423 sfpt->add_req(referent);
424 igvn()._worklist.push(sfpt);
425 }
426 }
427 // Eliminate processed RFs. They become redundant once reachability edges are added.
428 bool progress = (for_removal.size() > 0);
429 while (for_removal.size() > 0) {
430 remove_rf(for_removal.pop()->as_ReachabilityFence());
431 }
432
433 assert(C->reachability_fences_count() == no_of_constant_rfs, "");
434 return progress;
435 }
436
437 //======================================================================
438 //---------------------------- Phase 3 ---------------------------------
439
440 // Find a point in CFG right after safepoint node to insert reachability fence.
441 static Node* sfpt_ctrl_out(SafePointNode* sfpt) {
442 if (sfpt->is_Call()) {
443 CallProjections callprojs;
444 sfpt->as_Call()->extract_projections(&callprojs,
445 false /*separate_io_proj*/,
446 false /*do_asserts*/,
447 true /*allow_handlers*/);
448 // Calls can have multiple control projections. However, reachability edge expansion
449 // happens during final graph reshaping which is performed very late in compilation pipeline.
450 // The assumption here is that the control path chosen for insertion can't go away.
451 // So, materializing a reachability fence on a single control path produced by a call
452 // is enough to keep the referent oop alive across the call.
453 if (callprojs.fallthrough_catchproj != nullptr) {
454 return callprojs.fallthrough_catchproj;
455 } else if (callprojs.catchall_catchproj != nullptr) {
456 return callprojs.catchall_catchproj; // rethrow stub
457 } else if (callprojs.fallthrough_proj != nullptr) {
458 return callprojs.fallthrough_proj; // no exceptions thrown
459 } else {
460 ShouldNotReachHere();
461 }
462 } else {
463 return sfpt;
464 }
465 }
466
467 // Phase 3: materialize reachability fences from reachability edges on safepoints.
468 // Turn extra safepoint edges into reachability fences immediately following the safepoint.
469 //
470 // NB! As of now, a special care is needed to properly enumerate reachability edges because
471 // there are other use cases for non-debug safepoint edges. expand_reachability_edges() runs
472 // after macro expansion where runtime calls during array allocation are annotated with
473 // valid_length_test_input as an extra edges. Until there's a mechanism to distinguish between
474 // different types of non-debug edges, unrelated cases are filtered out explicitly and in ad-hoc manner.
475 void Compile::expand_reachability_edges(Unique_Node_List& safepoints) {
476 for (uint i = 0; i < safepoints.size(); i++) {
477 SafePointNode* sfpt = safepoints.at(i)->as_SafePoint();
478
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423 sfpt->add_req(referent);
424 igvn()._worklist.push(sfpt);
425 }
426 }
427 // Eliminate processed RFs. They become redundant once reachability edges are added.
428 bool progress = (for_removal.size() > 0);
429 while (for_removal.size() > 0) {
430 remove_rf(for_removal.pop()->as_ReachabilityFence());
431 }
432
433 assert(C->reachability_fences_count() == no_of_constant_rfs, "");
434 return progress;
435 }
436
437 //======================================================================
438 //---------------------------- Phase 3 ---------------------------------
439
440 // Find a point in CFG right after safepoint node to insert reachability fence.
441 static Node* sfpt_ctrl_out(SafePointNode* sfpt) {
442 if (sfpt->is_Call()) {
443 CallProjections* callprojs = sfpt->as_Call()->extract_projections(false /*separate_io_proj*/,
444 false /*do_asserts*/,
445 true /*allow_handlers*/);
446 // Calls can have multiple control projections. However, reachability edge expansion
447 // happens during final graph reshaping which is performed very late in compilation pipeline.
448 // The assumption here is that the control path chosen for insertion can't go away.
449 // So, materializing a reachability fence on a single control path produced by a call
450 // is enough to keep the referent oop alive across the call.
451 if (callprojs->fallthrough_catchproj != nullptr) {
452 return callprojs->fallthrough_catchproj;
453 } else if (callprojs->catchall_catchproj != nullptr) {
454 return callprojs->catchall_catchproj; // rethrow stub
455 } else if (callprojs->fallthrough_proj != nullptr) {
456 return callprojs->fallthrough_proj; // no exceptions thrown
457 } else {
458 ShouldNotReachHere();
459 }
460 } else {
461 return sfpt;
462 }
463 }
464
465 // Phase 3: materialize reachability fences from reachability edges on safepoints.
466 // Turn extra safepoint edges into reachability fences immediately following the safepoint.
467 //
468 // NB! As of now, a special care is needed to properly enumerate reachability edges because
469 // there are other use cases for non-debug safepoint edges. expand_reachability_edges() runs
470 // after macro expansion where runtime calls during array allocation are annotated with
471 // valid_length_test_input as an extra edges. Until there's a mechanism to distinguish between
472 // different types of non-debug edges, unrelated cases are filtered out explicitly and in ad-hoc manner.
473 void Compile::expand_reachability_edges(Unique_Node_List& safepoints) {
474 for (uint i = 0; i < safepoints.size(); i++) {
475 SafePointNode* sfpt = safepoints.at(i)->as_SafePoint();
476
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