[WIP] TrapHandler 2014/11/27.

src/compiler/bounds-check-lowering.cc

Index: src/compiler/bounds-check-lowering.cc
diff --git a/src/compiler/bounds-check-lowering.cc b/src/compiler/bounds-check-lowering.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fac51f8be13eccffd952b9564dd5748aaa582b28
--- /dev/null
+++ b/src/compiler/bounds-check-lowering.cc
@@ -0,0 +1,42 @@
+// 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/bounds-check-lowering.h"
+
+#include "src/compiler/js-graph.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+BoundsCheckLowering::~BoundsCheckLowering() {}
+
+
+Reduction BoundsCheckLowering::Reduce(Node* node) {
+  if (node->opcode() != IrOpcode::kBoundsCheck) return NoChange();
+  Node* const offset = node->InputAt(0);
+  Node* const length = node->InputAt(1);
+  Node* const select = graph()->NewNode(
+      common()->Select(kMachUint32, BranchHint::kTrue),
+      graph()->NewNode(machine()->Uint32LessThan(), offset, length), offset,
+      length);
+  return Replace(select);
+}
+
+
+Graph* BoundsCheckLowering::graph() const { return jsgraph()->graph(); }
+
+
+CommonOperatorBuilder* BoundsCheckLowering::common() const {
+  return jsgraph()->common();
+}
+
+
+MachineOperatorBuilder* BoundsCheckLowering::machine() const {
+  return jsgraph()->machine();
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8