Fixed HCheckSmiOrInt <-> HBoundsCheck interaction wrt. representations

BUG=v8:2556

Review URL: https://codereview.chromium.org/12321165

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13820 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.cc

@@ -930,12 +930,14 @@ void HBoundsCheck::PrintDataTo(StringStream* stream) {
 void HBoundsCheck::InferRepresentation(HInferRepresentation* h_infer) {
   ASSERT(CheckFlag(kFlexibleRepresentation));
   Representation r;
+  HValue* actual_length = length()->ActualValue();
+  HValue* actual_index = index()->ActualValue();
   if (key_mode_ == DONT_ALLOW_SMI_KEY ||
-      !length()->representation().IsTagged()) {
+      !actual_length->representation().IsTagged()) {
     r = Representation::Integer32();
-  } else if (index()->representation().IsTagged() ||
-      (index()->ActualValue()->IsConstant() &&
-       HConstant::cast(index()->ActualValue())->HasSmiValue())) {
+  } else if (actual_index->representation().IsTagged() ||
+      (actual_index->IsConstant() &&
+       HConstant::cast(actual_index)->HasSmiValue())) {
     // If the index is tagged, or a constant that holds a Smi, allow the length
     // to be tagged, since it is usually already tagged from loading it out of
     // the length field of a JSArray. This allows for direct comparison without
@@ -2566,8 +2568,9 @@ HType HCheckSmi::CalculateInferredType() {
 
 void HCheckSmiOrInt32::InferRepresentation(HInferRepresentation* h_infer) {
   ASSERT(CheckFlag(kFlexibleRepresentation));
-  Representation r = value()->representation().IsTagged()
-      ? Representation::Tagged() : Representation::Integer32();
+  ASSERT(UseCount() == 1);
+  HUseIterator use = uses();
+  Representation r = use.value()->RequiredInputRepresentation(use.index());
   UpdateRepresentation(r, h_infer, "checksmiorint32");
 }
 

src/hydrogen-instructions.h

@@ -2868,7 +2868,7 @@ class HCheckSmiOrInt32: public HUnaryOperation {
   }
 
   virtual HValue* Canonicalize() {
-    if (representation().IsTagged() && !type().IsSmi()) {
+    if (representation().IsTagged() && !value()->type().IsSmi()) {
       return this;
     } else {
       return value();