# HG changeset patch
# User Thomas Wuerthinger <thomas.wuerthinger@oracle.com>
# Date 1367091704 -7200
# Node ID ee75b4f569ed905b287c658eea6106771a71fcbf
# Parent  c408b74bfc42e8ddf7dfa97669dafff34d3936d9
Don't create null check guard if object is kown to be non-null.

diff -r c408b74bfc42 -r ee75b4f569ed graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/HotSpotRuntime.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/HotSpotRuntime.java	Sat Apr 27 21:25:53 2013 +0200
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/HotSpotRuntime.java	Sat Apr 27 21:41:44 2013 +0200
@@ -519,7 +519,7 @@
             ArrayLengthNode arrayLengthNode = (ArrayLengthNode) n;
             ValueNode array = arrayLengthNode.array();
             ReadNode arrayLengthRead = graph.add(new ReadNode(array, ConstantLocationNode.create(LocationNode.FINAL_LOCATION, Kind.Int, config.arrayLengthOffset, graph), StampFactory.positiveInt()));
-            arrayLengthRead.dependencies().add(tool.createNullCheckGuard(array));
+            tool.createNullCheckGuard(arrayLengthRead.dependencies(), array);
             graph.replaceFixedWithFixed(arrayLengthNode, arrayLengthRead);
         } else if (n instanceof Invoke) {
             Invoke invoke = (Invoke) n;
@@ -528,7 +528,7 @@
                 NodeInputList<ValueNode> parameters = callTarget.arguments();
                 ValueNode receiver = parameters.size() <= 0 ? null : parameters.get(0);
                 if (!callTarget.isStatic() && receiver.kind() == Kind.Object && !receiver.objectStamp().nonNull()) {
-                    invoke.asNode().dependencies().add(tool.createNullCheckGuard(receiver));
+                    tool.createNullCheckGuard(invoke.asNode().dependencies(), receiver);
                 }
                 JavaType[] signature = MetaUtil.signatureToTypes(callTarget.targetMethod().getSignature(), callTarget.isStatic() ? null : callTarget.targetMethod().getDeclaringClass());
 
@@ -571,7 +571,7 @@
             ValueNode object = loadField.isStatic() ? ConstantNode.forObject(field.getDeclaringClass().mirror(), this, graph) : loadField.object();
             assert loadField.kind() != Kind.Illegal;
             ReadNode memoryRead = graph.add(new ReadNode(object, ConstantLocationNode.create(field, field.getKind(), field.offset(), graph), loadField.stamp()));
-            memoryRead.dependencies().add(tool.createNullCheckGuard(object));
+            tool.createNullCheckGuard(memoryRead.dependencies(), object);
 
             graph.replaceFixedWithFixed(loadField, memoryRead);
 
@@ -588,7 +588,7 @@
             LocationNode location = ConstantLocationNode.create(field, field.getKind(), field.offset(), graph);
             WriteBarrierType barrierType = getFieldStoreBarrierType(storeField);
             WriteNode memoryWrite = graph.add(new WriteNode(object, storeField.value(), location, barrierType));
-            memoryWrite.dependencies().add(tool.createNullCheckGuard(object));
+            tool.createNullCheckGuard(memoryWrite.dependencies(), object);
             memoryWrite.setStateAfter(storeField.stateAfter());
             graph.replaceFixedWithFixed(storeField, memoryWrite);
             FixedWithNextNode last = memoryWrite;
@@ -671,9 +671,8 @@
             LocationNode location = ConstantLocationNode.create(LocationNode.FINAL_LOCATION, wordKind, config.hubOffset, graph);
             ValueNode object = loadHub.object();
             assert !object.isConstant() || object.asConstant().isNull();
-            ValueNode guard = tool.createNullCheckGuard(object);
             ReadNode hub = graph.add(new ReadNode(object, location, StampFactory.forKind(wordKind())));
-            hub.dependencies().add(guard);
+            tool.createNullCheckGuard(hub.dependencies(), object);
             graph.replaceFixed(loadHub, hub);
         } else if (n instanceof FixedGuardNode) {
             FixedGuardNode node = (FixedGuardNode) n;
diff -r c408b74bfc42 -r ee75b4f569ed graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/spi/LoweringTool.java
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/spi/LoweringTool.java	Sat Apr 27 21:25:53 2013 +0200
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/spi/LoweringTool.java	Sat Apr 27 21:41:44 2013 +0200
@@ -34,7 +34,7 @@
 
     Replacements getReplacements();
 
-    ValueNode createNullCheckGuard(ValueNode object);
+    ValueNode createNullCheckGuard(NodeInputList<ValueNode> dependencies, ValueNode object);
 
     ValueNode createGuard(LogicNode condition, DeoptimizationReason deoptReason, DeoptimizationAction action);
 
diff -r c408b74bfc42 -r ee75b4f569ed graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/LoweringPhase.java
--- a/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/LoweringPhase.java	Sat Apr 27 21:25:53 2013 +0200
+++ b/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/LoweringPhase.java	Sat Apr 27 21:41:44 2013 +0200
@@ -68,8 +68,14 @@
         }
 
         @Override
-        public ValueNode createNullCheckGuard(ValueNode object) {
-            return createGuard(object.graph().unique(new IsNullNode(object)), DeoptimizationReason.NullCheckException, DeoptimizationAction.InvalidateReprofile, true);
+        public ValueNode createNullCheckGuard(NodeInputList<ValueNode> list, ValueNode object) {
+            if (object.objectStamp().nonNull()) {
+                // Short cut creation of null check guard if the object is known to be non-null.
+                return null;
+            }
+            ValueNode guard = createGuard(object.graph().unique(new IsNullNode(object)), DeoptimizationReason.NullCheckException, DeoptimizationAction.InvalidateReprofile, true);
+            list.add(guard);
+            return guard;
         }
 
         @Override