6625997: CastPP, CheckCastPP and Proj nodes are not dead loop safe
Summary: EA and initialization optimizations could bypass these nodes.
Reviewed-by: rasbold, never
/*
* Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
class Matcher;
class ProjNode;
//------------------------------MultiNode--------------------------------------
// This class defines a MultiNode, a Node which produces many values. The
// values are wrapped up in a tuple Type, i.e. a TypeTuple.
class MultiNode : public Node {
public:
MultiNode( uint required ) : Node(required) {
init_class_id(Class_Multi);
}
virtual int Opcode() const;
virtual const Type *bottom_type() const = 0;
virtual bool is_CFG() const { return true; }
virtual uint hash() const { return NO_HASH; } // CFG nodes do not hash
virtual bool depends_only_on_test() const { return false; }
virtual const RegMask &out_RegMask() const;
virtual Node *match( const ProjNode *proj, const Matcher *m );
virtual uint ideal_reg() const { return NotAMachineReg; }
ProjNode* proj_out(uint which_proj) const; // Get a named projection
};
//------------------------------ProjNode---------------------------------------
// This class defines a Projection node. Projections project a single element
// out of a tuple (or Signature) type. Only MultiNodes produce TypeTuple
// results.
class ProjNode : public Node {
protected:
virtual uint hash() const;
virtual uint cmp( const Node &n ) const;
virtual uint size_of() const;
void check_con() const; // Called from constructor.
public:
ProjNode( Node *src, uint con, bool io_use = false )
: Node( src ), _con(con), _is_io_use(io_use)
{
init_class_id(Class_Proj);
// Optimistic setting. Need additional checks in Node::is_dead_loop_safe().
if (con != TypeFunc::Memory || src->is_Start())
init_flags(Flag_is_dead_loop_safe);
debug_only(check_con());
}
const uint _con; // The field in the tuple we are projecting
const bool _is_io_use; // Used to distinguish between the projections
// used on the control and io paths from a macro node
virtual int Opcode() const;
virtual bool is_CFG() const;
virtual bool depends_only_on_test() const { return false; }
virtual const Type *bottom_type() const;
virtual const TypePtr *adr_type() const;
virtual bool pinned() const;
virtual const Type *Value( PhaseTransform *phase ) const;
virtual uint ideal_reg() const;
virtual const RegMask &out_RegMask() const;
#ifndef PRODUCT
virtual void dump_spec(outputStream *st) const;
#endif
};