# HG changeset patch
# User Christos Kotselidis <christos.kotselidis@oracle.com>
# Date 1383576147 -3600
# Node ID a2b1ee69ce4625e71968975a9cc9e092b827f81d
# Parent  55b23f75d3b0a584a233ed182a964ab86ea0748e
Loose unnecessary input dependencies from write barriers

diff -r 55b23f75d3b0 -r a2b1ee69ce46 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/G1PostWriteBarrier.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/G1PostWriteBarrier.java	Mon Nov 04 12:17:37 2013 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/G1PostWriteBarrier.java	Mon Nov 04 15:42:27 2013 +0100
@@ -27,7 +27,14 @@
 
 public class G1PostWriteBarrier extends WriteBarrier {
 
-    public G1PostWriteBarrier(ValueNode object, ValueNode value, LocationNode location, boolean precise) {
+    private boolean alwaysNull;
+
+    public G1PostWriteBarrier(ValueNode object, ValueNode value, LocationNode location, boolean precise, boolean alwaysNull) {
         super(object, value, location, precise);
+        this.alwaysNull = alwaysNull;
+    }
+
+    public boolean alwaysNull() {
+        return alwaysNull;
     }
 }
diff -r 55b23f75d3b0 -r a2b1ee69ce46 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/SerialWriteBarrier.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/SerialWriteBarrier.java	Mon Nov 04 12:17:37 2013 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/SerialWriteBarrier.java	Mon Nov 04 15:42:27 2013 +0100
@@ -27,7 +27,14 @@
 
 public class SerialWriteBarrier extends WriteBarrier {
 
-    public SerialWriteBarrier(ValueNode object, ValueNode value, LocationNode location, boolean precise) {
-        super(object, value, location, precise);
+    private boolean alwaysNull;
+
+    public SerialWriteBarrier(ValueNode object, LocationNode location, boolean precise, boolean alwaysNull) {
+        super(object, null, location, precise);
+        this.alwaysNull = alwaysNull;
+    }
+
+    public boolean alwaysNull() {
+        return alwaysNull;
     }
 }
diff -r 55b23f75d3b0 -r a2b1ee69ce46 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/phases/WriteBarrierAdditionPhase.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/phases/WriteBarrierAdditionPhase.java	Mon Nov 04 12:17:37 2013 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/phases/WriteBarrierAdditionPhase.java	Mon Nov 04 15:42:27 2013 +0100
@@ -26,10 +26,11 @@
 
 import com.oracle.graal.graph.*;
 import com.oracle.graal.hotspot.nodes.*;
+import com.oracle.graal.nodes.HeapAccess.BarrierType;
 import com.oracle.graal.nodes.*;
-import com.oracle.graal.nodes.HeapAccess.BarrierType;
 import com.oracle.graal.nodes.extended.*;
 import com.oracle.graal.nodes.java.*;
+import com.oracle.graal.nodes.type.*;
 import com.oracle.graal.phases.*;
 
 public class WriteBarrierAdditionPhase extends Phase {
@@ -74,11 +75,14 @@
     }
 
     protected void addG1PostWriteBarrier(AccessNode node, ValueNode object, ValueNode value, LocationNode location, boolean precise, StructuredGraph graph) {
-        graph.addAfterFixed(node, graph.add(new G1PostWriteBarrier(object, value, location, precise)));
+        final boolean alwaysNull = ObjectStamp.isObjectAlwaysNull(value);
+        graph.addAfterFixed(node, graph.add(new G1PostWriteBarrier(object, value, location, precise, alwaysNull)));
     }
 
     protected void addSerialPostWriteBarrier(AccessNode node, ValueNode object, ValueNode value, LocationNode location, boolean precise, StructuredGraph graph) {
-        graph.addAfterFixed(node, graph.add(new SerialWriteBarrier(object, value, location, precise)));
+        final boolean alwaysNull = ObjectStamp.isObjectAlwaysNull(value);
+        final LocationNode loc = (precise ? location : null);
+        graph.addAfterFixed(node, graph.add(new SerialWriteBarrier(object, loc, precise, alwaysNull)));
     }
 
     private void addWriteNodeBarriers(WriteNode node, StructuredGraph graph) {
diff -r 55b23f75d3b0 -r a2b1ee69ce46 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/WriteBarrierSnippets.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/WriteBarrierSnippets.java	Mon Nov 04 12:17:37 2013 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/WriteBarrierSnippets.java	Mon Nov 04 15:42:27 2013 +0100
@@ -36,7 +36,6 @@
 import com.oracle.graal.nodes.HeapAccess.BarrierType;
 import com.oracle.graal.nodes.extended.*;
 import com.oracle.graal.nodes.spi.*;
-import com.oracle.graal.nodes.type.*;
 import com.oracle.graal.phases.*;
 import com.oracle.graal.phases.util.*;
 import com.oracle.graal.replacements.*;
@@ -346,7 +345,7 @@
             args.add("object", writeBarrier.getObject());
             args.add("location", writeBarrier.getLocation());
             args.addConst("usePrecise", writeBarrier.usePrecise());
-            args.addConst("alwaysNull", ObjectStamp.isObjectAlwaysNull(writeBarrier.getValue()));
+            args.addConst("alwaysNull", writeBarrier.alwaysNull());
             template(args).instantiate(providers.getMetaAccess(), writeBarrier, DEFAULT_REPLACER, args);
         }
 
@@ -386,7 +385,7 @@
             args.add("value", writeBarrierPost.getValue());
             args.add("location", writeBarrierPost.getLocation());
             args.addConst("usePrecise", writeBarrierPost.usePrecise());
-            args.addConst("alwaysNull", ObjectStamp.isObjectAlwaysNull(writeBarrierPost.getValue()));
+            args.addConst("alwaysNull", writeBarrierPost.alwaysNull());
             args.addConst("trace", traceBarrier());
             template(args).instantiate(providers.getMetaAccess(), writeBarrierPost, DEFAULT_REPLACER, args);
         }