diff -r 13588c901957 -r 9cf78a70fa4f src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot.aarch64/src/org/graalvm/compiler/hotspot/aarch64/AArch64HotSpotLIRGenerator.java
--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot.aarch64/src/org/graalvm/compiler/hotspot/aarch64/AArch64HotSpotLIRGenerator.java	Thu Oct 17 20:27:44 2019 +0100
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot.aarch64/src/org/graalvm/compiler/hotspot/aarch64/AArch64HotSpotLIRGenerator.java	Thu Oct 17 20:53:35 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2018, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -38,6 +38,7 @@
 import static org.graalvm.compiler.lir.LIRValueUtil.asConstant;
 import static org.graalvm.compiler.lir.LIRValueUtil.isConstantValue;
 
+import java.util.EnumSet;
 import java.util.function.Function;
 
 import org.graalvm.compiler.asm.Label;
@@ -48,6 +49,7 @@
 import org.graalvm.compiler.core.aarch64.AArch64LIRGenerator;
 import org.graalvm.compiler.core.aarch64.AArch64LIRKindTool;
 import org.graalvm.compiler.core.common.CompressEncoding;
+import org.graalvm.compiler.core.common.GraalOptions;
 import org.graalvm.compiler.core.common.LIRKind;
 import org.graalvm.compiler.core.common.calc.Condition;
 import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;
@@ -68,7 +70,7 @@
 import org.graalvm.compiler.lir.LIRFrameState;
 import org.graalvm.compiler.lir.LIRInstruction;
 import org.graalvm.compiler.lir.LabelRef;
-import org.graalvm.compiler.lir.StandardOp.SaveRegistersOp;
+import org.graalvm.compiler.lir.StandardOp.ZapRegistersOp;
 import org.graalvm.compiler.lir.SwitchStrategy;
 import org.graalvm.compiler.lir.Variable;
 import org.graalvm.compiler.lir.VirtualStackSlot;
@@ -167,10 +169,9 @@
     /**
      * @param savedRegisters the registers saved by this operation which may be subject to pruning
      * @param savedRegisterLocations the slots to which the registers are saved
-     * @param supportsRemove determines if registers can be pruned
      */
-    protected AArch64SaveRegistersOp emitSaveRegisters(Register[] savedRegisters, AllocatableValue[] savedRegisterLocations, boolean supportsRemove) {
-        AArch64SaveRegistersOp save = new AArch64SaveRegistersOp(savedRegisters, savedRegisterLocations, supportsRemove);
+    protected AArch64SaveRegistersOp emitSaveRegisters(Register[] savedRegisters, AllocatableValue[] savedRegisterLocations) {
+        AArch64SaveRegistersOp save = new AArch64SaveRegistersOp(savedRegisters, savedRegisterLocations);
         append(save);
         return save;
     }
@@ -182,7 +183,7 @@
         PlatformKind kind = target().arch.getLargestStorableKind(register.getRegisterCategory());
         if (kind.getVectorLength() > 1) {
             // we don't use vector registers, so there is no need to save them
-            kind = AArch64Kind.QWORD;
+            kind = AArch64Kind.DOUBLE;
         }
         return getResult().getFrameMapBuilder().allocateSpillSlot(LIRKind.value(kind));
     }
@@ -190,15 +191,14 @@
     /**
      * Adds a node to the graph that saves all allocatable registers to the stack.
      *
-     * @param supportsRemove determines if registers can be pruned
      * @return the register save node
      */
-    private AArch64SaveRegistersOp emitSaveAllRegisters(Register[] savedRegisters, boolean supportsRemove) {
+    private AArch64SaveRegistersOp emitSaveAllRegisters(Register[] savedRegisters) {
         AllocatableValue[] savedRegisterLocations = new AllocatableValue[savedRegisters.length];
         for (int i = 0; i < savedRegisters.length; i++) {
             savedRegisterLocations[i] = allocateSaveRegisterLocation(savedRegisters[i]);
         }
-        return emitSaveRegisters(savedRegisters, savedRegisterLocations, supportsRemove);
+        return emitSaveRegisters(savedRegisters, savedRegisterLocations);
     }
 
     protected void emitRestoreRegisters(AArch64SaveRegistersOp save) {
@@ -347,11 +347,9 @@
 
