Inline java.lang.Class.getComponentType() in Value Propagation

Also, mark result of inlined code for Object.getClass() as non-null.
nbhuiyan · Apr 25, 2024 · 4385039 · 4385039
1 parent 4998aab
commit 4385039
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Showing 3 changed files with 102 additions and 5 deletions.
diff --git a/runtime/compiler/env/VMJ9.cpp b/runtime/compiler/env/VMJ9.cpp
@@ -2883,6 +2883,28 @@ TR_J9VMBase::testAreSomeClassFlagsSet(TR::Node *j9ClassRefNode, uint32_t flagsTo
    return maskedFlags;
    }
 
+TR::Node *
+TR_J9VMBase::testAreSomeClassAndDepthFlagsSet(TR::Node *j9ClassRefNode, uint32_t flagsToTest)
+   {
+   TR::SymbolReference *classAndDepthFlagsSymRef = TR::comp()->getSymRefTab()->findOrCreateClassAndDepthFlagsSymbolRef();
+   TR::Node *classFlags = NULL;
+
+   if (TR::comp()->target().is32Bit())
+      {
+      classFlags = TR::Node::createWithSymRef(TR::iloadi, 1, 1, j9ClassRefNode, classAndDepthFlagsSymRef);
+      }
+   else
+      {
+      classFlags = TR::Node::createWithSymRef(TR::lloadi, 1, 1, j9ClassRefNode, classAndDepthFlagsSymRef);
+      classFlags = TR::Node::create(TR::l2i, 1, classFlags);
+      }
+
+   TR::Node *maskedFlags = TR::Node::create(TR::iand, 2, classFlags, TR::Node::iconst(j9ClassRefNode, flagsToTest));
+
+   return maskedFlags;
+   }
+
+
 TR::Node *
 TR_J9VMBase::testIsClassValueType(TR::Node *j9ClassRefNode)
    {
@@ -2902,13 +2924,21 @@ TR_J9VMBase::testIsClassIdentityType(TR::Node *j9ClassRefNode)
    }
 
 TR::Node *
-TR_J9VMBase::checkSomeArrayCompClassFlags(TR::Node *arrayBaseAddressNode, TR::ILOpCodes ifCmpOp, uint32_t flagsToTest)
+TR_J9VMBase::loadArrayClassComponentType(TR::Node *j9ClassRefNode)
    {
-   TR::SymbolReference *vftSymRef = TR::comp()->getSymRefTab()->findOrCreateVftSymbolRef();
    TR::SymbolReference *arrayCompSymRef = TR::comp()->getSymRefTab()->findOrCreateArrayComponentTypeSymbolRef();
+   TR::Node *arrayCompClass = TR::Node::createWithSymRef(TR::aloadi, 1, 1, j9ClassRefNode, arrayCompSymRef);
+
+   return arrayCompClass;
+   }
 
+TR::Node *
+TR_J9VMBase::checkSomeArrayCompClassFlags(TR::Node *arrayBaseAddressNode, TR::ILOpCodes ifCmpOp, uint32_t flagsToTest)
+   {
+   TR::SymbolReference *vftSymRef = TR::comp()->getSymRefTab()->findOrCreateVftSymbolRef();
    TR::Node *vft = TR::Node::createWithSymRef(TR::aloadi, 1, 1, arrayBaseAddressNode, vftSymRef);
-   TR::Node *arrayCompClass = TR::Node::createWithSymRef(TR::aloadi, 1, 1, vft, arrayCompSymRef);
+
+   TR::Node *arrayCompClass = loadArrayClassComponentType(vft);
    TR::Node *maskedFlagsNode = testAreSomeClassFlagsSet(arrayCompClass, flagsToTest);
    TR::Node *ifNode = TR::Node::createif(ifCmpOp, maskedFlagsNode, TR::Node::iconst(arrayBaseAddressNode, 0));
 
@@ -7642,6 +7672,7 @@ TR_J9VM::inlineNativeCall(TR::Compilation * comp, TR::TreeTop * callNodeTreeTop,
          TR::Node::recreate(callNode, TR::aloadi);
          callNode->setSymbolReference(comp->getSymRefTab()->findOrCreateVftSymbolRef());
          callNode = TR::Node::createWithSymRef(TR::aloadi, 1, 1, callNode, comp->getSymRefTab()->findOrCreateJavaLangClassFromClassSymbolRef());
+         callNode->setIsNonNull(true);
          return callNode;
 
       // Note: these cases are not tested and thus are commented out:

diff --git a/runtime/compiler/env/VMJ9.h b/runtime/compiler/env/VMJ9.h
@@ -1263,6 +1263,8 @@ class TR_J9VMBase : public TR_FrontEnd
     */
    TR::Node * testAreSomeClassFlagsSet(TR::Node *j9ClassRefNode, uint32_t flagsToTest);
 
+   TR::Node * testAreSomeClassAndDepthFlagsSet(TR::Node *j9ClassRefNode, uint32_t flagsToTest);
+
    /**
     * \brief Load class flags field of the specified class and test whether the value type
     *        flag is set.
@@ -1290,6 +1292,8 @@ class TR_J9VMBase : public TR_FrontEnd
     */
    TR::Node * testIsClassIdentityType(TR::Node *j9ClassRefNode);
 
+   TR::Node * loadArrayClassComponentType(TR::Node *j9ClassRefNode);
+
    /**
     * \brief Test whether any of the specified flags is set on the array's component class
     * \param arrayBaseAddressNode A node representing a reference to the array base address

diff --git a/runtime/compiler/optimizer/J9ValuePropagation.cpp b/runtime/compiler/optimizer/J9ValuePropagation.cpp
@@ -1691,8 +1691,11 @@ J9::ValuePropagation::constrainRecognizedMethod(TR::Node *node)
          TR::Node *classChild = node->getLastChild();
          bool classChildGlobal;
          TR::VPConstraint *classChildConstraint = getConstraint(classChild, classChildGlobal);
-         if (classChildConstraint && classChildConstraint->isJavaLangClassObject() == TR_yes
-             && classChildConstraint->isNonNullObject()
+         bool isNonNullJavaLangClass = classChildConstraint
+                                       && classChildConstraint->isJavaLangClassObject() == TR_yes
+                                       && classChildConstraint->isNonNullObject();
+
+         if (isNonNullJavaLangClass
              && classChildConstraint->getClassType()
              && classChildConstraint->getClassType()->asFixedClass())
             {
@@ -1748,6 +1751,65 @@ J9::ValuePropagation::constrainRecognizedMethod(TR::Node *node)
                return;
                }
             }
+         else if (isNonNullJavaLangClass)
+            {
+            if (!performTransformation(comp(), "%sTransforming %s on node %p to load component type inline\n", OPT_DETAILS, signature, node))
+               break;
+
+            // Consider two cases:
+            //
+            // (i)  The operand is an instance of java.lang.Class indirectly loaded through a vft.  In that case,
+            //      we can work with the vft directly
+            // (ii) The operand is definitely a non-null instance of java.lang.Class.  In that case, load the
+            //      J9Class from the java.lang.Class by way of <classFromJavaLangClass>
+            //
+
+            TR::SymbolReference *symRef = classChild->getOpCode().hasSymbolReference() ? classChild->getSymbolReference() : NULL;
+            TR::SymbolReference *jlcFromClassSymRef = comp()->getSymRefTab()->findOrCreateJavaLangClassFromClassSymbolRef();
+            TR::Node *classOperand = NULL;
+
+            if ((symRef != NULL) && (symRef == jlcFromClassSymRef))
+               {
+               classOperand = classChild->getFirstChild();
+               }
+            else
+               {
+               classOperand = TR::Node::createWithSymRef(TR::aloadi, 1, 1, classChild,
+                                 comp()->getSymRefTab()->findOrCreateClassFromJavaLangClassSymbolRef());
+               }
+
+            TR::Node *loadComponentTypeNode = comp()->fej9()->loadArrayClassComponentType(classOperand);
+            TR::Node *jlcOfComponentTypeNode = NULL;
+
+            if ((classChildConstraint == NULL)
+                || (classChildConstraint->getClassType() == NULL)
+                || !comp()->fej9()->isClassArray(classChildConstraint->getClass()))
+               {
+               TR::Node *testIsArrayClassNode =
+                     TR::Node::create(node, TR::icmpne, 2,
+                        comp()->fej9()->testAreSomeClassAndDepthFlagsSet(classOperand, comp()->fej9()->getFlagValueForArrayCheck()),
+                        TR::Node::iconst(node, 0));
+               loadComponentTypeNode =
+                  TR::Node::create(TR::aselect, 3,
+                                   testIsArrayClassNode,
+                                   loadComponentTypeNode,
+                                   classOperand);
+               loadComponentTypeNode =
+                  TR::Node::createWithSymRef(node, TR::aloadi, 1, loadComponentTypeNode, jlcFromClassSymRef);
+               jlcOfComponentTypeNode =
+                  TR::Node::create(TR::aselect, 3,
+                                   testIsArrayClassNode,
+                                   loadComponentTypeNode,
+                                   TR::Node::aconst(node, 0));
+               }
+            else
+               {
+               jlcOfComponentTypeNode =
+                  TR::Node::createWithSymRef(node, TR::aloadi, 1, loadComponentTypeNode, jlcFromClassSymRef);
+               }
+
+            transformCallToNodeDelayedTransformations(_curTree, jlcOfComponentTypeNode, false);
+            }
          break;
          }
       case TR::java_lang_J9VMInternals_getSuperclass: