regalloc.cpp revision 5776:de6a9e811145 
1/*
2 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25#include "precompiled.hpp"
26#include "opto/regalloc.hpp"
27
28static const int NodeRegsOverflowSize = 200;
29
30void (*PhaseRegAlloc::_alloc_statistics[MAX_REG_ALLOCATORS])();
31int PhaseRegAlloc::_num_allocators = 0;
32#ifndef PRODUCT
33int PhaseRegAlloc::_total_framesize = 0;
34int PhaseRegAlloc::_max_framesize = 0;
35#endif
36
37PhaseRegAlloc::PhaseRegAlloc( uint unique, PhaseCFG &cfg,
38                              Matcher &matcher,
39                              void (*pr_stats)() ):
40               Phase(Register_Allocation), _cfg(cfg), _matcher(matcher),
41               _node_oops(Thread::current()->resource_area()),
42               _node_regs(0),
43               _node_regs_max_index(0),
44               _framesize(0xdeadbeef)
45{
46    int i;
47
48    for (i=0; i < _num_allocators; i++) {
49        if (_alloc_statistics[i] == pr_stats)
50            return;
51    }
52    assert((_num_allocators + 1) < MAX_REG_ALLOCATORS, "too many register allocators");
53    _alloc_statistics[_num_allocators++] = pr_stats;
54}
55
56
57//------------------------------reg2offset-------------------------------------
58int PhaseRegAlloc::reg2offset_unchecked( OptoReg::Name reg ) const {
59  // Slots below _max_in_arg_stack_reg are offset by the entire frame.
60  // Slots above _max_in_arg_stack_reg are frame_slots and are not offset.
61  int slot = (reg < _matcher._new_SP)
62    ? reg - OptoReg::stack0() + _framesize
63    : reg - _matcher._new_SP;
64  // Note:  We use the direct formula (reg - SharedInfo::stack0) instead of
65  // OptoReg::reg2stack(reg), in order to avoid asserts in the latter
66  // function.  This routine must remain unchecked, so that dump_frame()
67  // can do its work undisturbed.
68  // %%% not really clear why reg2stack would assert here
69
70  return slot*VMRegImpl::stack_slot_size;
71}
72
73int PhaseRegAlloc::reg2offset( OptoReg::Name reg ) const {
74
75  // Not allowed in the out-preserve area.
76  // In-preserve area is allowed so Intel can fetch the return pc out.
77  assert( reg <  _matcher._old_SP ||
78          (reg >= OptoReg::add(_matcher._old_SP,C->out_preserve_stack_slots()) &&
79           reg <  _matcher._in_arg_limit) ||
80          reg >=  OptoReg::add(_matcher._new_SP,C->out_preserve_stack_slots()),
81          "register allocated in a preserve area" );
82  return reg2offset_unchecked( reg );
83}
84
85//------------------------------offset2reg-------------------------------------
86OptoReg::Name PhaseRegAlloc::offset2reg(int stk_offset) const {
87  int slot = stk_offset / jintSize;
88  int reg = (slot < (int) _framesize)
89    ? slot + _matcher._new_SP
90    : OptoReg::stack2reg(slot) - _framesize;
91  assert(stk_offset == reg2offset((OptoReg::Name) reg),
92         "offset2reg does not invert properly");
93  return (OptoReg::Name) reg;
94}
95
96//------------------------------set_oop----------------------------------------
97void PhaseRegAlloc::set_oop( const Node *n, bool is_an_oop ) {
98  if( is_an_oop ) {
99    _node_oops.set(n->_idx);
100  }
101}
102
103//------------------------------is_oop-----------------------------------------
104bool PhaseRegAlloc::is_oop( const Node *n ) const {
105  return _node_oops.test(n->_idx) != 0;
106}
107
108// Allocate _node_regs table with at least "size" elements
109void PhaseRegAlloc::alloc_node_regs(int size) {
110  _node_regs_max_index = size + (size >> 1) + NodeRegsOverflowSize;
111  _node_regs = NEW_RESOURCE_ARRAY( OptoRegPair, _node_regs_max_index );
112  // We assume our caller will fill in all elements up to size-1, so
113  // only the extra space we allocate is initialized here.
114  for( uint i = size; i < _node_regs_max_index; ++i )
115    _node_regs[i].set_bad();
116}
117
118#ifndef PRODUCT
119void
120PhaseRegAlloc::print_statistics() {
121  tty->print_cr("Total frameslots = %d, Max frameslots = %d", _total_framesize, _max_framesize);
122  int i;
123
124  for (i=0; i < _num_allocators; i++) {
125    _alloc_statistics[i]();
126  }
127}
128#endif
129