Insert representation changes before doing range analysis.

src/hydrogen-instructions.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 623 matching lines @@
   stream->Add("#%d", argument_count());
 }
 
 
 void HBoundsCheck::PrintDataTo(StringStream* stream) {
   index()->PrintNameTo(stream);
   stream->Add(" ");
   length()->PrintNameTo(stream);
 }
 
+
 void HCallConstantFunction::PrintDataTo(StringStream* stream) {
   if (IsApplyFunction()) {
     stream->Add("optimized apply ");
   } else {
     stream->Add("%o ", function()->shared()->DebugName());
   }
   stream->Add("#%d", argument_count());
 }
 
 
@@ skipping 214 matching lines @@
 
 
 Range* HValue::InferRange() {
   // Untagged integer32 cannot be -0, all other representations can.
   Range* result = new Range();
   result->set_can_be_minus_zero(!representation().IsInteger32());
   return result;
 }
 
 
+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_);
     result->set_can_be_minus_zero(false);
     return result;
   }
   return HValue::InferRange();
 }
 
 
@@ skipping 325 matching lines @@
 
 
 Range* HSar::InferRange() {
   if (right()->IsConstant()) {
     HConstant* c = HConstant::cast(right());
     if (c->HasInteger32Value()) {
       Range* result = (left()->range() != NULL)
           ? left()->range()->Copy()
           : new Range();
       result->Sar(c->Integer32Value());
+      result->set_can_be_minus_zero(false);
       return result;
     }
   }
   return HValue::InferRange();
 }
 
 
 Range* HShr::InferRange() {
   if (right()->IsConstant()) {
     HConstant* c = HConstant::cast(right());
     if (c->HasInteger32Value()) {
       int shift_count = c->Integer32Value() & 0x1f;
       if (left()->range()->CanBeNegative()) {
         // Only compute bounds if the result always fits into an int32.
         return (shift_count >= 1)
             ? new Range(0, static_cast<uint32_t>(0xffffffff) >> shift_count)
             : new Range();
       } else {
         // For positive inputs we can use the >> operator.
         Range* result = (left()->range() != NULL)
             ? left()->range()->Copy()
             : new Range();
         result->Sar(c->Integer32Value());
+        result->set_can_be_minus_zero(false);
         return result;
       }
     }
   }
   return HValue::InferRange();
 }
 
 
 Range* HShl::InferRange() {
   if (right()->IsConstant()) {
     HConstant* c = HConstant::cast(right());
     if (c->HasInteger32Value()) {
       Range* result = (left()->range() != NULL)
           ? left()->range()->Copy()
           : new Range();
       result->Shl(c->Integer32Value());
+      result->set_can_be_minus_zero(false);
       return result;
     }
   }
   return HValue::InferRange();
 }
 
 
 
 void HCompareGeneric::PrintDataTo(StringStream* stream) {
   stream->Add(Token::Name(token()));
@@ skipping 580 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal