graal-jvmci-8: src/share/vm/opto/parse1.cpp comparison

comparison src/share/vm/opto/parse1.cpp @ 2383:9dc311b8473e

7008866: Missing loop predicate for loop with multiple entries Summary: Add predicates when loop head bytecode is parsed instead of when back branch bytecode is parsed. Reviewed-by: never

author	kvn
date	Mon, 21 Mar 2011 11:28:14 -0700
parents	f95d63e2154a
children	1d1603768966

comparison

equal deleted inserted replaced

-:3ef1a1866a60
+:9dc311b8473e
 if (block->is_loop_head() || block->is_handler() || has_irreducible && !block->is_ready()) {
 // Not all preds have been parsed.  We must build phis everywhere.
 // (Note that dead locals do not get phis built, ever.)
 ensure_phis_everywhere();
+if (block->is_SEL_head() &&
+UseLoopPredicate) {
+// Add predicate to single entry (not irreducible) loop head.
+assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
+// Need correct bci for predicate.
+// It is fine to set it here since do_one_block() will set it anyway.
+set_parse_bci(block->start());
+add_predicate();
+// Add new region for back branches.
+int edges = block->pred_count() - block->preds_parsed() + 1; // +1 for original region
+RegionNode *r = new (C, edges+1) RegionNode(edges+1);
+_gvn.set_type(r, Type::CONTROL);
+record_for_igvn(r);
+r->init_req(edges, control());
+set_control(r);
+// Add new phis.
+ensure_phis_everywhere();
+}
 // Leave behind an undisturbed copy of the map, for future merges.
 set_map(clone_map());
 }
 if (control()->is_Region() && !block->is_loop_head() && !has_irreducible && !block->is_handler()) {
 _flow = outer->flow()->rpo_at(rpo);
 _pred_count = 0;
 _preds_parsed = 0;
 _count = 0;
 assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
-assert(!(is_merged() || is_parsed() || is_handler()), "sanity");
+assert(!(is_merged() || is_parsed() || is_handler() || has_merged_backedge()), "sanity");
 assert(_live_locals.size() == 0, "sanity");
 // entry point has additional predecessor
 if (flow()->is_start())  _pred_count++;
 assert(flow()->is_start() == (this == outer->start_block()), "");
 // Learn the current bci from the iterator:
 set_parse_bci(iter().cur_bci());
 if (bci() == block()->limit()) {
-// insert a predicate if it falls through to a loop head block
-if (should_add_predicate(bci())){
-add_predicate();
-}
 // Do not walk into the next block until directed by do_all_blocks.
 merge(bci());
 break;
 }
 assert(bci() < block()->limit(), "bci still in block");
 // which must not be allowed into this block's map.)
 if (pnum > PhiNode::Input         // Known multiple inputs.
 || target->is_handler()       // These have unpredictable inputs.
 || target->is_loop_head()     // Known multiple inputs
 || control()->is_Region()) {  // We must hide this guy.
+int current_bci = bci();
+set_parse_bci(target->start()); // Set target bci
+if (target->is_SEL_head()) {
+DEBUG_ONLY( target->mark_merged_backedge(block()); )
+if (target->start() == 0) {
+// Add loop predicate for the special case when
+// there are backbranches to the method entry.
+add_predicate();
+}
+}
 // Add a Region to start the new basic block.  Phis will be added
 // later lazily.
 int edges = target->pred_count();
 if (edges < pnum)  edges = pnum;  // might be a new path!
-Node *r = new (C, edges+1) RegionNode(edges+1);
+RegionNode *r = new (C, edges+1) RegionNode(edges+1);
 gvn().set_type(r, Type::CONTROL);
 record_for_igvn(r);
 // zap all inputs to NULL for debugging (done in Node(uint) constructor)
 // for (int j = 1; j < edges+1; j++) { r->init_req(j, NULL); }
 r->init_req(pnum, control());
 set_control(r);
+set_parse_bci(current_bci); // Restore bci
 }
 // Convert the existing Parser mapping into a mapping at this bci.
 store_state_to(target);
 assert(target->is_merged(), "do not come here twice");
 } else {                      // Prior mapping at this bci
 if (TraceOptoParse) {  tty->print(" with previous state"); }
+#ifdef ASSERT
+if (target->is_SEL_head()) {
+target->mark_merged_backedge(block());
+}
+#endif
 // We must not manufacture more phis if the target is already parsed.
 bool nophi = target->is_parsed();
 SafePointNode* newin = map();// Hang on to incoming mapping
 Block* save_block = block(); // Hang on to incoming block;
 assert(C->root() != NULL, "Expect parse is still valid");
 C->root()->add_prec(transformed_sfpnt);
 }
 }
-//------------------------------should_add_predicate--------------------------
-bool Parse::should_add_predicate(int target_bci) {
-if (!UseLoopPredicate) return false;
-Block* target = successor_for_bci(target_bci);
-if (target != NULL          &&
-target->is_loop_head()  &&
-block()->rpo() < target->rpo()) {
-return true;
-}
-return false;
-}
-//------------------------------add_predicate---------------------------------
-void Parse::add_predicate() {
-assert(UseLoopPredicate,"use only for loop predicate");
-Node *cont    = _gvn.intcon(1);
-Node* opq     = _gvn.transform(new (C, 2) Opaque1Node(C, cont));
-Node *bol     = _gvn.transform(new (C, 2) Conv2BNode(opq));
-IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
-Node* iffalse = _gvn.transform(new (C, 1) IfFalseNode(iff));
-C->add_predicate_opaq(opq);
-{
-PreserveJVMState pjvms(this);
-set_control(iffalse);
-uncommon_trap(Deoptimization::Reason_predicate,
-Deoptimization::Action_maybe_recompile);
-}
-Node* iftrue = _gvn.transform(new (C, 1) IfTrueNode(iff));
-set_control(iftrue);
-}
 #ifndef PRODUCT
 //------------------------show_parse_info--------------------------------------
 void Parse::show_parse_info() {
 InlineTree* ilt = NULL;
 if (C->ilt() != NULL) {

Mercurial > hg > graal-jvmci-8

comparison src/share/vm/opto/parse1.cpp @ 2383:9dc311b8473e