--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.hotspot.amd64.test/src/com/oracle/graal/hotspot/amd64/test/CompressedNullCheckTest.java	Wed Aug 06 15:01:16 2014 +0200
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.graal.hotspot.amd64.test;
+
+import org.junit.*;
+
+import com.oracle.graal.compiler.test.*;
+import com.oracle.graal.hotspot.nodes.*;
+import com.oracle.graal.nodes.*;
+import com.oracle.graal.nodes.calc.*;
+
+/**
+ * Ensures that frame omission works in cases where it is expected to.
+ */
+public class CompressedNullCheckTest extends GraalCompilerTest {
+
+    private static final class Container {
+        Integer i = new Integer(1);
+    }
+
+    public static void testSnippet(Container c) {
+        c.i.intValue();
+    }
+
+    @Test
+    public void test() {
+        test("testSnippet", new Container());
+    }
+
+    @Override
+    protected boolean checkMidTierGraph(StructuredGraph graph) {
+        int count = 0;
+        for (IsNullNode isNull : graph.getNodes().filter(IsNullNode.class).snapshot()) {
+            ValueNode value = isNull.getValue();
+            if (value instanceof CompressionNode) {
+                count++;
+                isNull.replaceFirstInput(value, ((CompressionNode) value).getValue());
+            }
+        }
+        Assert.assertEquals("graph should contain exactly one IsNullNode", 1, count);
+        return super.checkMidTierGraph(graph);
+    }
+}

--- a/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotLIRGenerator.java	Tue Aug 05 10:06:08 2014 +0200
+++ b/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotLIRGenerator.java	Wed Aug 06 15:01:16 2014 +0200
@@ -559,8 +559,20 @@
     }
 
     public void emitNullCheck(Value address, LIRFrameState state) {
-        assert address.getKind() == Kind.Object : address + " - " + address.getKind() + " not an object!";
-        append(new AMD64Move.NullCheckOp(load(address), state));
+        if (address.getLIRKind().getPlatformKind() == Kind.Int) {
+            CompressEncoding encoding = config.getOopEncoding();
+            System.out.println("compressed null check: " + address + " - " + address.getKind());
+            if (encoding.shift <= 3) {
+                AMD64AddressValue uncompressionAddress = emitAddress(getProviders().getRegisters().getHeapBaseRegister().asValue(), 0, load(address), 1 << encoding.shift);
+                append(new AMD64HotSpotMove.CompressedNullCheckOp(uncompressionAddress, state));
+            } else {
+                Value uncompress = emitUncompress(address, encoding, false);
+                append(new AMD64Move.NullCheckOp(load(uncompress), state));
+            }
+        } else {
+            assert address.getKind() == Kind.Object : address + " - " + address.getKind() + " not an object!";
+            append(new AMD64Move.NullCheckOp(load(address), state));
+        }
     }
 
     @Override

--- a/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotMove.java	Tue Aug 05 10:06:08 2014 +0200
+++ b/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotMove.java	Wed Aug 06 15:01:16 2014 +0200
@@ -25,6 +25,7 @@
 import static com.oracle.graal.api.code.ValueUtil.*;
 import static com.oracle.graal.lir.LIRInstruction.OperandFlag.*;
 
+import com.oracle.graal.amd64.*;
 import com.oracle.graal.api.code.*;
 import com.oracle.graal.api.meta.*;
 import com.oracle.graal.asm.*;
@@ -254,4 +255,24 @@
         }
     }
 
+    public static class CompressedNullCheckOp extends AMD64LIRInstruction {
+
+        @Use({COMPOSITE}) protected AMD64AddressValue address;
+        @State protected LIRFrameState state;
+
+        public CompressedNullCheckOp(AMD64AddressValue address, LIRFrameState state) {
+            this.address = address;
+            this.state = state;
+        }
+
+        @Override
+        public void emitCode(CompilationResultBuilder crb, AMD64MacroAssembler masm) {
+            crb.recordImplicitException(masm.position(), state);
+            masm.testl(AMD64.rax, address.toAddress());
+        }
+
+        public LIRFrameState getState() {
+            return state;
+        }
+    }
 }

--- a/mx/projects	Tue Aug 05 10:06:08 2014 +0200
+++ b/mx/projects	Wed Aug 06 15:01:16 2014 +0200
@@ -321,7 +321,7 @@
 # graal.hotspot.amd64.test
 project@com.oracle.graal.hotspot.amd64.test@subDir=graal
 project@com.oracle.graal.hotspot.amd64.test@sourceDirs=src
-project@com.oracle.graal.hotspot.amd64.test@dependencies=com.oracle.graal.asm.amd64,com.oracle.graal.compiler.test
+project@com.oracle.graal.hotspot.amd64.test@dependencies=com.oracle.graal.asm.amd64,com.oracle.graal.compiler.test,com.oracle.graal.hotspot
 project@com.oracle.graal.hotspot.amd64.test@checkstyle=com.oracle.graal.graph
 project@com.oracle.graal.hotspot.amd64.test@javaCompliance=1.8
 project@com.oracle.graal.hotspot.amd64.test@workingSets=Graal,HotSpot,AMD64,Test