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src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp
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rev 59195 : 8244594: [BACKOUT] 8244523: Shenandoah: Remove null-handling in LRB expansion
@@ -907,10 +907,80 @@
null_ctrl = new IfFalseNode(null_iff);
phase->register_control(null_ctrl, loop, null_iff);
}
}
+Node* ShenandoahBarrierC2Support::clone_null_check(Node*& c, Node* val, Node* unc_ctrl, PhaseIdealLoop* phase) {
+ IdealLoopTree *loop = phase->get_loop(c);
+ Node* iff = unc_ctrl->in(0);
+ assert(iff->is_If(), "broken");
+ Node* new_iff = iff->clone();
+ new_iff->set_req(0, c);
+ phase->register_control(new_iff, loop, c);
+ Node* iffalse = new IfFalseNode(new_iff->as_If());
+ phase->register_control(iffalse, loop, new_iff);
+ Node* iftrue = new IfTrueNode(new_iff->as_If());
+ phase->register_control(iftrue, loop, new_iff);
+ c = iftrue;
+ const Type *t = phase->igvn().type(val);
+ assert(val->Opcode() == Op_CastPP, "expect cast to non null here");
+ Node* uncasted_val = val->in(1);
+ val = new CastPPNode(uncasted_val, t);
+ val->init_req(0, c);
+ phase->register_new_node(val, c);
+ return val;
+}
+
+void ShenandoahBarrierC2Support::fix_null_check(Node* unc, Node* unc_ctrl, Node* new_unc_ctrl,
+ Unique_Node_List& uses, PhaseIdealLoop* phase) {
+ IfNode* iff = unc_ctrl->in(0)->as_If();
+ Node* proj = iff->proj_out(0);
+ assert(proj != unc_ctrl, "bad projection");
+ Node* use = proj->unique_ctrl_out();
+
+ assert(use == unc || use->is_Region(), "what else?");
+
+ uses.clear();
+ if (use == unc) {
+ phase->set_idom(use, new_unc_ctrl, phase->dom_depth(use));
+ for (uint i = 1; i < unc->req(); i++) {
+ Node* n = unc->in(i);
+ if (phase->has_ctrl(n) && phase->get_ctrl(n) == proj) {
+ uses.push(n);
+ }
+ }
+ } else {
+ assert(use->is_Region(), "what else?");
+ uint idx = 1;
+ for (; use->in(idx) != proj; idx++);
+ for (DUIterator_Fast imax, i = use->fast_outs(imax); i < imax; i++) {
+ Node* u = use->fast_out(i);
+ if (u->is_Phi() && phase->get_ctrl(u->in(idx)) == proj) {
+ uses.push(u->in(idx));
+ }
+ }
+ }
+ for(uint next = 0; next < uses.size(); next++ ) {
+ Node *n = uses.at(next);
+ assert(phase->get_ctrl(n) == proj, "bad control");
+ phase->set_ctrl_and_loop(n, new_unc_ctrl);
+ if (n->in(0) == proj) {
+ phase->igvn().replace_input_of(n, 0, new_unc_ctrl);
+ }
+ for (uint i = 0; i < n->req(); i++) {
+ Node* m = n->in(i);
+ if (m != NULL && phase->has_ctrl(m) && phase->get_ctrl(m) == proj) {
+ uses.push(m);
+ }
+ }
+ }
+
+ phase->igvn().rehash_node_delayed(use);
+ int nb = use->replace_edge(proj, new_unc_ctrl);
+ assert(nb == 1, "only use expected");
+}
+
void ShenandoahBarrierC2Support::in_cset_fast_test(Node*& ctrl, Node*& not_cset_ctrl, Node* val, Node* raw_mem, PhaseIdealLoop* phase) {
IdealLoopTree *loop = phase->get_loop(ctrl);
