0
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1 /*
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2 * Copyright 1998-2006 Sun Microsystems, Inc. All Rights Reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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20 * CA 95054 USA or visit www.sun.com if you need additional information or
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21 * have any questions.
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22 *
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23 */
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24
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25 #include "incls/_precompiled.incl"
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26 #include "incls/_ifg.cpp.incl"
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27
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28 #define EXACT_PRESSURE 1
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29
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30 //=============================================================================
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31 //------------------------------IFG--------------------------------------------
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32 PhaseIFG::PhaseIFG( Arena *arena ) : Phase(Interference_Graph), _arena(arena) {
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33 }
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34
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35 //------------------------------init-------------------------------------------
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36 void PhaseIFG::init( uint maxlrg ) {
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37 _maxlrg = maxlrg;
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38 _yanked = new (_arena) VectorSet(_arena);
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39 _is_square = false;
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40 // Make uninitialized adjacency lists
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41 _adjs = (IndexSet*)_arena->Amalloc(sizeof(IndexSet)*maxlrg);
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42 // Also make empty live range structures
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43 _lrgs = (LRG *)_arena->Amalloc( maxlrg * sizeof(LRG) );
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44 memset(_lrgs,0,sizeof(LRG)*maxlrg);
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45 // Init all to empty
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46 for( uint i = 0; i < maxlrg; i++ ) {
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47 _adjs[i].initialize(maxlrg);
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48 _lrgs[i].Set_All();
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49 }
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50 }
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51
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52 //------------------------------add--------------------------------------------
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53 // Add edge between vertices a & b. These are sorted (triangular matrix),
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54 // then the smaller number is inserted in the larger numbered array.
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55 int PhaseIFG::add_edge( uint a, uint b ) {
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56 lrgs(a).invalid_degree();
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57 lrgs(b).invalid_degree();
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58 // Sort a and b, so that a is bigger
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59 assert( !_is_square, "only on triangular" );
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60 if( a < b ) { uint tmp = a; a = b; b = tmp; }
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61 return _adjs[a].insert( b );
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62 }
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63
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64 //------------------------------add_vector-------------------------------------
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65 // Add an edge between 'a' and everything in the vector.
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66 void PhaseIFG::add_vector( uint a, IndexSet *vec ) {
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67 // IFG is triangular, so do the inserts where 'a' < 'b'.
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68 assert( !_is_square, "only on triangular" );
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69 IndexSet *adjs_a = &_adjs[a];
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70 if( !vec->count() ) return;
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71
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72 IndexSetIterator elements(vec);
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73 uint neighbor;
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74 while ((neighbor = elements.next()) != 0) {
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75 add_edge( a, neighbor );
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76 }
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77 }
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78
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79 //------------------------------test-------------------------------------------
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80 // Is there an edge between a and b?
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81 int PhaseIFG::test_edge( uint a, uint b ) const {
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82 // Sort a and b, so that a is larger
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83 assert( !_is_square, "only on triangular" );
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84 if( a < b ) { uint tmp = a; a = b; b = tmp; }
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85 return _adjs[a].member(b);
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86 }
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87
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88 //------------------------------SquareUp---------------------------------------
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89 // Convert triangular matrix to square matrix
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90 void PhaseIFG::SquareUp() {
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91 assert( !_is_square, "only on triangular" );
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92
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93 // Simple transpose
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94 for( uint i = 0; i < _maxlrg; i++ ) {
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95 IndexSetIterator elements(&_adjs[i]);
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96 uint datum;
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97 while ((datum = elements.next()) != 0) {
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98 _adjs[datum].insert( i );
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99 }
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100 }
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101 _is_square = true;
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102 }
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103
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104 //------------------------------Compute_Effective_Degree-----------------------
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105 // Compute effective degree in bulk
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106 void PhaseIFG::Compute_Effective_Degree() {
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107 assert( _is_square, "only on square" );
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108
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109 for( uint i = 0; i < _maxlrg; i++ )
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110 lrgs(i).set_degree(effective_degree(i));
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111 }
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112
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113 //------------------------------test_edge_sq-----------------------------------
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114 int PhaseIFG::test_edge_sq( uint a, uint b ) const {
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115 assert( _is_square, "only on square" );
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116 // Swap, so that 'a' has the lesser count. Then binary search is on
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117 // the smaller of a's list and b's list.
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118 if( neighbor_cnt(a) > neighbor_cnt(b) ) { uint tmp = a; a = b; b = tmp; }
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119 //return _adjs[a].unordered_member(b);
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120 return _adjs[a].member(b);
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121 }
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122
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123 //------------------------------Union------------------------------------------
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124 // Union edges of B into A
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125 void PhaseIFG::Union( uint a, uint b ) {
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126 assert( _is_square, "only on square" );
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127 IndexSet *A = &_adjs[a];
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128 IndexSetIterator b_elements(&_adjs[b]);
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129 uint datum;
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130 while ((datum = b_elements.next()) != 0) {
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131 if(A->insert(datum)) {
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132 _adjs[datum].insert(a);
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133 lrgs(a).invalid_degree();
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134 lrgs(datum).invalid_degree();
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135 }
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136 }
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137 }
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138
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139 //------------------------------remove_node------------------------------------
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140 // Yank a Node and all connected edges from the IFG. Return a
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141 // list of neighbors (edges) yanked.
