Shenandoah support

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/core/phases/EconomyLowTier.java

@@ -26,6 +26,7 @@
 
 import jdk.graal.compiler.debug.Assertions;
 import jdk.graal.compiler.graph.Graph;
+import jdk.graal.compiler.nodes.GraphState;
 import jdk.graal.compiler.options.OptionValues;
 import jdk.graal.compiler.phases.PlaceholderPhase;
 import jdk.graal.compiler.phases.common.AddressLoweringPhase;
@@ -36,6 +37,7 @@
 import jdk.graal.compiler.phases.common.LowTierLoweringPhase;
 import jdk.graal.compiler.phases.common.RemoveOpaqueValuePhase;
 import jdk.graal.compiler.phases.common.TransplantGraphsPhase;
+import jdk.graal.compiler.phases.common.WriteBarrierAdditionPhase;
 import jdk.graal.compiler.phases.schedule.SchedulePhase;
 import jdk.graal.compiler.phases.tiers.LowTierContext;
 
@@ -50,6 +52,8 @@ public EconomyLowTier(OptionValues options) {
         appendPhase(new LowTierLoweringPhase(canonicalizer));
         appendPhase(new ExpandLogicPhase(canonicalizer));
 
+        appendPhase(new WriteBarrierAdditionPhase(GraphState.StageFlag.LOW_TIER_BARRIER_ADDITION));
+
         if (Assertions.assertionsEnabled()) {
             appendPhase(new BarrierSetVerificationPhase());
         }

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/core/phases/LowTier.java

@@ -28,6 +28,7 @@
 
 import jdk.graal.compiler.core.common.GraalOptions;
 import jdk.graal.compiler.graph.Graph;
+import jdk.graal.compiler.nodes.GraphState;
 import jdk.graal.compiler.options.Option;
 import jdk.graal.compiler.options.OptionKey;
 import jdk.graal.compiler.options.OptionType;
@@ -47,6 +48,7 @@
 import jdk.graal.compiler.phases.common.PropagateDeoptimizeProbabilityPhase;
 import jdk.graal.compiler.phases.common.RemoveOpaqueValuePhase;
 import jdk.graal.compiler.phases.common.TransplantGraphsPhase;
+import jdk.graal.compiler.phases.common.WriteBarrierAdditionPhase;
 import jdk.graal.compiler.phases.schedule.SchedulePhase;
 import jdk.graal.compiler.phases.schedule.SchedulePhase.SchedulingStrategy;
 import jdk.graal.compiler.phases.tiers.LowTierContext;
@@ -87,6 +89,8 @@ public LowTier(OptionValues options) {
         appendPhase(new FixReadsPhase(true,
                         new SchedulePhase(GraalOptions.StressTestEarlyReads.getValue(options) ? SchedulingStrategy.EARLIEST : SchedulingStrategy.LATEST_OUT_OF_LOOPS_IMPLICIT_NULL_CHECKS)));
 
+        appendPhase(new WriteBarrierAdditionPhase(GraphState.StageFlag.LOW_TIER_BARRIER_ADDITION));
+
         appendPhase(canonicalizerWithoutGVN);
 
         /*

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/GraalHotSpotVMConfig.java

@@ -622,6 +622,44 @@ private long getZGCAddressField(String name) {
     public final long zBarrierSetRuntimeLoadBarrierOnOopArray = getZGCAddressField("ZBarrierSetRuntime::load_barrier_on_oop_array");
     public final int zPointerLoadShift = getConstant("ZPointerLoadShift", Integer.class, -1, osArch.equals("aarch64") && zgcSupport);
 
