Mercurial > hg > graal-jvmci-8
diff src/share/vm/opto/loopTransform.cpp @ 2468:6c97c830fb6f
Merge
author | jrose |
---|---|
date | Sat, 09 Apr 2011 21:16:12 -0700 |
parents | 1d1603768966 3af54845df98 |
children | ae93231c7a1f |
line wrap: on
line diff
--- a/src/share/vm/opto/loopTransform.cpp Fri Apr 08 16:18:48 2011 -0700 +++ b/src/share/vm/opto/loopTransform.cpp Sat Apr 09 21:16:12 2011 -0700 @@ -63,6 +63,46 @@ } } +//------------------------------compute_exact_trip_count----------------------- +// Compute loop exact trip count if possible. Do not recalculate trip count for +// split loops (pre-main-post) which have their limits and inits behind Opaque node. +void IdealLoopTree::compute_exact_trip_count( PhaseIdealLoop *phase ) { + if (!_head->as_Loop()->is_valid_counted_loop()) { + return; + } + CountedLoopNode* cl = _head->as_CountedLoop(); + // Trip count may become nonexact for iteration split loops since + // RCE modifies limits. Note, _trip_count value is not reset since + // it is used to limit unrolling of main loop. + cl->set_nonexact_trip_count(); + + // Loop's test should be part of loop. + if (!phase->is_member(this, phase->get_ctrl(cl->loopexit()->in(CountedLoopEndNode::TestValue)))) + return; // Infinite loop + +#ifdef ASSERT + BoolTest::mask bt = cl->loopexit()->test_trip(); + assert(bt == BoolTest::lt || bt == BoolTest::gt || + bt == BoolTest::ne, "canonical test is expected"); +#endif + + Node* init_n = cl->init_trip(); + Node* limit_n = cl->limit(); + if (init_n != NULL && init_n->is_Con() && + limit_n != NULL && limit_n->is_Con()) { + // Use longs to avoid integer overflow. + int stride_con = cl->stride_con(); + long init_con = cl->init_trip()->get_int(); + long limit_con = cl->limit()->get_int(); + int stride_m = stride_con - (stride_con > 0 ? 1 : -1); + long trip_count = (limit_con - init_con + stride_m)/stride_con; + if (trip_count > 0 && (julong)trip_count < (julong)max_juint) { + // Set exact trip count. + cl->set_exact_trip_count((uint)trip_count); + } + } +} + //------------------------------compute_profile_trip_cnt---------------------------- // Compute loop trip count from profile data as // (backedge_count + loop_exit_count) / loop_exit_count @@ -301,6 +341,132 @@ // 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 +481,10 @@ 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 +497,11 @@ #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 +509,15 @@ // 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 +528,12 @@ // 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 +541,15 @@ // 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)); } @@ -392,34 +562,26 @@ loop->record_for_igvn(); } +#define EMPTY_LOOP_SIZE 7 // number of nodes in an empty loop + //------------------------------policy_maximally_unroll------------------------ -// Return exact loop trip count, or 0 if not maximally unrolling +// Calculate exact loop trip count and return true if loop can be maximally +// unrolled. bool IdealLoopTree::policy_maximally_unroll( PhaseIdealLoop *phase ) const { CountedLoopNode *cl = _head->as_CountedLoop(); assert(cl->is_normal_loop(), ""); - - Node *init_n = cl->init_trip(); - Node *limit_n = cl->limit(); + if (!cl->is_valid_counted_loop()) + return false; // Malformed counted loop - // Non-constant bounds - if (init_n == NULL || !init_n->is_Con() || - limit_n == NULL || !limit_n->is_Con() || - // protect against stride not being a constant - !cl->stride_is_con()) { + if (!cl->has_exact_trip_count()) { + // Trip count is not exact. return false; } - int init = init_n->get_int(); - int limit = limit_n->get_int(); - int span = limit - init; - int stride = cl->stride_con(); - if (init >= limit || stride > span) { - // return a false (no maximally unroll) and the regular unroll/peel - // route will make a small mess which CCP will fold away. - return false; - } - uint trip_count = span/stride; // trip_count can be greater than 2 Gig. - assert( (int)trip_count*stride == span, "must divide evenly" ); + uint trip_count = cl->trip_count(); + // Note, max_juint is used to indicate unknown trip count. + assert(trip_count > 1, "one iteration loop should be optimized out already"); + assert(trip_count < max_juint, "exact trip_count should be less than max_uint."); // Real policy: if we maximally unroll, does it get too big? // Allow the unrolled mess to get larger than standard loop @@ -427,15 +589,29 @@ uint body_size = _body.size(); uint unroll_limit = (uint)LoopUnrollLimit * 4; assert( (intx)unroll_limit == LoopUnrollLimit * 4, "LoopUnrollLimit must fit in 32bits"); - cl->set_trip_count(trip_count); if (trip_count > unroll_limit || body_size > unroll_limit) { return false; } + // Take into account that after unroll conjoined heads and tails will fold, + // otherwise policy_unroll() may allow more unrolling than max unrolling. + uint new_body_size = EMPTY_LOOP_SIZE + (body_size - EMPTY_LOOP_SIZE) * trip_count; + uint tst_body_size = (new_body_size - EMPTY_LOOP_SIZE) / trip_count + EMPTY_LOOP_SIZE; + if (body_size != tst_body_size) // Check for int overflow + return false; + if (new_body_size > unroll_limit || + // Unrolling can result in a large amount of node construction + new_body_size >= MaxNodeLimit - phase->C->unique()) { + return false; + } + // Currently we don't have policy to optimize one iteration loops. // Maximally unrolling transformation is used for that: // it is peeled and the original loop become non reachable (dead). - if (trip_count == 1) + // Also fully unroll a loop with few iterations regardless next + // conditions since following loop optimizations will split + // such loop anyway (pre-main-post). + if (trip_count <= 3) return true; // Do not unroll a loop with String intrinsics code. @@ -452,17 +628,7 @@ } // switch } - if (body_size <= unroll_limit) { - uint new_body_size = body_size * trip_count; - if (new_body_size <= unroll_limit && - body_size == new_body_size / trip_count && - // Unrolling can result in a large amount of node construction - new_body_size < MaxNodeLimit - phase->C->unique()) { - return true; // maximally unroll - } - } - - return false; // Do not maximally unroll + return true; // Do maximally unroll } @@ -474,12 +640,15 @@ CountedLoopNode *cl = _head->as_CountedLoop(); assert(cl->is_normal_loop() || cl->is_main_loop(), ""); - // protect against stride not being a constant - if (!cl->stride_is_con()) return false; + if (!cl->is_valid_counted_loop()) + return false; // Malformed counted loop // protect against over-unrolling if (cl->trip_count() <= 1) return false; + // Check for stride being a small enough constant + if (abs(cl->stride_con()) > (1<<3)) return false; + int future_unroll_ct = cl->unrolled_count() * 2; // Don't unroll if the next round of unrolling would push us @@ -560,9 +729,6 @@ return false; } - // Check for stride being a small enough constant - if (abs(cl->stride_con()) > (1<<3)) return false; - // Unroll once! (Each trip will soon do double iterations) return true; } @@ -956,7 +1122,11 @@ tty->print("Unrolling "); loop->dump_head(); } else if (TraceLoopOpts) { - tty->print("Unroll %d ", loop_head->unrolled_count()*2); + if (loop_head->trip_count() < (uint)LoopUnrollLimit) { + tty->print("Unroll %d(%2d) ", loop_head->unrolled_count()*2, loop_head->trip_count()); + } else { + tty->print("Unroll %d ", loop_head->unrolled_count()*2); + } loop->dump_head(); } #endif @@ -1631,7 +1801,7 @@ // have on the last iteration. This will break the loop. bool IdealLoopTree::policy_do_remove_empty_loop( PhaseIdealLoop *phase ) { // Minimum size must be empty loop - if (_body.size() > 7/*number of nodes in an empty loop*/) + if (_body.size() > EMPTY_LOOP_SIZE) return false; if (!_head->is_CountedLoop()) @@ -1658,8 +1828,19 @@ // main and post loops have explicitly created zero trip guard bool needs_guard = !cl->is_main_loop() && !cl->is_post_loop(); if (needs_guard) { + // Skip guard if values not overlap. + const TypeInt* init_t = phase->_igvn.type(cl->init_trip())->is_int(); + const TypeInt* limit_t = phase->_igvn.type(cl->limit())->is_int(); + int stride_con = cl->stride_con(); + if (stride_con > 0) { + needs_guard = (init_t->_hi >= limit_t->_lo); + } else { + needs_guard = (init_t->_lo <= limit_t->_hi); + } + } + 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); @@ -1702,12 +1883,49 @@ return true; } +//------------------------------policy_do_one_iteration_loop------------------- +// Convert one iteration loop into normal code. +bool IdealLoopTree::policy_do_one_iteration_loop( PhaseIdealLoop *phase ) { + if (!_head->as_Loop()->is_valid_counted_loop()) + return false; // Only for counted loop + + CountedLoopNode *cl = _head->as_CountedLoop(); + if (!cl->has_exact_trip_count() || cl->trip_count() != 1) { + return false; + } + +#ifndef PRODUCT + if(TraceLoopOpts) { + tty->print("OneIteration "); + this->dump_head(); + } +#endif + + Node *init_n = cl->init_trip(); +#ifdef ASSERT + // Loop boundaries should be constant since trip count is exact. + assert(init_n->get_int() + cl->stride_con() >= cl->limit()->get_int(), "should be one iteration"); +#endif + // Replace the phi at loop head with the value of the init_trip. + // Then the CountedLoopEnd will collapse (backedge will not be taken) + // and all loop-invariant uses of the exit values will be correct. + phase->_igvn.replace_node(cl->phi(), cl->init_trip()); + phase->C->set_major_progress(); + return true; +} //============================================================================= //------------------------------iteration_split_impl--------------------------- bool IdealLoopTree::iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_new ) { + // Compute exact loop trip count if possible. + compute_exact_trip_count(phase); + + // Convert one iteration loop into normal code. + if (policy_do_one_iteration_loop(phase)) + return true; + // Check and remove empty loops (spam micro-benchmarks) - if( policy_do_remove_empty_loop(phase) ) + if (policy_do_remove_empty_loop(phase)) return true; // Here we removed an empty loop bool should_peel = policy_peeling(phase); // Should we peel? @@ -1716,40 +1934,40 @@ // Non-counted loops may be peeled; exactly 1 iteration is peeled. // This removes loop-invariant tests (usually null checks). - if( !