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1 /* |
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2 * Copyright (c) 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 #include "precompiled.hpp" |
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26 #include "c1/c1_ValueStack.hpp" |
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27 #include "c1/c1_RangeCheckElimination.hpp" |
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28 #include "c1/c1_IR.hpp" |
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29 #include "c1/c1_Canonicalizer.hpp" |
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30 #include "c1/c1_ValueMap.hpp" |
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31 #include "ci/ciMethodData.hpp" |
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32 #include "runtime/deoptimization.hpp" |
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33 |
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34 // Macros for the Trace and the Assertion flag |
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35 #ifdef ASSERT |
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36 #define TRACE_RANGE_CHECK_ELIMINATION(code) if (TraceRangeCheckElimination) { code; } |
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37 #define ASSERT_RANGE_CHECK_ELIMINATION(code) if (AssertRangeCheckElimination) { code; } |
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38 #define TRACE_OR_ASSERT_RANGE_CHECK_ELIMINATION(code) if (TraceRangeCheckElimination || AssertRangeCheckElimination) { code; } |
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39 #else |
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40 #define TRACE_RANGE_CHECK_ELIMINATION(code) |
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41 #define ASSERT_RANGE_CHECK_ELIMINATION(code) |
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42 #define TRACE_OR_ASSERT_RANGE_CHECK_ELIMINATION(code) |
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43 #endif |
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44 |
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45 // Entry point for the optimization |
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46 void RangeCheckElimination::eliminate(IR *ir) { |
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47 bool do_elimination = ir->compilation()->has_access_indexed(); |
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48 ASSERT_RANGE_CHECK_ELIMINATION(do_elimination = true); |
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49 if (do_elimination) { |
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50 RangeCheckEliminator rce(ir); |
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51 } |
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52 } |
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53 |
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54 // Constructor |
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55 RangeCheckEliminator::RangeCheckEliminator(IR *ir) : |
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56 _bounds(Instruction::number_of_instructions(), NULL), |
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57 _access_indexed_info(Instruction::number_of_instructions(), NULL) |
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58 { |
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59 _visitor.set_range_check_eliminator(this); |
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60 _ir = ir; |
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61 _number_of_instructions = Instruction::number_of_instructions(); |
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62 _optimistic = ir->compilation()->is_optimistic(); |
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63 |
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64 TRACE_RANGE_CHECK_ELIMINATION( |
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65 tty->print_cr(""); |
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66 tty->print_cr("Range check elimination"); |
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67 ir->method()->print_name(tty); |
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68 tty->print_cr(""); |
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69 ); |
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70 |
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71 TRACE_RANGE_CHECK_ELIMINATION( |
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72 tty->print_cr("optimistic=%d", (int)_optimistic); |
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73 ); |
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74 |
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75 #ifdef ASSERT |
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76 // Verifies several conditions that must be true on the IR-input. Only used for debugging purposes. |
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77 TRACE_RANGE_CHECK_ELIMINATION( |
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78 tty->print_cr("Verification of IR . . ."); |
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79 ); |
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80 Verification verification(ir); |
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81 #endif |
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82 |
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83 // Set process block flags |
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84 // Optimization so a blocks is only processed if it contains an access indexed instruction or if |
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85 // one of its children in the dominator tree contains an access indexed instruction. |
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86 set_process_block_flags(ir->start()); |
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87 |
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88 // Pass over instructions in the dominator tree |
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89 TRACE_RANGE_CHECK_ELIMINATION( |
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90 tty->print_cr("Starting pass over dominator tree . . .") |
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91 ); |
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92 calc_bounds(ir->start(), NULL); |
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93 |
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94 TRACE_RANGE_CHECK_ELIMINATION( |
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95 tty->print_cr("Finished!") |
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96 ); |
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97 } |
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98 |
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99 // Instruction specific work for some instructions |
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100 // Constant |
