Second attempt: Improve our type feedback by recogizining never-executed IC c...

src/type-info.cc

Index: src/type-info.cc
===================================================================
--- src/type-info.cc	(revision 6011)
+++ src/type-info.cc	(working copy)
@@ -142,6 +142,9 @@
   CompareIC::State state = static_cast<CompareIC::State>(code->compare_state());
   switch (state) {
     case CompareIC::UNINITIALIZED:
+      // Uninitialized means never executed.
+      // TODO(fschneider): Introduce a separate value for never-executed ICs.
+      return unknown;
     case CompareIC::SMIS:
       return TypeInfo::Smi();
     case CompareIC::HEAP_NUMBERS:
@@ -184,6 +187,9 @@
 
     switch (type) {
       case TRBinaryOpIC::UNINITIALIZED:
+        // Uninitialized means never executed.
+        // TODO(fschneider): Introduce a separate value for never-executed ICs
+        return unknown;
       case TRBinaryOpIC::SMI:
         switch (result_type) {
           case TRBinaryOpIC::UNINITIALIZED:
@@ -224,6 +230,9 @@
   CompareIC::State state = static_cast<CompareIC::State>(code->compare_state());
   switch (state) {
     case CompareIC::UNINITIALIZED:
+      // Uninitialized means never executed.
+      // TODO(fschneider): Introduce a separate value for never-executed ICs.
+      return unknown;
     case CompareIC::SMIS:
       return TypeInfo::Smi();
     case CompareIC::HEAP_NUMBERS: