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Add inlined itable walk for Class.isAssignableFrom on Z #22693

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Add inlined itable walk for Class.isAssignableFrom on Z #22693

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80 changes: 71 additions & 9 deletions runtime/compiler/z/codegen/J9TreeEvaluator.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -11861,9 +11861,55 @@ static TR::SymbolReference *getClassSymRefAndDepth(TR::Node *classNode, TR::Comp
return classSymRef;
}

static void genITableTest(TR::Node *node, TR::CodeGenerator *cg, TR_S390ScratchRegisterManager *srm, TR::Register *fromClassReg, TR::Register *toClassReg, TR::LabelSymbol *successLabel, TR::LabelSymbol *failLabel)
{
TR::Compilation *comp = cg->comp();
TR_Debug * debugObj = cg->getDebug();
bool traceCG = comp->getOption(TR_TraceCG);
TR::LabelSymbol *cacheCastClassLabel = generateLabelSymbol(cg);
TR::LabelSymbol *startWalkLabel = generateLabelSymbol(cg);

TR::Register *iTableReg = srm->findOrCreateScratchRegister();
// lastITable Test
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/interfaceTest/lastITable"), 1, TR::DebugCounter::Undetermined);
TR::Instruction *cursor = generateRXInstruction(cg, TR::InstOpCode::getLoadOpCode(), node, iTableReg,
generateS390MemoryReference(fromClassReg, offsetof(J9Class, lastITable), cg));
// last itable is never null
generateRXInstruction(cg, TR::InstOpCode::getCmpLogicalOpCode(), node, toClassReg,
generateS390MemoryReference(iTableReg, offsetof(J9ITable, interfaceClass), cg));
generateS390BranchInstruction(cg, TR::InstOpCode::BRC, TR::InstOpCode::COND_BE, node, successLabel);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/interfaceTest/lastITable/fail"), 1, TR::DebugCounter::Undetermined);
// Itable Test
cursor = generateS390LabelInstruction(cg, TR::InstOpCode::label, node, startWalkLabel);
cursor = generateRXInstruction(cg, TR::InstOpCode::getLoadOpCode(), node, iTableReg,
generateS390MemoryReference(fromClassReg, offsetof(J9Class, iTable), cg));

cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/interfaceTest/ITableWalk"), 1, TR::DebugCounter::Undetermined);

TR::LabelSymbol *startLoop = generateLabelSymbol(cg);
cursor = generateS390LabelInstruction(cg, TR::InstOpCode::label, node, startLoop);
if (debugObj && traceCG)
debugObj->addInstructionComment(cursor, "--> Start of iTable walk");

generateRRInstruction(cg, TR::InstOpCode::getLoadTestRegOpCode(), node, iTableReg, iTableReg);
generateS390BranchInstruction(cg, TR::InstOpCode::BRC, TR::InstOpCode::COND_BE, node, failLabel);
generateRXInstruction(cg, TR::InstOpCode::getCmpLogicalOpCode(), node, toClassReg,
generateS390MemoryReference(iTableReg, offsetof(J9ITable, interfaceClass), cg));
generateS390BranchInstruction(cg, TR::InstOpCode::BRC, TR::InstOpCode::COND_BE, node, successLabel);
generateRXInstruction(cg, TR::InstOpCode::getLoadOpCode(), node, iTableReg,
generateS390MemoryReference(iTableReg, offsetof(J9ITable, next), cg));
cursor = generateS390BranchInstruction(cg, TR::InstOpCode::BRC, TR::InstOpCode::COND_BRC, node, startLoop);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/interfaceTest/ITableWalk/fail"), 1, TR::DebugCounter::Undetermined);
if (debugObj && traceCG)
debugObj->addInstructionComment(cursor, "to start of loop");

srm->reclaimScratchRegister(iTableReg);
}

TR::Register *J9::Z::TreeEvaluator::inlineCheckAssignableFromEvaluator(TR::Node *node, TR::CodeGenerator *cg)
{
TR::Compilation *comp = cg->comp();
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromPath/(%s)", comp->signature()), 1, TR::DebugCounter::Undetermined);
// recognizedCallTransformer swaps the args - caller class obj is the second argument after the transformation
TR::Node *fromClass = node->getFirstChild();
TR::Node *toClass = node->getSecondChild();
Expand All @@ -11875,6 +11921,7 @@ TR::Register *J9::Z::TreeEvaluator::inlineCheckAssignableFromEvaluator(TR::Node
TR::LabelSymbol *failLabel = generateLabelSymbol(cg);
TR::LabelSymbol *successLabel = doneLabel;
TR::LabelSymbol* cFlowRegionStart = generateLabelSymbol(cg);
TR::LabelSymbol* ITableTestLabel = generateLabelSymbol(cg);

TR_S390ScratchRegisterManager *srm = cg->generateScratchRegisterManager(2);

