter* f) const {
-  f->Print("    ");
-  computation()->PrintTo(f);
-}
-
-
 void BindInstr::PrintTo(BufferFormatter* f) const {
-  if (ssa_temp_index() != -1) {
+  if (!is_used()) {
+    f->Print("    ");
+  } else if (ssa_temp_index() != -1) {
     f->Print("    v%d <- ", ssa_temp_index());
   } else {
     f->Print("    t%d <- ", temp_index());
   }
   computation()->PrintTo(f);
 }
 
 
 void ReturnInstr::PrintTo(BufferFormatter* f) const {
   f->Print("    %s ", DebugName());
@@ skipping 223 matching lines @@
 void TargetEntryInstr::PrintToVisualizer(BufferFormatter* f) const {
   f->Print("_ [target");
   if (HasTryIndex()) {
     f->Print(" catch %d]", try_index());
   } else {
     f->Print("]");
   }
 }
 
 
-void DoInstr::PrintToVisualizer(BufferFormatter* f) const {
-  f->Print("_ ");
-  computation()->PrintTo(f);
-}
-
-
 void BindInstr::PrintToVisualizer(BufferFormatter* f) const {
-  if (ssa_temp_index() != -1) {
+  if (!is_used()) {
+    f->Print("_ ");
+  } else if (ssa_temp_index() != -1) {
     f->Print("v%d ", ssa_temp_index());
   } else {
     f->Print("t%d ", temp_index());
   }
   computation()->PrintTo(f);
 }
 
 
 void ReturnInstr::PrintToVisualizer(BufferFormatter* f) const {
   f->Print("_ %s ", DebugName());
@@ skipping 33 matching lines @@
 void Environment::PrintTo(BufferFormatter* f) const {
   f->Print(" env={ ");
   for (intptr_t i = 0; i < values_.length(); ++i) {
     if (i > 0) f->Print(", ");
     values_[i]->PrintTo(f);
   }
   f->Print(" }");
 }
 
 }  // namespace dart