# HG changeset patch
# User Tom Rodriguez <tom.rodriguez@oracle.com>
# Date 1421864441 28800
# Node ID b7cb27a82d518dd2efce1f6fb48b0f133b209876
# Parent  06536c3846e7762d0cad3e4e1f35acfc64e6ff69
Don't allow guards with action == None to float

diff -r 06536c3846e7 -r b7cb27a82d51 graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/FixedGuardNode.java
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/FixedGuardNode.java	Wed Jan 21 10:19:33 2015 -0800
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/FixedGuardNode.java	Wed Jan 21 10:20:41 2015 -0800
@@ -69,7 +69,14 @@
 
     @Override
     public void lower(LoweringTool tool) {
-        if (graph().getGuardsStage() == StructuredGraph.GuardsStage.FLOATING_GUARDS) {
+        /*
+         * Don't allow guards with action None to float. In cases where 2 guards are testing
+         * equivalent conditions they might be lowered at the same location. If the guard with the
+         * None action is lowered before the the other guard then the code will be stuck repeatedly
+         * deoptimizing without invalidating the code. Conditional elimination will eliminate the
+         * guard if it's truly redundant in this case.
+         */
+        if (graph().getGuardsStage() == StructuredGraph.GuardsStage.FLOATING_GUARDS && getAction() != DeoptimizationAction.None) {
             ValueNode guard = tool.createGuard(this, condition(), getReason(), getAction(), isNegated()).asNode();
             this.replaceAtUsages(guard);
             ValueAnchorNode newAnchor = graph().add(new ValueAnchorNode(guard.asNode()));