+    /*
+     * Shenandoah GC support.
+     */
+    /**
+     * Indicates whether or not the HotSpot VM has been built with Shenandoah support.
+     * If not, then we don't expect the Shenandoah symbols to be present in JVMCI.
+     */
+    public final boolean hasShenandoahGC = getStore().getConstants().containsKey("INCLUDE_SHENANDOAHGC") && getConstant("INCLUDE_SHENANDOAHGC", Boolean.class);
+
+    /*
+     * Various Shenandoah GC constants.
+     */
+    public final int shenandoahGCStateOffset = getConstant("ShenandoahThreadLocalData::gc_state_offset", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahSATBIndexOffset = getConstant("ShenandoahThreadLocalData::satb_mark_queue_index_offset", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahSATBBufferOffset = getConstant("ShenandoahThreadLocalData::satb_mark_queue_buffer_offset", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahCardTableOffset = getConstant("ShenandoahThreadLocalData::card_table_offset", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahGCRegionSizeBytesShift = getFieldValue("CompilerToVM::Data::shenandoah_region_size_bytes_shift", Integer.class, "int", -1, hasShenandoahGC);
+    public final long shenandoahGCCSetFastTestAddress = getFieldValue("CompilerToVM::Data::shenandoah_in_cset_fast_test_addr", Long.class, "address", -1L, hasShenandoahGC);
+
+    public final int shenandoahGCStateHasForwarded = getConstant("ShenandoahHeap::HAS_FORWARDED", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahGCStateMarking = getConstant("ShenandoahHeap::MARKING", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahGCStateEvacuation = getConstant("ShenandoahHeap::EVACUATION", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahGCStateUpdateRefs = getConstant("ShenandoahHeap::UPDATE_REFS", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahGCStateWeakRoots = getConstant("ShenandoahHeap::WEAK_ROOTS", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahGCStateYoungMarking = getConstant("ShenandoahHeap::YOUNG_MARKING", Integer.class, -1, hasShenandoahGC);
+    public final int shenandoahGCStateOldMarking = getConstant("ShenandoahHeap::OLD_MARKING", Integer.class, -1, hasShenandoahGC);
+
+    /*
+     * Shenandoah barrier slow-paths.
+     */
+    public final long shenandoahLoadBarrierStrong = getAddress("ShenandoahRuntime::load_reference_barrier_strong", -1L, hasShenandoahGC);
+    public final long shenandoahLoadBarrierStrongNarrow = getAddress("ShenandoahRuntime::load_reference_barrier_strong_narrow", -1L, hasShenandoahGC);
+    public final long shenandoahLoadBarrierWeak = getAddress("ShenandoahRuntime::load_reference_barrier_weak", -1L, hasShenandoahGC);
+    public final long shenandoahLoadBarrierWeakNarrow = getAddress("ShenandoahRuntime::load_reference_barrier_weak_narrow", -1L, hasShenandoahGC);
+    public final long shenandoahLoadBarrierPhantom = getAddress("ShenandoahRuntime::load_reference_barrier_phantom", -1L, hasShenandoahGC);
+    public final long shenandoahLoadBarrierPhantomNarrow = getAddress("ShenandoahRuntime::load_reference_barrier_phantom_narrow", -1L, hasShenandoahGC);
+    public final long shenandoahWriteBarrierPre = getAddress("ShenandoahRuntime::write_barrier_pre", -1L, hasShenandoahGC);
+
     // aarch64 specific nmethod entry barrier support
     // @formatter:off
     public final int BarrierSetAssembler_nmethod_patching_type = getFieldValue("CompilerToVM::Data::BarrierSetAssembler_nmethod_patching_type", Integer.class, "int", -1, osArch.equals("aarch64"));

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/HotSpotBackendFactory.java

@@ -259,6 +259,8 @@ private BarrierSet createBarrierSet(GraalHotSpotVMConfig config, MetaAccessProvi
         ResolvedJavaField referentField = HotSpotReplacementsUtil.referentField(metaAccess);
         if (config.gc == HotSpotGraalRuntime.HotSpotGC.Z) {
             return new HotSpotZBarrierSet(objectArrayType, referentField);
+        } else if (config.gc == HotSpotGraalRuntime.HotSpotGC.Shenandoah) {
+            return new HotSpotShenandoahBarrierSet(objectArrayType, referentField, config);
         } else if (config.gc == HotSpotGraalRuntime.HotSpotGC.Epsilon) {
             return new NoBarrierSet();
         } else if (config.useG1GC()) {

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/HotSpotGraalRuntime.java

@@ -209,9 +209,7 @@ public enum HotSpotGC {
         G1("UseG1GC"),
         Z(true, true, flagIsSet("UseZGC")),
         Epsilon(true, true, flagIsSet("UseEpsilonGC")),
-
-        // Unsupported GCs
-        Shenandoah(false, true, flagIsSet("UseShenandoahGC"));
+        Shenandoah(true, true, flagIsSet("UseShenandoahGC"));
 
         HotSpotGC(String flag) {
             this(true, true, flagIsSet(flag));

