[turbofan] Fix -Wsign-compare warnings.

src/compiler/int64-lowering.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/int64-lowering.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/diamond.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 224 matching lines @@
       } else {
         if (HasReplacementLow(node->InputAt(2))) {
           node->ReplaceInput(2, GetReplacementLow(node->InputAt(2)));
         }
       }
       break;
     }
     case IrOpcode::kStart: {
       int parameter_count = GetParameterCountAfterLowering(signature());
       // Only exchange the node if the parameter count actually changed.
-      if (parameter_count != signature()->parameter_count()) {
+      if (parameter_count != static_cast<int>(signature()->parameter_count())) {
         int delta =
             parameter_count - static_cast<int>(signature()->parameter_count());
         int new_output_count = node->op()->ValueOutputCount() + delta;
         NodeProperties::ChangeOp(node, common()->Start(new_output_count));
       }
       break;
     }
     case IrOpcode::kParameter: {
       DCHECK(node->InputCount() == 1);
       // Only exchange the node if the parameter count actually changed. We do
       // not even have to do the default lowering because the the start node,
       // the only input of a parameter node, only changes if the parameter count
       // changes.
       if (GetParameterCountAfterLowering(signature()) !=
-          signature()->parameter_count()) {
+          static_cast<int>(signature()->parameter_count())) {
         int old_index = ParameterIndexOf(node->op());
         int new_index = GetParameterIndexAfterLowering(signature(), old_index);
         NodeProperties::ChangeOp(node, common()->Parameter(new_index));
 
         Node* high_node = nullptr;
         if (signature()->GetParam(old_index) ==
             MachineRepresentation::kWord64) {
           high_node = graph()->NewNode(common()->Parameter(new_index + 1),
                                        graph()->start());
         }
         ReplaceNode(node, node, high_node);
       }
       break;
     }
     case IrOpcode::kReturn: {
       DefaultLowering(node);
       int new_return_count = GetReturnCountAfterLowering(signature());
-      if (signature()->return_count() != new_return_count) {
+      if (static_cast<int>(signature()->return_count()) != new_return_count) {
         NodeProperties::ChangeOp(node, common()->Return(new_return_count));
       }
       break;
     }
     case IrOpcode::kCall: {
       // TODO(turbofan): Make WASM code const-correct wrt. CallDescriptor.
       CallDescriptor* descriptor =
           const_cast<CallDescriptor*>(CallDescriptorOf(node->op()));
       if (DefaultLowering(node) ||
           (descriptor->ReturnCount() == 1 &&
@@ skipping 599 matching lines @@
                     common()->Phi(MachineRepresentation::kWord32, value_count),
                     value_count + 1, inputs_low, false),
                 graph()->NewNode(
                     common()->Phi(MachineRepresentation::kWord32, value_count),
                     value_count + 1, inputs_high, false));
   }
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8