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comparison src/share/vm/opto/reg_split.cpp @ 330:1c6e3bfb543a

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6746892: Register Allocator does not process a data phi with one unique input correctly Summary: Always look for the existing phi for a processed live_range. Reviewed-by: rasbold
author kvn
date Wed, 10 Sep 2008 14:29:32 -0700
parents ea18057223c4
children 9ee9cf798b59
comparison
equal deleted inserted replaced
322:f9847b70eccd 330:1c6e3bfb543a
525 } 525 }
526 526
527 // Initialize needs_phi and needs_split 527 // Initialize needs_phi and needs_split
528 bool needs_phi = false; 528 bool needs_phi = false;
529 bool needs_split = false; 529 bool needs_split = false;
530 bool has_phi = false;
530 // Walk the predecessor blocks to check inputs for that live range 531 // Walk the predecessor blocks to check inputs for that live range
531 // Grab predecessor block header 532 // Grab predecessor block header
532 n1 = b->pred(1); 533 n1 = b->pred(1);
533 // Grab the appropriate reaching def info for inpidx 534 // Grab the appropriate reaching def info for inpidx
534 pred = _cfg._bbs[n1->_idx]; 535 pred = _cfg._bbs[n1->_idx];
568 n3 = n2; 569 n3 = n2;
569 u3 = u2; 570 u3 = u2;
570 } 571 }
571 } // End for all potential Phi inputs 572 } // End for all potential Phi inputs
572 573
573 // If a phi is needed, check for it 574 // check block for appropriate phinode & update edges
574 if( needs_phi ) { 575 for( insidx = 1; insidx <= b->end_idx(); insidx++ ) {
575 // check block for appropriate phinode & update edges 576 n1 = b->_nodes[insidx];
576 for( insidx = 1; insidx <= b->end_idx(); insidx++ ) { 577 // bail if this is not a phi
577 n1 = b->_nodes[insidx]; 578 phi = n1->is_Phi() ? n1->as_Phi() : NULL;
578 // bail if this is not a phi 579 if( phi == NULL ) {
579 phi = n1->is_Phi() ? n1->as_Phi() : NULL; 580 // Keep track of index of first non-PhiNode instruction in block
580 if( phi == NULL ) { 581 non_phi = insidx;
581 // Keep track of index of first non-PhiNode instruction in block 582 // break out of the for loop as we have handled all phi nodes
582 non_phi = insidx; 583 break;
583 // break out of the for loop as we have handled all phi nodes 584 }
584 break; 585 // must be looking at a phi
585 } 586 if( Find_id(n1) == lidxs.at(slidx) ) {
586 // must be looking at a phi 587 // found the necessary phi
587 if( Find_id(n1) == lidxs.at(slidx) ) { 588 needs_phi = false;
588 // found the necessary phi 589 has_phi = true;
589 needs_phi = false; 590 // initialize the Reaches entry for this LRG
590 // initialize the Reaches entry for this LRG 591 Reachblock[slidx] = phi;
591 Reachblock[slidx] = phi; 592 break;
592 break; 593 } // end if found correct phi
593 } // end if found correct phi 594 } // end for all phi's
594 } // end for all phi's 595
596 // If a phi is needed or exist, check for it
597 if( needs_phi || has_phi ) {
595 // add new phinode if one not already found 598 // add new phinode if one not already found
596 if( needs_phi ) { 599 if( needs_phi ) {
597 // create a new phi node and insert it into the block 600 // create a new phi node and insert it into the block
598 // type is taken from left over pointer to a predecessor 601 // type is taken from left over pointer to a predecessor
599 assert(n3,"No non-NULL reaching DEF for a Phi"); 602 assert(n3,"No non-NULL reaching DEF for a Phi");
693 break; 696 break;
694 u = n->in(i); // Else record it 697 u = n->in(i); // Else record it
695 } 698 }
696 } 699 }
697 assert( u, "at least 1 valid input expected" ); 700 assert( u, "at least 1 valid input expected" );
698 if( i >= cnt ) { // Didn't find 2+ unique inputs? 701 if( i >= cnt ) { // Found one unique input
702 assert(Find_id(n) == Find_id(u), "should be the same lrg");
699 n->replace_by(u); // Then replace with unique input 703 n->replace_by(u); // Then replace with unique input
700 n->disconnect_inputs(NULL); 704 n->disconnect_inputs(NULL);
701 b->_nodes.remove(insidx); 705 b->_nodes.remove(insidx);
702 insidx--; 706 insidx--;
703 b->_ihrp_index--; 707 b->_ihrp_index--;