Node* raw_rbtrue = new CastP2XNode(ctrl, val);
phase->register_new_node(raw_rbtrue, ctrl);
Node* cset_offset = new URShiftXNode(raw_rbtrue, phase->igvn().intcon(ShenandoahHeapRegion::region_size_bytes_shift_jint()));
@@ -954,11 +1024,11 @@
CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier);
address calladdr = is_native ? CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_native)
: target;
const char* name = is_native ? "load_reference_barrier_native" : "load_reference_barrier";
- Node* call = new CallLeafNode(ShenandoahBarrierSetC2::shenandoah_load_reference_barrier_Type(obj_type), calladdr, name, TypeRawPtr::BOTTOM);
+ Node* call = new CallLeafNode(ShenandoahBarrierSetC2::shenandoah_load_reference_barrier_Type(), calladdr, name, TypeRawPtr::BOTTOM);
call->init_req(TypeFunc::Control, ctrl);
call->init_req(TypeFunc::I_O, phase->C->top());
call->init_req(TypeFunc::Memory, mm);
call->init_req(TypeFunc::FramePtr, phase->C->top());
@@ -970,10 +1040,12 @@
phase->register_control(ctrl, loop, call);
result_mem = new ProjNode(call, TypeFunc::Memory);
phase->register_new_node(result_mem, call);
val = new ProjNode(call, TypeFunc::Parms);
phase->register_new_node(val, call);
+ val = new CheckCastPPNode(ctrl, val, obj_type);
+ phase->register_new_node(val, ctrl);
}
void ShenandoahBarrierC2Support::fix_ctrl(Node* barrier, Node* region, const MemoryGraphFixer& fixer, Unique_Node_List& uses, Unique_Node_List& uses_to_ignore, uint last, PhaseIdealLoop* phase) {
Node* ctrl = phase->get_ctrl(barrier);
Node* init_raw_mem = fixer.find_mem(ctrl, barrier);
@@ -1075,10 +1147,123 @@
if (lrb->is_redundant()) {
continue;
}
Node* ctrl = phase->get_ctrl(lrb);
+ Node* val = lrb->in(ShenandoahLoadReferenceBarrierNode::ValueIn);
+
+ CallStaticJavaNode* unc = NULL;
+ Node* unc_ctrl = NULL;
+ Node* uncasted_val = val;
+
+ for (DUIterator_Fast imax, i = lrb->fast_outs(imax); i < imax; i++) {
+ Node* u = lrb->fast_out(i);
+ if (u->Opcode() == Op_CastPP &&
+ u->in(0) != NULL &&
+ phase->is_dominator(u->in(0), ctrl)) {
+ const Type* u_t = phase->igvn().type(u);
+
+ if (u_t->meet(TypePtr::NULL_PTR) != u_t &&
+ u->in(0)->Opcode() == Op_IfTrue &&
+ u->in(0)->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none) &&
+ u->in(0)->in(0)->is_If() &&
+ u->in(0)->in(0)->in(1)->Opcode() == Op_Bool &&
+ u->in(0)->in(0)->in(1)->as_Bool()->_test._test == BoolTest::ne &&
+ u->in(0)->in(0)->in(1)->in(1)->Opcode() == Op_CmpP &&
+ u->in(0)->in(0)->in(1)->in(1)->in(1) == val &&
+ u->in(0)->in(0)->in(1)->in(1)->in(2)->bottom_type() == TypePtr::NULL_PTR) {
+ IdealLoopTree* loop = phase->get_loop(ctrl);
+ IdealLoopTree* unc_loop = phase->get_loop(u->in(0));
+
+ if (!unc_loop->is_member(loop)) {
+ continue;
+ }
+
+ Node* branch = no_branches(ctrl, u->in(0), false, phase);
+ assert(branch == NULL || branch == NodeSentinel, "was not looking for a branch");
