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comparison src/share/vm/c1/c1_IR.cpp @ 428:334969144810

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6758445: loop heads that are exception entry points can crash during count_edges/mark_loops Reviewed-by: kvn, jrose
author never
date Tue, 11 Nov 2008 23:03:35 -0800
parents a61af66fc99e
children ad8c8ca4ab0f
comparison
equal deleted inserted replaced
421:577f3a2e0662 428:334969144810
572 572
573 if (is_active(cur)) { 573 if (is_active(cur)) {
574 TRACE_LINEAR_SCAN(3, tty->print_cr("backward branch")); 574 TRACE_LINEAR_SCAN(3, tty->print_cr("backward branch"));
575 assert(is_visited(cur), "block must be visisted when block is active"); 575 assert(is_visited(cur), "block must be visisted when block is active");
576 assert(parent != NULL, "must have parent"); 576 assert(parent != NULL, "must have parent");
577 assert(parent->number_of_sux() == 1, "loop end blocks must have one successor (critical edges are split)");
578 577
579 cur->set(BlockBegin::linear_scan_loop_header_flag); 578 cur->set(BlockBegin::linear_scan_loop_header_flag);
580 cur->set(BlockBegin::backward_branch_target_flag); 579 cur->set(BlockBegin::backward_branch_target_flag);
581 580
582 parent->set(BlockBegin::linear_scan_loop_end_flag); 581 parent->set(BlockBegin::linear_scan_loop_end_flag);
582
583 // When a loop header is also the start of an exception handler, then the backward branch is
584 // an exception edge. Because such edges are usually critical edges which cannot be split, the
585 // loop must be excluded here from processing.
586 if (cur->is_set(BlockBegin::exception_entry_flag)) {
587 // Make sure that dominators are correct in this weird situation
588 _iterative_dominators = true;
589 return;
590 }
591 assert(parent->number_of_sux() == 1 && parent->sux_at(0) == cur,
592 "loop end blocks must have one successor (critical edges are split)");
593
583 _loop_end_blocks.append(parent); 594 _loop_end_blocks.append(parent);
584 return; 595 return;
585 } 596 }
586 597
587 // increment number of incoming forward branches 598 // increment number of incoming forward branches