Index: tests/language/issue11793_test.dart |
=================================================================== |
--- tests/language/issue11793_test.dart (revision 0) |
+++ tests/language/issue11793_test.dart (revision 0) |
@@ -0,0 +1,47 @@ |
+// Copyright (c) 2013, 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. |
+ |
+// Regression test for dart2js, whose value range analysis phase |
+// assumed loop phis that were integer necessarily had integer inputs. |
+ |
+var array = const [0, 0.5]; |
+var globalB = array[0]; |
+var otherArray = [5]; |
+ |
+main() { |
+ var b = globalB; |
+ var a = b + 1; |
+ if (otherArray[0] == 0) { |
+ // Use a non-existing selector to prevent adding a bailout check. |
+ a.noSuch(); |
+ a = otherArray[0]; |
+ } |
+ |
+ // Use [a] to make sure it does not become dead code. |
+ var f = array[a]; |
+ |
+ // Add an integer check on [b]. |
+ var d = array[b]; |
+ |
+ // This instruction will be GVN to the same value as [a]. |
+ // By being GVN'ed, [e] will have its type changed from integer |
+ // to number: because of the int type check on [b], we know |
+ // [: b + 1 :] returns an integer. |
+ // However we update this instruction with the previous [: b + 1 :] |
+ // that did not have that information and therefore only knows that |
+ // the instruction returns a number. |
+ var e = b + 1; |
+ |
+ // Introduce a loop phi that has [e] as header input, and [e++] as |
+ // update input. By having [e] as input, dart2js will compute an |
+ // integer type for the phi. However, after GVN, [e] becomes a |
+ // number. |
+ |
+ while (otherArray[0] == 0) { |
+ // Use [e] as an index for an array so that the value range |
+ // analysis tries to compute a range for [e]. |
+ otherArray[e] = d + f; |
+ e++; |
+ } |
+} |