+ if (branch == NodeSentinel) {
+ continue;
+ }
+
+ phase->igvn().replace_input_of(u, 1, val);
+ phase->igvn().replace_input_of(lrb, ShenandoahLoadReferenceBarrierNode::ValueIn, u);
+ phase->set_ctrl(u, u->in(0));
+ phase->set_ctrl(lrb, u->in(0));
+ unc = u->in(0)->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none);
+ unc_ctrl = u->in(0);
+ val = u;
+
+ for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) {
+ Node* u = val->fast_out(j);
+ if (u == lrb) continue;
+ phase->igvn().rehash_node_delayed(u);
+ int nb = u->replace_edge(val, lrb);
+ --j; jmax -= nb;
+ }
+
+ RegionNode* r = new RegionNode(3);
+ IfNode* iff = unc_ctrl->in(0)->as_If();
+
+ Node* ctrl_use = unc_ctrl->unique_ctrl_out();
+ Node* unc_ctrl_clone = unc_ctrl->clone();
+ phase->register_control(unc_ctrl_clone, loop, iff);
+ Node* c = unc_ctrl_clone;
+ Node* new_cast = clone_null_check(c, val, unc_ctrl_clone, phase);
+ r->init_req(1, new_cast->in(0)->in(0)->as_If()->proj_out(0));
+
+ phase->igvn().replace_input_of(unc_ctrl, 0, c->in(0));
+ phase->set_idom(unc_ctrl, c->in(0), phase->dom_depth(unc_ctrl));
+ phase->lazy_replace(c, unc_ctrl);
+ c = NULL;;
+ phase->igvn().replace_input_of(val, 0, unc_ctrl_clone);
+ phase->set_ctrl(val, unc_ctrl_clone);
+
+ IfNode* new_iff = new_cast->in(0)->in(0)->as_If();
+ fix_null_check(unc, unc_ctrl_clone, r, uses, phase);
+ Node* iff_proj = iff->proj_out(0);
+ r->init_req(2, iff_proj);
+ phase->register_control(r, phase->ltree_root(), iff);
+
+ Node* new_bol = new_iff->in(1)->clone();
+ Node* new_cmp = new_bol->in(1)->clone();
+ assert(new_cmp->Opcode() == Op_CmpP, "broken");
+ assert(new_cmp->in(1) == val->in(1), "broken");
+ new_bol->set_req(1, new_cmp);
+ new_cmp->set_req(1, lrb);
+ phase->register_new_node(new_bol, new_iff->in(0));
+ phase->register_new_node(new_cmp, new_iff->in(0));
+ phase->igvn().replace_input_of(new_iff, 1, new_bol);
+ phase->igvn().replace_input_of(new_cast, 1, lrb);
+
+ for (DUIterator_Fast imax, i = lrb->fast_outs(imax); i < imax; i++) {
+ Node* u = lrb->fast_out(i);
+ if (u == new_cast || u == new_cmp) {
+ continue;
+ }
+ phase->igvn().rehash_node_delayed(u);
+ int nb = u->replace_edge(lrb, new_cast);
+ assert(nb > 0, "no update?");
+ --i; imax -= nb;
+ }
+
+ for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) {
+ Node* u = val->fast_out(i);
+ if (u == lrb) {
+ continue;
+ }
+ phase->igvn().rehash_node_delayed(u);
+ int nb = u->replace_edge(val, new_cast);
+ assert(nb > 0, "no update?");
+ --i; imax -= nb;
+ }
+
+ ctrl = unc_ctrl_clone;
+ phase->set_ctrl_and_loop(lrb, ctrl);
+ break;
+ }
+ }
+ }
if ((ctrl->is_Proj() && ctrl->in(0)->is_CallJava()) || ctrl->is_CallJava()) {
CallNode* call = ctrl->is_Proj() ? ctrl->in(0)->as_CallJava() : ctrl->as_CallJava();
if (call->entry_point() == OptoRuntime::rethrow_stub()) {
