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7004535: Clone loop predicate during loop unswitch

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Clone loop predicate for clonned loops

Reviewed-by: never
This commit is contained in:
Vladimir Kozlov 2011-04-02 10:54:15 -07:00
parent 68f1177f59
commit 00eca5e982
14 changed files with 1298 additions and 716 deletions
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824
hotspot/src/share/vm/opto/loopTransform.cpp
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@ -301,6 +301,132 @@ void PhaseIdealLoop::peeled_dom_test_elim( IdealLoopTree *loop, Node_List &old_n
// peeled-loop backedge has 2 users.
// Step 3: Cut the backedge on the clone (so its not a loop) and remove the
// extra backedge user.
//
// orig
//
// stmt1
// |
// v
// loop predicate
// |
// v
// loop<----+
// | |
// stmt2 |
// | |
// v |
// if ^
// / \ |
// / \ |
// v v |
// false true |
// / \ |
// / ----+
// |
// v
// exit
//
//
// after clone loop
//
// stmt1
// |
// v
// loop predicate
// / \
// clone / \ orig
// / \
// / \
// v v
// +---->loop clone loop<----+
// | | | |
// | stmt2 clone stmt2 |
// | | | |
// | v v |
// ^ if clone If ^
// | / \ / \ |
// | / \ / \ |
// | v v v v |
// | true false false true |
// | / \ / \ |
// +---- \ / ----+
// \ /
// 1v v2
// region
// |
// v
// exit
//
//
// after peel and predicate move
//
// stmt1
// /
// /
// clone / orig
// /
// / +----------+
// / | |
// / loop predicate |
// / | |
// v v |
// TOP-->loop clone loop<----+ |
// | | | |
// stmt2 clone stmt2 | |
// | | | ^
// v v | |
// if clone If ^ |
// / \ / \ | |
// / \ / \ | |
// v v v v | |
// true false false true | |
// | \ / \ | |
// | \ / ----+ ^
// | \ / |
// | 1v v2 |
// v region |
// | | |
// | v |
// | exit |
// | |
// +--------------->-----------------+
//
//
// final graph
//
// stmt1
// |
// v
// stmt2 clone
// |
// v
// if clone
// / |
// / |
// v v
// false true
// | |
// | v
// | loop predicate
// | |
// | v
// | loop<----+
// | | |
// | stmt2 |
// | | |
// | v |
// v if ^
// | / \ |
// | / \ |
// | v v |
// | false true |
// | | \ |
// v v --+
// region
// |
// v
// exit
//
void PhaseIdealLoop::do_peeling( IdealLoopTree *loop, Node_List &old_new ) {
C->set_major_progress();
@ -315,9 +441,10 @@ void PhaseIdealLoop::do_peeling( IdealLoopTree *loop, Node_List &old_new ) {
loop->dump_head();
}
#endif
Node *h = loop->_head;
if (h->is_CountedLoop()) {
CountedLoopNode *cl = h->as_CountedLoop();
Node* head = loop->_head;
bool counted_loop = head->is_CountedLoop();
if (counted_loop) {
CountedLoopNode *cl = head->as_CountedLoop();
assert(cl->trip_count() > 0, "peeling a fully unrolled loop");
cl->set_trip_count(cl->trip_count() - 1);
if (cl->is_main_loop()) {
@ -330,11 +457,11 @@ void PhaseIdealLoop::do_peeling( IdealLoopTree *loop, Node_List &old_new ) {
#endif
}
}
Node* entry = head->in(LoopNode::EntryControl);
// Step 1: Clone the loop body. The clone becomes the peeled iteration.
// The pre-loop illegally has 2 control users (old & new loops).
clone_loop( loop, old_new, dom_depth(loop->_head) );
clone_loop( loop, old_new, dom_depth(head) );
// Step 2: Make the old-loop fall-in edges point to the peeled iteration.
