truffle: src/share/vm/opto/graphKit.cpp comparison

comparison src/share/vm/opto/graphKit.cpp @ 12966:b2ee5dc63353

8024070: C2 needs some form of type speculation Summary: record unused type profile information with type system, propagate and use it. Reviewed-by: kvn, twisti

author	roland
date	Wed, 23 Oct 2013 12:40:23 +0200
parents	3213ba4d3dff
children	096c224171c4 de6a9e811145 2113136690bc

comparison

equal deleted inserted replaced

-:8b4bbba322d3
+:b2ee5dc63353
 set_argument(j, arg);
 }
 }
 }
+/**
+* Record profiling data exact_kls for Node n with the type system so
+* that it can propagate it (speculation)
+*
+* @param n          node that the type applies to
+* @param exact_kls  type from profiling
+*
+* @return           node with improved type
+*/
+Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls) {
+const TypeOopPtr* current_type = _gvn.type(n)->isa_oopptr();
+assert(UseTypeSpeculation, "type speculation must be on");
+if (exact_kls != NULL &&
+// nothing to improve if type is already exact
+(current_type == NULL ||
+(!current_type->klass_is_exact() &&
+(current_type->speculative() == NULL ||
+!current_type->speculative()->klass_is_exact())))) {
+const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
+const TypeOopPtr* xtype = tklass->as_instance_type();
+assert(xtype->klass_is_exact(), "Should be exact");
+// Build a type with a speculative type (what we think we know
+// about the type but will need a guard when we use it)
+const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, xtype);
+// We're changing the type, we need a new cast node to carry the
+// new type. The new type depends on the control: what profiling
+// tells us is only valid from here as far as we can tell.
+Node* cast = new(C) CastPPNode(n, spec_type);
+cast->init_req(0, control());
+cast = _gvn.transform(cast);
+replace_in_map(n, cast);
+n = cast;
+}
+return n;
+}
+/**
+* Record profiling data from receiver profiling at an invoke with the
+* type system so that it can propagate it (speculation)
+*
+* @param n  receiver node
+*
+* @return           node with improved type
+*/
+Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
+if (!UseTypeSpeculation) {
+return n;
+}
+ciKlass* exact_kls = profile_has_unique_klass();
+return record_profile_for_speculation(n, exact_kls);
+}
+/**
+* Record profiling data from argument profiling at an invoke with the
+* type system so that it can propagate it (speculation)
+*
+* @param dest_method  target method for the call
+* @param bc           what invoke bytecode is this?
+*/
+void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
+if (!UseTypeSpeculation) {
+return;
+}
+const TypeFunc* tf    = TypeFunc::make(dest_method);
+int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
+int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
+for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
+const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
+if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
+ciKlass* better_type = method()->argument_profiled_type(bci(), i);
+if (better_type != NULL) {
+record_profile_for_speculation(argument(j), better_type);
+}
+i++;
+}
+}
+}
+/**
+* Record profiling data from parameter profiling at an invoke with
+* the type system so that it can propagate it (speculation)
+*/
+void GraphKit::record_profiled_parameters_for_speculation() {
+if (!UseTypeSpeculation) {
+return;
+}
+for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
+if (_gvn.type(local(i))->isa_oopptr()) {
+ciKlass* better_type = method()->parameter_profiled_type(j);
+if (better_type != NULL) {
+record_profile_for_speculation(local(i), better_type);
+}
+j++;
+}
+}
+}
 void GraphKit::round_double_result(ciMethod* dest_method) {
 // A non-strict method may return a double value which has an extended
 // exponent, but this must not be visible in a caller which is 'strict'
 // If a strict caller invokes a non-strict callee, round a double result
 //------------------------maybe_cast_profiled_receiver-------------------------
 // If the profile has seen exactly one type, narrow to exactly that type.