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142 IndexSet *PhaseIFG::remove_node( uint a ) {
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143 assert( _is_square, "only on square" );
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144 assert( !_yanked->test(a), "" );
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145 _yanked->set(a);
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146
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147 // I remove the LRG from all neighbors.
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148 IndexSetIterator elements(&_adjs[a]);
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149 LRG &lrg_a = lrgs(a);
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150 uint datum;
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151 while ((datum = elements.next()) != 0) {
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152 _adjs[datum].remove(a);
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153 lrgs(datum).inc_degree( -lrg_a.compute_degree(lrgs(datum)) );
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154 }
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155 return neighbors(a);
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156 }
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157
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158 //------------------------------re_insert--------------------------------------
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159 // Re-insert a yanked Node.
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160 void PhaseIFG::re_insert( uint a ) {
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161 assert( _is_square, "only on square" );
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162 assert( _yanked->test(a), "" );
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163 (*_yanked) >>= a;
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164
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165 IndexSetIterator elements(&_adjs[a]);
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166 uint datum;
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167 while ((datum = elements.next()) != 0) {
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168 _adjs[datum].insert(a);
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169 lrgs(datum).invalid_degree();
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170 }
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171 }
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172
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173 //------------------------------compute_degree---------------------------------
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174 // Compute the degree between 2 live ranges. If both live ranges are
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175 // aligned-adjacent powers-of-2 then we use the MAX size. If either is
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176 // mis-aligned (or for Fat-Projections, not-adjacent) then we have to
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177 // MULTIPLY the sizes. Inspect Brigg's thesis on register pairs to see why
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178 // this is so.
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179 int LRG::compute_degree( LRG &l ) const {
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180 int tmp;
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181 int num_regs = _num_regs;
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182 int nregs = l.num_regs();
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183 tmp = (_fat_proj || l._fat_proj) // either is a fat-proj?
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184 ? (num_regs * nregs) // then use product
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185 : MAX2(num_regs,nregs); // else use max
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186 return tmp;
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187 }
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188
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189 //------------------------------effective_degree-------------------------------
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190 // Compute effective degree for this live range. If both live ranges are
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191 // aligned-adjacent powers-of-2 then we use the MAX size. If either is
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192 // mis-aligned (or for Fat-Projections, not-adjacent) then we have to
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193 // MULTIPLY the sizes. Inspect Brigg's thesis on register pairs to see why
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194 // this is so.
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195 int PhaseIFG::effective_degree( uint lidx ) const {
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196 int eff = 0;
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197 int num_regs = lrgs(lidx).num_regs();
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198 int fat_proj = lrgs(lidx)._fat_proj;
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199 IndexSet *s = neighbors(lidx);
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200 IndexSetIterator elements(s);
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201 uint nidx;
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202 while((nidx = elements.next()) != 0) {
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203 LRG &lrgn = lrgs(nidx);
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204 int nregs = lrgn.num_regs();
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205 eff += (fat_proj || lrgn._fat_proj) // either is a fat-proj?
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206 ? (num_regs * nregs) // then use product
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207 : MAX2(num_regs,nregs); // else use max
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208 }
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209 return eff;
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210 }
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211
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212
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213 #ifndef PRODUCT
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214 //------------------------------dump-------------------------------------------
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215 void PhaseIFG::dump() const {
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216 tty->print_cr("-- Interference Graph --%s--",
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217 _is_square ? "square" : "triangular" );
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218 if( _is_square ) {
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219 for( uint i = 0; i < _maxlrg; i++ ) {
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220 tty->print( (*_yanked)[i] ? "XX " : " ");
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221 tty->print("L%d: { ",i);
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222 IndexSetIterator elements(&_adjs[i]);
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223 uint datum;
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224 while ((datum = elements.next()) != 0) {
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225 tty->print("L%d ", datum);
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226 }
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227 tty->print_cr("}");
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228
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229 }
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230 return;
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231 }
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232
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233 // Triangular
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234 for( uint i = 0; i < _maxlrg; i++ ) {
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235 uint j;
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236 tty->print( (*_yanked)[i] ? "XX " : " ");
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237 tty->print("L%d: { ",i);
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238 for( j = _maxlrg; j > i; j-- )
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239 if( test_edge(j - 1,i) ) {
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240 tty->print("L%d ",j - 1);
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241 }
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242 tty->print("| ");
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243 IndexSetIterator elements(&_adjs[i]);
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244 uint datum;
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245 while ((datum = elements.next()) != 0) {
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246 tty->print("L%d ", datum);
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247 }
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248 tty->print("}\n");
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249 }
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250 tty->print("\n");
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251 }
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252
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253 //------------------------------stats------------------------------------------
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254 void PhaseIFG::stats() const {
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255 ResourceMark rm;
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256 int *h_cnt = NEW_RESOURCE_ARRAY(int,_maxlrg*2);
