Stephen Adams
b3502f17cb
Redundant phi elimination removes phis that join the same value.
However, this does not work when one or more of the inputs has a refinement (HTypeKnown). This change adds redundant phi elimination when the phi inputs have refinements.
The need for this optimization shows up when static js_interop needs a dispatch on type for conversion:
```
final JSAny? jsValue;
if (value is String) {
jsValue = value.toJS;
} else if (value is bool) {
jsValue = value.toJS;
...
```
(The `.toJS` calls become no-ops since, for dart2js, we are already in JavaScript, and so leave an otherwise pointless if-then-else chain).
Change-Id: If1a94856592163a81ac36c686cee04232c16d197
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/403950
Reviewed-by: Nate Biggs <natebiggs@google.com>
Commit-Queue: Stephen Adams <sra@google.com>
34 lines
855 B
Dart
34 lines
855 B
Dart
// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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@pragma('dart2js:never-inline')
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/*member: foo1:function(x) {
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if (Date.now() > 0) {
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if (typeof x != "string")
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return "bad1";
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} else if (typeof x != "string")
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return "bad2";
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return x;
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}*/
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String foo1(Object x) {
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final Object y;
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if (DateTime.now().millisecondsSinceEpoch > 0) {
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if (x is! String) return 'bad1';
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y = x;
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} else {
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if (x is! String) return 'bad2';
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y = x;
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}
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// The phi for y has refinements to String on both branches, so the return
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// should not need stringification.
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return '$y';
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}
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/*member: main:ignore*/
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main() {
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print(foo1('a'));
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print(foo1('b'));
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print(foo1(123));
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}
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