--- a/src/hotspot/share/opto/loopTransform.cpp Mon Jan 14 13:45:19 2019 -0800
+++ b/src/hotspot/share/opto/loopTransform.cpp Mon Jan 14 15:07:22 2019 +0100
@@ -1067,8 +1067,9 @@
// CastII/ConvI2L nodes cause some data paths to die. For consistency,
// the control paths must die too but the range checks were removed by
// predication. The range checks that we add here guarantee that they do.
-void PhaseIdealLoop::duplicate_predicates_helper(Node* predicate, Node* castii, IdealLoopTree* outer_loop,
- LoopNode* outer_main_head, uint dd_main_head) {
+void PhaseIdealLoop::duplicate_predicates_helper(Node* predicate, Node* start, Node* end,
+ IdealLoopTree* outer_loop, LoopNode* outer_main_head,
+ uint dd_main_head) {
if (predicate != NULL) {
IfNode* iff = predicate->in(0)->as_If();
ProjNode* uncommon_proj = iff->proj_out(1 - predicate->as_Proj()->_con);
@@ -1084,13 +1085,14 @@
if (uncommon_proj->unique_ctrl_out() != rgn)
break;
if (iff->in(1)->Opcode() == Op_Opaque4) {
+ assert(skeleton_predicate_has_opaque(iff), "unexpected");
// Clone the predicate twice and initialize one with the initial
// value of the loop induction variable. Leave the other predicate
// to be initialized when increasing the stride during loop unrolling.
- prev_proj = update_skeleton_predicate(iff, castii, predicate, uncommon_proj, current_proj, outer_loop, prev_proj);
- Node* value = new Opaque1Node(C, castii);
- register_new_node(value, current_proj);
- prev_proj = update_skeleton_predicate(iff, value, predicate, uncommon_proj, current_proj, outer_loop, prev_proj);
+ prev_proj = clone_skeleton_predicate(iff, start, predicate, uncommon_proj, current_proj, outer_loop, prev_proj);
+ assert(skeleton_predicate_has_opaque(prev_proj->in(0)->as_If()) == (start->Opcode() == Op_Opaque1), "");
+ prev_proj = clone_skeleton_predicate(iff, end, predicate, uncommon_proj, current_proj, outer_loop, prev_proj);
+ assert(skeleton_predicate_has_opaque(prev_proj->in(0)->as_If()) == (end->Opcode() == Op_Opaque1), "");
// Remove the skeleton predicate from the pre-loop
_igvn.replace_input_of(iff, 1, _igvn.intcon(1));
}
@@ -1101,9 +1103,47 @@
}
}
-Node* PhaseIdealLoop::update_skeleton_predicate(Node* iff, Node* value, Node* predicate, Node* uncommon_proj,
- Node* current_proj, IdealLoopTree* outer_loop, Node* prev_proj) {
- bool clone = (outer_loop != NULL); // Clone the predicate?
+static bool skeleton_follow_inputs(Node* n, int op) {
+ return (n->is_Bool() ||
+ n->is_Cmp() ||
+ op == Op_AndL ||
+ op == Op_OrL ||
+ op == Op_RShiftL ||
+ op == Op_LShiftL ||
+ op == Op_AddL ||
+ op == Op_AddI ||
+ op == Op_MulL ||
+ op == Op_MulI ||
+ op == Op_SubL ||
+ op == Op_SubI ||
+ op == Op_ConvI2L);
+}
+
+bool PhaseIdealLoop::skeleton_predicate_has_opaque(IfNode* iff) {
+ ResourceMark rm;
+ Unique_Node_List wq;
+ wq.push(iff->in(1)->in(1));
+ for (uint i = 0; i < wq.size(); i++) {
+ Node* n = wq.at(i);
+ int op = n->Opcode();
+ if (skeleton_follow_inputs(n, op)) {
+ for (uint j = 1; j < n->req(); j++) {
+ Node* m = n->in(j);
+ if (m != NULL) {
+ wq.push(m);
+ }
+ }
+ continue;
+ }
+ if (op == Op_Opaque1) {
+ return true;
+ }
+ }
+ return false;
+}
+
+Node* PhaseIdealLoop::clone_skeleton_predicate(Node* iff, Node* value, Node* predicate, Node* uncommon_proj,
+ Node* current_proj, IdealLoopTree* outer_loop, Node* prev_proj) {
Node_Stack to_clone(2);
to_clone.push(iff->in(1), 1);
uint current = C->unique();
@@ -1118,28 +1158,11 @@
uint i = to_clone.index();
Node* m = n->in(i);
int op = m->Opcode();
- if (m->is_Bool() ||
- m->is_Cmp() ||
- op == Op_AndL ||
- op == Op_OrL ||
- op == Op_RShiftL ||
- op == Op_LShiftL ||
