1.1 --- a/src/share/vm/opto/parse1.cpp Mon Mar 21 02:30:49 2011 -0700
1.2 +++ b/src/share/vm/opto/parse1.cpp Mon Mar 21 11:28:14 2011 -0700
1.3 @@ -637,6 +637,25 @@
1.4 // (Note that dead locals do not get phis built, ever.)
1.5 ensure_phis_everywhere();
1.6
1.7 + if (block->is_SEL_head() &&
1.8 + UseLoopPredicate) {
1.9 + // Add predicate to single entry (not irreducible) loop head.
1.10 + assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
1.11 + // Need correct bci for predicate.
1.12 + // It is fine to set it here since do_one_block() will set it anyway.
1.13 + set_parse_bci(block->start());
1.14 + add_predicate();
1.15 + // Add new region for back branches.
1.16 + int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
1.17 + RegionNode *r = new (C, edges+1) RegionNode(edges+1);
1.18 + _gvn.set_type(r, Type::CONTROL);
1.19 + record_for_igvn(r);
1.20 + r->init_req(edges, control());
1.21 + set_control(r);
1.22 + // Add new phis.
1.23 + ensure_phis_everywhere();
1.24 + }
1.25 +
1.26 // Leave behind an undisturbed copy of the map, for future merges.
1.27 set_map(clone_map());
1.28 }
1.29 @@ -1113,7 +1132,7 @@
1.30 _preds_parsed = 0;
1.31 _count = 0;
1.32 assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
1.33 - assert(!(is_merged() || is_parsed() || is_handler()), "sanity");
1.34 + assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
1.35 assert(_live_locals.size() == 0, "sanity");
1.36
1.37 // entry point has additional predecessor
1.38 @@ -1350,10 +1369,6 @@
1.39 set_parse_bci(iter().cur_bci());
1.40
1.41 if (bci() == block()->limit()) {
1.42 - // insert a predicate if it falls through to a loop head block
1.43 - if (should_add_predicate(bci())){
1.44 - add_predicate();
1.45 - }
1.46 // Do not walk into the next block until directed by do_all_blocks.
1.47 merge(bci());
1.48 break;
1.49 @@ -1498,17 +1513,29 @@
1.50 || target->is_handler() // These have unpredictable inputs.
1.51 || target->is_loop_head() // Known multiple inputs
1.52 || control()->is_Region()) { // We must hide this guy.
1.53 +
1.54 + int current_bci = bci();
1.55 + set_parse_bci(target->start()); // Set target bci
1.56 + if (target->is_SEL_head()) {
1.57 + DEBUG_ONLY( target->mark_merged_backedge(block()); )
1.58 + if (target->start() == 0) {
1.59 + // Add loop predicate for the special case when
1.60 + // there are backbranches to the method entry.
1.61 + add_predicate();
1.62 + }
1.63 + }
1.64 // Add a Region to start the new basic block. Phis will be added
1.65 // later lazily.
1.66 int edges = target->pred_count();
1.67 if (edges < pnum) edges = pnum; // might be a new path!
1.68 - Node *r = new (C, edges+1) RegionNode(edges+1);
1.69 + RegionNode *r = new (C, edges+1) RegionNode(edges+1);
1.70 gvn().set_type(r, Type::CONTROL);
1.71 record_for_igvn(r);
1.72 // zap all inputs to NULL for debugging (done in Node(uint) constructor)
1.73 // for (int j = 1; j < edges+1; j++) { r->init_req(j, NULL); }
1.74 r->init_req(pnum, control());
1.75 set_control(r);
1.76 + set_parse_bci(current_bci); // Restore bci
1.77 }
1.78
1.79 // Convert the existing Parser mapping into a mapping at this bci.
1.80 @@ -1517,7 +1544,11 @@
1.81
1.82 } else { // Prior mapping at this bci
1.83 if (TraceOptoParse) { tty->print(" with previous state"); }
1.84 -
1.85 +#ifdef ASSERT
1.86 + if (target->is_SEL_head()) {
1.87 + target->mark_merged_backedge(block());
1.88 + }
1.89 +#endif
1.90 // We must not manufacture more phis if the target is already parsed.
1.91 bool nophi = target->is_parsed();
1.92
1.93 @@ -2054,37 +2085,6 @@
1.94 }
1.95 }
1.96
1.97 -//------------------------------should_add_predicate--------------------------
1.98 -bool Parse::should_add_predicate(int target_bci) {
1.99 - if (!UseLoopPredicate) return false;
1.100 - Block* target = successor_for_bci(target_bci);
1.101 - if (target != NULL &&
1.102 - target->is_loop_head() &&
1.103 - block()->rpo() < target->rpo()) {
1.104 - return true;
1.105 - }
1.106 - return false;
1.107 -}
1.108 -
1.109 -//------------------------------add_predicate---------------------------------
1.110 -void Parse::add_predicate() {
1.111 - assert(UseLoopPredicate,"use only for loop predicate");
1.112 - Node *cont = _gvn.intcon(1);
1.113 - Node* opq = _gvn.transform(new (C, 2) Opaque1Node(C, cont));
1.114 - Node *bol = _gvn.transform(new (C, 2) Conv2BNode(opq));
1.115 - IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
1.116 - Node* iffalse = _gvn.transform(new (C, 1) IfFalseNode(iff));
1.117 - C->add_predicate_opaq(opq);
1.118 - {
1.119 - PreserveJVMState pjvms(this);
1.120 - set_control(iffalse);
1.121 - uncommon_trap(Deoptimization::Reason_predicate,
1.122 - Deoptimization::Action_maybe_recompile);
1.123 - }
1.124 - Node* iftrue = _gvn.transform(new (C, 1) IfTrueNode(iff));
1.125 - set_control(iftrue);
1.126 -}
1.127 -
1.128 #ifndef PRODUCT
1.129 //------------------------show_parse_info--------------------------------------
1.130 void Parse::show_parse_info() {