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101 void RangeCheckEliminator::Visitor::do_Constant(Constant *c) { |
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102 IntConstant *ic = c->type()->as_IntConstant(); |
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103 if (ic != NULL) { |
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104 int value = ic->value(); |
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105 _bound = new Bound(value, NULL, value, NULL); |
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106 } |
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107 } |
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108 |
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109 // LogicOp |
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110 void RangeCheckEliminator::Visitor::do_LogicOp(LogicOp *lo) { |
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111 if (lo->type()->as_IntType() && lo->op() == Bytecodes::_iand && (lo->x()->as_Constant() || lo->y()->as_Constant())) { |
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112 int constant = 0; |
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113 Constant *c = lo->x()->as_Constant(); |
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114 if (c != NULL) { |
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115 constant = c->type()->as_IntConstant()->value(); |
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116 } else { |
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117 constant = lo->y()->as_Constant()->type()->as_IntConstant()->value(); |
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118 } |
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119 if (constant >= 0) { |
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120 _bound = new Bound(0, NULL, constant, NULL); |
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121 } |
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122 } |
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123 } |
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124 |
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125 // Phi |
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126 void RangeCheckEliminator::Visitor::do_Phi(Phi *phi) { |
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127 if (!phi->type()->as_IntType() && !phi->type()->as_ObjectType()) return; |
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128 |
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129 BlockBegin *block = phi->block(); |
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130 int op_count = phi->operand_count(); |
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131 bool has_upper = true; |
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132 bool has_lower = true; |
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133 assert(phi, "Phi must not be null"); |
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134 Bound *bound = NULL; |
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135 |
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136 // TODO: support more difficult phis |
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137 for (int i=0; i<op_count; i++) { |
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138 Value v = phi->operand_at(i); |
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139 |
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140 if (v == phi) continue; |
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141 |
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142 // Check if instruction is connected with phi itself |
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143 Op2 *op2 = v->as_Op2(); |
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144 if (op2 != NULL) { |
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145 Value x = op2->x(); |
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146 Value y = op2->y(); |
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147 if ((x == phi || y == phi)) { |
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148 Value other = x; |
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149 if (other == phi) { |
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150 other = y; |
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151 } |
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152 ArithmeticOp *ao = v->as_ArithmeticOp(); |
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153 if (ao != NULL && ao->op() == Bytecodes::_iadd) { |
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154 assert(ao->op() == Bytecodes::_iadd, "Has to be add!"); |
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155 if (ao->type()->as_IntType()) { |
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156 Constant *c = other->as_Constant(); |
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157 if (c != NULL) { |
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158 assert(c->type()->as_IntConstant(), "Constant has to be of type integer"); |
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159 int value = c->type()->as_IntConstant()->value(); |
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160 if (value == 1) { |
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161 has_upper = false; |
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162 } else if (value > 1) { |
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163 // Overflow not guaranteed |
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164 has_upper = false; |
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165 has_lower = false; |
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166 } else if (value < 0) { |
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167 has_lower = false; |
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168 } |
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169 continue; |
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170 } |
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171 } |
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172 } |
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173 } |
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174 } |
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175 |
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176 // No connection -> new bound |
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177 Bound *v_bound = _rce->get_bound(v); |
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178 Bound *cur_bound; |
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179 int cur_constant = 0; |
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180 Value cur_value = v; |
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181 |
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182 if (v->type()->as_IntConstant()) { |
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183 cur_constant = v->type()->as_IntConstant()->value(); |
