Fix bug in optimization in the presence of externalized strings.

runtime/vm/intermediate_language.cc

Index: runtime/vm/intermediate_language.cc
===================================================================
--- runtime/vm/intermediate_language.cc	(revision 17269)
+++ runtime/vm/intermediate_language.cc	(working copy)
@@ -102,6 +102,17 @@
   return true;
 }
 

[Vyacheslav Egorov (Google), 2013/01/18 13:34:44]

new line here

[Florian Schneider, 2013/01/18 16:22:38]

Done.

+bool CheckClassInstr::AffectedBySideEffect() const {
+  // The class-id of string objects is not invariant: Externalization of strings
+  // via the API can change the class-id.
+  for (intptr_t i = 0; i < unary_checks().NumberOfChecks(); i++) {

[Vyacheslav Egorov (Google), 2013/01/18 13:34:44]

optimizer has ICDataHasReceiverClassId that does something like this. 

Can we make it into a utility function and use it here?

return !unary_checks().Contains(kOneByteStringCid) &&
!unary_checks().Contains(kTwoByteStringCid); ?

[Florian Schneider, 2013/01/18 16:22:38]

Done.

+    intptr_t cid = unary_checks().GetReceiverClassIdAt(i);
+    if (cid == kOneByteStringCid || cid == kTwoByteStringCid) {
+      return true;
+    }
+  }
+  return false;
+}
 

[Vyacheslav Egorov (Google), 2013/01/18 13:34:44]

new line here

[Florian Schneider, 2013/01/18 16:22:38]

Done.

 bool CheckArrayBoundInstr::AttributesEqual(Instruction* other) const {
   CheckArrayBoundInstr* other_check = other->AsCheckArrayBound();