[turbofan] Weakening of types must handle ranges inside unions.

test/cctest/test-types.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <vector>
 
 #include "src/hydrogen-types.h"
 #include "src/isolate-inl.h"
 #include "src/types.h"
 #include "test/cctest/cctest.h"
@@ skipping 1813 matching lines @@
           TypeHandle union23 = T.Union(type2, type3);
           TypeHandle intersect1_23 = T.Intersect(type1, union23);
           TypeHandle union12_13 = T.Union(intersect12, intersect13);
           CHECK(Equal(intersect1_23, union12_13));
         }
       }
     }
     */
   }
 
+  TypeHandle RangeToHandle(typename Type::RangeType* range) {

[rossberg, 2014/11/12 14:51:15]

That seems a bit hacky. Can we instead have a proper generic handlify function
inherited from the respective Rep classes?

+    return T.Range(range->Min(), range->Max());
+  }
+
+  void GetRange() {
+    // GetRange(Range(a, b)) = Range(a, b).
+    for (TypeIterator it1 = T.types.begin(); it1 != T.types.end(); ++it1) {
+      TypeHandle type1 = *it1;
+      if (type1->IsRange()) {
+        typename Type::RangeType* range = type1->GetRange();
+        CHECK(type1->Equals(RangeToHandle(range)));
+      }
+    }
+
+    // GetRange(Union(Constant(x), Range(min,max))) == Range(min, max).
+    for (TypeIterator it1 = T.types.begin(); it1 != T.types.end(); ++it1) {
+      for (TypeIterator it2 = T.types.begin(); it2 != T.types.end(); ++it2) {
+        TypeHandle type1 = *it1;
+        TypeHandle type2 = *it2;
+        if (type1->IsConstant() && type2->IsRange()) {
+          TypeHandle u = T.Union(type1, type2);
+
+          CHECK(type2->Equals(RangeToHandle(u->GetRange())));
+        }
+      }
+    }
+
+    // GetRange is monotone whenever it is defined.
+    for (TypeIterator it1 = T.types.begin(); it1 != T.types.end(); ++it1) {
+      for (TypeIterator it2 = T.types.begin(); it2 != T.types.end(); ++it2) {
+        TypeHandle type1 = *it1;
+        TypeHandle type2 = *it2;
+        if (type1->GetRange() != NULL && type2->GetRange() != NULL &&
+            type1->Is(type2)) {
+          TypeHandle r1 = RangeToHandle(type1->GetRange());
+          TypeHandle r2 = RangeToHandle(type2->GetRange());
+          CHECK(r1->Is(r2));
+        }
+      }
+    }
+  }
+
   template<class Type2, class TypeHandle2, class Region2, class Rep2>
   void Convert() {
     Types<Type2, TypeHandle2, Region2> T2(
         Rep2::ToRegion(&zone, isolate), isolate);
     for (TypeIterator it = T.types.begin(); it != T.types.end(); ++it) {
       TypeHandle type1 = *it;
       TypeHandle2 type2 = T2.template Convert<Type>(type1);
       TypeHandle type3 = T.template Convert<Type2>(type2);
       CheckEqual(type1, type3);
     }
@@ skipping 179 matching lines @@
 }
 
 
 TEST(Distributivity) {
   CcTest::InitializeVM();
   ZoneTests().Distributivity();
   HeapTests().Distributivity();
 }
 
 
+TEST(GetRange) {
+  CcTest::InitializeVM();
+  ZoneTests().GetRange();
+  HeapTests().GetRange();
+}
+
+
 TEST(Convert) {
   CcTest::InitializeVM();
   ZoneTests().Convert<HeapType, Handle<HeapType>, Isolate, HeapRep>();
   HeapTests().Convert<Type, Type*, Zone, ZoneRep>();
 }
 
 
 TEST(HTypeFromType) {
   CcTest::InitializeVM();
   ZoneTests().HTypeFromType();
   HeapTests().HTypeFromType();
 }