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184 cur_value = NULL; |
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185 } |
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186 if (!v_bound->has_upper() || !v_bound->has_lower()) { |
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187 cur_bound = new Bound(cur_constant, cur_value, cur_constant, cur_value); |
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188 } else { |
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189 cur_bound = v_bound; |
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190 } |
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191 if (cur_bound) { |
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192 if (!bound) { |
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193 bound = cur_bound->copy(); |
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194 } else { |
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195 bound->or_op(cur_bound); |
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196 } |
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197 } else { |
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198 // No bound! |
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199 bound = NULL; |
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200 break; |
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201 } |
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202 } |
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203 |
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204 if (bound) { |
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205 if (!has_upper) { |
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206 bound->remove_upper(); |
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207 } |
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208 if (!has_lower) { |
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209 bound->remove_lower(); |
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210 } |
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211 _bound = bound; |
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212 } else { |
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213 _bound = new Bound(); |
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214 } |
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215 } |
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216 |
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217 |
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218 // ArithmeticOp |
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219 void RangeCheckEliminator::Visitor::do_ArithmeticOp(ArithmeticOp *ao) { |
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220 Value x = ao->x(); |
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221 Value y = ao->y(); |
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222 |
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223 if (ao->op() == Bytecodes::_irem) { |
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224 Bound* x_bound = _rce->get_bound(x); |
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225 Bound* y_bound = _rce->get_bound(y); |
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226 if (x_bound->lower() >= 0 && x_bound->lower_instr() == NULL && y->as_ArrayLength() != NULL) { |
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227 _bound = new Bound(0, NULL, -1, y); |
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228 } else { |
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229 _bound = new Bound(); |
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230 } |
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231 } else if (!x->as_Constant() || !y->as_Constant()) { |
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232 assert(!x->as_Constant() || !y->as_Constant(), "One of the operands must be non-constant!"); |
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233 if (((x->as_Constant() || y->as_Constant()) && (ao->op() == Bytecodes::_iadd)) || (y->as_Constant() && ao->op() == Bytecodes::_isub)) { |
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234 assert(ao->op() == Bytecodes::_iadd || ao->op() == Bytecodes::_isub, "Operand must be iadd or isub"); |
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235 |
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236 if (y->as_Constant()) { |
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237 Value tmp = x; |
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238 x = y; |
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239 y = tmp; |
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240 } |
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241 assert(x->as_Constant()->type()->as_IntConstant(), "Constant must be int constant!"); |
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242 |
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243 // Constant now in x |
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244 int const_value = x->as_Constant()->type()->as_IntConstant()->value(); |
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245 if (ao->op() == Bytecodes::_iadd || const_value != min_jint) { |
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246 if (ao->op() == Bytecodes::_isub) { |
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247 const_value = -const_value; |
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248 } |
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249 |
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250 Bound * bound = _rce->get_bound(y); |
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251 if (bound->has_upper() && bound->has_lower()) { |
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252 int new_lower = bound->lower() + const_value; |
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253 jlong new_lowerl = ((jlong)bound->lower()) + const_value; |
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254 int new_upper = bound->upper() + const_value; |
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255 jlong new_upperl = ((jlong)bound->upper()) + const_value; |
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256 |
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257 if (((jlong)new_lower) == new_lowerl && ((jlong)new_upper == new_upperl)) { |
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258 Bound *newBound = new Bound(new_lower, bound->lower_instr(), new_upper, bound->upper_instr()); |
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259 _bound = newBound; |
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260 } else { |
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261 // overflow |
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262 _bound = new Bound(); |
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263 } |
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264 } else { |
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265 _bound = new Bound(); |