         AArch64SaveRegistersOp save = null;
         Stub stub = getStub();
-        if (destroysRegisters) {
-            if (stub != null && stub.preservesRegisters()) {
-                Register[] savedRegisters = getRegisterConfig().getAllocatableRegisters().toArray();
-                save = emitSaveAllRegisters(savedRegisters, true);
-            }
+        if (destroysRegisters && stub != null && stub.shouldSaveRegistersAroundCalls()) {
+            Register[] savedRegisters = getRegisterConfig().getAllocatableRegisters().toArray();
+            save = emitSaveAllRegisters(savedRegisters);
         }
 
         Variable result;
@@ -379,19 +377,15 @@
             result = super.emitForeignCall(hotspotLinkage, debugInfo, args);
         }
 
-        if (destroysRegisters) {
-            if (stub != null) {
-                if (stub.preservesRegisters()) {
-                    HotSpotLIRGenerationResult generationResult = getResult();
-                    LIRFrameState key = currentRuntimeCallInfo;
-                    if (key == null) {
-                        key = LIRFrameState.NO_STATE;
-                    }
-                    assert !generationResult.getCalleeSaveInfo().containsKey(key);
-                    generationResult.getCalleeSaveInfo().put(key, save);
-                    emitRestoreRegisters(save);
-                }
+        if (save != null) {
+            HotSpotLIRGenerationResult generationResult = getResult();
+            LIRFrameState key = currentRuntimeCallInfo;
+            if (key == null) {
+                key = LIRFrameState.NO_STATE;
             }
+            assert !generationResult.getCalleeSaveInfo().containsKey(key);
+            generationResult.getCalleeSaveInfo().put(key, save);
+            emitRestoreRegisters(save);
         }
 
         return result;
@@ -539,7 +533,7 @@
     }
 
     @Override
-    public SaveRegistersOp createZapRegisters(Register[] zappedRegisters, JavaConstant[] zapValues) {
+    public ZapRegistersOp createZapRegisters(Register[] zappedRegisters, JavaConstant[] zapValues) {
         throw GraalError.unimplemented();
     }
 
@@ -547,4 +541,27 @@
     public LIRInstruction createZapArgumentSpace(StackSlot[] zappedStack, JavaConstant[] zapValues) {
         throw GraalError.unimplemented();
     }
+
+    @Override
+    public void emitZeroMemory(Value address, Value length, boolean isAligned) {
+        int dczidValue = config.psrInfoDczidValue;
+        EnumSet<AArch64.Flag> flags = ((AArch64) target().arch).getFlags();
+
+        // ARMv8-A architecture reference manual D12.2.35 Data Cache Zero ID register says:
+        // * BS, bits [3:0] indicate log2 of the DC ZVA block size in (4-byte) words.
+        // * DZP, bit [4] of indicates whether use of DC ZVA instruction is prohibited.
+        int zvaLength = 4 << (dczidValue & 0xF);
+        boolean isDcZvaProhibited = ((dczidValue & 0x10) != 0);
+
+        // Use DC ZVA if it's not prohibited and AArch64 HotSpot flag UseBlockZeroing is on.
+        boolean useDcZva = !isDcZvaProhibited && flags.contains(AArch64.Flag.UseBlockZeroing);
+
+        // Set zva length negative (unknown at compile-time) for AOT compilation, since the value
+        // could be different on different AArch64 CPU implementations.
+        if (GraalOptions.ImmutableCode.getValue(getResult().getLIR().getOptions())) {
+            useDcZva = false;
+        }
+
+        emitZeroMemory(address, length, isAligned, useDcZva, zvaLength);
+    }
 }