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257 memset( h_cnt, 0, sizeof(int)*_maxlrg*2 );
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258 uint i;
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259 for( i = 0; i < _maxlrg; i++ ) {
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260 h_cnt[neighbor_cnt(i)]++;
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261 }
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262 tty->print_cr("--Histogram of counts--");
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263 for( i = 0; i < _maxlrg*2; i++ )
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264 if( h_cnt[i] )
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265 tty->print("%d/%d ",i,h_cnt[i]);
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266 tty->print_cr("");
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267 }
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268
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269 //------------------------------verify-----------------------------------------
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270 void PhaseIFG::verify( const PhaseChaitin *pc ) const {
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271 // IFG is square, sorted and no need for Find
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272 for( uint i = 0; i < _maxlrg; i++ ) {
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273 assert(!((*_yanked)[i]) || !neighbor_cnt(i), "Is removed completely" );
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274 IndexSet *set = &_adjs[i];
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275 IndexSetIterator elements(set);
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276 uint idx;
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277 uint last = 0;
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278 while ((idx = elements.next()) != 0) {
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279 assert( idx != i, "Must have empty diagonal");
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280 assert( pc->Find_const(idx) == idx, "Must not need Find" );
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281 assert( _adjs[idx].member(i), "IFG not square" );
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282 assert( !(*_yanked)[idx], "No yanked neighbors" );
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283 assert( last < idx, "not sorted increasing");
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284 last = idx;
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285 }
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286 assert( !lrgs(i)._degree_valid ||
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287 effective_degree(i) == lrgs(i).degree(), "degree is valid but wrong" );
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288 }
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289 }
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290 #endif
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291
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292 //------------------------------interfere_with_live----------------------------
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293 // Interfere this register with everything currently live. Use the RegMasks
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294 // to trim the set of possible interferences. Return a count of register-only
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295 // inteferences as an estimate of register pressure.
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296 void PhaseChaitin::interfere_with_live( uint r, IndexSet *liveout ) {
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297 uint retval = 0;
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298 // Interfere with everything live.
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299 const RegMask &rm = lrgs(r).mask();
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300 // Check for interference by checking overlap of regmasks.
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301 // Only interfere if acceptable register masks overlap.
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302 IndexSetIterator elements(liveout);
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303 uint l;
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304 while( (l = elements.next()) != 0 )
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305 if( rm.overlap( lrgs(l).mask() ) )
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306 _ifg->add_edge( r, l );
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307 }
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308
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309 //------------------------------build_ifg_virtual------------------------------
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310 // Actually build the interference graph. Uses virtual registers only, no
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311 // physical register masks. This allows me to be very aggressive when
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312 // coalescing copies. Some of this aggressiveness will have to be undone
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313 // later, but I'd rather get all the copies I can now (since unremoved copies
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314 // at this point can end up in bad places). Copies I re-insert later I have
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315 // more opportunity to insert them in low-frequency locations.
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316 void PhaseChaitin::build_ifg_virtual( ) {
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317
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318 // For all blocks (in any order) do...
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319 for( uint i=0; i<_cfg._num_blocks; i++ ) {
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320 Block *b = _cfg._blocks[i];
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321 IndexSet *liveout = _live->live(b);
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322
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323 // The IFG is built by a single reverse pass over each basic block.
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324 // Starting with the known live-out set, we remove things that get
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325 // defined and add things that become live (essentially executing one
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326 // pass of a standard LIVE analysis). Just before a Node defines a value
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327 // (and removes it from the live-ness set) that value is certainly live.
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328 // The defined value interferes with everything currently live. The
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329 // value is then removed from the live-ness set and it's inputs are
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330 // added to the live-ness set.
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331 for( uint j = b->end_idx() + 1; j > 1; j-- ) {
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332 Node *n = b->_nodes[j-1];
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333
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334 // Get value being defined
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335 uint r = n2lidx(n);
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336
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337 // Some special values do not allocate
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338 if( r ) {
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339
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340 // Remove from live-out set
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341 liveout->remove(r);
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342
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343 // Copies do not define a new value and so do not interfere.
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344 // Remove the copies source from the liveout set before interfering.
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345 uint idx = n->is_Copy();
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346 if( idx ) liveout->remove( n2lidx(n->in(idx)) );
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347
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348 // Interfere with everything live
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349 interfere_with_live( r, liveout );
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350 }
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351
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352 // Make all inputs live
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353 if( !n->is_Phi() ) { // Phi function uses come from prior block
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354 for( uint k = 1; k < n->req(); k++ )
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355 liveout->insert( n2lidx(n->in(k)) );
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356 }
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357
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358 // 2-address instructions always have the defined value live
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359 // on entry to the instruction, even though it is being defined
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360 // by the instruction. We pretend a virtual copy sits just prior
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361 // to the instruction and kills the src-def'd register.
