--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/lir/HotSpotZapRegistersPhase.java	2017-02-15 16:59:44.988619196 -0800
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2016, 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.lir;
+
+import static jdk.vm.ci.code.ValueUtil.isStackSlot;
+
+import java.util.ArrayList;
+
+import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
+import org.graalvm.compiler.debug.Debug;
+import org.graalvm.compiler.debug.Indent;
+import org.graalvm.compiler.hotspot.HotSpotLIRGenerationResult;
+import org.graalvm.compiler.hotspot.stubs.Stub;
+import org.graalvm.compiler.lir.LIR;
+import org.graalvm.compiler.lir.LIRFrameState;
+import org.graalvm.compiler.lir.LIRInsertionBuffer;
+import org.graalvm.compiler.lir.LIRInstruction;
+import org.graalvm.compiler.lir.StandardOp.SaveRegistersOp;
+import org.graalvm.compiler.lir.gen.DiagnosticLIRGeneratorTool;
+import org.graalvm.compiler.lir.gen.DiagnosticLIRGeneratorTool.ZapRegistersAfterInstruction;
+import org.graalvm.compiler.lir.gen.DiagnosticLIRGeneratorTool.ZapStackArgumentSpaceBeforeInstruction;
+import org.graalvm.compiler.lir.gen.LIRGenerationResult;
+import org.graalvm.compiler.lir.phases.PostAllocationOptimizationPhase;
+
+import jdk.vm.ci.code.TargetDescription;
+import jdk.vm.ci.meta.AllocatableValue;
+
+/**
+ * Inserts a {@link DiagnosticLIRGeneratorTool#createZapRegisters ZapRegistersOp} after
+ * {@link ZapRegistersAfterInstruction} for stubs and
+ * {@link DiagnosticLIRGeneratorTool#zapArgumentSpace ZapArgumentSpaceOp} after
+ * {@link ZapStackArgumentSpaceBeforeInstruction} for all compiles.
+ */
+public final class HotSpotZapRegistersPhase extends PostAllocationOptimizationPhase {
+
+    @Override
+    protected void run(TargetDescription target, LIRGenerationResult lirGenRes, PostAllocationOptimizationContext context) {
+        Stub stub = ((HotSpotLIRGenerationResult) lirGenRes).getStub();
+        boolean zapRegisters = stub != null && !stub.preservesRegisters();
+        boolean zapStack = false;
+        for (AllocatableValue arg : lirGenRes.getCallingConvention().getArguments()) {
+            if (isStackSlot(arg)) {
+                zapStack = true;
+                break;
+            }
+        }
+        if (zapRegisters || zapStack) {
+            LIR lir = lirGenRes.getLIR();
+            processLIR(context.diagnosticLirGenTool, (HotSpotLIRGenerationResult) lirGenRes, lir, zapRegisters, zapStack);
+        }
+    }
+
+    private static void processLIR(DiagnosticLIRGeneratorTool diagnosticLirGenTool, HotSpotLIRGenerationResult res, LIR lir, boolean zapRegisters, boolean zapStack) {
+        LIRInsertionBuffer buffer = new LIRInsertionBuffer();
+        for (AbstractBlockBase<?> block : lir.codeEmittingOrder()) {
+            if (block != null) {
+                processBlock(diagnosticLirGenTool, res, lir, buffer, block, zapRegisters, zapStack);
+            }
+        }
+    }
+
+    @SuppressWarnings("try")
+    private static void processBlock(DiagnosticLIRGeneratorTool diagnosticLirGenTool, HotSpotLIRGenerationResult res, LIR lir, LIRInsertionBuffer buffer, AbstractBlockBase<?> block,
+                    boolean zapRegisters, boolean zapStack) {
+        try (Indent indent = Debug.logAndIndent("Process block %s", block)) {
+            ArrayList<LIRInstruction> instructions = lir.getLIRforBlock(block);
+            buffer.init(instructions);
+            for (int index = 0; index < instructions.size(); index++) {
+                LIRInstruction inst = instructions.get(index);
+                if (zapStack && inst instanceof ZapStackArgumentSpaceBeforeInstruction) {
+                    LIRInstruction zap = diagnosticLirGenTool.zapArgumentSpace();
+                    if (zap != null) {
+                        buffer.append(index, zap);
+                    }
+                }
+                if (zapRegisters && inst instanceof ZapRegistersAfterInstruction) {
+                    LIRFrameState state = getLIRState(inst);
+                    if (state != null) {
+                        SaveRegistersOp zap = diagnosticLirGenTool.createZapRegisters();
+                        SaveRegistersOp old = res.getCalleeSaveInfo().put(state, zap);
+                        assert old == null : "Already another SaveRegisterOp registered! " + old;
+                        buffer.append(index + 1, (LIRInstruction) zap);
+                        Debug.log("Insert ZapRegister after %s", inst);
+                    }
+                }
+            }
+            buffer.finish();
+        }
+    }
+
+    /**
+     * Returns the {@link LIRFrameState} of an instruction.
+     */
+    private static LIRFrameState getLIRState(LIRInstruction inst) {
+        final LIRFrameState[] lirState = {null};
+        inst.forEachState(state -> {
+            assert lirState[0] == null : "Multiple states: " + inst;
+            lirState[0] = state;
+        });
+        assert lirState[0] != null : "No state: " + inst;
+        return lirState[0];
+    }
+
+}