- op == Op_AddL ||
- op == Op_AddI ||
- op == Op_MulL ||
- op == Op_MulI ||
- op == Op_SubL ||
- op == Op_SubI ||
- op == Op_ConvI2L) {
+ if (skeleton_follow_inputs(m, op)) {
to_clone.push(m, 1);
continue;
}
if (op == Op_Opaque1) {
- if (!clone) {
- // Update the input of the Opaque1Node and exit
- _igvn.replace_input_of(m, 1, value);
- return prev_proj;
- }
if (n->_idx < current) {
n = n->clone();
}
@@ -1161,20 +1184,17 @@
}
Node* next = to_clone.node();
j = to_clone.index();
- if (clone && cur->_idx >= current) {
+ if (next->in(j) != cur) {
+ assert(cur->_idx >= current || next->in(j)->Opcode() == Op_Opaque1, "new node or Opaque1 being replaced");
if (next->_idx < current) {
next = next->clone();
register_new_node(next, current_proj);
to_clone.set_node(next);
}
- assert(next->in(j) != cur, "input should have been cloned");
next->set_req(j, cur);
}
}
} while (result == NULL);
- if (!clone) {
- return NULL;
- }
assert(result->_idx >= current, "new node expected");
Node* proj = predicate->clone();
@@ -1197,8 +1217,9 @@
return proj;
}
-void PhaseIdealLoop::duplicate_predicates(CountedLoopNode* pre_head, Node* castii, IdealLoopTree* outer_loop,
- LoopNode* outer_main_head, uint dd_main_head) {
+void PhaseIdealLoop::duplicate_predicates(CountedLoopNode* pre_head, Node* start, Node* end,
+ IdealLoopTree* outer_loop, LoopNode* outer_main_head,
+ uint dd_main_head) {
if (UseLoopPredicate) {
Node* entry = pre_head->in(LoopNode::EntryControl);
Node* predicate = NULL;
@@ -1214,8 +1235,8 @@
}
}
predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate);
- duplicate_predicates_helper(predicate, castii, outer_loop, outer_main_head, dd_main_head);
- duplicate_predicates_helper(profile_predicate, castii, outer_loop, outer_main_head, dd_main_head);
+ duplicate_predicates_helper(predicate, start, end, outer_loop, outer_main_head, dd_main_head);
+ duplicate_predicates_helper(profile_predicate, start, end, outer_loop, outer_main_head, dd_main_head);
}
}
@@ -1362,7 +1383,9 @@
// CastII for the main loop:
Node* castii = cast_incr_before_loop( pre_incr, min_taken, main_head );
assert(castii != NULL, "no castII inserted");
- duplicate_predicates(pre_head, castii, outer_loop, outer_main_head, dd_main_head);
+ Node* opaque_castii = new Opaque1Node(C, castii);
+ register_new_node(opaque_castii, outer_main_head->in(LoopNode::EntryControl));
+ duplicate_predicates(pre_head, castii, opaque_castii, outer_loop, outer_main_head, dd_main_head);
// Step B4: Shorten the pre-loop to run only 1 iteration (for now).
// RCE and alignment may change this later.
@@ -1641,6 +1664,49 @@
return !is_member(_phase->get_loop(n_c));
}
+void PhaseIdealLoop::update_skeleton_predicates(Node* ctrl, CountedLoopNode* loop_head, Node* init, int stride_con) {
+ // Search for skeleton predicates and update them according to the new stride
+ Node* entry = ctrl;
+ Node* prev_proj = ctrl;
+ LoopNode* outer_loop_head = loop_head->skip_strip_mined();
+ IdealLoopTree* outer_loop = get_loop(outer_loop_head);
+ while (entry != NULL && entry->is_Proj() && entry->in(0)->is_If()) {
+ IfNode* iff = entry->in(0)->as_If();
+ ProjNode* proj = iff->proj_out(1 - entry->as_Proj()->_con);
+ if (proj->unique_ctrl_out()->Opcode() != Op_Halt) {
+ break;
+ }
+ if (iff->in(1)->Opcode() == Op_Opaque4) {
+ // Look for predicate with an Opaque1 node that can be used as a template
+ if (!skeleton_predicate_has_opaque(iff)) {
+ // No Opaque1 node? It's either the check for the first value
+ // of the first iteration or the check for the last value of
+ // the first iteration of an unrolled loop. We can't
+ // tell. Kill it in any case.