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362 // In other words, for 2-address instructions the defined value
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363 // interferes with all inputs.
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364 uint idx;
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365 if( n->is_Mach() && (idx = n->as_Mach()->two_adr()) ) {
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366 const MachNode *mach = n->as_Mach();
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367 // Sometimes my 2-address ADDs are commuted in a bad way.
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368 // We generally want the USE-DEF register to refer to the
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369 // loop-varying quantity, to avoid a copy.
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370 uint op = mach->ideal_Opcode();
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371 // Check that mach->num_opnds() == 3 to ensure instruction is
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372 // not subsuming constants, effectively excludes addI_cin_imm
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373 // Can NOT swap for instructions like addI_cin_imm since it
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374 // is adding zero to yhi + carry and the second ideal-input
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375 // points to the result of adding low-halves.
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376 // Checking req() and num_opnds() does NOT distinguish addI_cout from addI_cout_imm
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377 if( (op == Op_AddI && mach->req() == 3 && mach->num_opnds() == 3) &&
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378 n->in(1)->bottom_type()->base() == Type::Int &&
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379 // See if the ADD is involved in a tight data loop the wrong way
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380 n->in(2)->is_Phi() &&
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381 n->in(2)->in(2) == n ) {
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382 Node *tmp = n->in(1);
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383 n->set_req( 1, n->in(2) );
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384 n->set_req( 2, tmp );
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385 }
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386 // Defined value interferes with all inputs
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387 uint lidx = n2lidx(n->in(idx));
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388 for( uint k = 1; k < n->req(); k++ ) {
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389 uint kidx = n2lidx(n->in(k));
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390 if( kidx != lidx )
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391 _ifg->add_edge( r, kidx );
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392 }
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393 }
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394 } // End of forall instructions in block
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395 } // End of forall blocks
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396 }
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397
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398 //------------------------------count_int_pressure-----------------------------
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399 uint PhaseChaitin::count_int_pressure( IndexSet *liveout ) {
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400 IndexSetIterator elements(liveout);
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401 uint lidx;
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402 uint cnt = 0;
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403 while ((lidx = elements.next()) != 0) {
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404 if( lrgs(lidx).mask().is_UP() &&
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405 lrgs(lidx).mask_size() &&
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406 !lrgs(lidx)._is_float &&
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407 lrgs(lidx).mask().overlap(*Matcher::idealreg2regmask[Op_RegI]) )
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408 cnt += lrgs(lidx).reg_pressure();
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409 }
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410 return cnt;
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411 }
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412
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413 //------------------------------count_float_pressure---------------------------
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414 uint PhaseChaitin::count_float_pressure( IndexSet *liveout ) {
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415 IndexSetIterator elements(liveout);
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416 uint lidx;
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417 uint cnt = 0;
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418 while ((lidx = elements.next()) != 0) {
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419 if( lrgs(lidx).mask().is_UP() &&
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420 lrgs(lidx).mask_size() &&
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421 lrgs(lidx)._is_float )
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422 cnt += lrgs(lidx).reg_pressure();
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423 }
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424 return cnt;
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425 }
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426
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427 //------------------------------lower_pressure---------------------------------
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428 // Adjust register pressure down by 1. Capture last hi-to-low transition,
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429 static void lower_pressure( LRG *lrg, uint where, Block *b, uint *pressure, uint *hrp_index ) {
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430 if( lrg->mask().is_UP() && lrg->mask_size() ) {
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431 if( lrg->_is_float ) {
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432 pressure[1] -= lrg->reg_pressure();
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433 if( pressure[1] == (uint)FLOATPRESSURE ) {
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434 hrp_index[1] = where;
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435 #ifdef EXACT_PRESSURE
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436 if( pressure[1] > b->_freg_pressure )
|
|
437 b->_freg_pressure = pressure[1]+1;
|
|
438 #else
|
|
439 b->_freg_pressure = (uint)FLOATPRESSURE+1;
|
|
440 #endif
|
|
441 }
|
|
442 } else if( lrg->mask().overlap(*Matcher::idealreg2regmask[Op_RegI]) ) {
|
|
443 pressure[0] -= lrg->reg_pressure();
|
|
444 if( pressure[0] == (uint)INTPRESSURE ) {
|
|
445 hrp_index[0] = where;
|
|
446 #ifdef EXACT_PRESSURE
|
|
447 if( pressure[0] > b->_reg_pressure )
|
|
448 b->_reg_pressure = pressure[0]+1;
|
|
449 #else
|
|
450 b->_reg_pressure = (uint)INTPRESSURE+1;
|
|
451 #endif
|
|
452 }
|
|
453 }
|
|
454 }
|
|
455 }
|
|
456
|
|
457 //------------------------------build_ifg_physical-----------------------------
|
|
458 // Build the interference graph using physical registers when available.
