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changeset 23149:cca72677127b

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author Tom Rodriguez <tom.rodriguez@oracle.com>
date Tue, 08 Dec 2015 20:47:09 -0800
parents fea7e5ffe8ce
children cda21cbf6ac0 dfae34f1fe9b
files graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/CanonicalizerPhase.java
diffstat 1 files changed, 4 insertions(+), 3 deletions(-) [+]
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line diff
--- a/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/CanonicalizerPhase.java	Tue Dec 08 17:29:03 2015 -0800
+++ b/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/CanonicalizerPhase.java	Tue Dec 08 20:47:09 2015 -0800
@@ -253,9 +253,10 @@
         }
 
         /**
-         * Ensure that leaf nodes have already been GVN'ed. This is normally handled automatically
-         * but it's possible to add nodes to the graph with looking for duplicates and it's the
-         * responsibility of code that does that to clean it up.
+         * Ensures that leaf nodes have already been GVN'ed. This is handled automatically by the
+         * various {@code add} methods in {@link Graph} but uses of
+         * {@link Graph#addWithoutUnique(Node)} and {@link Graph#addWithoutUniqueWithInputs(Node)}
+         * will leave non-unique copies floating around which defeats GVN of users of those nodes.
          */
         private boolean assertLeafGVN(Node node, NodeClass<?> nodeClass) {
             if (node.isAlive() && nodeClass.valueNumberable() && nodeClass.isLeafNode()) {