// Do this by making the old-loop fall-in edges act as if they came
@ -342,12 +469,15 @@ void PhaseIdealLoop::do_peeling( IdealLoopTree *loop, Node_List &old_new ) {
// backedges) and then map to the new peeled iteration. This leaves
// the pre-loop with only 1 user (the new peeled iteration), but the
// peeled-loop backedge has 2 users.
for (DUIterator_Fast jmax, j = loop->_head->fast_outs(jmax); j < jmax; j++) {
Node* old = loop->_head->fast_out(j);
if( old->in(0) == loop->_head && old->req() == 3 &&
(old->is_Loop() || old->is_Phi()) ) {
Node *new_exit_value = old_new[old->in(LoopNode::LoopBackControl)->_idx];
if( !new_exit_value ) // Backedge value is ALSO loop invariant?
Node* new_exit_value = old_new[head->in(LoopNode::LoopBackControl)->_idx];
new_exit_value = move_loop_predicates(entry, new_exit_value);
_igvn.hash_delete(head);
head->set_req(LoopNode::EntryControl, new_exit_value);
for (DUIterator_Fast jmax, j = head->fast_outs(jmax); j < jmax; j++) {
Node* old = head->fast_out(j);
if (old->in(0) == loop->_head && old->req() == 3 && old->is_Phi()) {
new_exit_value = old_new[old->in(LoopNode::LoopBackControl)->_idx];
if (!new_exit_value ) // Backedge value is ALSO loop invariant?
// Then loop body backedge value remains the same.
new_exit_value = old->in(LoopNode::LoopBackControl);
_igvn.hash_delete(old);
@ -358,12 +488,12 @@ void PhaseIdealLoop::do_peeling( IdealLoopTree *loop, Node_List &old_new ) {
// Step 3: Cut the backedge on the clone (so its not a loop) and remove the
// extra backedge user.
Node *nnn = old_new[loop->_head->_idx];
_igvn.hash_delete(nnn);
nnn->set_req(LoopNode::LoopBackControl, C->top());
for (DUIterator_Fast j2max, j2 = nnn->fast_outs(j2max); j2 < j2max; j2++) {
Node* use = nnn->fast_out(j2);
if( use->in(0) == nnn && use->req() == 3 && use->is_Phi() ) {
Node* new_head = old_new[head->_idx];
_igvn.hash_delete(new_head);
new_head->set_req(LoopNode::LoopBackControl, C->top());
for (DUIterator_Fast j2max, j2 = new_head->fast_outs(j2max); j2 < j2max; j2++) {
Node* use = new_head->fast_out(j2);
if (use->in(0) == new_head && use->req() == 3 && use->is_Phi()) {
_igvn.hash_delete(use);
use->set_req(LoopNode::LoopBackControl, C->top());
}
@ -371,15 +501,15 @@ void PhaseIdealLoop::do_peeling( IdealLoopTree *loop, Node_List &old_new ) {
// Step 4: Correct dom-depth info. Set to loop-head depth.
int dd = dom_depth(loop->_head);
set_idom(loop->_head, loop->_head->in(1), dd);
int dd = dom_depth(head);
set_idom(head, head->in(1), dd);
for (uint j3 = 0; j3 < loop->_body.size(); j3++) {
Node *old = loop->_body.at(j3);
Node *nnn = old_new[old->_idx];
if (!has_ctrl(nnn))
set_idom(nnn, idom(nnn), dd-1);
// While we're at it, remove any SafePoints from the peeled code
if( old->Opcode() == Op_SafePoint ) {
if (old->Opcode() == Op_SafePoint) {
Node *nnn = old_new[old->_idx];
lazy_replace(nnn,nnn->in(TypeFunc::Control));
}
@ -1659,7 +1789,7 @@ bool IdealLoopTree::policy_do_remove_empty_loop( PhaseIdealLoop *phase ) {
bool needs_guard = !cl->is_main_loop() && !cl->is_post_loop();
if (needs_guard) {
// Check for an obvious zero trip guard.
