# HG changeset patch
# User Lukas Stadler <lukas.stadler@oracle.com>
# Date 1398241579 -7200
# Node ID f37a81a76000509ecc9331db8b0df5cc57c2a035
# Parent  d9c64f6a11c7f9e329bb1eb83c84dd38ba39d795
handle array length in PEAReadElimination

diff -r d9c64f6a11c7 -r f37a81a76000 graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/phases/ea/PEReadEliminationBlockState.java
--- a/graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/phases/ea/PEReadEliminationBlockState.java	Wed Apr 23 10:26:19 2014 +0200
+++ b/graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/phases/ea/PEReadEliminationBlockState.java	Wed Apr 23 10:26:19 2014 +0200
@@ -34,10 +34,10 @@
 
     static class ReadCacheEntry {
 
-        public final ResolvedJavaField identity;
+        public final LocationIdentity identity;
         public final ValueNode object;
 
-        public ReadCacheEntry(ResolvedJavaField identity, ValueNode object) {
+        public ReadCacheEntry(LocationIdentity identity, ValueNode object) {
             this.identity = identity;
             this.object = object;
         }
@@ -95,7 +95,7 @@
         return super.equivalentTo(other);
     }
 
-    public void addReadCache(ValueNode object, ResolvedJavaField identity, ValueNode value, PartialEscapeClosure<?> closure) {
+    public void addReadCache(ValueNode object, LocationIdentity identity, ValueNode value, PartialEscapeClosure<?> closure) {
         ValueNode cacheObject;
         ObjectState obj = closure.getObjectState(this, object);
         if (obj != null) {
@@ -107,7 +107,7 @@
         readCache.put(new ReadCacheEntry(identity, cacheObject), value);
     }
 
-    public ValueNode getReadCache(ValueNode object, ResolvedJavaField identity, PartialEscapeClosure<?> closure) {
+    public ValueNode getReadCache(ValueNode object, LocationIdentity identity, PartialEscapeClosure<?> closure) {
         ValueNode cacheObject;
         ObjectState obj = closure.getObjectState(this, object);
         if (obj != null) {
diff -r d9c64f6a11c7 -r f37a81a76000 graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/phases/ea/PEReadEliminationClosure.java
--- a/graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/phases/ea/PEReadEliminationClosure.java	Wed Apr 23 10:26:19 2014 +0200
+++ b/graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/phases/ea/PEReadEliminationClosure.java	Wed Apr 23 10:26:19 2014 +0200
@@ -83,6 +83,17 @@
                 } else {
                     processIdentity(state, ANY_LOCATION);
                 }
+            } else if (node instanceof ArrayLengthNode) {
+                ArrayLengthNode length = (ArrayLengthNode) node;
+                ValueNode array = GraphUtil.unproxify(length.array());
+                ValueNode cachedValue = state.getReadCache(array, ARRAY_LENGTH_LOCATION, this);
+                if (cachedValue != null) {
+                    effects.replaceAtUsages(length, cachedValue);
+                    addScalarAlias(length, cachedValue);
+                    deleted = true;
+                } else {
+                    state.addReadCache(array, ARRAY_LENGTH_LOCATION, length, this);
+                }
             } else if (node instanceof MemoryCheckpoint.Single) {
                 METRIC_MEMORYCHECKPOINT.increment();
                 LocationIdentity identity = ((MemoryCheckpoint.Single) node).getLocationIdentity();
@@ -183,7 +194,7 @@
             }
         }
 
-        private void mergeReadCachePhi(PhiNode phi, ResolvedJavaField identity, List<PEReadEliminationBlockState> states) {
+        private void mergeReadCachePhi(PhiNode phi, LocationIdentity identity, List<PEReadEliminationBlockState> states) {
             ValueNode[] values = new ValueNode[phi.valueCount()];
             for (int i = 0; i < phi.valueCount(); i++) {
                 ValueNode value = states.get(i).getReadCache(phi.valueAt(i), identity, PEReadEliminationClosure.this);