Mercurial > hg > truffle
view src/share/vm/opto/regalloc.hpp @ 452:00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
Summary: When we encounter marking stack overflow during precleaning of Reference lists, we were using the overflow list mechanism, which can cause problems on account of mutating the mark word of the header because of conflicts with mutator accesses and updates of that field. Instead we should use the usual mechanism for overflow handling in concurrent phases, namely dirtying of the card on which the overflowed object lies. Since precleaning effectively does a form of discovered list processing, albeit with discovery enabled, we needed to adjust some code to be correct in the face of interleaved processing and discovery.
Reviewed-by: apetrusenko, jcoomes
author | ysr |
---|---|
date | Thu, 20 Nov 2008 12:27:41 -0800 |
parents | a61af66fc99e |
children | c18cbe5936b8 |
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/* * Copyright 2000-2006 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 Node; class Matcher; class PhaseCFG; #define MAX_REG_ALLOCATORS 10 //------------------------------PhaseRegAlloc------------------------------------ // Abstract register allocator class PhaseRegAlloc : public Phase { static void (*_alloc_statistics[MAX_REG_ALLOCATORS])(); static int _num_allocators; protected: OptoRegPair *_node_regs; uint _node_regs_max_index; VectorSet _node_oops; // Mapping from node indices to oopiness void alloc_node_regs(int size); // allocate _node_regs table with at least "size" elements PhaseRegAlloc( uint unique, PhaseCFG &cfg, Matcher &matcher, void (*pr_stats)()); public: PhaseCFG &_cfg; // Control flow graph uint _framesize; // Size of frame in stack-slots. not counting preserve area OptoReg::Name _max_reg; // Past largest register seen Matcher &_matcher; // Convert Ideal to MachNodes uint node_regs_max_index() const { return _node_regs_max_index; } // Get the register associated with the Node OptoReg::Name get_reg_first( const Node *n ) const { debug_only( if( n->_idx >= _node_regs_max_index ) n->dump(); ); assert( n->_idx < _node_regs_max_index, "Exceeded _node_regs array"); return _node_regs[n->_idx].first(); } OptoReg::Name get_reg_second( const Node *n ) const { debug_only( if( n->_idx >= _node_regs_max_index ) n->dump(); ); assert( n->_idx < _node_regs_max_index, "Exceeded _node_regs array"); return _node_regs[n->_idx].second(); } // Do all the real work of allocate virtual void Register_Allocate() = 0; // notify the register allocator that "node" is a new reference // to the value produced by "old_node" virtual void add_reference( const Node *node, const Node *old_node) = 0; // Set the register associated with a new Node void set_bad( uint idx ) { assert( idx < _node_regs_max_index, "Exceeded _node_regs array"); _node_regs[idx].set_bad(); } void set1( uint idx, OptoReg::Name reg ) { assert( idx < _node_regs_max_index, "Exceeded _node_regs array"); _node_regs[idx].set1(reg); } void set2( uint idx, OptoReg::Name reg ) { assert( idx < _node_regs_max_index, "Exceeded _node_regs array"); _node_regs[idx].set2(reg); } void set_pair( uint idx, OptoReg::Name hi, OptoReg::Name lo ) { assert( idx < _node_regs_max_index, "Exceeded _node_regs array"); _node_regs[idx].set_pair(hi, lo); } void set_ptr( uint idx, OptoReg::Name reg ) { assert( idx < _node_regs_max_index, "Exceeded _node_regs array"); _node_regs[idx].set_ptr(reg); } // Set and query if a node produces an oop void set_oop( const Node *n, bool ); bool is_oop( const Node *n ) const; // Convert a register number to a stack offset int reg2offset ( OptoReg::Name reg ) const; int reg2offset_unchecked( OptoReg::Name reg ) const; // Convert a stack offset to a register number OptoReg::Name offset2reg( int stk_offset ) const; // Get the register encoding associated with the Node int get_encode( const Node *n ) const { assert( n->_idx < _node_regs_max_index, "Exceeded _node_regs array"); OptoReg::Name first = _node_regs[n->_idx].first(); OptoReg::Name second = _node_regs[n->_idx].second(); assert( !OptoReg::is_valid(second) || second == first+1, "" ); assert(OptoReg::is_reg(first), "out of range"); return Matcher::_regEncode[first]; } // Platform dependent hook for actions prior to allocation void pd_preallocate_hook(); #ifdef ASSERT // Platform dependent hook for verification after allocation. Will // only get called when compiling with asserts. void pd_postallocate_verify_hook(); #endif #ifndef PRODUCT static int _total_framesize; static int _max_framesize; virtual void dump_frame() const = 0; virtual char *dump_register( const Node *n, char *buf ) const = 0; static void print_statistics(); #endif };