Node* inctrl = cl->in(LoopNode::EntryControl);
Node* inctrl = PhaseIdealLoop::skip_loop_predicates(cl->in(LoopNode::EntryControl));
if (inctrl->Opcode() == Op_IfTrue) {
// The test should look like just the backedge of a CountedLoop
Node* iff = inctrl->in(0);
@ -1861,651 +1991,8 @@ bool IdealLoopTree::iteration_split( PhaseIdealLoop *phase, Node_List &old_new )
return true;
}
//-------------------------------is_uncommon_trap_proj----------------------------
// Return true if proj is the form of "proj->[region->..]call_uct"
bool PhaseIdealLoop::is_uncommon_trap_proj(ProjNode* proj, Deoptimization::DeoptReason reason) {
int path_limit = 10;
assert(proj, "invalid argument");
Node* out = proj;
for (int ct = 0; ct < path_limit; ct++) {
out = out->unique_ctrl_out();
if (out == NULL || out->is_Root() || out->is_Start())
return false;
if (out->is_CallStaticJava()) {
int req = out->as_CallStaticJava()->uncommon_trap_request();
if (req != 0) {
Deoptimization::DeoptReason trap_reason = Deoptimization::trap_request_reason(req);
if (trap_reason == reason || reason == Deoptimization::Reason_none) {
return true;
}
}
return false; // don't do further after call
}
}
return false;
}
//-------------------------------is_uncommon_trap_if_pattern-------------------------
// Return true for "if(test)-> proj -> ...
// |
// V
// other_proj->[region->..]call_uct"
//
// "must_reason_predicate" means the uct reason must be Reason_predicate
bool PhaseIdealLoop::is_uncommon_trap_if_pattern(ProjNode *proj, Deoptimization::DeoptReason reason) {
Node *in0 = proj->in(0);
if (!in0->is_If()) return false;
// Variation of a dead If node.
if (in0->outcnt() < 2) return false;
IfNode* iff = in0->as_If();
// we need "If(Conv2B(Opaque1(...)))" pattern for reason_predicate
if (reason != Deoptimization::Reason_none) {
if (iff->in(1)->Opcode() != Op_Conv2B ||
iff->in(1)->in(1)->Opcode() != Op_Opaque1) {
return false;
}
}
ProjNode* other_proj = iff->proj_out(1-proj->_con)->as_Proj();
return is_uncommon_trap_proj(other_proj, reason);
}
//-------------------------------register_control-------------------------
void PhaseIdealLoop::register_control(Node* n, IdealLoopTree *loop, Node* pred) {
assert(n->is_CFG(), "must be control node");
_igvn.register_new_node_with_optimizer(n);
loop->_body.push(n);
set_loop(n, loop);
// When called from beautify_loops() idom is not constructed yet.
if (_idom != NULL) {
set_idom(n, pred, dom_depth(pred));
}
}
//------------------------------create_new_if_for_predicate------------------------
// create a new if above the uct_if_pattern for the predicate to be promoted.
//
// before after
// ---------- ----------
// ctrl ctrl
// | |
// | |
// v v
// iff new_iff
// / \ / \
// / \ / \
// v v v v
// uncommon_proj cont_proj if_uct if_cont
// \ | | | |
// \ | | | |
// v v v | v
// rgn loop | iff
// | | / \
// | | / \
// v | v v
// uncommon_trap | uncommon_proj cont_proj
// \ \ | |
// \ \ | |
// v v v v
// rgn loop
// |
// |
// v
// uncommon_trap
//
//
// We will create a region to guard the uct call if there is no one there.
// The true projecttion (if_cont) of the new_iff is returned.
// This code is also used to clone predicates to clonned loops.
