Extract CallStructure from Selector.

pkg/compiler/lib/src/util/util.dart

 // Copyright (c) 2011, 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.
 
 library dart2js.util;
 
 import 'util_implementation.dart';
 import 'characters.dart';
 
 export 'setlet.dart';
 export 'maplet.dart';
 export 'emptyset.dart';
 
 part 'indentation.dart';
 part 'link.dart';
 
 /// If an integer is masked by this constant, the result is guaranteed to be in
 /// Smi range.
 const int SMI_MASK = 0x3fffffff;
 
+/// Mix the bits of [value] and merge them with [existing].
+int mixHashCodeBits(int existing, int value) {
+  // Spread the bits of value. Try to stay in the 30-bit range to
+  // avoid overflowing into a more expensive integer representation.
+  int h = value & 0x1fffffff;
+  h += ((h & 0x3fff) << 15) ^ 0x1fffcd7d;
+  h ^= (h >> 10);
+  h += ((h & 0x3ffffff) << 3);
+  h ^= (h >> 6);
+  h += ((h & 0x7ffffff) << 2) + ((h & 0x7fff) << 14);
+  h ^= (h >> 16);
+  // Combine the two hash values.
+  int high = existing >> 15;
+  int low = existing & 0x7fff;
+  return ((high * 13) ^ (low * 997) ^ h) & SMI_MASK;
+}
+
 /**
  * Tagging interface for classes from which source spans can be generated.
  */
 // TODO(johnniwinther): Find a better name.
 // TODO(ahe): How about "Bolt"?
 abstract class Spannable {}
 
 class _SpannableSentinel implements Spannable {
   final String name;
 
@@ skipping 177 matching lines @@
   if (usedNames.contains(suggestedName)) {
     int counter = 0;
     while (usedNames.contains(result)) {
       counter++;
       result = "$suggestedName$counter";
     }
   }
   usedNames.add(result);
   return result;
 }