Disable fast path allocation for types which must be slow path allocated

(cherry picked from commit 6cbcc1a)
oracle · Oct 3, 2023 · 7e2bd5c · 7e2bd5c
1 parent 33bde2c
commit 7e2bd5c
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Showing 4 changed files with 12 additions and 13 deletions.
diff --git a/...iler.hotspot/src/org/graalvm/compiler/hotspot/replacements/HotSpotAllocationSnippets.java b/...iler.hotspot/src/org/graalvm/compiler/hotspot/replacements/HotSpotAllocationSnippets.java
@@ -146,10 +146,11 @@ public HotSpotAllocationSnippets(GraalHotSpotVMConfig config, HotSpotRegistersPr
     @Snippet
     protected Object allocateInstance(KlassPointer hub,
                     @ConstantParameter long size,
+                    @ConstantParameter boolean forceSlowPath,
                     @ConstantParameter FillContent fillContents,
                     @ConstantParameter boolean emitMemoryBarrier,
                     @ConstantParameter HotSpotAllocationProfilingData profilingData) {
-        Object result = allocateInstanceImpl(hub.asWord(), WordFactory.unsigned(size), fillContents, emitMemoryBarrier, true, profilingData);
+        Object result = allocateInstanceImpl(hub.asWord(), WordFactory.unsigned(size), forceSlowPath, fillContents, emitMemoryBarrier, true, profilingData);
         return piCastToSnippetReplaceeStamp(result);
     }
 
@@ -194,7 +195,7 @@ public Object allocateInstanceDynamic(@NonNullParameter Class<?> type,
                      * binding of parameters is not yet supported by the GraphBuilderPlugin system.
                      */
                     UnsignedWord size = WordFactory.unsigned(layoutHelper);
-                    return allocateInstanceImpl(nonNullHub.asWord(), size, fillContents, emitMemoryBarrier, false, profilingData);
+                    return allocateInstanceImpl(nonNullHub.asWord(), size, false, fillContents, emitMemoryBarrier, false, profilingData);
                 }
             } else {
                 DeoptimizeNode.deopt(None, RuntimeConstraint);
@@ -657,12 +658,14 @@ public void lower(NewInstanceNode node, LoweringTool tool) {
             HotSpotResolvedObjectType type = (HotSpotResolvedObjectType) node.instanceClass();
             assert !type.isArray();
             ConstantNode hub = ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), type.klass(), tool.getMetaAccess(), graph);
-            long size = instanceSize(type);
+            long size = type.instanceSize();
 
             OptionValues localOptions = graph.getOptions();
             Arguments args = new Arguments(allocateInstance, graph.getGuardsStage(), tool.getLoweringStage());
             args.add("hub", hub);
-            args.addConst("size", size);
+            // instanceSize returns a negative number for types which should be slow path allocated
+            args.addConst("size", Math.abs(size));
+            args.addConst("forceSlowPath", size < 0);
             args.addConst("fillContents", FillContent.fromBoolean(node.fillContents()));
             args.addConst("emitMemoryBarrier", node.emitMemoryBarrier());
             args.addConst("profilingData", getProfilingData(localOptions, "instance", type));
@@ -794,11 +797,6 @@ private static HotSpotResolvedObjectType lookupArrayClass(LoweringTool tool, Jav
             return HotSpotAllocationSnippets.lookupArrayClass(tool.getMetaAccess(), kind);
         }
 
-        private static long instanceSize(HotSpotResolvedObjectType type) {
-            long size = type.instanceSize();
-            assert size >= 0;
-            return size;
-        }
     }
 
     private static class HotSpotAllocationProfilingData extends AllocationProfilingData {

diff --git a/...aalvm.compiler.replacements/src/org/graalvm/compiler/replacements/AllocationSnippets.java b/...aalvm.compiler.replacements/src/org/graalvm/compiler/replacements/AllocationSnippets.java
@@ -49,6 +49,7 @@
 public abstract class AllocationSnippets implements Snippets {
     protected Object allocateInstanceImpl(Word hub,
                     UnsignedWord size,
+                    boolean forceSlowPath,
                     FillContent fillContents,
                     boolean emitMemoryBarrier,
                     boolean constantSize,
@@ -58,7 +59,7 @@ protected Object allocateInstanceImpl(Word hub,
         Word top = readTlabTop(tlabInfo);
         Word end = readTlabEnd(tlabInfo);
         Word newTop = top.add(size);
-        if (useTLAB() && probability(FAST_PATH_PROBABILITY, shouldAllocateInTLAB(size, false)) && probability(FAST_PATH_PROBABILITY, newTop.belowOrEqual(end))) {
+        if (!forceSlowPath && useTLAB() && probability(FAST_PATH_PROBABILITY, shouldAllocateInTLAB(size, false)) && probability(FAST_PATH_PROBABILITY, newTop.belowOrEqual(end))) {
             writeTlabTop(tlabInfo, newTop);
             emitPrefetchAllocate(newTop, false);
             result = formatObject(hub, size, top, fillContents, emitMemoryBarrier, constantSize, profilingData.snippetCounters);

diff --git a/...tspot/src/org/graalvm/compiler/truffle/runtime/hotspot/AbstractHotSpotTruffleRuntime.java b/...tspot/src/org/graalvm/compiler/truffle/runtime/hotspot/AbstractHotSpotTruffleRuntime.java
@@ -593,7 +593,7 @@ protected int getBaseInstanceSize(Class<?> type) {
 
         HotSpotMetaAccessProvider meta = (HotSpotMetaAccessProvider) getMetaAccess();
         HotSpotResolvedObjectType resolvedType = (HotSpotResolvedObjectType) meta.lookupJavaType(type);
-        return resolvedType.instanceSize();
+        return Math.abs(resolvedType.instanceSize());
     }
 
     private static boolean fieldIsNotEligible(Class<?> clazz, ResolvedJavaField f) {

diff --git a/...m.oracle.svm.core/src/com/oracle/svm/core/graal/snippets/SubstrateAllocationSnippets.java b/...m.oracle.svm.core/src/com/oracle/svm/core/graal/snippets/SubstrateAllocationSnippets.java
@@ -131,7 +131,7 @@ protected Object allocateInstance(@NonNullParameter DynamicHub hub,
                     @ConstantParameter FillContent fillContents,
                     @ConstantParameter boolean emitMemoryBarrier,
                     @ConstantParameter AllocationProfilingData profilingData) {
-        Object result = allocateInstanceImpl(encodeAsTLABObjectHeader(hub), WordFactory.unsigned(size), fillContents, emitMemoryBarrier, true, profilingData);
+        Object result = allocateInstanceImpl(encodeAsTLABObjectHeader(hub), WordFactory.unsigned(size), false, fillContents, emitMemoryBarrier, true, profilingData);
         return piCastToSnippetReplaceeStamp(result);
     }
 
@@ -230,7 +230,7 @@ protected Object allocateInstanceDynamicImpl(DynamicHub hub, FillContent fillCon
                     @SuppressWarnings("unused") boolean supportsOptimizedFilling, AllocationProfilingData profilingData) {
         // The hub was already verified by a ValidateNewInstanceClassNode.
         UnsignedWord size = LayoutEncoding.getPureInstanceAllocationSize(hub.getLayoutEncoding());
-        Object result = allocateInstanceImpl(encodeAsTLABObjectHeader(hub), size, fillContents, emitMemoryBarrier, false, profilingData);
+        Object result = allocateInstanceImpl(encodeAsTLABObjectHeader(hub), size, false, fillContents, emitMemoryBarrier, false, profilingData);
         return piCastToSnippetReplaceeStamp(result);
     }