ProjNode* PhaseIdealLoop::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry,
Deoptimization::DeoptReason reason) {
assert(is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!");
IfNode* iff = cont_proj->in(0)->as_If();
ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con);
Node *rgn = uncommon_proj->unique_ctrl_out();
assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct");
if (!rgn->is_Region()) { // create a region to guard the call
assert(rgn->is_Call(), "must be call uct");
CallNode* call = rgn->as_Call();
IdealLoopTree* loop = get_loop(call);
rgn = new (C, 1) RegionNode(1);
rgn->add_req(uncommon_proj);
register_control(rgn, loop, uncommon_proj);
_igvn.hash_delete(call);
call->set_req(0, rgn);
// When called from beautify_loops() idom is not constructed yet.
if (_idom != NULL) {
set_idom(call, rgn, dom_depth(rgn));
}
}
Node* entry = iff->in(0);
if (new_entry != NULL) {
// Clonning the predicate to new location.
entry = new_entry;
}
// Create new_iff
IdealLoopTree* lp = get_loop(entry);
IfNode *new_iff = new (C, 2) IfNode(entry, NULL, iff->_prob, iff->_fcnt);
register_control(new_iff, lp, entry);
Node *if_cont = new (C, 1) IfTrueNode(new_iff);
Node *if_uct = new (C, 1) IfFalseNode(new_iff);
if (cont_proj->is_IfFalse()) {
// Swap
Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp;
}
register_control(if_cont, lp, new_iff);
register_control(if_uct, get_loop(rgn), new_iff);
// if_uct to rgn
_igvn.hash_delete(rgn);
rgn->add_req(if_uct);
// When called from beautify_loops() idom is not constructed yet.
if (_idom != NULL) {
Node* ridom = idom(rgn);
Node* nrdom = dom_lca(ridom, new_iff);
set_idom(rgn, nrdom, dom_depth(rgn));
}
// rgn must have no phis
assert(!rgn->as_Region()->has_phi(), "region must have no phis");
if (new_entry == NULL) {
// Attach if_cont to iff
_igvn.hash_delete(iff);
iff->set_req(0, if_cont);
if (_idom != NULL) {
set_idom(iff, if_cont, dom_depth(iff));
}
}
return if_cont->as_Proj();
}
//--------------------------find_predicate_insertion_point-------------------
// Find a good location to insert a predicate
ProjNode* PhaseIdealLoop::find_predicate_insertion_point(Node* start_c, Deoptimization::DeoptReason reason) {
if (start_c == NULL || !start_c->is_Proj())
return NULL;
if (is_uncommon_trap_if_pattern(start_c->as_Proj(), reason)) {
return start_c->as_Proj();
}
return NULL;
}
//--------------------------find_predicate------------------------------------
// Find a predicate
Node* PhaseIdealLoop::find_predicate(Node* entry) {
Node* predicate = NULL;
if (UseLoopPredicate) {
predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate);
if (predicate != NULL) { // right pattern that can be used by loop predication
assert(entry->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be");
return entry;
}
}
return NULL;
}
//------------------------------Invariance-----------------------------------
// Helper class for loop_predication_impl to compute invariance on the fly and
// clone invariants.
class Invariance : public StackObj {
VectorSet _visited, _invariant;
Node_Stack _stack;
VectorSet _clone_visited;
Node_List _old_new; // map of old to new (clone)
IdealLoopTree* _lpt;
PhaseIdealLoop* _phase;
// Helper function to set up the invariance for invariance computation
// If n is a known invariant, set up directly. Otherwise, look up the
// the possibility to push n onto the stack for further processing.