// The rethrow call may have too many projections to be
// properly handled here. Given there's no reason for a
@@ -1215,49 +1400,94 @@
}
uint last = phase->C->unique();
Node* ctrl = phase->get_ctrl(lrb);
Node* val = lrb->in(ShenandoahLoadReferenceBarrierNode::ValueIn);
+
Node* orig_ctrl = ctrl;
Node* raw_mem = fixer.find_mem(ctrl, lrb);
Node* init_raw_mem = raw_mem;
Node* raw_mem_for_ctrl = fixer.find_mem(ctrl, NULL);
- IdealLoopTree* loop = phase->get_loop(ctrl);
+ IdealLoopTree *loop = phase->get_loop(ctrl);
+ CallStaticJavaNode* unc = lrb->pin_and_expand_null_check(phase->igvn());
+ Node* unc_ctrl = NULL;
+ if (unc != NULL) {
+ if (val->in(ShenandoahLoadReferenceBarrierNode::Control) != ctrl) {
+ unc = NULL;
+ } else {
+ unc_ctrl = val->in(ShenandoahLoadReferenceBarrierNode::Control);
+ }
+ }
+
+ Node* uncasted_val = val;
+ if (unc != NULL) {
+ uncasted_val = val->in(1);
+ }
+
+ Node* heap_stable_ctrl = NULL;
+ Node* null_ctrl = NULL;
assert(val->bottom_type()->make_oopptr(), "need oop");
assert(val->bottom_type()->make_oopptr()->const_oop() == NULL, "expect non-constant");
- enum { _heap_stable = 1, _not_cset, _evac_path, PATH_LIMIT };
+ enum { _heap_stable = 1, _not_cset, _evac_path, _null_path, PATH_LIMIT };
Node* region = new RegionNode(PATH_LIMIT);
- Node* val_phi = new PhiNode(region, val->bottom_type()->is_oopptr());
+ Node* val_phi = new PhiNode(region, uncasted_val->bottom_type()->is_oopptr());
Node* raw_mem_phi = PhiNode::make(region, raw_mem, Type::MEMORY, TypeRawPtr::BOTTOM);
// Stable path.
- Node* heap_stable_ctrl = NULL;
test_heap_state(ctrl, raw_mem, heap_stable_ctrl, phase, ShenandoahHeap::HAS_FORWARDED);
IfNode* heap_stable_iff = heap_stable_ctrl->in(0)->as_If();
// Heap stable case
region->init_req(_heap_stable, heap_stable_ctrl);
- val_phi->init_req(_heap_stable, val);
+ val_phi->init_req(_heap_stable, uncasted_val);
raw_mem_phi->init_req(_heap_stable, raw_mem);
+ Node* reg2_ctrl = NULL;
+ // Null case
+ test_null(ctrl, val, null_ctrl, phase);
+ if (null_ctrl != NULL) {
+ reg2_ctrl = null_ctrl->in(0);
+ region->init_req(_null_path, null_ctrl);
+ val_phi->init_req(_null_path, uncasted_val);
+ raw_mem_phi->init_req(_null_path, raw_mem);
+ } else {
+ region->del_req(_null_path);
+ val_phi->del_req(_null_path);
+ raw_mem_phi->del_req(_null_path);
+ }
+
// Test for in-cset.
// Wires !in_cset(obj) to slot 2 of region and phis
Node* not_cset_ctrl = NULL;
- in_cset_fast_test(ctrl, not_cset_ctrl, val, raw_mem, phase);
+ in_cset_fast_test(ctrl, not_cset_ctrl, uncasted_val, raw_mem, phase);
if (not_cset_ctrl != NULL) {
+ if (reg2_ctrl == NULL) reg2_ctrl = not_cset_ctrl->in(0);
region->init_req(_not_cset, not_cset_ctrl);
- val_phi->init_req(_not_cset, val);
+ val_phi->init_req(_not_cset, uncasted_val);
raw_mem_phi->init_req(_not_cset, raw_mem);
}
+ // Resolve object when orig-value is in cset.
