src/share/vm/opto/postaloc.cpp

rev 2647 : 7087453: PhaseChaitin::yank_if_dead() should handle MachTemp inputs
Summary: PhaseChaitin::yank_if_dead() should be able to handle MachTemp inputs as a special case and yank them.
Reviewed-by:

*** 70,99 ****
    // we must have discovered that it was not a callee save
    // else we would have returned.
    return i == limit;
  }
  
! 
! 
! //------------------------------yank_if_dead-----------------------------------
! // Removed an edge from 'old'.  Yank if dead.  Return adjustment counts to
! // iterators in the current block.
! int PhaseChaitin::yank_if_dead( Node *old, Block *current_block, Node_List *value, Node_List *regnd ) {
    int blk_adjust=0;
-   while (old->outcnt() == 0 && old != C->top()) {
      Block *oldb = _cfg._bbs[old->_idx];
      oldb->find_remove(old);
      // Count 1 if deleting an instruction from the current block
      if( oldb == current_block ) blk_adjust++;
      _cfg._bbs.map(old->_idx,NULL);
      OptoReg::Name old_reg = lrgs(n2lidx(old)).reg();
      if( regnd && (*regnd)[old_reg]==old ) { // Instruction is currently available?
        value->map(old_reg,NULL);  // Yank from value/regnd maps
        regnd->map(old_reg,NULL);  // This register's value is now unknown
      }
!     assert(old->req() <= 2, "can't handle more inputs");
!     Node *tmp = old->req() > 1 ? old->in(1) : NULL;
      old->disconnect_inputs(NULL);
      if( !tmp ) break;
      old = tmp;
    }
    return blk_adjust;
--- 70,116 ----
    // we must have discovered that it was not a callee save
    // else we would have returned.
    return i == limit;
  }
  
! //------------------------------yank-----------------------------------
! // Helper function for yank_if_dead
! int PhaseChaitin::yank( Node *old, Block *current_block, Node_List *value, Node_List *regnd ) {
    int blk_adjust=0;
    Block *oldb = _cfg._bbs[old->_idx];
    oldb->find_remove(old);
    // Count 1 if deleting an instruction from the current block
    if( oldb == current_block ) blk_adjust++;
    _cfg._bbs.map(old->_idx,NULL);
    OptoReg::Name old_reg = lrgs(n2lidx(old)).reg();
    if( regnd && (*regnd)[old_reg]==old ) { // Instruction is currently available?
      value->map(old_reg,NULL);  // Yank from value/regnd maps
      regnd->map(old_reg,NULL);  // This register's value is now unknown
    }
!   return blk_adjust;
! }
! 
! //------------------------------yank_if_dead-----------------------------------
! // Removed an edge from 'old'.  Yank if dead.  Return adjustment counts to
! // iterators in the current block.
! int PhaseChaitin::yank_if_dead( Node *old, Block *current_block, Node_List *value, Node_List *regnd ) {
!   int blk_adjust=0;
!   while (old->outcnt() == 0 && old != C->top()) {
!     blk_adjust += yank(old, current_block, value, regnd);
! 
!     Node *tmp = NULL;
!     for (uint i = 1; i < old->req(); i++) {
!       if (old->in(i)->is_MachTemp()) {
!         Node* machtmp = old->in(i);
!         assert(machtmp->outcnt() == 1, "expected for a MachTemp");
!         blk_adjust += yank(machtmp, current_block, value, regnd);
!         machtmp->disconnect_inputs(NULL);
!       } else {
!         assert(tmp == NULL, "can't handle more non MachTemp inputs");
!         tmp = old->in(i);
!       }
!     }
      old->disconnect_inputs(NULL);
      if( !tmp ) break;
      old = tmp;
    }
    return blk_adjust;