 // Subsequent type checks will always fold up.
 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
-ciProfileData* data,
+ciKlass* require_klass,
-ciKlass* require_klass) {
+ciKlass* spec_klass,
+bool safe_for_replace) {
 if (!UseTypeProfile || !TypeProfileCasts) return NULL;
-if (data == NULL)  return NULL;
 // Make sure we haven't already deoptimized from this tactic.
 if (too_many_traps(Deoptimization::Reason_class_check))
 return NULL;
 // (No, this isn't a call, but it's enough like a virtual call
 // to use the same ciMethod accessor to get the profile info...)
-ciCallProfile profile = method()->call_profile_at_bci(bci());
+// If we have a speculative type use it instead of profiling (which
-if (profile.count() >= 0 &&         // no cast failures here
+// may not help us)
-profile.has_receiver(0) &&
+ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
-profile.morphism() == 1) {
+if (exact_kls != NULL) {// no cast failures here
-ciKlass* exact_kls = profile.receiver(0);
 if (require_klass == NULL ||
 static_subtype_check(require_klass, exact_kls) == SSC_always_true) {
-// If we narrow the type to match what the type profile sees,
+// If we narrow the type to match what the type profile sees or
-// we can then remove the rest of the cast.
+// the speculative type, we can then remove the rest of the
+// cast.
 // This is a win, even if the exact_kls is very specific,
 // because downstream operations, such as method calls,
 // will often benefit from the sharper type.
 Node* exact_obj = not_null_obj; // will get updated in place...
 Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
 { PreserveJVMState pjvms(this);
 set_control(slow_ctl);
 uncommon_trap(Deoptimization::Reason_class_check,
 Deoptimization::Action_maybe_recompile);
 }
+if (safe_for_replace) {
+replace_in_map(not_null_obj, exact_obj);
+}
+return exact_obj;
+}
+// assert(ssc == SSC_always_true)... except maybe the profile lied to us.
+}
+return NULL;
+}
+/**
+* Cast obj to type and emit guard unless we had too many traps here
+* already
+*
+* @param obj       node being casted
+* @param type      type to cast the node to
+* @param not_null  true if we know node cannot be null
+*/
+Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
+ciKlass* type,
+bool not_null) {
+// type == NULL if profiling tells us this object is always null
+if (type != NULL) {
+if (!too_many_traps(Deoptimization::Reason_null_check) &&
+!too_many_traps(Deoptimization::Reason_class_check)) {
+Node* not_null_obj = NULL;
+// not_null is true if we know the object is not null and
+// there's no need for a null check
+if (!not_null) {
+Node* null_ctl = top();
+not_null_obj = null_check_oop(obj, &null_ctl, true, true);
+assert(null_ctl->is_top(), "no null control here");
+} else {
+not_null_obj = obj;
+}
+Node* exact_obj = not_null_obj;
+ciKlass* exact_kls = type;
+Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
+&exact_obj);
+{
+PreserveJVMState pjvms(this);
+set_control(slow_ctl);
+uncommon_trap(Deoptimization::Reason_class_check,
+Deoptimization::Action_maybe_recompile);
+}
 replace_in_map(not_null_obj, exact_obj);
-return exact_obj;
+obj = exact_obj;
 }
-// assert(ssc == SSC_always_true)... except maybe the profile lied to us.
+} else {
-}
+if (!too_many_traps(Deoptimization::Reason_null_assert)) {
+Node* exact_obj = null_assert(obj);
-return NULL;
+replace_in_map(obj, exact_obj);
-}
+obj = exact_obj;
+}
+}
+return obj;
+}
 //-------------------------------gen_instanceof--------------------------------
 // Generate an instance-of idiom.  Used by both the instance-of bytecode
 // and the reflective instance-of call.
-Node* GraphKit::gen_instanceof(Node* obj, Node* superklass) {
+Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
 kill_dead_locals();           // Benefit all the uncommon traps
 assert( !stopped(), "dead parse path should be checked in callers" );
 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
 "must check for not-null not-dead klass in callers");
 RegionNode* region = new(C) RegionNode(PATH_LIMIT);
 Node*       phi    = new(C) PhiNode(region, TypeInt::BOOL);
