7179138: Incorrect result with String concatenation optimization
Summary: check for and skip diamond shaped NULL check code for the result of toString()
Reviewed-by: twisti, roland
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
#ifndef SHARE_VM_OPTO_ROOTNODE_HPP
#define SHARE_VM_OPTO_ROOTNODE_HPP
#include "opto/loopnode.hpp"
//------------------------------RootNode---------------------------------------
// The one-and-only before-all-else and after-all-else RootNode. The RootNode
// represents what happens if the user runs the whole program repeatedly. The
// RootNode produces the initial values of I/O and memory for the program or
// procedure start.
class RootNode : public LoopNode {
public:
RootNode( ) : LoopNode(0,0) {
init_class_id(Class_Root);
del_req(2);
del_req(1);
}
virtual int Opcode() const;
virtual const Node *is_block_proj() const { return this; }
virtual const Type *bottom_type() const { return Type::BOTTOM; }
virtual Node *Identity( PhaseTransform *phase ) { return this; }
virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
virtual const Type *Value( PhaseTransform *phase ) const { return Type::BOTTOM; }
};
//------------------------------HaltNode---------------------------------------
// Throw an exception & die
class HaltNode : public Node {
public:
HaltNode( Node *ctrl, Node *frameptr );
virtual int Opcode() const;
virtual bool pinned() const { return true; };
virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
virtual const Type *Value( PhaseTransform *phase ) const;
virtual const Type *bottom_type() const;
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 Node *is_block_proj() const { return this; }
virtual const RegMask &out_RegMask() const;
virtual uint ideal_reg() const { return NotAMachineReg; }
virtual uint match_edge(uint idx) const { return 0; }
};
#endif // SHARE_VM_OPTO_ROOTNODE_HPP