void visit(Node* use, Node* n) {
if (_lpt->is_invariant(n)) { // known invariant
_invariant.set(n->_idx);
} else if (!n->is_CFG()) {
Node *n_ctrl = _phase->ctrl_or_self(n);
Node *u_ctrl = _phase->ctrl_or_self(use); // self if use is a CFG
if (_phase->is_dominator(n_ctrl, u_ctrl)) {
_stack.push(n, n->in(0) == NULL ? 1 : 0);
}
}
}
// Compute invariance for "the_node" and (possibly) all its inputs recursively
// on the fly
void compute_invariance(Node* n) {
assert(_visited.test(n->_idx), "must be");
visit(n, n);
while (_stack.is_nonempty()) {
Node* n = _stack.node();
uint idx = _stack.index();
if (idx == n->req()) { // all inputs are processed
_stack.pop();
// n is invariant if it's inputs are all invariant
bool all_inputs_invariant = true;
for (uint i = 0; i < n->req(); i++) {
Node* in = n->in(i);
if (in == NULL) continue;
assert(_visited.test(in->_idx), "must have visited input");
if (!_invariant.test(in->_idx)) { // bad guy
all_inputs_invariant = false;
break;
}
}
if (all_inputs_invariant) {
_invariant.set(n->_idx); // I am a invariant too
}
} else { // process next input
_stack.set_index(idx + 1);
Node* m = n->in(idx);
if (m != NULL && !_visited.test_set(m->_idx)) {
visit(n, m);
}
}
}
}
// Helper function to set up _old_new map for clone_nodes.
// If n is a known invariant, set up directly ("clone" of n == n).
// Otherwise, push n onto the stack for real cloning.
void clone_visit(Node* n) {
assert(_invariant.test(n->_idx), "must be invariant");
if (_lpt->is_invariant(n)) { // known invariant
_old_new.map(n->_idx, n);
} else{ // to be cloned
assert (!n->is_CFG(), "should not see CFG here");
_stack.push(n, n->in(0) == NULL ? 1 : 0);
}
}
// Clone "n" and (possibly) all its inputs recursively
void clone_nodes(Node* n, Node* ctrl) {
clone_visit(n);
while (_stack.is_nonempty()) {
Node* n = _stack.node();
uint idx = _stack.index();
if (idx == n->req()) { // all inputs processed, clone n!
_stack.pop();
// clone invariant node
Node* n_cl = n->clone();
_old_new.map(n->_idx, n_cl);
_phase->register_new_node(n_cl, ctrl);
for (uint i = 0; i < n->req(); i++) {
Node* in = n_cl->in(i);
if (in == NULL) continue;
n_cl->set_req(i, _old_new[in->_idx]);
}
} else { // process next input
_stack.set_index(idx + 1);
Node* m = n->in(idx);
if (m != NULL && !_clone_visited.test_set(m->_idx)) {
clone_visit(m); // visit the input
}
}
}
}
public:
Invariance(Arena* area, IdealLoopTree* lpt) :
_lpt(lpt), _phase(lpt->_phase),
_visited(area), _invariant(area), _stack(area, 10 /* guess */),
_clone_visited(area), _old_new(area)
{}
// Map old to n for invariance computation and clone
void map_ctrl(Node* old, Node* n) {
assert(old->is_CFG() && n->is_CFG(), "must be");
_old_new.map(old->_idx, n); // "clone" of old is n
_invariant.set(old->_idx); // old is invariant
_clone_visited.set(old->_idx);
}
// Driver function to compute invariance
bool is_invariant(Node* n) {
if (!_visited.test_set(n->_idx))
compute_invariance(n);
return (_invariant.test(n->_idx) != 0);
}
// Driver function to clone invariant
Node* clone(Node* n, Node* ctrl) {
assert(ctrl->is_CFG(), "must be");
assert(_invariant.test(n->_idx), "must be an invariant");
if (!_clone_visited.test(n->_idx))
clone_nodes(n, ctrl);
return _old_new[n->_idx];
}
};
//------------------------------is_range_check_if -----------------------------------
// Returns true if the predicate of iff is in "scale*iv + offset u< load_range(ptr)" format
// Note: this function is particularly designed for loop predication. We require load_range
// and offset to be loop invariant computed on the fly by "invar"
bool IdealLoopTree::is_range_check_if(IfNode *iff, PhaseIdealLoop *phase, Invariance& invar) const {
if (!is_loop_exit(iff)) {
return false;
}
if (!iff->in(1)->is_Bool()) {
return false;
}
const BoolNode *bol = iff->in(1)->as_Bool();
if (bol->_test._test != BoolTest::lt) {
return false;
}
if (!bol->in(1)->is_Cmp()) {
return false;
}
const CmpNode *cmp = bol->in(1)->as_Cmp();
if (cmp->Opcode() != Op_CmpU ) {
return false;
}
Node* range = cmp->in(2);
if (range->Opcode() != Op_LoadRange) {
const TypeInt* tint = phase->_igvn.type(range)->isa_int();
if (!OptimizeFill || tint == NULL || tint->empty() || tint->_lo < 0) {
// Allow predication on positive values that aren't LoadRanges.