|
|
459 // That is, if 2 live ranges are simultaneously alive but in their acceptable
|
|
460 // register sets do not overlap, then they do not interfere.
|
|
461 uint PhaseChaitin::build_ifg_physical( ResourceArea *a ) {
|
|
462 NOT_PRODUCT( Compile::TracePhase t3("buildIFG", &_t_buildIFGphysical, TimeCompiler); )
|
|
463
|
|
464 uint spill_reg = LRG::SPILL_REG;
|
|
465 uint must_spill = 0;
|
|
466
|
|
467 // For all blocks (in any order) do...
|
|
468 for( uint i = 0; i < _cfg._num_blocks; i++ ) {
|
|
469 Block *b = _cfg._blocks[i];
|
|
470 // Clone (rather than smash in place) the liveout info, so it is alive
|
|
471 // for the "collect_gc_info" phase later.
|
|
472 IndexSet liveout(_live->live(b));
|
|
473 uint last_inst = b->end_idx();
|
|
474 // Compute last phi index
|
|
475 uint last_phi;
|
|
476 for( last_phi = 1; last_phi < last_inst; last_phi++ )
|
|
477 if( !b->_nodes[last_phi]->is_Phi() )
|
|
478 break;
|
|
479
|
|
480 // Reset block's register pressure values for each ifg construction
|
|
481 uint pressure[2], hrp_index[2];
|
|
482 pressure[0] = pressure[1] = 0;
|
|
483 hrp_index[0] = hrp_index[1] = last_inst+1;
|
|
484 b->_reg_pressure = b->_freg_pressure = 0;
|
|
485 // Liveout things are presumed live for the whole block. We accumulate
|
|
486 // 'area' accordingly. If they get killed in the block, we'll subtract
|
|
487 // the unused part of the block from the area.
|
|
488 double cost = b->_freq * double(last_inst-last_phi);
|
|
489 assert( cost >= 0, "negative spill cost" );
|
|
490 IndexSetIterator elements(&liveout);
|
|
491 uint lidx;
|
|
492 while ((lidx = elements.next()) != 0) {
|
|
493 LRG &lrg = lrgs(lidx);
|
|
494 lrg._area += cost;
|
|
495 // Compute initial register pressure
|
|
496 if( lrg.mask().is_UP() && lrg.mask_size() ) {
|
|
497 if( lrg._is_float ) { // Count float pressure
|
|
498 pressure[1] += lrg.reg_pressure();
|
|
499 #ifdef EXACT_PRESSURE
|
|
500 if( pressure[1] > b->_freg_pressure )
|
|
501 b->_freg_pressure = pressure[1];
|
|
502 #endif
|
|
503 // Count int pressure, but do not count the SP, flags
|
|
504 } else if( lrgs(lidx).mask().overlap(*Matcher::idealreg2regmask[Op_RegI]) ) {
|
|
505 pressure[0] += lrg.reg_pressure();
|
|
506 #ifdef EXACT_PRESSURE
|
|
507 if( pressure[0] > b->_reg_pressure )
|
|
508 b->_reg_pressure = pressure[0];
|
|
509 #endif
|
|
510 }
|
|
511 }
|
|
512 }
|
|
513 assert( pressure[0] == count_int_pressure (&liveout), "" );
|
|
514 assert( pressure[1] == count_float_pressure(&liveout), "" );
|
|
515
|
|
516 // The IFG is built by a single reverse pass over each basic block.
|
|
517 // Starting with the known live-out set, we remove things that get
|
|
518 // defined and add things that become live (essentially executing one
|
|
519 // pass of a standard LIVE analysis). Just before a Node defines a value
|
|
520 // (and removes it from the live-ness set) that value is certainly live.
|
|
521 // The defined value interferes with everything currently live. The
|
|
522 // value is then removed from the live-ness set and it's inputs are added
|
|
523 // to the live-ness set.
|
|
524 uint j;
|
|
525 for( j = last_inst + 1; j > 1; j-- ) {
|
|
526 Node *n = b->_nodes[j - 1];
|
|
527
|
|
528 // Get value being defined
|
|
529 uint r = n2lidx(n);
|
|
530
|
|
531 // Some special values do not allocate
|
|
532 if( r ) {
|
|
533 // A DEF normally costs block frequency; rematerialized values are
|
|
534 // removed from the DEF sight, so LOWER costs here.
|
|
535 lrgs(r)._cost += n->rematerialize() ? 0 : b->_freq;
|
|
536
|
|
537 // If it is not live, then this instruction is dead. Probably caused
|
|
538 // by spilling and rematerialization. Who cares why, yank this baby.
|
|
539 if( !liveout.member(r) && n->Opcode() != Op_SafePoint ) {
|
|
540 Node *def = n->in(0);
|
|
541 if( !n->is_Proj() ||
|
|
542 // Could also be a flags-projection of a dead ADD or such.