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266 } |
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267 } else { |
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268 _bound = new Bound(); |
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269 } |
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270 } else { |
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271 Bound *bound = _rce->get_bound(x); |
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272 if (ao->op() == Bytecodes::_isub) { |
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273 if (bound->lower_instr() == y) { |
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274 _bound = new Bound(Instruction::geq, NULL, bound->lower()); |
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275 } else { |
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276 _bound = new Bound(); |
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277 } |
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278 } else { |
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279 _bound = new Bound(); |
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280 } |
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281 } |
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282 } |
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283 } |
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284 |
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285 // IfOp |
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286 void RangeCheckEliminator::Visitor::do_IfOp(IfOp *ifOp) |
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287 { |
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288 if (ifOp->tval()->type()->as_IntConstant() && ifOp->fval()->type()->as_IntConstant()) { |
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289 int min = ifOp->tval()->type()->as_IntConstant()->value(); |
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290 int max = ifOp->fval()->type()->as_IntConstant()->value(); |
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291 if (min > max) { |
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292 // min ^= max ^= min ^= max; |
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293 int tmp = min; |
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294 min = max; |
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295 max = tmp; |
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296 } |
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297 _bound = new Bound(min, NULL, max, NULL); |
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298 } |
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299 } |
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300 |
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301 // Get bound. Returns the current bound on Value v. Normally this is the topmost element on the bound stack. |
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302 RangeCheckEliminator::Bound *RangeCheckEliminator::get_bound(Value v) { |
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303 // Wrong type or NULL -> No bound |
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304 if (!v || (!v->type()->as_IntType() && !v->type()->as_ObjectType())) return NULL; |
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305 |
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306 if (!_bounds[v->id()]) { |
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307 // First (default) bound is calculated |
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308 // Create BoundStack |
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309 _bounds[v->id()] = new BoundStack(); |
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310 _visitor.clear_bound(); |
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311 Value visit_value = v; |
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312 visit_value->visit(&_visitor); |
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313 Bound *bound = _visitor.bound(); |
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314 if (bound) { |
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315 _bounds[v->id()]->push(bound); |
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316 } |
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317 if (_bounds[v->id()]->length() == 0) { |
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318 assert(!(v->as_Constant() && v->type()->as_IntConstant()), "constants not handled here"); |
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319 _bounds[v->id()]->push(new Bound()); |
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320 } |
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321 } else if (_bounds[v->id()]->length() == 0) { |
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322 // To avoid endless loops, bound is currently in calculation -> nothing known about it |
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323 return new Bound(); |
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324 } |
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325 |
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326 // Return bound |
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327 return _bounds[v->id()]->top(); |
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328 } |
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329 |
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330 // Update bound |
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331 void RangeCheckEliminator::update_bound(IntegerStack &pushed, Value v, Instruction::Condition cond, Value value, int constant) { |
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332 if (cond == Instruction::gtr) { |
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333 cond = Instruction::geq; |
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334 constant++; |
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335 } else if (cond == Instruction::lss) { |
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336 cond = Instruction::leq; |
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337 constant--; |
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338 } |
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339 Bound *bound = new Bound(cond, value, constant); |
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340 update_bound(pushed, v, bound); |
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341 } |
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342 |
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343 // Checks for loop invariance. Returns true if the instruction is outside of the loop which is identified by loop_header. |
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344 bool RangeCheckEliminator::loop_invariant(BlockBegin *loop_header, Instruction *instruction) { |
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345 assert(loop_header, "Loop header must not be null!"); |
