[turbofan] Allow indexed access to node inputs/input_edges

src/compiler/ast-graph-builder.cc

 // Copyright 2014 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/ast-graph-builder.h"
 
 #include "src/ast/compile-time-value.h"
 #include "src/ast/scopes.h"
 #include "src/compilation-info.h"
 #include "src/compiler.h"
@@ skipping 640 matching lines @@
     loop->Merge(osr_env);
   }
   return loop;
 }
 
 
 void AstGraphBuilder::Environment::UpdateStateValues(Node** state_values,
                                                      int offset, int count) {
   bool should_update = false;
   Node** env_values = (count == 0) ? nullptr : &values()->at(offset);
-  if (*state_values == nullptr || (*state_values)->InputCount() != count) {
+  if (*state_values == nullptr) {
     should_update = true;
   } else {
-    DCHECK(static_cast<size_t>(offset + count) <= values()->size());
-    for (int i = 0; i < count; i++) {
-      if ((*state_values)->InputAt(i) != env_values[i]) {
-        should_update = true;
-        break;
+    Node::Inputs inputs = (*state_values)->inputs();
+    if (inputs.count() != count) {
+      should_update = true;
+    } else {
+      DCHECK(static_cast<size_t>(offset + count) <= values()->size());
+      for (int i = 0; i < count; i++) {
+        if (inputs[i] != env_values[i]) {
+          should_update = true;
+          break;
+        }

[Jarin, 2017/01/10 10:53:38]

This looks longer and harder to read. Do we have to do this?

[Leszek Swirski, 2017/01/10 12:03:38]

We don't, especially since this code is dying soon. I've reverted it.

       }
     }
   }
   if (should_update) {
     const Operator* op = common()->StateValues(count, SparseInputMask::Dense());
     (*state_values) = graph()->NewNode(op, count, env_values);
   }
 }
 
 
@@ skipping 2620 matching lines @@
     float invocation_frequency, LoopAssignmentAnalysis* loop_assignment,
     SourcePositionTable* source_positions, int inlining_id)
     : AstGraphBuilder(local_zone, info, jsgraph, invocation_frequency,
                       loop_assignment),
       source_positions_(source_positions),
       start_position_(info->shared_info()->start_position(), inlining_id) {}
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8