--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotAddressLowering.java	Mon Jun 08 19:32:53 2015 +0200
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2015, 2015, 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;
+
+import com.oracle.graal.asm.*;
+import com.oracle.graal.asm.amd64.AMD64Address.Scale;
+import com.oracle.graal.compiler.amd64.*;
+import com.oracle.graal.compiler.common.type.*;
+import com.oracle.graal.graph.*;
+import com.oracle.graal.hotspot.nodes.*;
+import com.oracle.graal.hotspot.nodes.CompressionNode.CompressionOp;
+import com.oracle.graal.nodeinfo.*;
+import com.oracle.graal.nodes.*;
+import com.oracle.graal.nodes.calc.*;
+import com.oracle.graal.nodes.spi.*;
+import com.oracle.jvmci.code.*;
+import com.oracle.jvmci.hotspot.HotSpotVMConfig.CompressEncoding;
+import com.oracle.jvmci.meta.*;
+
+public class AMD64HotSpotAddressLowering extends AMD64AddressLowering {
+
+    private final long heapBase;
+    private final Register heapBaseRegister;
+
+    @NodeInfo
+    public static class HeapBaseNode extends FloatingNode implements LIRLowerable {
+
+        public static final NodeClass<HeapBaseNode> TYPE = NodeClass.create(HeapBaseNode.class);
+
+        private final Register heapBaseRegister;
+
+        public HeapBaseNode(Register heapBaseRegister) {
+            super(TYPE, StampFactory.pointer());
+            this.heapBaseRegister = heapBaseRegister;
+        }
+
+        public void generate(NodeLIRBuilderTool generator) {
+            LIRKind kind = generator.getLIRGeneratorTool().getLIRKind(stamp());
+            generator.setResult(this, heapBaseRegister.asValue(kind));
+        }
+    }
+
+    public AMD64HotSpotAddressLowering(CodeCacheProvider codeCache, long heapBase, Register heapBaseRegister) {
+        super(codeCache);
+        this.heapBase = heapBase;
+        if (heapBase == 0) {
+            this.heapBaseRegister = null;
+        } else {
+            this.heapBaseRegister = heapBaseRegister;
+        }
+    }
+
+    @Override
+    protected boolean improve(AMD64AddressNode addr) {
+        if (addr.getScale() == Scale.Times1) {
+            if (addr.getBase() == null && addr.getIndex() instanceof CompressionNode) {
+                if (improveUncompression(addr, (CompressionNode) addr.getIndex())) {
+                    return true;
+                }
+            }
+
+            if (addr.getIndex() == null && addr.getBase() instanceof CompressionNode) {
+                if (improveUncompression(addr, (CompressionNode) addr.getBase())) {
+                    return true;
+                }
+            }
+        }
+
+        return super.improve(addr);
+    }
+
+    private boolean improveUncompression(AMD64AddressNode addr, CompressionNode compression) {
+        if (compression.getOp() == CompressionOp.Uncompress) {
+            CompressEncoding encoding = compression.getEncoding();
+            Scale scale = Scale.fromShift(encoding.shift);
+            if (scale == null) {
+                return false;
+            }
+
+            if (heapBaseRegister != null && encoding.base == heapBase) {
+                ValueNode base = compression.graph().unique(new HeapBaseNode(heapBaseRegister));
+                addr.setBase(base);
+            } else if (encoding.base != 0) {
+                long disp = addr.getDisplacement() + heapBase;
+                if (NumUtil.isInt(disp)) {
+                    addr.setDisplacement((int) disp);
+                } else {
+                    return false;
+                }
+            } else {
+                addr.setBase(null);
+            }
+
+            addr.setScale(scale);
+            addr.setIndex(compression.getValue());
+            return true;
+        } else {
+            return false;
+        }
+    }
+}

--- a/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotBackendFactory.java	Mon Jun 08 19:19:51 2015 +0200
+++ b/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotBackendFactory.java	Mon Jun 08 19:32:53 2015 +0200
@@ -27,7 +27,6 @@
 import java.util.*;
 
 import com.oracle.graal.api.replacements.*;
-import com.oracle.graal.compiler.amd64.*;
 import com.oracle.graal.graphbuilderconf.GraphBuilderConfiguration.Plugins;
 import com.oracle.graal.hotspot.*;
 import com.oracle.graal.hotspot.meta.*;
@@ -92,7 +91,7 @@
                 replacements.setGraphBuilderPlugins(plugins);
             }
             try (InitTimer rt = timer("create Suites provider")) {
-                suites = createSuites(runtime, plugins, codeCache);
+                suites = createSuites(runtime, plugins, codeCache, registers);
             }
             providers = new HotSpotProviders(metaAccess, codeCache, constantReflection, foreignCalls, lowerer, replacements, suites, registers, snippetReflection, wordTypes, plugins);
         }
@@ -126,8 +125,8 @@
         return new AMD64HotSpotForeignCallsProvider(runtime, metaAccess, codeCache, nativeABICallerSaveRegisters);
     }
 
-    protected HotSpotSuitesProvider createSuites(HotSpotGraalRuntimeProvider runtime, Plugins plugins, CodeCacheProvider codeCache) {
-        return new HotSpotSuitesProvider(runtime, plugins, new AMD64AddressLowering(codeCache));
+    protected HotSpotSuitesProvider createSuites(HotSpotGraalRuntimeProvider runtime, Plugins plugins, CodeCacheProvider codeCache, HotSpotRegistersProvider registers) {
+        return new HotSpotSuitesProvider(runtime, plugins, new AMD64HotSpotAddressLowering(codeCache, runtime.getConfig().getOopEncoding().base, registers.getHeapBaseRegister()));
     }
 
     protected HotSpotSnippetReflectionProvider createSnippetReflection(HotSpotGraalRuntimeProvider runtime) {

--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/CompressionNode.java	Mon Jun 08 19:19:51 2015 +0200
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/CompressionNode.java	Mon Jun 08 19:32:53 2015 +0200
@@ -154,6 +154,10 @@
         throw JVMCIError.shouldNotReachHere(String.format("Unexpected input stamp %s", input));
     }
 
+    public CompressionOp getOp() {
+        return op;
+    }
+
     public CompressEncoding getEncoding() {
         return encoding;
     }