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346 if (!instruction) return true; |
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347 return instruction->dominator_depth() < loop_header->dominator_depth(); |
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348 } |
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349 |
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350 // Update bound. Pushes a new bound onto the stack. Tries to do a conjunction with the current bound. |
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351 void RangeCheckEliminator::update_bound(IntegerStack &pushed, Value v, Bound *bound) { |
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352 if (v->as_Constant()) { |
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353 // No bound update for constants |
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354 return; |
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355 } |
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356 if (!_bounds[v->id()]) { |
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357 get_bound(v); |
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358 assert(_bounds[v->id()], "Now Stack must exist"); |
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359 } |
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360 Bound *top = NULL; |
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361 if (_bounds[v->id()]->length() > 0) { |
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362 top = _bounds[v->id()]->top(); |
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363 } |
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364 if (top) { |
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365 bound->and_op(top); |
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366 } |
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367 _bounds[v->id()]->push(bound); |
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368 pushed.append(v->id()); |
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369 } |
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370 |
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371 // Add instruction + idx for in block motion |
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372 void RangeCheckEliminator::add_access_indexed_info(InstructionList &indices, int idx, Value instruction, AccessIndexed *ai) { |
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373 int id = instruction->id(); |
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374 AccessIndexedInfo *aii = _access_indexed_info[id]; |
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375 if (aii == NULL) { |
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376 aii = new AccessIndexedInfo(); |
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377 _access_indexed_info[id] = aii; |
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378 indices.append(instruction); |
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379 aii->_min = idx; |
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380 aii->_max = idx; |
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381 aii->_list = new AccessIndexedList(); |
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382 } else if (idx >= aii->_min && idx <= aii->_max) { |
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383 remove_range_check(ai); |
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384 return; |
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385 } |
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386 aii->_min = MIN2(aii->_min, idx); |
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387 aii->_max = MAX2(aii->_max, idx); |
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388 aii->_list->append(ai); |
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389 } |
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390 |
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391 // In block motion. Tries to reorder checks in order to reduce some of them. |
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392 // Example: |
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393 // a[i] = 0; |
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394 // a[i+2] = 0; |
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395 // a[i+1] = 0; |
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396 // In this example the check for a[i+1] would be considered as unnecessary during the first iteration. |
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397 // After this i is only checked once for i >= 0 and i+2 < a.length before the first array access. If this |
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398 // check fails, deoptimization is called. |
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399 void RangeCheckEliminator::in_block_motion(BlockBegin *block, AccessIndexedList &accessIndexed, InstructionList &arrays) { |
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400 InstructionList indices; |
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401 |
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402 // Now iterate over all arrays |
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403 for (int i=0; i<arrays.length(); i++) { |
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404 int max_constant = -1; |
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405 AccessIndexedList list_constant; |
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406 Value array = arrays.at(i); |
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407 |
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408 // For all AccessIndexed-instructions in this block concerning the current array. |
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409 for(int j=0; j<accessIndexed.length(); j++) { |
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410 AccessIndexed *ai = accessIndexed.at(j); |
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411 if (ai->array() != array || !ai->check_flag(Instruction::NeedsRangeCheckFlag)) continue; |
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412 |
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413 Value index = ai->index(); |
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414 Constant *c = index->as_Constant(); |
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415 if (c != NULL) { |
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416 int constant_value = c->type()->as_IntConstant()->value(); |
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417 if (constant_value >= 0) { |
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418 if (constant_value <= max_constant) { |
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419 // No range check needed for this |
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420 remove_range_check(ai); |
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421 } else { |