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/HotSpotShenandoahBarrierSet.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2025, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 jdk.graal.compiler.hotspot;
+
+import jdk.graal.compiler.core.common.CompressEncoding;
+import jdk.graal.compiler.debug.GraalError;
+import jdk.graal.compiler.hotspot.nodes.HotSpotCompressionNode;
+import org.graalvm.word.LocationIdentity;
+
+import jdk.graal.compiler.core.common.memory.BarrierType;
+import jdk.graal.compiler.core.common.type.AbstractObjectStamp;
+import jdk.graal.compiler.core.common.type.Stamp;
+import jdk.graal.compiler.hotspot.replacements.HotSpotReplacementsUtil;
+import jdk.graal.compiler.nodes.ValueNode;
+import jdk.graal.compiler.nodes.gc.shenandoah.ShenandoahBarrierSet;
+import jdk.vm.ci.meta.JavaKind;
+import jdk.vm.ci.meta.ResolvedJavaField;
+import jdk.vm.ci.meta.ResolvedJavaType;
+
+/**
+ * Specialization of {@link ShenandoahBarrierSet} that adds support for read barriers on handle
+ * locations and compressed references.
+ */
+public class HotSpotShenandoahBarrierSet extends ShenandoahBarrierSet {
+    private final CompressEncoding oopEncoding;
+
+    public HotSpotShenandoahBarrierSet(ResolvedJavaType objectArrayType, ResolvedJavaField referentField, GraalHotSpotVMConfig config) {
+        super(objectArrayType, referentField);
+        this.oopEncoding = config.getOopEncoding();
+        this.useLoadRefBarrier = config.getFlag("ShenandoahLoadRefBarrier", Boolean.class);
+        this.useSATBBarrier = config.getFlag("ShenandoahSATBBarrier", Boolean.class);
+        this.useCASBarrier = config.getFlag("ShenandoahCASBarrier", Boolean.class);
+        this.useCardBarrier = config.getFlag("ShenandoahCardBarrier", Boolean.class);
+    }
+
+    @Override
+    protected BarrierType barrierForLocation(BarrierType currentBarrier, LocationIdentity location, JavaKind storageKind) {
+        if (location instanceof HotSpotReplacementsUtil.OopHandleLocationIdentity) {
+            return BarrierType.READ;
+        }
+        return super.barrierForLocation(currentBarrier, location, storageKind);
+    }
+
+    @Override
+    public BarrierType readBarrierType(LocationIdentity location, ValueNode address, Stamp loadStamp) {
+        if (location instanceof HotSpotReplacementsUtil.OopHandleLocationIdentity) {
+            GraalError.guarantee(loadStamp instanceof AbstractObjectStamp, "expect object, got: " + loadStamp);
+            return BarrierType.READ;
+        }
+        return super.readBarrierType(location, address, loadStamp);
+    }
+
+    @Override
+    public BarrierType writeBarrierType(LocationIdentity location) {
+        if (location instanceof HotSpotReplacementsUtil.OopHandleLocationIdentity) {
+            return BarrierType.FIELD;
+        }
+        return BarrierType.NONE;
+    }
+
+    @Override
+    protected ValueNode maybeUncompressReference(ValueNode value, boolean narrow) {
+        if (value != null && narrow) {
+            return HotSpotCompressionNode.uncompressWithoutUnique(value.graph(), value, oopEncoding);
+        }
+        return value;
+    }
+
+    @Override
+    protected ValueNode maybeCompressReference(ValueNode value, boolean narrow) {
+        if (value != null && narrow) {
+            return HotSpotCompressionNode.compressWithoutUnique(value.graph(), value, oopEncoding);
+        }
+        return value;
+    }
+}

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/aarch64/AArch64HotSpotLIRGenerator.java

@@ -62,6 +62,7 @@
 import jdk.graal.compiler.hotspot.HotSpotLIRGenerator;
 import jdk.graal.compiler.hotspot.HotSpotLockStack;
 import jdk.graal.compiler.hotspot.aarch64.g1.AArch64HotSpotG1BarrierSetLIRTool;
+import jdk.graal.compiler.hotspot.aarch64.shenandoah.AArch64HotSpotShenandoahBarrierSetLIRGenerator;
 import jdk.graal.compiler.hotspot.aarch64.z.AArch64HotSpotZBarrierSetLIRGenerator;
 import jdk.graal.compiler.hotspot.debug.BenchmarkCounters;
 import jdk.graal.compiler.hotspot.meta.HotSpotProviders;
@@ -119,6 +120,9 @@ protected static BarrierSetLIRGeneratorTool getBarrierSet(GraalHotSpotVMConfig c
         if (config.gc == HotSpotGraalRuntime.HotSpotGC.Z) {
             return new AArch64HotSpotZBarrierSetLIRGenerator(config, providers);
         }
+        if (config.gc == HotSpotGraalRuntime.HotSpotGC.Shenandoah) {
+            return new AArch64HotSpotShenandoahBarrierSetLIRGenerator(config, providers);
+        }
         return null;
     }
 

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/aarch64/AArch64HotSpotMove.java

@@ -112,6 +112,10 @@ public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
             Register resultRegister = asRegister(result);
             Register ptr = asRegister(input);
             Register base = (isRegister(baseRegister) ? asRegister(baseRegister) : zr);
+            emitCompressCode(masm, ptr, resultRegister, base, encoding, nonNull);
+        }
+
+        public static void emitCompressCode(AArch64MacroAssembler masm,  Register ptr, Register resultRegister, Register base, CompressEncoding encoding, boolean nonNull) {
             // result = (ptr - base) >> shift
             if (!encoding.hasBase()) {
                 if (encoding.hasShift()) {