Make start node a value input to parameter nodes.

src/compiler/verifier.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/verifier.h"
 
 #include "src/compiler/generic-algorithm.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/generic-node.h"
 #include "src/compiler/graph-inl.h"
@@ skipping 84 matching lines @@
     CHECK(NodeProperties::HasControlOutput(control));
     CHECK(IsDefUseChainLinkPresent(control, node));
     CHECK(IsUseDefChainLinkPresent(control, node));
   }
 
   // Verify all successors are projections if multiple value outputs exist.
   if (NodeProperties::GetValueOutputCount(node) > 1) {
     Node::Uses uses = node->uses();
     for (Node::Uses::iterator it = uses.begin(); it != uses.end(); ++it) {
       CHECK(!NodeProperties::IsValueEdge(it.edge()) ||
-            (*it)->opcode() == IrOpcode::kProjection);
+            (*it)->opcode() == IrOpcode::kProjection ||
+            (*it)->opcode() == IrOpcode::kParameter);
     }
   }
 
   switch (node->opcode()) {
     case IrOpcode::kStart:
       // Start has no inputs.
       CHECK_EQ(0, input_count);
       break;
     case IrOpcode::kEnd:
       // End has no outputs.
@@ skipping 25 matching lines @@
       break;
     case IrOpcode::kLoop:
     case IrOpcode::kMerge:
       break;
     case IrOpcode::kReturn:
       // TODO(rossberg): check successor is End
       break;
     case IrOpcode::kThrow:
       // TODO(rossberg): what are the constraints on these?
       break;
-    case IrOpcode::kParameter:
-      // Parameters have no inputs.
-      CHECK_EQ(0, input_count);
+    case IrOpcode::kParameter: {
+      // Parameters have the start node as inputs.
+      CHECK_EQ(1, input_count);
+      CHECK_EQ(IrOpcode::kStart,
+               NodeProperties::GetValueInput(node, 0)->opcode());
+      // Parameter has an input that produces enough values.
+      int index = static_cast<Operator1<int>*>(node->op())->parameter();
+      Node* input = NodeProperties::GetValueInput(node, 0);
+      // Currently, parameter indices start at -1 instead of 0.
+      CHECK_GT(NodeProperties::GetValueOutputCount(input), index + 1);
       break;
+    }
     case IrOpcode::kInt32Constant:
     case IrOpcode::kInt64Constant:
     case IrOpcode::kFloat64Constant:
     case IrOpcode::kExternalConstant:
     case IrOpcode::kNumberConstant:
     case IrOpcode::kHeapConstant:
       // Constants have no inputs.
       CHECK_EQ(0, input_count);
       break;
     case IrOpcode::kPhi: {
@@ skipping 58 matching lines @@
   // All control nodes reachable from end are reachable from start.
   for (NodeSet::iterator it = visitor.reached_from_end.begin();
        it != visitor.reached_from_end.end(); ++it) {
     CHECK(!NodeProperties::IsControl(*it) ||
           visitor.reached_from_start.count(*it));
   }
 }
 }
 }
 }  // namespace v8::internal::compiler