Insert representation changes before doing range analysis.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
===================================================================
--- src/hydrogen-instructions.cc	(revision 8984)
+++ src/hydrogen-instructions.cc	(working copy)
@@ -641,6 +641,7 @@
   length()->PrintNameTo(stream);
 }
 
+
 void HCallConstantFunction::PrintDataTo(StringStream* stream) {
   if (IsApplyFunction()) {
     stream->Add("optimized apply ");
@@ -875,6 +876,17 @@
 }
 
 
+Range* HChange::InferRange() {
+  Range* input_range = value()->range();
+  if (from().IsInteger32() &&
+      to().IsTagged() &&
+      input_range != NULL && input_range->IsInSmiRange()) {
+    set_type(HType::Smi());
+  }
+  return input_range != NULL ? input_range->Copy() : HValue::InferRange();

[Vyacheslav Egorov (Chromium), 2011/08/22 12:53:31]

It seems that if we are converting to integer type we can clear minus zero from
resulting range.

[fschneider, 2011/08/23 07:36:10]

Done.

+}
+
+
 Range* HConstant::InferRange() {
   if (has_int32_value_) {
     Range* result = new Range(int32_value_, int32_value_);
@@ -1220,6 +1232,7 @@
           ? left()->range()->Copy()
           : new Range();
       result->Sar(c->Integer32Value());
+      result->set_can_be_minus_zero(false);
       return result;
     }
   }
@@ -1243,6 +1256,7 @@
             ? left()->range()->Copy()
             : new Range();
         result->Sar(c->Integer32Value());
+        result->set_can_be_minus_zero(false);
         return result;
       }
     }
@@ -1259,6 +1273,7 @@
           ? left()->range()->Copy()
           : new Range();
       result->Shl(c->Integer32Value());
+      result->set_can_be_minus_zero(false);
       return result;
     }
   }