+ _igvn.replace_input_of(iff, 1, iff->in(1)->in(2));
+ } else {
+ // Add back the predicate for the value at the beginning of the first entry
+ prev_proj = clone_skeleton_predicate(iff, init, entry, proj, ctrl, outer_loop, prev_proj);
+ assert(!skeleton_predicate_has_opaque(prev_proj->in(0)->as_If()), "unexpected");
+ // Compute the value of the loop induction variable at the end of the
+ // first iteration of the unrolled loop: init + new_stride_con - init_inc
+ int init_inc = stride_con/loop_head->unrolled_count();
+ assert(init_inc != 0, "invalid loop increment");
+ int new_stride_con = stride_con * 2;
+ Node* max_value = _igvn.intcon(new_stride_con - init_inc);
+ max_value = new AddINode(init, max_value);
+ register_new_node(max_value, get_ctrl(iff->in(1)));
+ prev_proj = clone_skeleton_predicate(iff, max_value, entry, proj, ctrl, outer_loop, prev_proj);
+ assert(!skeleton_predicate_has_opaque(prev_proj->in(0)->as_If()), "unexpected");
+ }
+ }
+ entry = entry->in(0)->in(0);
+ }
+ if (prev_proj != ctrl) {
+ _igvn.replace_input_of(outer_loop_head, LoopNode::EntryControl, prev_proj);
+ set_idom(outer_loop_head, prev_proj, dom_depth(outer_loop_head));
+ }
+}
//------------------------------do_unroll--------------------------------------
// Unroll the loop body one step - make each trip do 2 iterations.
@@ -1706,29 +1772,7 @@
assert(old_trip_count > 1 &&
(!adjust_min_trip || stride_p <= (1<<3)*loop_head->unrolled_count()), "sanity");
- if (UseLoopPredicate) {
- // Search for skeleton predicates and update them according to the new stride
- Node* entry = ctrl;
- while (entry != NULL && entry->is_Proj() && entry->in(0)->is_If()) {
- IfNode* iff = entry->in(0)->as_If();
- ProjNode* proj = iff->proj_out(1 - entry->as_Proj()->_con);
- if (proj->unique_ctrl_out()->Opcode() != Op_Halt) {
- break;
- }
- if (iff->in(1)->Opcode() == Op_Opaque4) {
- // Compute the value of the loop induction variable at the end of the
- // first iteration of the unrolled loop: init + new_stride_con - init_inc
- int init_inc = stride_con/loop_head->unrolled_count();
- assert(init_inc != 0, "invalid loop increment");
- int new_stride_con = stride_con * 2;
- Node* max_value = _igvn.intcon(new_stride_con - init_inc);
- max_value = new AddINode(init, max_value);
- register_new_node(max_value, get_ctrl(iff->in(1)));
- update_skeleton_predicate(iff, max_value);
- }
- entry = entry->in(0)->in(0);
- }
- }
+ update_skeleton_predicates(ctrl, loop_head, init, stride_con);
// Adjust loop limit to keep valid iterations number after unroll.
// Use (limit - stride) instead of (((limit - init)/stride) & (-2))*stride
@@ -2296,9 +2340,9 @@
// eliminated by iteration splitting.
