Do not trust nullable arrayclass type in VP

Update isUnreliableSignatureType to check if the class is an array class, and if its component class is value type, and if the array class is not null-restricted array. If so, the type is not reliable because it can either be a nullable array class type or a null-restricted array type. Fixes: #19914 Signed-off-by: Annabelle Huo <[email protected]>
eclipse-openj9 · Oct 29, 2024 · 04ce59f · 04ce59f
1 parent c67b5f4
commit 04ce59f
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diff --git a/runtime/compiler/optimizer/J9ValuePropagation.cpp b/runtime/compiler/optimizer/J9ValuePropagation.cpp
@@ -3782,9 +3782,28 @@ bool J9::ValuePropagation::isUnreliableSignatureType(
       return false;
 
    int32_t numDims = 0;
+   TR_OpaqueClassBlock *originClass = klass;
    klass = comp()->fej9()->getBaseComponentClass(klass, numDims);
+
    if (!TR::Compiler->cls.isInterfaceClass(comp(), klass))
-      return false;
+      {
+      // If the original class is an array class and it is not a null-restricted array,
+      // we can not trust its type as a nullable array because it can either be a nullable
+      // array class type or a null-restricted array type.
+      // TODO-VALUETYPE: However, if in the future Value Propagation constraints are able
+      // to distinguish between nullable and null-restricted arrays, this test can change.
+      if (TR::Compiler->om.areFlattenableValueTypesEnabled() &&
+         (numDims > 0) &&
+         TR::Compiler->cls.isValueTypeClass(klass) &&
+         !TR::Compiler->cls.isArrayNullRestricted(comp(), originClass))
+         {
+         // Do nothing here and will be handled next like an interface array
+         }
+      else
+         {
+         return false;
+         }
+      }
 
    // Find the best array type that we can guarantee based on an
    // array-of-interface signature.

diff --git a/test/functional/Valhalla/playlist.xml b/test/functional/Valhalla/playlist.xml
@@ -339,8 +339,7 @@
 			<variation>-Xint</variation>
 			<variation>-Xint -Xgcpolicy:optthruput -XX:ValueTypeFlatteningThreshold=99999</variation>
 			<variation>-Xint -Xgcpolicy:optthruput -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
-			<!-- https://github.com/eclipse-openj9/openj9/issues/19914 -->
-			<!--<variation>-Xjit:count=0</variation>
+			<variation>-Xjit:count=0</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation -Xgcpolicy:optthruput</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation -Xgcpolicy:optthruput -XX:ValueTypeFlatteningThreshold=99999 -XX:-EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation -Xgcpolicy:optthruput -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
@@ -349,17 +348,17 @@
 			<variation>-Xjit:count=1,disableAsyncCompilation -Xgcpolicy:gencon -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation -Xnocompressedrefs -Xgcpolicy:optthruput -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation -Xnocompressedrefs -Xgcpolicy:gencon -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
-			<variation>-Xjit:count=1,disableAsyncCompilation -Xnocompressedrefs -Xgcpolicy:gencon</variation>-->
+			<variation>-Xjit:count=1,disableAsyncCompilation -Xnocompressedrefs -Xgcpolicy:gencon</variation>
 			<!-- Test the above options with initialOptLevel=warm -->
-			<!--<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xgcpolicy:optthruput</variation>
+			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xgcpolicy:optthruput</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xgcpolicy:optthruput -XX:ValueTypeFlatteningThreshold=99999 -XX:-EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xgcpolicy:optthruput -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xgcpolicy:gencon -XX:ValueTypeFlatteningThreshold=12 -XX:-EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xgcpolicy:gencon -XX:ValueTypeFlatteningThreshold=99999 -XX:-EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xgcpolicy:gencon -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xnocompressedrefs -Xgcpolicy:optthruput -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
 			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xnocompressedrefs -Xgcpolicy:gencon -XX:ValueTypeFlatteningThreshold=99999 -XX:+EnableArrayFlattening</variation>
-			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xnocompressedrefs -Xgcpolicy:gencon</variation>-->
+			<variation>-Xjit:count=1,disableAsyncCompilation,initialOptLevel=warm -Xnocompressedrefs -Xgcpolicy:gencon</variation>
 		</variations>
 		<command>$(JAVA_COMMAND) $(JVM_OPTIONS) \
 		--enable-preview \