|
|
543 (n2lidx(def) && !liveout.member(n2lidx(def)) ) ) {
|
|
544 b->_nodes.remove(j - 1);
|
|
545 if( lrgs(r)._def == n ) lrgs(r)._def = 0;
|
|
546 n->disconnect_inputs(NULL);
|
|
547 _cfg._bbs.map(n->_idx,NULL);
|
|
548 n->replace_by(C->top());
|
|
549 // Since yanking a Node from block, high pressure moves up one
|
|
550 hrp_index[0]--;
|
|
551 hrp_index[1]--;
|
|
552 continue;
|
|
553 }
|
|
554
|
|
555 // Fat-projections kill many registers which cannot be used to
|
|
556 // hold live ranges.
|
|
557 if( lrgs(r)._fat_proj ) {
|
|
558 // Count the int-only registers
|
|
559 RegMask itmp = lrgs(r).mask();
|
|
560 itmp.AND(*Matcher::idealreg2regmask[Op_RegI]);
|
|
561 int iregs = itmp.Size();
|
|
562 #ifdef EXACT_PRESSURE
|
|
563 if( pressure[0]+iregs > b->_reg_pressure )
|
|
564 b->_reg_pressure = pressure[0]+iregs;
|
|
565 #endif
|
|
566 if( pressure[0] <= (uint)INTPRESSURE &&
|
|
567 pressure[0]+iregs > (uint)INTPRESSURE ) {
|
|
568 #ifndef EXACT_PRESSURE
|
|
569 b->_reg_pressure = (uint)INTPRESSURE+1;
|
|
570 #endif
|
|
571 hrp_index[0] = j-1;
|
|
572 }
|
|
573 // Count the float-only registers
|
|
574 RegMask ftmp = lrgs(r).mask();
|
|
575 ftmp.AND(*Matcher::idealreg2regmask[Op_RegD]);
|
|
576 int fregs = ftmp.Size();
|
|
577 #ifdef EXACT_PRESSURE
|
|
578 if( pressure[1]+fregs > b->_freg_pressure )
|
|
579 b->_freg_pressure = pressure[1]+fregs;
|
|
580 #endif
|
|
581 if( pressure[1] <= (uint)FLOATPRESSURE &&
|
|
582 pressure[1]+fregs > (uint)FLOATPRESSURE ) {
|
|
583 #ifndef EXACT_PRESSURE
|
|
584 b->_freg_pressure = (uint)FLOATPRESSURE+1;
|
|
585 #endif
|
|
586 hrp_index[1] = j-1;
|
|
587 }
|
|
588 }
|
|
589
|
|
590 } else { // Else it is live
|
|
591 // A DEF also ends 'area' partway through the block.
|
|
592 lrgs(r)._area -= cost;
|
|
593 assert( lrgs(r)._area >= 0, "negative spill area" );
|
|
594
|
|
595 // Insure high score for immediate-use spill copies so they get a color
|
|
596 if( n->is_SpillCopy()
|
|
597 && lrgs(r)._def != NodeSentinel // MultiDef live range can still split
|
|
598 && n->outcnt() == 1 // and use must be in this block
|
|
599 && _cfg._bbs[n->unique_out()->_idx] == b ) {
|
|
600 // All single-use MachSpillCopy(s) that immediately precede their
|
|
601 // use must color early. If a longer live range steals their
|
|
602 // color, the spill copy will split and may push another spill copy
|
|
603 // further away resulting in an infinite spill-split-retry cycle.
|
|
604 // Assigning a zero area results in a high score() and a good
|
|
605 // location in the simplify list.
|
|
606 //
|
|
607
|
|
608 Node *single_use = n->unique_out();
|
|
609 assert( b->find_node(single_use) >= j, "Use must be later in block");
|
|
610 // Use can be earlier in block if it is a Phi, but then I should be a MultiDef
|
|
611
|
|
612 // Find first non SpillCopy 'm' that follows the current instruction
|
|
613 // (j - 1) is index for current instruction 'n'
|
|
614 Node *m = n;
|
|
615 for( uint i = j; i <= last_inst && m->is_SpillCopy(); ++i ) { m = b->_nodes[i]; }
|
|
616 if( m == single_use ) {
|
|
617 lrgs(r)._area = 0.0;
|
|
618 }
|
|
619 }
|
|
620
|
|
621 // Remove from live-out set
|
|
622 if( liveout.remove(r) ) {
|
|
623 // Adjust register pressure.
|
|
624 // Capture last hi-to-lo pressure transition
|
|
625 lower_pressure( &lrgs(r), j-1, b, pressure, hrp_index );
|
|
626 assert( pressure[0] == count_int_pressure (&liveout), "" );
|
|
627 assert( pressure[1] == count_float_pressure(&liveout), "" );
|
|
628 }
|
|
629
|
|
630 // Copies do not define a new value and so do not interfere.