Node* PhaseIdealLoop::add_range_check_predicate(IdealLoopTree* loop, CountedLoopNode* cl,
Node* predicate_proj, int scale_con, Node* offset,
- Node* limit, jint stride_con) {
+ Node* limit, jint stride_con, Node* value) {
bool overflow = false;
- BoolNode* bol = rc_predicate(loop, predicate_proj, scale_con, offset, cl->init_trip(), NULL, stride_con, limit, (stride_con > 0) != (scale_con > 0), overflow);
+ BoolNode* bol = rc_predicate(loop, predicate_proj, scale_con, offset, value, NULL, stride_con, limit, (stride_con > 0) != (scale_con > 0), overflow);
Node* opaque_bol = new Opaque4Node(C, bol, _igvn.intcon(1));
register_new_node(opaque_bol, predicate_proj);
IfNode* new_iff = NULL;
@@ -2497,7 +2541,23 @@
add_constraint( stride_con, scale_con, offset, zero, limit, pre_ctrl, &pre_limit, &main_limit );
// (0-offset)/scale could be outside of loop iterations range.
conditional_rc = true;
- predicate_proj = add_range_check_predicate(loop, cl, predicate_proj, scale_con, offset, limit, stride_con);
+ Node* init = cl->init_trip();
+ Node* opaque_init = new Opaque1Node(C, init);
+ register_new_node(opaque_init, predicate_proj);
+ // template predicate so it can be updated on next unrolling
+ predicate_proj = add_range_check_predicate(loop, cl, predicate_proj, scale_con, offset, limit, stride_con, opaque_init);
+ assert(skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If()), "unexpected");
+ // predicate on first value of first iteration
+ predicate_proj = add_range_check_predicate(loop, cl, predicate_proj, scale_con, offset, limit, stride_con, init);
+ assert(!skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If()), "unexpected");
+ int init_inc = stride_con/cl->unrolled_count();
+ assert(init_inc != 0, "invalid loop increment");
+ Node* max_value = _igvn.intcon(stride_con - init_inc);
+ max_value = new AddINode(init, max_value);
+ register_new_node(max_value, predicate_proj);
+ // predicate on last value of first iteration (in case unrolling has already happened)
+ predicate_proj = add_range_check_predicate(loop, cl, predicate_proj, scale_con, offset, limit, stride_con, max_value);
+ assert(!skeleton_predicate_has_opaque(predicate_proj->in(0)->as_If()), "unexpected");
} else {
if (PrintOpto) {
tty->print_cr("missed RCE opportunity");
--- a/src/hotspot/share/opto/loopnode.hpp Mon Jan 14 13:45:19 2019 -0800
+++ b/src/hotspot/share/opto/loopnode.hpp Mon Jan 14 15:07:22 2019 +0100
@@ -747,12 +747,14 @@
}
Node* cast_incr_before_loop(Node* incr, Node* ctrl, Node* loop);
- void duplicate_predicates_helper(Node* predicate, Node* castii, IdealLoopTree* outer_loop,
+ void duplicate_predicates_helper(Node* predicate, Node* start, Node* end, IdealLoopTree* outer_loop,
LoopNode* outer_main_head, uint dd_main_head);
- void duplicate_predicates(CountedLoopNode* pre_head, Node* castii, IdealLoopTree* outer_loop,
+ void duplicate_predicates(CountedLoopNode* pre_head, Node* start, Node* end, IdealLoopTree* outer_loop,
LoopNode* outer_main_head, uint dd_main_head);
- Node* update_skeleton_predicate(Node* iff, Node* value, Node* predicate = NULL, Node* uncommon_proj = NULL,
- Node* current_proj = NULL, IdealLoopTree* outer_loop = NULL, Node* prev_proj = NULL);
+ Node* clone_skeleton_predicate(Node* iff, Node* value, Node* predicate, Node* uncommon_proj,
+ Node* current_proj, IdealLoopTree* outer_loop, Node* prev_proj);
+ bool skeleton_predicate_has_opaque(IfNode* iff);
+ void update_skeleton_predicates(Node* ctrl, CountedLoopNode* loop_head, Node* init, int stride_con);
void insert_loop_limit_check(ProjNode* limit_check_proj, Node* cmp_limit, Node* bol);
public:
@@ -1128,7 +1130,7 @@
Deoptimization::DeoptReason reason);
Node* add_range_check_predicate(IdealLoopTree* loop, CountedLoopNode* cl,
Node* predicate_proj, int scale_con, Node* offset,
- Node* limit, jint stride_con);
+ Node* limit, jint stride_con, Node* value);
// Helper function to collect predicate for eliminating the useless ones
void collect_potentially_useful_predicates(IdealLoopTree *loop, Unique_Node_List &predicate_opaque1);