Expand All @@ -11897,11 +11944,11 @@ TR::Register *J9::Z::TreeEvaluator::inlineCheckAssignableFromEvaluator(TR::Node
if (comp->getOption(TR_TraceCG))
traceMsg(comp,"%s: Emitting Class Equality Test\n",node->getOpCode().getName());
// for isAssignableFrom we can always generate the class equality test since both arguments are classes
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/(%s)/ClassEqualityTest", comp->signature()), 1, TR::DebugCounter::Undetermined);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/ClassEqualityTest"), 1, TR::DebugCounter::Undetermined);
cursor = generateS390CompareAndBranchInstruction(cg, TR::InstOpCode::getCmpRegOpCode(), node, toClassReg, fromClassReg, TR::InstOpCode::COND_BE, successLabel, false, false);
if (debugObj)
debugObj->addInstructionComment(cursor, "class equality test");
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/(%s)/ClassEqualityTest/Fail", comp->signature()), 1, TR::DebugCounter::Undetermined);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/ClassEqualityTest/Fail"), 1, TR::DebugCounter::Undetermined);

int32_t toClassDepth = -1;
TR::SymbolReference *toClassSymRef = getClassSymRefAndDepth(toClass, comp, toClassDepth);
Expand Down Expand Up @@ -11940,30 +11987,45 @@ TR::Register *J9::Z::TreeEvaluator::inlineCheckAssignableFromEvaluator(TR::Node
if (comp->getOption(TR_TraceCG))
traceMsg(comp,"%s: Emitting CastClassCacheTest\n",node->getOpCode().getName());
TR::Register *castClassCacheReg = srm->findOrCreateScratchRegister();
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/(%s)/Cache", comp->signature()), 1, TR::DebugCounter::Undetermined);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/Cache"), 1, TR::DebugCounter::Undetermined);
generateRXInstruction(cg, TR::InstOpCode::getLoadOpCode(), node, castClassCacheReg,
generateS390MemoryReference(fromClassReg, offsetof(J9Class, castClassCache), cg));
cursor = generateS390CompareAndBranchInstruction(cg, TR::InstOpCode::getCmpRegOpCode(), node, castClassCacheReg, toClassReg, TR::InstOpCode::COND_BE, successLabel, false, false);
if (debugObj)
debugObj->addInstructionComment(cursor, "castclass cache test");
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/(%s)/Cache/Fail", comp->signature()), 1, TR::DebugCounter::Undetermined);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/Cache/Fail"), 1, TR::DebugCounter::Undetermined);
srm->reclaimScratchRegister(castClassCacheReg);
}

// superclass test
if((NULL == toClassSymRef) || !toClassSymRef->isClassInterface(comp))
{
const int32_t flags = (J9AccInterface | J9AccClassArray);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/(%s)/SuperclassTest", comp->signature()), 1, TR::DebugCounter::Undetermined);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/SuperclassTest"), 1, TR::DebugCounter::Undetermined);
if (toClassDepth == -1)
{
genTestModifierFlags(cg, node, toClassReg, toClassDepth, helperCallLabel, srm, flags);
if (feGetEnv("enableInlineItableWalkForIsAssignableFrom")) {
TR::Register *modifierReg = srm->findOrCreateScratchRegister();
generateRXInstruction(cg, TR::InstOpCode::getLoadOpCode(), node, modifierReg,
generateS390MemoryReference(toClassReg, offsetof(J9Class, classDepthAndFlags), cg));
genTestModifierFlags(cg, node, toClassReg, toClassDepth, ITableTestLabel, srm, J9AccInterface, modifierReg);
genTestModifierFlags(cg, node, toClassReg, toClassDepth, helperCallLabel, srm, J9AccClassArray, modifierReg);
srm->reclaimScratchRegister(modifierReg);
} else {
genTestModifierFlags(cg, node, toClassReg, toClassDepth, helperCallLabel, srm, J9AccInterface | J9AccClassArray);
}
}
genSuperclassTest(cg, node, toClassReg, toClassDepth, fromClassReg, failLabel, srm);
generateS390BranchInstruction(cg, TR::InstOpCode::BRC, TR::InstOpCode::COND_BE, node, successLabel);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/(%s)/SuperclassTest/Fail", comp->signature()), 1, TR::DebugCounter::Undetermined);
cg->generateDebugCounter(TR::DebugCounter::debugCounterName(comp, "isAssignableFromStats/SuperclassTest/Fail"), 1, TR::DebugCounter::Undetermined);
generateS390BranchInstruction(cg, TR::InstOpCode::BRC, TR::InstOpCode::COND_BRC, node, helperCallLabel);
}
// we don't generate ITable test if we know we don't have an interface
if ((toClassDepth == -1) || (NULL == toClassSymRef || toClassSymRef->isClassInterface(comp)))
{
generateS390LabelInstruction(cg, TR::InstOpCode::label, node, ITableTestLabel);
// no need for helper if we fail interface test - we known the cast class is an interface
genITableTest(node, cg, srm, fromClassReg, toClassReg, doneLabel, failLabel);
}
generateS390BranchInstruction(cg, TR::InstOpCode::BRC, TR::InstOpCode::COND_BRC, node, helperCallLabel);
}

srm->stopUsingRegisters();
Expand Down