| // 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. |
| |
| // @dart = 2.9 |
| |
| // 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 as dynamic).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++; |
| } |
| } |