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422 max_constant = constant_value; |
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423 list_constant.append(ai); |
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424 } |
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425 } |
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426 } else { |
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427 int last_integer = 0; |
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428 Instruction *last_instruction = index; |
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429 int base = 0; |
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430 ArithmeticOp *ao = index->as_ArithmeticOp(); |
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431 |
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432 while (ao != NULL && (ao->x()->as_Constant() || ao->y()->as_Constant()) && (ao->op() == Bytecodes::_iadd || ao->op() == Bytecodes::_isub)) { |
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433 c = ao->y()->as_Constant(); |
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434 Instruction *other = ao->x(); |
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435 if (!c && ao->op() == Bytecodes::_iadd) { |
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436 c = ao->x()->as_Constant(); |
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437 other = ao->y(); |
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438 } |
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439 |
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440 if (c) { |
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441 int value = c->type()->as_IntConstant()->value(); |
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442 if (value != min_jint) { |
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443 if (ao->op() == Bytecodes::_isub) { |
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444 value = -value; |
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445 } |
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446 base += value; |
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447 last_integer = base; |
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448 last_instruction = other; |
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449 } |
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450 index = other; |
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451 } else { |
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452 break; |
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453 } |
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454 ao = index->as_ArithmeticOp(); |
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455 } |
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456 add_access_indexed_info(indices, last_integer, last_instruction, ai); |
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457 } |
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458 } |
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459 |
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460 // Iterate over all different indices |
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461 if (_optimistic) { |
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462 for (int i=0; i<indices.length(); i++) { |
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463 Instruction *index_instruction = indices.at(i); |
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464 AccessIndexedInfo *info = _access_indexed_info[index_instruction->id()]; |
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465 assert(info != NULL, "Info must not be null"); |
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466 |
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467 // if idx < 0, max > 0, max + idx may fall between 0 and |
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468 // length-1 and if min < 0, min + idx may overflow and be >= |
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469 // 0. The predicate wouldn't trigger but some accesses could |
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470 // be with a negative index. This test guarantees that for the |
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471 // min and max value that are kept the predicate can't let |
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472 // some incorrect accesses happen. |
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473 bool range_cond = (info->_max < 0 || info->_max + min_jint <= info->_min); |
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474 |
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475 // Generate code only if more than 2 range checks can be eliminated because of that. |
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476 // 2 because at least 2 comparisons are done |
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477 if (info->_list->length() > 2 && range_cond) { |
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478 AccessIndexed *first = info->_list->at(0); |
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479 Instruction *insert_position = first->prev(); |
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480 assert(insert_position->next() == first, "prev was calculated"); |
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481 ValueStack *state = first->state_before(); |
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482 |
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483 // Load min Constant |
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484 Constant *min_constant = NULL; |
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485 if (info->_min != 0) { |
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486 min_constant = new Constant(new IntConstant(info->_min)); |
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487 NOT_PRODUCT(min_constant->set_printable_bci(first->printable_bci())); |
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488 insert_position = insert_position->insert_after(min_constant); |
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489 } |
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490 |
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491 // Load max Constant |
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492 Constant *max_constant = NULL; |
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493 if (info->_max != 0) { |
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494 max_constant = new Constant(new IntConstant(info->_max)); |
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495 NOT_PRODUCT(max_constant->set_printable_bci(first->printable_bci())); |
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496 insert_position = insert_position->insert_after(max_constant); |
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497 } |
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498 |