|
|
631 // Remove the copies source from the liveout set before interfering.
|
|
632 uint idx = n->is_Copy();
|
|
633 if( idx ) {
|
|
634 uint x = n2lidx(n->in(idx));
|
|
635 if( liveout.remove( x ) ) {
|
|
636 lrgs(x)._area -= cost;
|
|
637 // Adjust register pressure.
|
|
638 lower_pressure( &lrgs(x), j-1, b, pressure, hrp_index );
|
|
639 assert( pressure[0] == count_int_pressure (&liveout), "" );
|
|
640 assert( pressure[1] == count_float_pressure(&liveout), "" );
|
|
641 }
|
|
642 }
|
|
643 } // End of if live or not
|
|
644
|
|
645 // Interfere with everything live. If the defined value must
|
|
646 // go in a particular register, just remove that register from
|
|
647 // all conflicting parties and avoid the interference.
|
|
648
|
|
649 // Make exclusions for rematerializable defs. Since rematerializable
|
|
650 // DEFs are not bound but the live range is, some uses must be bound.
|
|
651 // If we spill live range 'r', it can rematerialize at each use site
|
|
652 // according to its bindings.
|
|
653 const RegMask &rmask = lrgs(r).mask();
|
|
654 if( lrgs(r).is_bound() && !(n->rematerialize()) && rmask.is_NotEmpty() ) {
|
|
655 // Smear odd bits; leave only aligned pairs of bits.
|
|
656 RegMask r2mask = rmask;
|
|
657 r2mask.SmearToPairs();
|
|
658 // Check for common case
|
|
659 int r_size = lrgs(r).num_regs();
|
|
660 OptoReg::Name r_reg = (r_size == 1) ? rmask.find_first_elem() : OptoReg::Physical;
|
|
661
|
|
662 IndexSetIterator elements(&liveout);
|
|
663 uint l;
|
|
664 while ((l = elements.next()) != 0) {
|
|
665 LRG &lrg = lrgs(l);
|
|
666 // If 'l' must spill already, do not further hack his bits.
|
|
667 // He'll get some interferences and be forced to spill later.
|
|
668 if( lrg._must_spill ) continue;
|
|
669 // Remove bound register(s) from 'l's choices
|
|
670 RegMask old = lrg.mask();
|
|
671 uint old_size = lrg.mask_size();
|
|
672 // Remove the bits from LRG 'r' from LRG 'l' so 'l' no
|
|
673 // longer interferes with 'r'. If 'l' requires aligned
|
|
674 // adjacent pairs, subtract out bit pairs.
|
|
675 if( lrg.num_regs() == 2 && !lrg._fat_proj ) {
|
|
676 lrg.SUBTRACT( r2mask );
|
|
677 lrg.compute_set_mask_size();
|
|
678 } else if( r_size != 1 ) {
|
|
679 lrg.SUBTRACT( rmask );
|
|
680 lrg.compute_set_mask_size();
|
|
681 } else { // Common case: size 1 bound removal
|
|
682 if( lrg.mask().Member(r_reg) ) {
|
|
683 lrg.Remove(r_reg);
|
|
684 lrg.set_mask_size(lrg.mask().is_AllStack() ? 65535:old_size-1);
|
|
685 }
|
|
686 }
|
|
687 // If 'l' goes completely dry, it must spill.
|
|
688 if( lrg.not_free() ) {
|
|
689 // Give 'l' some kind of reasonable mask, so he picks up
|
|
690 // interferences (and will spill later).
|
|
691 lrg.set_mask( old );
|
|
692 lrg.set_mask_size(old_size);
|
|
693 must_spill++;
|
|
694 lrg._must_spill = 1;
|
|
695 lrg.set_reg(OptoReg::Name(LRG::SPILL_REG));
|
|
696 }
|
|
697 }
|
|
698 } // End of if bound
|
|
699
|
|
700 // Now interference with everything that is live and has
|
|
701 // compatible register sets.
|
|
702 interfere_with_live(r,&liveout);
|
|
703
|
|
704 } // End of if normal register-allocated value
|
|
705
|
|
706 cost -= b->_freq; // Area remaining in the block
|
|
707 if( cost < 0.0 ) cost = 0.0; // Cost goes negative in the Phi area
|
|
708
|
|
709 // Make all inputs live
|
|
710 if( !n->is_Phi() ) { // Phi function uses come from prior block
|
|
711 JVMState* jvms = n->jvms();
|
|
712 uint debug_start = jvms ? jvms->debug_start() : 999999;
|
|
713 // Start loop at 1 (skip control edge) for most Nodes.
|
|
714 // SCMemProj's might be the sole use of a StoreLConditional.
|
|
715 // While StoreLConditionals set memory (the SCMemProj use)
|
|
716 // they also def flags; if that flag def is unused the
|
|
717 // allocator sees a flag-setting instruction with no use of
|
|
718 // the flags and assumes it's dead. This keeps the (useless)
|
|
719 // flag-setting behavior alive while also keeping the (useful)
|
|
720 // memory update effect.