// This allows optimization of loops where the length of the
// array is a known value and doesn't need to be loaded back
// from the array.
return false;
}
}
if (!invar.is_invariant(range)) {
return false;
}
Node *iv = _head->as_CountedLoop()->phi();
int scale = 0;
Node *offset = NULL;
if (!phase->is_scaled_iv_plus_offset(cmp->in(1), iv, &scale, &offset)) {
return false;
}
if(offset && !invar.is_invariant(offset)) { // offset must be invariant
return false;
}
return true;
}
//------------------------------rc_predicate-----------------------------------
// Create a range check predicate
//
// for (i = init; i < limit; i += stride) {
// a[scale*i+offset]
// }
//
// Compute max(scale*i + offset) for init <= i < limit and build the predicate
// as "max(scale*i + offset) u< a.length".
//
// There are two cases for max(scale*i + offset):
// (1) stride*scale > 0
// max(scale*i + offset) = scale*(limit-stride) + offset
// (2) stride*scale < 0
// max(scale*i + offset) = scale*init + offset
BoolNode* PhaseIdealLoop::rc_predicate(Node* ctrl,
int scale, Node* offset,
Node* init, Node* limit, Node* stride,
Node* range, bool upper) {
DEBUG_ONLY(ttyLocker ttyl);
if (TraceLoopPredicate) tty->print("rc_predicate ");
Node* max_idx_expr = init;
int stride_con = stride->get_int();
if ((stride_con > 0) == (scale > 0) == upper) {
max_idx_expr = new (C, 3) SubINode(limit, stride);
register_new_node(max_idx_expr, ctrl);
if (TraceLoopPredicate) tty->print("(limit - stride) ");
} else {
if (TraceLoopPredicate) tty->print("init ");
}
if (scale != 1) {
ConNode* con_scale = _igvn.intcon(scale);
max_idx_expr = new (C, 3) MulINode(max_idx_expr, con_scale);
register_new_node(max_idx_expr, ctrl);
if (TraceLoopPredicate) tty->print("* %d ", scale);
}
if (offset && (!offset->is_Con() || offset->get_int() != 0)){
max_idx_expr = new (C, 3) AddINode(max_idx_expr, offset);
register_new_node(max_idx_expr, ctrl);
if (TraceLoopPredicate)
if (offset->is_Con()) tty->print("+ %d ", offset->get_int());
else tty->print("+ offset ");
}
CmpUNode* cmp = new (C, 3) CmpUNode(max_idx_expr, range);
register_new_node(cmp, ctrl);
BoolNode* bol = new (C, 2) BoolNode(cmp, BoolTest::lt);
register_new_node(bol, ctrl);
if (TraceLoopPredicate) tty->print_cr("<u range");
return bol;
}
//------------------------------ loop_predication_impl--------------------------
// Insert loop predicates for null checks and range checks
bool PhaseIdealLoop::loop_predication_impl(IdealLoopTree *loop) {
if (!UseLoopPredicate) return false;
if (!loop->_head->is_Loop()) {
// Could be a simple region when irreducible loops are present.