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499 // Load array length |
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500 Value length_instr = first->length(); |
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501 if (!length_instr) { |
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502 ArrayLength *length = new ArrayLength(array, first->state_before()->copy()); |
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503 length->set_exception_state(length->state_before()); |
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504 length->set_flag(Instruction::DeoptimizeOnException, true); |
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505 insert_position = insert_position->insert_after_same_bci(length); |
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506 length_instr = length; |
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507 } |
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508 |
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509 // Calculate lower bound |
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510 Instruction *lower_compare = index_instruction; |
|
511 if (min_constant) { |
|
512 ArithmeticOp *ao = new ArithmeticOp(Bytecodes::_iadd, min_constant, lower_compare, false, NULL); |
|
513 insert_position = insert_position->insert_after_same_bci(ao); |
|
514 lower_compare = ao; |
|
515 } |
|
516 |
|
517 // Calculate upper bound |
|
518 Instruction *upper_compare = index_instruction; |
|
519 if (max_constant) { |
|
520 ArithmeticOp *ao = new ArithmeticOp(Bytecodes::_iadd, max_constant, upper_compare, false, NULL); |
|
521 insert_position = insert_position->insert_after_same_bci(ao); |
|
522 upper_compare = ao; |
|
523 } |
|
524 |
|
525 // Trick with unsigned compare is done |
|
526 int bci = NOT_PRODUCT(first->printable_bci()) PRODUCT_ONLY(-1); |
|
527 insert_position = predicate(upper_compare, Instruction::aeq, length_instr, state, insert_position, bci); |
|
528 insert_position = predicate_cmp_with_const(lower_compare, Instruction::leq, -1, state, insert_position); |
|
529 for (int j = 0; j<info->_list->length(); j++) { |
|
530 AccessIndexed *ai = info->_list->at(j); |
|
531 remove_range_check(ai); |
|
532 } |
|
533 } |
|
534 _access_indexed_info[index_instruction->id()] = NULL; |
|
535 } |
|
536 indices.clear(); |
|
537 |
|
538 if (list_constant.length() > 1) { |
|
539 AccessIndexed *first = list_constant.at(0); |
|
540 Instruction *insert_position = first->prev(); |
|
541 ValueStack *state = first->state_before(); |
|
542 // Load max Constant |
|
543 Constant *constant = new Constant(new IntConstant(max_constant)); |
|
544 NOT_PRODUCT(constant->set_printable_bci(first->printable_bci())); |
|
545 insert_position = insert_position->insert_after(constant); |
|
546 Instruction *compare_instr = constant; |
|
547 Value length_instr = first->length(); |
|
548 if (!length_instr) { |
|
549 ArrayLength *length = new ArrayLength(array, state->copy()); |
|
550 length->set_exception_state(length->state_before()); |
|
551 length->set_flag(Instruction::DeoptimizeOnException, true); |
|
552 insert_position = insert_position->insert_after_same_bci(length); |
|
553 length_instr = length; |
|
554 } |
|
555 // Compare for greater or equal to array length |
|
556 insert_position = predicate(compare_instr, Instruction::geq, length_instr, state, insert_position); |
|
557 for (int j = 0; j<list_constant.length(); j++) { |
|
558 AccessIndexed *ai = list_constant.at(j); |
|
559 remove_range_check(ai); |
|
560 } |
|
561 } |
|
562 } |
|
563 } |
|
564 } |
|
565 |
|
566 bool RangeCheckEliminator::set_process_block_flags(BlockBegin *block) { |
|
567 Instruction *cur = block; |
|
568 bool process = false; |
|
569 |
|
570 while (cur) { |
|
571 process |= (cur->as_AccessIndexed() != NULL); |
|
572 cur = cur->next(); |
|
573 } |
|
574 |
|
575 BlockList *dominates = block->dominates(); |
|
576 for (int i=0; i<dominates->length(); i++) { |
|
577 BlockBegin *next = dominates->at(i); |
|
578 process |= set_process_block_flags(next); |
|
579 } |
|
580 |
|
581 if (!process) { |
|
582 block->set(BlockBegin::donot_eliminate_range_checks); |
|
583 } |
|
584 return process; |
|
585 } |
|
586 |
|
587 bool RangeCheckEliminator::is_ok_for_deoptimization(Instruction *insert_position, Instruction *array_instr, Instruction *length_instr, Instruction *lower_instr, int lower, Instruction *upper_instr, int upper) { |
|
588 bool upper_check = true; |
|
589 assert(lower_instr || lower >= 0, "If no lower_instr present, lower must be greater 0"); |
|
590 assert(!lower_instr || lower_instr->dominator_depth() <= insert_position->dominator_depth(), "Dominator depth must be smaller"); |
|
591 assert(!upper_instr || upper_instr->dominator_depth() <= insert_position->dominator_depth(), "Dominator depth must be smaller"); |
|
592 assert(array_instr, "Array instruction must exist"); |
|
593 assert(array_instr->dominator_depth() <= insert_position->dominator_depth(), "Dominator depth must be smaller"); |
|
594 assert(!length_instr || length_instr->dominator_depth() <= insert_position->dominator_depth(), "Dominator depth must be smaller"); |
|
595 |
|
596 if (upper_instr && upper_instr->as_ArrayLength() && upper_instr->as_ArrayLength()->array() == array_instr) { |
|
597 // static check |
|
598 if (upper >= 0) return false; // would always trigger a deopt: |
|
599 // array_length + x >= array_length, x >= 0 is always true |
|
600 upper_check = false; |
|
601 } |
|
602 if (lower_instr && lower_instr->as_ArrayLength() && lower_instr->as_ArrayLength()->array() == array_instr) { |
|
603 if (lower > 0) return false; |
|
604 } |
|
605 // No upper check required -> skip |
|
606 if (upper_check && upper_instr && upper_instr->type()->as_ObjectType() && upper_instr == array_instr) { |
|
607 // upper_instr is object means that the upper bound is the length |
|
608 // of the upper_instr. |
|
609 return false; |
|
610 } |
|
611 return true; |
|
612 } |
|
613 |
|
614 Instruction* RangeCheckEliminator::insert_after(Instruction* insert_position, Instruction* instr, int bci) { |
|
615 if (bci != -1) { |
|
616 NOT_PRODUCT(instr->set_printable_bci(bci)); |
|
617 return insert_position->insert_after(instr); |
|
618 } else { |
|
619 return insert_position->insert_after_same_bci(instr); |
|
620 } |
|
621 } |
|
622 |
|
623 Instruction* RangeCheckEliminator::predicate(Instruction* left, Instruction::Condition cond, Instruction* right, ValueStack* state, Instruction *insert_position, int bci) { |
|
624 RangeCheckPredicate *deoptimize = new RangeCheckPredicate(left, cond, true, right, state->copy()); |
|
625 return insert_after(insert_position, deoptimize, bci); |
|
626 } |
|
627 |
|
628 Instruction* RangeCheckEliminator::predicate_cmp_with_const(Instruction* instr, Instruction::Condition cond, int constant, ValueStack* state, Instruction *insert_position, int bci) { |
|
629 Constant *const_instr = new Constant(new IntConstant(constant)); |
|