+ // Make the unconditional resolve for fwdptr.
+ Node* new_val = uncasted_val;
+ if (unc_ctrl != NULL) {
+ // Clone the null check in this branch to allow implicit null check
+ new_val = clone_null_check(ctrl, val, unc_ctrl, phase);
+ fix_null_check(unc, unc_ctrl, ctrl->in(0)->as_If()->proj_out(0), uses, phase);
+
+ IfNode* iff = unc_ctrl->in(0)->as_If();
+ phase->igvn().replace_input_of(iff, 1, phase->igvn().intcon(1));
+ }
+
// Call lrb-stub and wire up that path in slots 4
Node* result_mem = NULL;
+ Node* fwd = new_val;
Node* addr;
if (ShenandoahSelfFixing) {
VectorSet visited(Thread::current()->resource_area());
addr = get_load_addr(phase, visited, lrb);
} else {
@@ -1286,13 +1516,13 @@
addr->set_req(AddPNode::Address, addr2);
phase->register_new_node(addr, ctrl);
}
}
}
- call_lrb_stub(ctrl, val, addr, result_mem, raw_mem, lrb->is_native(), phase);
+ call_lrb_stub(ctrl, fwd, addr, result_mem, raw_mem, lrb->is_native(), phase);
region->init_req(_evac_path, ctrl);
- val_phi->init_req(_evac_path, val);
+ val_phi->init_req(_evac_path, fwd);
raw_mem_phi->init_req(_evac_path, result_mem);
phase->register_control(region, loop, heap_stable_iff);
Node* out_val = val_phi;
phase->register_new_node(val_phi, region);
@@ -1300,10 +1530,24 @@
fix_ctrl(lrb, region, fixer, uses, uses_to_ignore, last, phase);
ctrl = orig_ctrl;
+ if (unc != NULL) {
+ for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) {
+ Node* u = val->fast_out(i);
+ Node* c = phase->ctrl_or_self(u);
+ if (u != lrb && (c != ctrl || is_dominator_same_ctrl(c, lrb, u, phase))) {
+ phase->igvn().rehash_node_delayed(u);
+ int nb = u->replace_edge(val, out_val);
+ --i, imax -= nb;
+ }
+ }
+ if (val->outcnt() == 0) {
+ phase->igvn()._worklist.push(val);
+ }
+ }
phase->igvn().replace_node(lrb, out_val);
follow_barrier_uses(out_val, ctrl, uses, phase);
for(uint next = 0; next < uses.size(); next++ ) {
@@ -3068,5 +3312,28 @@
}
// No need for barrier found.
return true;
}
+
+CallStaticJavaNode* ShenandoahLoadReferenceBarrierNode::pin_and_expand_null_check(PhaseIterGVN& igvn) {
+ Node* val = in(ValueIn);
+
+ const Type* val_t = igvn.type(val);
+
+ if (val_t->meet(TypePtr::NULL_PTR) != val_t &&
+ val->Opcode() == Op_CastPP &&
+ val->in(0) != NULL &&
+ val->in(0)->Opcode() == Op_IfTrue &&
+ val->in(0)->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none) &&
+ val->in(0)->in(0)->is_If() &&
+ val->in(0)->in(0)->in(1)->Opcode() == Op_Bool &&
+ val->in(0)->in(0)->in(1)->as_Bool()->_test._test == BoolTest::ne &&
+ val->in(0)->in(0)->in(1)->in(1)->Opcode() == Op_CmpP &&
+ val->in(0)->in(0)->in(1)->in(1)->in(1) == val->in(1) &&
+ val->in(0)->in(0)->in(1)->in(1)->in(2)->bottom_type() == TypePtr::NULL_PTR) {
+ assert(val->in(0)->in(0)->in(1)->in(1)->in(1) == val->in(1), "");
+ CallStaticJavaNode* unc = val->in(0)->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none);
+ return unc;
+ }
+ return NULL;
+}
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