[WIP] TrapHandler 2014/11/27.

src/compiler/simplified-operator-reducer.cc

Index: src/compiler/simplified-operator-reducer.cc
diff --git a/src/compiler/simplified-operator-reducer.cc b/src/compiler/simplified-operator-reducer.cc
index a1a6a02bc89381481d961f9e7c22047b6a86e5bb..baa747c6724d604e912c7d93e053cdb9765cd4f4 100644
--- a/src/compiler/simplified-operator-reducer.cc
+++ b/src/compiler/simplified-operator-reducer.cc
@@ -99,40 +99,62 @@ Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
       if (m.HasValue()) return ReplaceNumber(FastUI2D(m.Value()));
       break;
     }
-    case IrOpcode::kLoadElement: {
-      ElementAccess access = ElementAccessOf(node->op());
-      if (access.bounds_check == kTypedArrayBoundsCheck) {
-        NumberMatcher mkey(node->InputAt(1));
-        NumberMatcher mlength(node->InputAt(2));
-        if (mkey.HasValue() && mlength.HasValue()) {
-          // Skip the typed array bounds check if key and length are constant.
-          if (mkey.Value() >= 0 && mkey.Value() < mlength.Value()) {
-            access.bounds_check = kNoBoundsCheck;
-            node->set_op(simplified()->LoadElement(access));
-            return Changed(node);
-          }
-        }
-      }
+    case IrOpcode::kBoundsCheck:
+      return ReduceBoundsCheck(node);
+    default:
       break;
+  }
+  return NoChange();
+}
+
+
+namespace {
+
+// TODO(bmeurer): Move to node-matchers.h/cc
+class BoundsCheckMatcher FINAL : public NodeMatcher {
+ public:
+  typedef Uint32Matcher Offset;
+  typedef Uint32Matcher Length;
+
+  explicit BoundsCheckMatcher(Node* node)
+      : NodeMatcher(node), offset_(InputAt(0)), length_(InputAt(1)) {
+    DCHECK_EQ(IrOpcode::kBoundsCheck, opcode());
+  }
+
+  Offset const& offset() const { return offset_; }
+  Length const& length() const { return length_; }
+  size_t guard() const { return OpParameter<size_t>(op()); }
+
+ private:
+  Offset const offset_;
+  Length const length_;
+};
+
+}  // namespace
+
+
+Reduction SimplifiedOperatorReducer::ReduceBoundsCheck(Node* const node) {
+  BoundsCheckMatcher m(node);
+  if (m.offset().HasValue()) {
+    if (m.length().HasValue()) {
+      return Replace((m.offset().Value() < m.length().Value())
+                         ? m.offset().node()
+                         : m.length().node());
     }
-    case IrOpcode::kStoreElement: {
-      ElementAccess access = ElementAccessOf(node->op());
-      if (access.bounds_check == kTypedArrayBoundsCheck) {
-        NumberMatcher mkey(node->InputAt(1));
-        NumberMatcher mlength(node->InputAt(2));
-        if (mkey.HasValue() && mlength.HasValue()) {
-          // Skip the typed array bounds check if key and length are constant.
-          if (mkey.Value() >= 0 && mkey.Value() < mlength.Value()) {
-            access.bounds_check = kNoBoundsCheck;
-            node->set_op(simplified()->StoreElement(access));
-            return Changed(node);
-          }
-        }
-      }
-      break;
+    if (m.offset().Value() <= m.guard()) {
+      return Replace(m.offset().node());
+    }
+  }
+  if (m.offset().IsInt32Add()) {
+    Uint32BinopMatcher moffset(m.offset().node());
+    if (moffset.right().IsInRange(0, m.guard())) {
+      Node* const chk = graph()->NewNode(
+          simplified()->BoundsCheck(m.guard() - moffset.right().Value()),
+          moffset.left().node(), m.length().node());
+      Node* const add =
+          graph()->NewNode(machine()->Int32Add(), chk, moffset.right().node());
+      return Replace(add);
     }
-    default:
-      break;
   }
   return NoChange();
 }