return false;
}
if (loop->_head->unique_ctrl_out()->Opcode() == Op_NeverBranch) {
// do nothing for infinite loops
return false;
}
CountedLoopNode *cl = NULL;
if (loop->_head->is_CountedLoop()) {
cl = loop->_head->as_CountedLoop();
// do nothing for iteration-splitted loops
if (!cl->is_normal_loop()) return false;
}
LoopNode *lpn = loop->_head->as_Loop();
Node* entry = lpn->in(LoopNode::EntryControl);
ProjNode *predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate);
if (!predicate_proj) {
#ifndef PRODUCT
if (TraceLoopPredicate) {
tty->print("missing predicate:");
loop->dump_head();
lpn->dump(1);
}
#endif
return false;
}
ConNode* zero = _igvn.intcon(0);
set_ctrl(zero, C->root());
ResourceArea *area = Thread::current()->resource_area();
Invariance invar(area, loop);
// Create list of if-projs such that a newer proj dominates all older
// projs in the list, and they all dominate loop->tail()
Node_List if_proj_list(area);
LoopNode *head = loop->_head->as_Loop();
Node *current_proj = loop->tail(); //start from tail
while ( current_proj != head ) {
if (loop == get_loop(current_proj) && // still in the loop ?
current_proj->is_Proj() && // is a projection ?
current_proj->in(0)->Opcode() == Op_If) { // is a if projection ?
if_proj_list.push(current_proj);
}
current_proj = idom(current_proj);
}
bool hoisted = false; // true if at least one proj is promoted
while (if_proj_list.size() > 0) {
// Following are changed to nonnull when a predicate can be hoisted
ProjNode* new_predicate_proj = NULL;
ProjNode* proj = if_proj_list.pop()->as_Proj();
IfNode* iff = proj->in(0)->as_If();
if (!is_uncommon_trap_if_pattern(proj, Deoptimization::Reason_none)) {
if (loop->is_loop_exit(iff)) {
// stop processing the remaining projs in the list because the execution of them
// depends on the condition of "iff" (iff->in(1)).
break;
} else {
// Both arms are inside the loop. There are two cases:
// (1) there is one backward branch. In this case, any remaining proj
// in the if_proj list post-dominates "iff". So, the condition of "iff"
// does not determine the execution the remining projs directly, and we
// can safely continue.
// (2) both arms are forwarded, i.e. a diamond shape. In this case, "proj"
// does not dominate loop->tail(), so it can not be in the if_proj list.
continue;
}
}
Node* test = iff->in(1);
if (!test->is_Bool()){ //Conv2B, ...
continue;
}
BoolNode* bol = test->as_Bool();
if (invar.is_invariant(bol)) {
// Invariant test
new_predicate_proj = create_new_if_for_predicate(predicate_proj, NULL,
Deoptimization::Reason_predicate);
Node* ctrl = new_predicate_proj->in(0)->as_If()->in(0);
BoolNode* new_predicate_bol = invar.clone(bol, ctrl)->as_Bool();
// Negate test if necessary
bool negated = false;
if (proj->_con != predicate_proj->_con) {
new_predicate_bol = new (C, 2) BoolNode(new_predicate_bol->in(1), new_predicate_bol->_test.negate());
register_new_node(new_predicate_bol, ctrl);
negated = true;
}
IfNode* new_predicate_iff = new_predicate_proj->in(0)->as_If();
_igvn.hash_delete(new_predicate_iff);
new_predicate_iff->set_req(1, new_predicate_bol);
#ifndef PRODUCT
if (TraceLoopPredicate) {
tty->print("Predicate invariant if%s: %d ", negated ? " negated" : "", new_predicate_iff->_idx);
loop->dump_head();
} else if (TraceLoopOpts) {
tty->print("Predicate IC ");
loop->dump_head();
}
#endif
} else if (cl != NULL && loop->is_range_check_if(iff, this, invar)) {
assert(proj->_con == predicate_proj->_con, "must match");
// Range check for counted loops
const Node* cmp = bol->in(1)->as_Cmp();
Node* idx = cmp->in(1);
assert(!invar.is_invariant(idx), "index is variant");
assert(cmp->in(2)->Opcode() == Op_LoadRange || OptimizeFill, "must be");
Node* rng = cmp->in(2);
assert(invar.is_invariant(rng), "range must be invariant");
int scale = 1;
Node* offset = zero;
bool ok = is_scaled_iv_plus_offset(idx, cl->phi(), &scale, &offset);
assert(ok, "must be index expression");
Node* init = cl->init_trip();
Node* limit = cl->limit();
Node* stride = cl->stride();
// Build if's for the upper and lower bound tests. The
// lower_bound test will dominate the upper bound test and all
// cloned or created nodes will use the lower bound test as
// their declared control.
