Implement TypeMask.isDisjoint instead of using intersection.

pkg/compiler/lib/src/ssa/optimize.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of ssa;
 
 abstract class OptimizationPhase {
   String get name;
   void visitGraph(HGraph graph);
 }
@@ skipping 575 matching lines @@
     HInstruction right = node.right;
     TypeMask leftType = left.instructionType;
     TypeMask rightType = right.instructionType;
 
     HInstruction makeTrue() => graph.addConstantBool(true, compiler);
     HInstruction makeFalse() => graph.addConstantBool(false, compiler);
 
     // Intersection of int and double return conflicting, so
     // we don't optimize on numbers to preserve the runtime semantics.
     if (!(left.isNumberOrNull(compiler) && right.isNumberOrNull(compiler))) {
-      TypeMask intersection = leftType.intersection(rightType, compiler.world);
-      if (intersection.isEmpty && !intersection.isNullable) {
+      if (leftType.isDisjoint(rightType, compiler.world)) {
         return makeFalse();
       }
     }
 
     if (left.isNull() && right.isNull()) {
       return makeTrue();
     }
 
     HInstruction compareConstant(HConstant constant, HInstruction input) {
       if (constant.constant.isTrue) {
@@ skipping 122 matching lines @@
     // a class [:A<T>:], is currently always considered to have the
     // raw type.
     } else if (!RuntimeTypes.hasTypeArguments(type)) {
       TypeMask expressionMask = expression.instructionType;
       assert(TypeMask.assertIsNormalized(expressionMask, classWorld));
       TypeMask typeMask = (element == coreClasses.nullClass)
           ? new TypeMask.subtype(element, classWorld)
           : new TypeMask.nonNullSubtype(element, classWorld);
       if (expressionMask.union(typeMask, classWorld) == typeMask) {
         return graph.addConstantBool(true, compiler);
-      } else if (expressionMask.intersection(typeMask,
-                                             compiler.world).isEmpty) {
+      } else if (expressionMask.isDisjoint(typeMask, compiler.world)) {
         return graph.addConstantBool(false, compiler);
       }
     }
     return node;
   }
 
   HInstruction visitTypeConversion(HTypeConversion node) {
     DartType type = node.typeExpression;
     if (type != null) {
       if (type.isMalformed) {
@@ skipping 1395 matching lines @@
   /**
    * Returns whether [first] and [second] may alias to the same object.
    */
   bool mayAlias(HInstruction first, HInstruction second) {
     if (mustAlias(first, second)) return true;
     if (isConcrete(first) && isConcrete(second)) return false;
     if (nonEscapingReceivers.contains(first)) return false;
     if (nonEscapingReceivers.contains(second)) return false;
     // Typed arrays of different types might have a shared buffer.
     if (couldBeTypedArray(first) && couldBeTypedArray(second)) return true;
-    TypeMask intersection = first.instructionType.intersection(
+    return !first.instructionType.isDisjoint(
         second.instructionType, compiler.world);
-    if (intersection.isEmpty) return false;
-    return true;
   }
 
   bool isFinal(Element element) {
     return compiler.world.fieldNeverChanges(element);
   }
 
   bool isConcrete(HInstruction instruction) {
     return instruction is HForeignNew
         || instruction is HConstant
         || instruction is HLiteralList;
@@ skipping 231 matching lines @@
 
     keyedValues.forEach((receiver, values) {
       result.keyedValues[receiver] =
           new Map<HInstruction, HInstruction>.from(values);
     });
 
     result.nonEscapingReceivers.addAll(nonEscapingReceivers);
     return result;
   }
 }