Re-land Crankshaft-generated KeyedLoad stubs.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index c6bf71d8356d58b1020128c10cbcc8009de984de..b7866c6837f13736d199be7198f0d916da623ec7 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -1944,7 +1944,7 @@ class HJSArrayLength: public HTemplateInstruction<2> {
     // object. It is guaranteed to be 32 bit integer, but it can be
     // represented as either a smi or heap number.
     SetOperandAt(0, value);
-    SetOperandAt(1, typecheck);
+    SetOperandAt(1, typecheck != NULL ? typecheck : value);

[Jakob Kummerow, 2012/12/11 14:05:54]

I could swear I've reviewed this change before... ah, yes:
https://codereview.chromium.org/11464027/

[danno, 2012/12/12 00:36:03]

Landed the other patch first, rebased on it.
On 2012/12/11 14:05:54, Jakob wrote:

     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnArrayLengths);
@@ -1958,7 +1958,11 @@ class HJSArrayLength: public HTemplateInstruction<2> {
   virtual void PrintDataTo(StringStream* stream);
 
   HValue* value() { return OperandAt(0); }
-  HValue* typecheck() { return OperandAt(1); }
+  HValue* typecheck() {
+    ASSERT(HasTypeCheck());
+    return OperandAt(1);
+  }
+  bool HasTypeCheck() const { return OperandAt(0) != OperandAt(1); }
 
   DECLARE_CONCRETE_INSTRUCTION(JSArrayLength)
 
@@ -2159,14 +2163,18 @@ class HLoadElements: public HTemplateInstruction<2> {
  public:
   HLoadElements(HValue* value, HValue* typecheck) {
     SetOperandAt(0, value);
-    SetOperandAt(1, typecheck);
+    SetOperandAt(1, typecheck != NULL ? typecheck : value);
     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnElementsPointer);
   }
 
   HValue* value() { return OperandAt(0); }
-  HValue* typecheck() { return OperandAt(1); }
+  HValue* typecheck() {
+    ASSERT(HasTypeCheck());
+    return OperandAt(1);
+  }
+  bool HasTypeCheck() const { return OperandAt(0) != OperandAt(1); }
 
   virtual void PrintDataTo(StringStream* stream);
 
@@ -4387,7 +4395,7 @@ class HLoadKeyed
     bit_field_ = ElementsKindField::encode(elements_kind);
     SetOperandAt(0, obj);
     SetOperandAt(1, HBoundsCheck::ExtractUncheckedIndex(checked_key));
-    SetOperandAt(2, dependency);
+    SetOperandAt(2, dependency != NULL ? dependency : obj);
     SetOperandAt(3, checked_key);
 
     if (!is_external()) {
@@ -4429,7 +4437,11 @@ class HLoadKeyed
   }
   HValue* elements() { return OperandAt(0); }
   HValue* key() { return OperandAt(1); }
-  HValue* dependency() { return OperandAt(2); }
+  HValue* dependency() {
+    ASSERT(HasDependency());
+    return OperandAt(2);
+  }
+  bool HasDependency() const { return OperandAt(0) != OperandAt(2); }
   HValue* checked_key() { return OperandAt(3); }
   uint32_t index_offset() { return IndexOffsetField::decode(bit_field_); }
   void SetIndexOffset(uint32_t index_offset) {