|
|
721 for( uint k = ((n->Opcode() == Op_SCMemProj) ? 0:1); k < n->req(); k++ ) {
|
|
722 Node *def = n->in(k);
|
|
723 uint x = n2lidx(def);
|
|
724 if( !x ) continue;
|
|
725 LRG &lrg = lrgs(x);
|
|
726 // No use-side cost for spilling debug info
|
|
727 if( k < debug_start )
|
|
728 // A USE costs twice block frequency (once for the Load, once
|
|
729 // for a Load-delay). Rematerialized uses only cost once.
|
|
730 lrg._cost += (def->rematerialize() ? b->_freq : (b->_freq + b->_freq));
|
|
731 // It is live now
|
|
732 if( liveout.insert( x ) ) {
|
|
733 // Newly live things assumed live from here to top of block
|
|
734 lrg._area += cost;
|
|
735 // Adjust register pressure
|
|
736 if( lrg.mask().is_UP() && lrg.mask_size() ) {
|
|
737 if( lrg._is_float ) {
|
|
738 pressure[1] += lrg.reg_pressure();
|
|
739 #ifdef EXACT_PRESSURE
|
|
740 if( pressure[1] > b->_freg_pressure )
|
|
741 b->_freg_pressure = pressure[1];
|
|
742 #endif
|
|
743 } else if( lrg.mask().overlap(*Matcher::idealreg2regmask[Op_RegI]) ) {
|
|
744 pressure[0] += lrg.reg_pressure();
|
|
745 #ifdef EXACT_PRESSURE
|
|
746 if( pressure[0] > b->_reg_pressure )
|
|
747 b->_reg_pressure = pressure[0];
|
|
748 #endif
|
|
749 }
|
|
750 }
|
|
751 assert( pressure[0] == count_int_pressure (&liveout), "" );
|
|
752 assert( pressure[1] == count_float_pressure(&liveout), "" );
|
|
753 }
|
|
754 assert( lrg._area >= 0, "negative spill area" );
|
|
755 }
|
|
756 }
|
|
757 } // End of reverse pass over all instructions in block
|
|
758
|
|
759 // If we run off the top of the block with high pressure and
|
|
760 // never see a hi-to-low pressure transition, just record that
|
|
761 // the whole block is high pressure.
|
|
762 if( pressure[0] > (uint)INTPRESSURE ) {
|
|
763 hrp_index[0] = 0;
|
|
764 #ifdef EXACT_PRESSURE
|
|
765 if( pressure[0] > b->_reg_pressure )
|
|
766 b->_reg_pressure = pressure[0];
|
|
767 #else
|
|
768 b->_reg_pressure = (uint)INTPRESSURE+1;
|
|
769 #endif
|
|
770 }
|
|
771 if( pressure[1] > (uint)FLOATPRESSURE ) {
|
|
772 hrp_index[1] = 0;
|
|
773 #ifdef EXACT_PRESSURE
|
|
774 if( pressure[1] > b->_freg_pressure )
|
|
775 b->_freg_pressure = pressure[1];
|
|
776 #else
|
|
777 b->_freg_pressure = (uint)FLOATPRESSURE+1;
|
|
778 #endif
|
|
779 }
|
|
780
|
|
781 // Compute high pressure indice; avoid landing in the middle of projnodes
|
|
782 j = hrp_index[0];
|
|
783 if( j < b->_nodes.size() && j < b->end_idx()+1 ) {
|
|
784 Node *cur = b->_nodes[j];
|
|
785 while( cur->is_Proj() || (cur->is_MachNullCheck()) || cur->is_Catch() ) {
|
|
786 j--;
|
|
787 cur = b->_nodes[j];
|
|
788 }
|
|
789 }
|
|
790 b->_ihrp_index = j;
|
|
791 j = hrp_index[1];
|
|
792 if( j < b->_nodes.size() && j < b->end_idx()+1 ) {
|
|
793 Node *cur = b->_nodes[j];
|
|
794 while( cur->is_Proj() || (cur->is_MachNullCheck()) || cur->is_Catch() ) {
|
|
795 j--;
|
|
796 cur = b->_nodes[j];
|
|
797 }
|
|
798 }
|
|
799 b->_fhrp_index = j;
|
|
800
|
|
801 #ifndef PRODUCT
|
|
802 // Gather Register Pressure Statistics
|
|
803 if( PrintOptoStatistics ) {
|
|
804 if( b->_reg_pressure > (uint)INTPRESSURE || b->_freg_pressure > (uint)FLOATPRESSURE )
|
|
805 _high_pressure++;
|
|
806 else
|
|
807 _low_pressure++;
|
|
808 }
|
|
809 #endif
|
|
810 } // End of for all blocks
|
|
811
|
|
812 return must_spill;
|
|
813 }
|