_head->is_CountedLoop() ) { // Non-counted loop + if (!_head->is_CountedLoop()) { // Non-counted loop if (PartialPeelLoop && phase->partial_peel(this, old_new)) { // Partial peel succeeded so terminate this round of loop opts return false; } - if( should_peel ) { // Should we peel? + if (should_peel) { // Should we peel? #ifndef PRODUCT if (PrintOpto) tty->print_cr("should_peel"); #endif phase->do_peeling(this,old_new); - } else if( should_unswitch ) { + } else if (should_unswitch) { phase->do_unswitching(this, old_new); } return true; } CountedLoopNode *cl = _head->as_CountedLoop(); - if( !cl->loopexit() ) return true; // Ignore various kinds of broken loops + if (!cl->loopexit()) return true; // Ignore various kinds of broken loops // Do nothing special to pre- and post- loops - if( cl->is_pre_loop() || cl->is_post_loop() ) return true; + if (cl->is_pre_loop() || cl->is_post_loop()) return true; // Compute loop trip count from profile data compute_profile_trip_cnt(phase); // Before attempting fancy unrolling, RCE or alignment, see if we want // to completely unroll this loop or do loop unswitching. - if( cl->is_normal_loop() ) { + if (cl->is_normal_loop()) { if (should_unswitch) { phase->do_unswitching(this, old_new); return true; } bool should_maximally_unroll = policy_maximally_unroll(phase); - if( should_maximally_unroll ) { + if (should_maximally_unroll) { // Here we did some unrolling and peeling. Eventually we will // completely unroll this loop and it will no longer be a loop. phase->do_maximally_unroll(this,old_new); @@ -1757,6 +1975,12 @@ } } + // Skip next optimizations if running low on nodes. Note that + // policy_unswitching and policy_maximally_unroll have this check. + uint nodes_left = MaxNodeLimit - phase->C->unique(); + if ((2 * _body.size()) > nodes_left) { + return true; + } // Counted loops may be peeled, may need some iterations run up // front for RCE, and may want to align loop refs to a cache @@ -1787,14 +2011,14 @@ // If we have any of these conditions (RCE, alignment, unrolling) met, then // we switch to the pre-/main-/post-loop model. This model also covers // peeling. - if( should_rce || should_align || should_unroll ) { - if( cl->is_normal_loop() ) // Convert to 'pre/main/post' loops + if (should_rce || should_align || should_unroll) { + if (cl->is_normal_loop()) // Convert to 'pre/main/post' loops phase->insert_pre_post_loops(this,old_new, !may_rce_align); // Adjust the pre- and main-loop limits to let the pre and post loops run // with full checks, but the main-loop with no checks. Remove said // checks from the main body. - if( should_rce ) + if (should_rce) phase->do_range_check(this,old_new); // Double loop body for unrolling. Adjust the minimum-trip test (will do @@ -1802,16 +2026,16 @@ // an even number of trips). If we are peeling, we might enable some RCE // and we'd rather unroll the post-RCE'd loop SO... do not unroll if // peeling. - if( should_unroll && !should_peel ) - phase->do_unroll(this,old_new, true); + if (should_unroll && !should_peel) + phase->do_unroll(this,old_new, true); // Adjust the pre-loop limits to align the main body // iterations. - if( should_align ) + if (should_align) Unimplemented(); } else { // Else we have an unchanged counted loop - if( should_peel ) // Might want to peel but do nothing else + if (should_peel) // Might want to peel but do nothing else phase->do_peeling(this,old_new); } return true; @@ -1861,651 +2085,8 @@ 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() { @@ -2625,9 +2206,12 @@ if (value != head->phi()) { msg = "unhandled shift in address"; } else { - found_index = true; - shift = n; - assert(type2aelembytes(store->as_Mem()->memory_type(), true) == 1 << shift->in(2)->get_int(), "scale should match"); + if (type2aelembytes(store->as_Mem()->memory_type(), true) != (1 << n->in(2)->get_int())) { + msg = "scale doesn't match"; + } else { + found_index = true; + shift = n; + } } } else if (n->Opcode() == Op_ConvI2L && conv == NULL) { if (n->in(1) == head->phi()) { @@ -2762,6 +2346,13 @@ 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);