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VPKnownObject Constraints for JITServer #7565

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merged 1 commit into from
Dec 3, 2024
Merged

VPKnownObject Constraints for JITServer #7565

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32 changes: 11 additions & 21 deletions compiler/optimizer/VPConstraint.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1353,28 +1353,18 @@ TR::VPKnownObject *TR::VPKnownObject::create(OMR::ValuePropagation *vp, TR::Know
//
constraint = NULL;
#ifdef J9_PROJECT_SPECIFIC
{
TR::VMAccessCriticalSection vpKnownObjectCriticalSection(vp->comp(),
TR::VMAccessCriticalSection::tryToAcquireVMAccess);

if (vpKnownObjectCriticalSection.hasVMAccess())
{
TR_OpaqueClassBlock *clazz = TR::Compiler->cls.objectClass(vp->comp(), knot->getPointer(index));
TR_OpaqueClassBlock *jlClass = vp->fe()->getClassClassPointer(clazz);
if (isJavaLangClass)
{
TR_ASSERT(clazz == jlClass, "Use createForJavaLangClass only for instances of java/lang/Class");
clazz = TR::Compiler->cls.classFromJavaLangClass(vp->comp(), knot->getPointer(index));
}
else
{
// clazz is already right
TR_ASSERT(clazz != jlClass, "For java/lang/Class instances, caller needs to use createForJavaLangClass.");
}
constraint = new (vp->trStackMemory()) TR::VPKnownObject(clazz, vp->comp(), index, isJavaLangClass);
vp->addConstraint(constraint, hash);
}
}
bool matchJavaLangClass;
TR_OpaqueClassBlock *clazz = vp->comp()->fej9()->getObjectClassFromKnownObjectIndex
(vp->comp(), index, &matchJavaLangClass);
TR_ASSERT_FATAL(matchJavaLangClass == isJavaLangClass,
"Use createForJavaLangClass if and only if the object is an instance of java/lang/Class");

constraint = new (vp->trStackMemory()) TR::VPKnownObject(clazz,
vp->comp(),
index,
isJavaLangClass);
vp->addConstraint(constraint, hash);
#endif
return constraint;
}
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53 changes: 14 additions & 39 deletions compiler/optimizer/VPHandlers.cpp
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Expand Up @@ -1698,18 +1698,12 @@ static const char *getFieldSignature(OMR::ValuePropagation *vp, TR::Node *node,
*/
static bool addKnownObjectConstraints(OMR::ValuePropagation *vp, TR::Node *node)
{
// Access to VM for multiple operations including KnownObjectTable::getOrCreateIndex()
// is not supported at the server for OMR.
if (vp->comp()->isOutOfProcessCompilation())
return false;

TR::KnownObjectTable *knot = vp->comp()->getKnownObjectTable();
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We should keep this test that makes sure knot exists

if (!knot)
return false;

TR::SymbolReference *symRef = node->getSymbolReference();
if (symRef->isUnresolved())
return false;

if (!vp->comp()->getKnownObjectTable())
return false;

uintptr_t *objectReferenceLocation = NULL;
if (symRef->hasKnownObjectIndex())
Expand All @@ -1720,30 +1714,11 @@ static bool addKnownObjectConstraints(OMR::ValuePropagation *vp, TR::Node *node)
#ifdef J9_PROJECT_SPECIFIC
if (objectReferenceLocation)
{
bool isString;
bool isFixedJavaLangClass;
TR::KnownObjectTable::Index knownObjectIndex;
TR_OpaqueClassBlock *clazz, *jlClass;

{
TR::VMAccessCriticalSection getObjectReferenceLocation(vp->comp());
uintptr_t objectReference = vp->comp()->fej9()->getStaticReferenceFieldAtAddress((uintptr_t)objectReferenceLocation);
clazz = TR::Compiler->cls.objectClass(vp->comp(), objectReference);
isString = TR::Compiler->cls.isString(vp->comp(), clazz);
jlClass = vp->fe()->getClassClassPointer(clazz);
isFixedJavaLangClass = (jlClass == clazz);
if (isFixedJavaLangClass)
{
// A FixedClass constraint means something different when the class happens to be java/lang/Class.
// Must add constraints pertaining to the class that the java/lang/Class object represents.
//
clazz = TR::Compiler->cls.classFromJavaLangClass(vp->comp(), objectReference);
}
knownObjectIndex = knot->getOrCreateIndex(objectReference);
}

TR_J9VMBase::ObjectClassInfo ci =
vp->comp()->fej9()->getObjectClassInfoFromObjectReferenceLocation(vp->comp(),
(uintptr_t)objectReferenceLocation);

if (isString && symRef->getSymbol()->isStatic())
if (ci.isString && symRef->getSymbol()->isStatic())
{
// There's a lot of machinery around optimizing const strings. Even
// though we lose object identity info this way, it's likely better to
Expand All @@ -1754,27 +1729,27 @@ static bool addKnownObjectConstraints(OMR::ValuePropagation *vp, TR::Node *node)
TR::VPNonNullObject::create(vp), NULL, NULL,
TR::VPObjectLocation::create(vp, TR::VPObjectLocation::HeapObject)));
}
else if (jlClass) // without a jlClass, we can't tell what kind of constraint to add
else if (ci.jlClass) // without a jlClass, we can't tell what kind of constraint to add
{
TR::VPConstraint *constraint = NULL;
const char *classSig = TR::Compiler->cls.classSignature(vp->comp(), clazz, vp->trMemory());
if (isFixedJavaLangClass)
const char *classSig = TR::Compiler->cls.classSignature(vp->comp(), ci.clazz, vp->trMemory());
if (ci.isFixedJavaLangClass)
{
if (performTransformation(vp->comp(), "%sAdd ClassObject constraint to %p based on known java/lang/Class %s =obj%d\n", OPT_DETAILS, node, classSig, knownObjectIndex))
if (performTransformation(vp->comp(), "%sAdd ClassObject constraint to %p based on known java/lang/Class %s =obj%d\n", OPT_DETAILS, node, classSig, ci.knownObjectIndex))
{
constraint = TR::VPClass::create(vp,
TR::VPKnownObject::createForJavaLangClass(vp, knownObjectIndex),
TR::VPKnownObject::createForJavaLangClass(vp, ci.knownObjectIndex),
TR::VPNonNullObject::create(vp), NULL, NULL,
TR::VPObjectLocation::create(vp, TR::VPObjectLocation::JavaLangClassObject));
vp->addGlobalConstraint(node, constraint);
}
}
else
{
if (performTransformation(vp->comp(), "%sAdd known-object constraint to %p based on known object obj%d of class %s\n", OPT_DETAILS, node, knownObjectIndex, classSig))
if (performTransformation(vp->comp(), "%sAdd known-object constraint to %p based on known object obj%d of class %s\n", OPT_DETAILS, node, ci.knownObjectIndex, classSig))
{
constraint = TR::VPClass::create(vp,
TR::VPKnownObject::create(vp, knownObjectIndex),
TR::VPKnownObject::create(vp, ci.knownObjectIndex),
TR::VPNonNullObject::create(vp), NULL, NULL,
TR::VPObjectLocation::create(vp, TR::VPObjectLocation::HeapObject));
vp->addBlockConstraint(node, constraint);
Expand Down