 C->set_has_split_ifs(true); // Has chance for split-if optimization
 ciProfileData* data = NULL;
-bool safe_for_replace = false;
 if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
 data = method()->method_data()->bci_to_data(bci());
-safe_for_replace = true;
 }
 bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
 && seems_never_null(obj, data));
 // Null check; get casted pointer; set region slot 3
 assert(_null_path == PATH_LIMIT-1, "delete last");
 region->del_req(_null_path);
 phi   ->del_req(_null_path);
 }
-if (ProfileDynamicTypes && data != NULL) {
+// Do we know the type check always succeed?
-Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, NULL);
+bool known_statically = false;
-if (stopped()) {            // Profile disagrees with this path.
+if (_gvn.type(superklass)->singleton()) {
-set_control(null_ctl);    // Null is the only remaining possibility.
+ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
-return intcon(0);
+ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
-}
+if (subk != NULL && subk->is_loaded()) {
-if (cast_obj != NULL)
+int static_res = static_subtype_check(superk, subk);
-not_null_obj = cast_obj;
+known_statically = (static_res == SSC_always_true || static_res == SSC_always_false);
+}
+}
+if (known_statically && UseTypeSpeculation) {
+// If we know the type check always succeed then we don't use the
+// profiling data at this bytecode. Don't lose it, feed it to the
+// type system as a speculative type.
+not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
+} else {
+const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
+// We may not have profiling here or it may not help us. If we
+// have a speculative type use it to perform an exact cast.
+ciKlass* spec_obj_type = obj_type->speculative_type();
+if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
+Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
+if (stopped()) {            // Profile disagrees with this path.
+set_control(null_ctl);    // Null is the only remaining possibility.
+return intcon(0);
+}
+if (cast_obj != NULL) {
+not_null_obj = cast_obj;
+}
+}
 }
 // Load the object's klass
 Node* obj_klass = load_object_klass(not_null_obj);
 if (tk->singleton()) {
 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
 if (objtp != NULL && objtp->klass() != NULL) {
 switch (static_subtype_check(tk->klass(), objtp->klass())) {
 case SSC_always_true:
-return obj;
+// If we know the type check always succeed then we don't use
+// the profiling data at this bytecode. Don't lose it, feed it
+// to the type system as a speculative type.
+return record_profiled_receiver_for_speculation(obj);
 case SSC_always_false:
 // It needs a null check because a null will *pass* the cast check.
 // A non-null value will always produce an exception.
 return null_assert(obj);
 }
 region->del_req(_null_path);
 phi   ->del_req(_null_path);
 }
 Node* cast_obj = NULL;
-if (data != NULL &&
+const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
-// Counter has never been decremented (due to cast failure).
+// We may not have profiling here or it may not help us. If we have
-// ...This is a reasonable thing to expect.  It is true of
+// a speculative type use it to perform an exact cast.
-// all casts inserted by javac to implement generic types.
+ciKlass* spec_obj_type = obj_type->speculative_type();
-data->as_CounterData()->count() >= 0) {
+if (spec_obj_type != NULL ||
-cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, tk->klass());
+(data != NULL &&
+// Counter has never been decremented (due to cast failure).
+// ...This is a reasonable thing to expect.  It is true of
+// all casts inserted by javac to implement generic types.
+data->as_CounterData()->count() >= 0)) {
+cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
 if (cast_obj != NULL) {
 if (failure_control != NULL) // failure is now impossible
 (*failure_control) = top();
 // adjust the type of the phi to the exact klass:
 phi->raise_bottom_type(_gvn.type(cast_obj)->meet(TypePtr::NULL_PTR));

Mercurial > hg > truffle

comparison src/share/vm/opto/graphKit.cpp @ 12966:b2ee5dc63353