When canonicalizing branch on StrictCompare don't fuse comparisons that can deoptimize or serve as pending deoptimization target for representation changes.
R=fschneider@google.com
BUG=
Review URL: https://codereview.chromium.org//12220150
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@18443 260f80e4-7a28-3924-810f-c04153c831b5
diff --git a/runtime/vm/intermediate_language.cc b/runtime/vm/intermediate_language.cc
index 7b8e997..48edba3 100644
--- a/runtime/vm/intermediate_language.cc
+++ b/runtime/vm/intermediate_language.cc
@@ -1821,7 +1821,16 @@
Definition* replacement = comparison()->Canonicalize(optimizer);
if (replacement == comparison() || replacement == NULL) return this;
ComparisonInstr* comp = replacement->AsComparison();
- if (comp == NULL) return this;
+ if ((comp == NULL) || comp->CanDeoptimize()) return this;
+
+ // Check that comparison is not serving as a pending deoptimization target
+ // for conversions.
+ for (intptr_t i = 0; i < comp->InputCount(); i++) {
+ if (comp->RequiredInputRepresentation(i) !=
+ comp->InputAt(i)->definition()->representation()) {
+ return this;
+ }
+ }
// Replace the comparison if the replacement is used at this branch,
// and has exactly one use.
diff --git a/tests/language/branch_canonicalization_test.dart b/tests/language/branch_canonicalization_test.dart
new file mode 100644
index 0000000..7e39572
--- /dev/null
+++ b/tests/language/branch_canonicalization_test.dart
@@ -0,0 +1,65 @@
+// 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.
+// Test that branch fusion correctly sets branch environment for comparisons
+// that require unboxing and does not fuse branches that can deoptimize.
+
+var sideEffect = true;
+
+barDouble(a, b) {
+ sideEffect = false;
+ final result = (a == b);
+ sideEffect = !sideEffect;
+ return result;
+}
+fooDouble(a, b) => barDouble(a, b) ? 1 : 0;
+
+barMint(a, b) {
+ sideEffect = false;
+ final result = (a == b);
+ sideEffect = !sideEffect;
+ return result;
+}
+fooMint(a, b) => barMint(a, b) ? 1 : 0;
+
+class A {
+ operator == (other) => identical(this, other);
+}
+
+class B extends A {
+}
+
+class C extends A {
+}
+
+barPoly(a, b) {
+ sideEffect = false;
+ final result = a == b;
+ sideEffect = !sideEffect;
+ return result;
+}
+
+fooPoly(a, b) => barPoly(a, b) ? 1 : 0;
+
+main () {
+ final a = 1.0;
+ final b = 1 << 62;
+ final x = new A(), y = new B(), z = new C();
+ for (var i = 0; i < 10000; i++) {
+ Expect.equals(1, fooDouble(a, a));
+ Expect.isTrue(sideEffect);
+ Expect.equals(0, fooMint(b, 0));
+ Expect.isTrue(sideEffect);
+ Expect.equals(1, fooPoly(x, x));
+ Expect.equals(0, fooPoly(y, x));
+ }
+ Expect.equals(1, fooDouble(z, z));
+ Expect.isTrue(sideEffect);
+ Expect.equals(1, fooMint(z, z));
+ Expect.isTrue(sideEffect);
+ Expect.equals(1, fooPoly(z, z));
+ Expect.isTrue(sideEffect);
+}
+
+
+
