Allow boundscheck elimination to work on Smi keys.

R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/16035016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15001 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.cc

@@ -1058,6 +1058,7 @@ void HBoundsCheck::ApplyIndexChange() {
         block()->graph()->GetInvalidContext(), current_index, add_offset);
     add->InsertBefore(this);
     add->AssumeRepresentation(index()->representation());
+    add->ClearFlag(kCanOverflow);
     current_index = add;
   }
 

src/hydrogen-instructions.h

@@ -3660,9 +3660,6 @@ class HBoundsCheck: public HTemplateInstruction<2> {
   virtual Representation RequiredInputRepresentation(int arg_index) {
     return representation();
   }
-  virtual Representation observed_input_representation(int index) {
-    return Representation::Integer32();
-  }
 
   virtual bool IsRelationTrueInternal(NumericRelation relation,
                                       HValue* related_value,

src/hydrogen.cc

@@ -4115,7 +4115,7 @@ class BoundsCheckKey : public ZoneObject {
   static BoundsCheckKey* Create(Zone* zone,
                                 HBoundsCheck* check,
                                 int32_t* offset) {
-    if (!check->index()->representation().IsInteger32()) return NULL;
+    if (!check->index()->representation().IsSmiOrInteger32()) return NULL;
 
     HValue* index_base = NULL;
     HConstant* constant = NULL;
@@ -4211,7 +4211,7 @@ class BoundsCheckBbData: public ZoneObject {
   // returns false, otherwise it returns true.
   bool CoverCheck(HBoundsCheck* new_check,
                   int32_t new_offset) {
-    ASSERT(new_check->index()->representation().IsInteger32());
+    ASSERT(new_check->index()->representation().IsSmiOrInteger32());
     bool keep_new_check = false;
 
     if (new_offset > upper_offset_) {
@@ -4320,8 +4320,8 @@ class BoundsCheckBbData: public ZoneObject {
     HValue* index_context = IndexContext(*add, check);
     if (index_context == NULL) return false;
 
-    HConstant* new_constant = new(BasicBlock()->zone())
-       HConstant(new_offset, Representation::Integer32());
+    HConstant* new_constant = new(BasicBlock()->zone()) HConstant(
+        new_offset, representation);
     if (*add == NULL) {
       new_constant->InsertBefore(check);
       (*add) = HAdd::New(
@@ -4453,7 +4453,7 @@ void HGraph::EliminateRedundantBoundsChecks() {
 
 static void DehoistArrayIndex(ArrayInstructionInterface* array_operation) {
   HValue* index = array_operation->GetKey()->ActualValue();
-  if (!index->representation().IsInteger32()) return;
+  if (!index->representation().IsSmiOrInteger32()) return;
 
   HConstant* constant;
   HValue* subexpression;