ProjNode* lower_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate);
ProjNode* upper_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate);
assert(upper_bound_proj->in(0)->as_If()->in(0) == lower_bound_proj, "should dominate");
Node *ctrl = lower_bound_proj->in(0)->as_If()->in(0);
// Perform cloning to keep Invariance state correct since the
// late schedule will place invariant things in the loop.
rng = invar.clone(rng, ctrl);
if (offset && offset != zero) {
assert(invar.is_invariant(offset), "offset must be loop invariant");
offset = invar.clone(offset, ctrl);
}
// Test the lower bound
Node* lower_bound_bol = rc_predicate(ctrl, scale, offset, init, limit, stride, rng, false);
IfNode* lower_bound_iff = lower_bound_proj->in(0)->as_If();
_igvn.hash_delete(lower_bound_iff);
lower_bound_iff->set_req(1, lower_bound_bol);
if (TraceLoopPredicate) tty->print_cr("lower bound check if: %d", lower_bound_iff->_idx);
// Test the upper bound
Node* upper_bound_bol = rc_predicate(ctrl, scale, offset, init, limit, stride, rng, true);
IfNode* upper_bound_iff = upper_bound_proj->in(0)->as_If();
_igvn.hash_delete(upper_bound_iff);
upper_bound_iff->set_req(1, upper_bound_bol);
if (TraceLoopPredicate) tty->print_cr("upper bound check if: %d", lower_bound_iff->_idx);
// Fall through into rest of the clean up code which will move
// any dependent nodes onto the upper bound test.
new_predicate_proj = upper_bound_proj;
#ifndef PRODUCT
if (TraceLoopOpts && !TraceLoopPredicate) {
tty->print("Predicate RC ");
loop->dump_head();
}
#endif
} else {
// Loop variant check (for example, range check in non-counted loop)
// with uncommon trap.
continue;
}
assert(new_predicate_proj != NULL, "sanity");
// Success - attach condition (new_predicate_bol) to predicate if
invar.map_ctrl(proj, new_predicate_proj); // so that invariance test can be appropriate
// Eliminate the old If in the loop body
dominated_by( new_predicate_proj, iff, proj->_con != new_predicate_proj->_con );
hoisted = true;
C->set_major_progress();
} // end while
#ifndef PRODUCT
// report that the loop predication has been actually performed
// for this loop
if (TraceLoopPredicate && hoisted) {
tty->print("Loop Predication Performed:");
loop->dump_head();
}
#endif
return hoisted;
}
//------------------------------loop_predication--------------------------------
// driver routine for loop predication optimization
bool IdealLoopTree::loop_predication( PhaseIdealLoop *phase) {
bool hoisted = false;
// Recursively promote predicates
if ( _child ) {
hoisted = _child->loop_predication( phase);
}
// self
if (!_irreducible && !tail()->is_top()) {
hoisted |= phase->loop_predication_impl(this);
}
if ( _next ) { //sibling
hoisted |= _next->loop_predication( phase);
}
return hoisted;
}
//=============================================================================
// Process all the loops in the loop tree and replace any fill
// patterns with an intrisc version.
bool PhaseIdealLoop::do_intrinsify_fill() {
@ -2762,6 +2249,13 @@ bool PhaseIdealLoop::intrinsify_fill(IdealLoopTree* lpt) {
return false;
}
#ifndef PRODUCT
if (TraceLoopOpts) {
tty->print("ArrayFill ");
lpt->dump_head();
}
#endif
// Now replace the whole loop body by a call to a fill routine that
// covers the same region as the loop.
Node* base = store->in(MemNode::Address)->as_AddP()->in(AddPNode::Base);