[turbofan] cleanup InstructionOperand a little

src/compiler/graph-visualizer.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/graph-visualizer.h"
 
 #include <sstream>
 #include <string>
 
 #include "src/code-stubs.h"
@@ skipping 690 matching lines @@
     PrintLiveRange(range, "object");
   }
 }
 
 
 void GraphC1Visualizer::PrintLiveRange(LiveRange* range, const char* type) {
   if (range != NULL && !range->IsEmpty()) {
     PrintIndent();
     os_ << range->id() << " " << type;
     if (range->HasRegisterAssigned()) {
-      InstructionOperand op = range->GetAssignedOperand();
+      AllocatedOperand op = AllocatedOperand::cast(range->GetAssignedOperand());
       int assigned_reg = op.index();
       if (op.IsDoubleRegister()) {
         os_ << " \"" << DoubleRegister::AllocationIndexToString(assigned_reg)
             << "\"";
       } else {
         DCHECK(op.IsRegister());
         os_ << " \"" << Register::AllocationIndexToString(assigned_reg) << "\"";
       }
     } else if (range->IsSpilled()) {
+      auto top = range->TopLevel();
       int index = -1;
-      if (range->TopLevel()->HasSpillRange()) {
+      if (top->HasSpillRange()) {
         index = kMaxInt;  // This hasn't been set yet.
+      } else if (top->GetSpillOperand()->IsConstant()) {
+        os_ << " \"const(nostack):"
+            << ConstantOperand::cast(top->GetSpillOperand())->virtual_register()
+            << "\"";
       } else {
-        index = range->TopLevel()->GetSpillOperand()->index();
-      }
-      if (range->TopLevel()->Kind() == DOUBLE_REGISTERS) {
-        os_ << " \"double_stack:" << index << "\"";
-      } else if (range->TopLevel()->Kind() == GENERAL_REGISTERS) {
-        os_ << " \"stack:" << index << "\"";
-      } else {
-        os_ << " \"const(nostack):" << index << "\"";
+        index = AllocatedOperand::cast(top->GetSpillOperand())->index();
+        if (top->Kind() == DOUBLE_REGISTERS) {
+          os_ << " \"double_stack:" << index << "\"";
+        } else if (top->Kind() == GENERAL_REGISTERS) {
+          os_ << " \"stack:" << index << "\"";
+        }
       }
     }
     int parent_index = -1;
     if (range->IsChild()) {
       parent_index = range->parent()->id();
     } else {
       parent_index = range->id();
     }
     InstructionOperand* op = range->FirstHint();
     int hint_index = -1;
@@ skipping 74 matching lines @@
         os << "#" << SafeId(i) << ":" << SafeMnemonic(i);
       }
       os << ")" << std::endl;
     }
   }
   return os;
 }
 }
 }
 }  // namespace v8::internal::compiler