--- /dev/null	2016-05-31 09:42:47.975716356 -0700
+++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/HotSpotHostBackend.java	2016-12-09 00:49:19.566883318 -0800
@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2013, 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 org.graalvm.compiler.hotspot;
+
+import static jdk.vm.ci.code.CodeUtil.getCallingConvention;
+import static jdk.vm.ci.common.InitTimer.timer;
+
+import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;
+import org.graalvm.compiler.hotspot.meta.HotSpotHostForeignCallsProvider;
+import org.graalvm.compiler.hotspot.meta.HotSpotLoweringProvider;
+import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
+import org.graalvm.compiler.hotspot.stubs.DeoptimizationStub;
+import org.graalvm.compiler.hotspot.stubs.Stub;
+import org.graalvm.compiler.hotspot.stubs.UncommonTrapStub;
+import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
+import org.graalvm.compiler.lir.framemap.ReferenceMapBuilder;
+import org.graalvm.compiler.nodes.StructuredGraph;
+
+import jdk.vm.ci.code.CallingConvention;
+import jdk.vm.ci.common.InitTimer;
+import jdk.vm.ci.hotspot.HotSpotCallingConventionType;
+import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;
+import jdk.vm.ci.meta.JavaType;
+import jdk.vm.ci.runtime.JVMCICompiler;
+
+/**
+ * Common functionality of HotSpot host backends.
+ */
+public abstract class HotSpotHostBackend extends HotSpotBackend {
+
+    /**
+     * Descriptor for {@code SharedRuntime::deopt_blob()->unpack()} or
+     * {@link DeoptimizationStub#deoptimizationHandler} depending on
+     * {@link HotSpotBackend.Options#PreferGraalStubs}.
+     */
+    public static final ForeignCallDescriptor DEOPTIMIZATION_HANDLER = new ForeignCallDescriptor("deoptHandler", void.class);
+
+    /**
+     * Descriptor for {@code SharedRuntime::deopt_blob()->uncommon_trap()} or
+     * {@link UncommonTrapStub#uncommonTrapHandler} depending on
+     * {@link HotSpotBackend.Options#PreferGraalStubs}.
+     */
+    public static final ForeignCallDescriptor UNCOMMON_TRAP_HANDLER = new ForeignCallDescriptor("uncommonTrapHandler", void.class);
+
+    protected final GraalHotSpotVMConfig config;
+
+    public HotSpotHostBackend(GraalHotSpotVMConfig config, HotSpotGraalRuntimeProvider runtime, HotSpotProviders providers) {
+        super(runtime, providers);
+        this.config = config;
+    }
+
+    @Override
+    @SuppressWarnings("try")
+    public void completeInitialization(HotSpotJVMCIRuntime jvmciRuntime) {
+        final HotSpotProviders providers = getProviders();
+        HotSpotHostForeignCallsProvider foreignCalls = (HotSpotHostForeignCallsProvider) providers.getForeignCalls();
+        final HotSpotLoweringProvider lowerer = (HotSpotLoweringProvider) providers.getLowerer();
+
+        try (InitTimer st = timer("foreignCalls.initialize")) {
+            foreignCalls.initialize(providers);
+        }
+        try (InitTimer st = timer("lowerer.initialize")) {
+            lowerer.initialize(providers, config);
+        }
+    }
+
+    protected CallingConvention makeCallingConvention(StructuredGraph graph, Stub stub) {
+        if (stub != null) {
+            return stub.getLinkage().getIncomingCallingConvention();
+        }
+
+        CallingConvention cc = getCallingConvention(getCodeCache(), HotSpotCallingConventionType.JavaCallee, graph.method(), this);
+        if (graph.getEntryBCI() != JVMCICompiler.INVOCATION_ENTRY_BCI) {
+            // for OSR, only a pointer is passed to the method.
+            JavaType[] parameterTypes = new JavaType[]{getMetaAccess().lookupJavaType(long.class)};
+            CallingConvention tmp = getCodeCache().getRegisterConfig().getCallingConvention(HotSpotCallingConventionType.JavaCallee, getMetaAccess().lookupJavaType(void.class), parameterTypes, this);
+            cc = new CallingConvention(cc.getStackSize(), cc.getReturn(), tmp.getArgument(0));
+        }
+        return cc;
+    }
+
+    public void emitStackOverflowCheck(CompilationResultBuilder crb) {
+        if (config.useStackBanging) {
+            // Each code entry causes one stack bang n pages down the stack where n
+            // is configurable by StackShadowPages. The setting depends on the maximum
+            // depth of VM call stack or native before going back into java code,
+            // since only java code can raise a stack overflow exception using the
+            // stack banging mechanism. The VM and native code does not detect stack
+            // overflow.
+            // The code in JavaCalls::call() checks that there is at least n pages
+            // available, so all entry code needs to do is bang once for the end of
+            // this shadow zone.
+            // The entry code may need to bang additional pages if the framesize
+            // is greater than a page.
+
+            int pageSize = config.vmPageSize;
+            int bangEnd = config.stackShadowPages * pageSize;
+
+            // This is how far the previous frame's stack banging extended.
+            int bangEndSafe = bangEnd;
+
+            int frameSize = Math.max(crb.frameMap.frameSize(), crb.compilationResult.getMaxInterpreterFrameSize());
+            if (frameSize > pageSize) {
+                bangEnd += frameSize;
+            }
+
+            int bangOffset = bangEndSafe;
+            if (bangOffset <= bangEnd) {
+                crb.blockComment("[stack overflow check]");
+            }
+            while (bangOffset <= bangEnd) {
+                // Need at least one stack bang at end of shadow zone.
+                bangStackWithOffset(crb, bangOffset);
+                bangOffset += pageSize;
+            }
+        }
+    }
+
+    protected abstract void bangStackWithOffset(CompilationResultBuilder crb, int bangOffset);
+
+    @Override
+    public ReferenceMapBuilder newReferenceMapBuilder(int totalFrameSize) {
+        return new HotSpotReferenceMapBuilder(totalFrameSize, config.maxOopMapStackOffset);
+    }
+
+}