630 insert_position = insert_after(insert_position, const_instr, bci); |
|
631 return predicate(instr, cond, const_instr, state, insert_position); |
|
632 } |
|
633 |
|
634 Instruction* RangeCheckEliminator::predicate_add(Instruction* left, int left_const, Instruction::Condition cond, Instruction* right, ValueStack* state, Instruction *insert_position, int bci) { |
|
635 Constant *constant = new Constant(new IntConstant(left_const)); |
|
636 insert_position = insert_after(insert_position, constant, bci); |
|
637 ArithmeticOp *ao = new ArithmeticOp(Bytecodes::_iadd, constant, left, false, NULL); |
|
638 insert_position = insert_position->insert_after_same_bci(ao); |
|
639 return predicate(ao, cond, right, state, insert_position); |
|
640 } |
|
641 |
|
642 Instruction* RangeCheckEliminator::predicate_add_cmp_with_const(Instruction* left, int left_const, Instruction::Condition cond, int constant, ValueStack* state, Instruction *insert_position, int bci) { |
|
643 Constant *const_instr = new Constant(new IntConstant(constant)); |
|
644 insert_position = insert_after(insert_position, const_instr, bci); |
|
645 return predicate_add(left, left_const, cond, const_instr, state, insert_position); |
|
646 } |
|
647 |
|
648 // Insert deoptimization, returns true if sucessful or false if range check should not be removed |
|
649 void RangeCheckEliminator::insert_deoptimization(ValueStack *state, Instruction *insert_position, Instruction *array_instr, Instruction *length_instr, Instruction *lower_instr, int lower, Instruction *upper_instr, int upper, AccessIndexed *ai) { |
|
650 assert(is_ok_for_deoptimization(insert_position, array_instr, length_instr, lower_instr, lower, upper_instr, upper), "should have been tested before"); |
|
651 bool upper_check = !(upper_instr && upper_instr->as_ArrayLength() && upper_instr->as_ArrayLength()->array() == array_instr); |
|
652 |
|
653 int bci = NOT_PRODUCT(ai->printable_bci()) PRODUCT_ONLY(-1); |
|
654 if (lower_instr) { |
|
655 assert(!lower_instr->type()->as_ObjectType(), "Must not be object type"); |
|
656 if (lower == 0) { |
|
657 // Compare for less than 0 |
|
658 insert_position = predicate_cmp_with_const(lower_instr, Instruction::lss, 0, state, insert_position, bci); |
|
659 } else if (lower > 0) { |
|
660 // Compare for smaller 0 |
|
661 insert_position = predicate_add_cmp_with_const(lower_instr, lower, Instruction::lss, 0, state, insert_position, bci); |
|
662 } else { |
|
663 assert(lower < 0, ""); |
|
664 // Add 1 |
|
665 lower++; |
|
666 lower = -lower; |
|
667 // Compare for smaller or equal 0 |
|
668 insert_position = predicate_cmp_with_const(lower_instr, Instruction::leq, lower, state, insert_position, bci); |
|
669 } |
|
670 } |
|
671 |
|
672 // We need to know length of array |
|
673 if (!length_instr) { |
|
674 // Load length if necessary |
|
675 ArrayLength *length = new ArrayLength(array_instr, state->copy()); |
|
676 NOT_PRODUCT(length->set_printable_bci(ai->printable_bci())); |
|
677 length->set_exception_state(length->state_before()); |
|
678 length->set_flag(Instruction::DeoptimizeOnException, true); |
|
679 insert_position = insert_position->insert_after(length); |
|
680 length_instr = length; |
|
681 } |
|
682 |
|
683 // No upper check required -> skip |
|
684 if (!upper_check) return; |
|
685 |
|
686 if (!upper_instr) { |
|
687 // Compare for geq array.length |
|
688 insert_position = predicate_cmp_with_const(length_instr, Instruction::leq, upper, state, insert_position, bci); |
|
689 } else { |
|
690 if (upper_instr->type()->as_ObjectType()) { |
|
691 assert(state, "must not be null"); |
|
692 assert(upper_instr != array_instr, "should be"); |
|
693 ArrayLength *length = new ArrayLength(upper_instr, state->copy()); |
|
694 NOT_PRODUCT(length->set_printable_bci(ai->printable_bci())); |
|
695 length->set_flag(Instruction::DeoptimizeOnException, true); |
|
696 length->set_exception_state(length->state_before()); |
|
697 insert_position = insert_position->insert_after(length); |
|
698 upper_instr = length; |
|
699 } |
|
700 assert(upper_instr->type()->as_IntType(), "Must not be object type!"); |
|
701 |
|
702 if (upper == 0) { |
|
703 // Compare for geq array.length |
|
704 insert_position = predicate(upper_instr, Instruction::geq, length_instr, state, insert_position, bci); |
|
705 } else if (upper < 0) { |
|
706 // Compare for geq array.length |
|
707 insert_position = predicate_add(upper_instr, upper, Instruction::geq, length_instr, state, insert_position, bci); |
|
708 } else { |
|
709 assert(upper > 0, ""); |
|
710 upper = -upper; |
|
711 // Compare for geq array.length |
|
712 insert_position = predicate_add(length_instr, upper, Instruction::leq, upper_instr, state, insert_position, bci); |
|
713 } |
|
714 } |
|
715 } |
|
716 |
|
717 // Add if condition |
|
718 void RangeCheckEliminator::add_if_condition(IntegerStack &pushed, Value x, Value y, Instruction::Condition condition) { |
|
719 if (y->as_Constant()) return; |
|
720 |
|
721 int const_value = 0; |
|
722 Value instr_value = x; |
|
723 Constant *c = x->as_Constant(); |
|
724 ArithmeticOp *ao = x->as_ArithmeticOp(); |
|
725 |
|
726 if (c != NULL) { |
|
727 const_value = c->type()->as_IntConstant()->value(); |
|
728 instr_value = NULL; |
|
729 } else if (ao != NULL && (!ao->x()->as_Constant() || !ao->y()->as_Constant()) && ((ao->op() == Bytecodes::_isub && ao->y()->as_Constant()) || ao->op() == Bytecodes::_iadd)) { |
|
730 assert(!ao->x()->as_Constant() || !ao->y()->as_Constant(), "At least one operator must be non-constant!"); |
|
731 assert(ao->op() == Bytecodes::_isub || ao->op() == Bytecodes::_iadd, "Operation has to be add or sub!"); |
|
732 c = ao->x()->as_Constant(); |
|
733 if (c != NULL) { |
|
734 const_value = c->type()->as_IntConstant()->value(); |
|
735 instr_value = ao->y(); |
|
736 } else { |
|
737 c = ao->y()->as_Constant(); |
|
738 if (c != NULL) { |
|
739 const_value = c->type()->as_IntConstant()->value(); |
|
740 instr_value = ao->x(); |
|
741 } |
|
742 } |
|
743 if (ao->op() == Bytecodes::_isub) { |
|
744 assert(ao->y()->as_Constant(), "1 - x not supported, only x - 1 is valid!"); |
|
745 if (const_value > min_jint) { |
|
746 const_value = -const_value; |
|
747 } else { |
|
748 const_value = 0; |
|
749 instr_value = x; |
|
750 } |
|
751 } |
|
752 } |
|
753 |
|
754 update_bound(pushed, y, condition, instr_value, const_value); |
|
755 } |
|
756 |
|
757 // Process If |
|
758 void RangeCheckEliminator::process_if(IntegerStack &pushed, BlockBegin *block, If *cond) { |
|
759 // Only if we are direct true / false successor and NOT both ! (even this may occur) |
|
760 if ((cond->tsux() == block || cond->fsux() == block) && cond->tsux() != cond->fsux()) { |
|
761 Instruction::Condition condition = cond->cond(); |
|
762 if (cond->fsux() == block) { |
|
763 condition = Instruction::negate(condition); |
|
764 } |
|
765 Value x = cond->x(); |
|
766 Value y = cond->y(); |
|
767 if (x->type()->as_IntType() && y->type()->as_IntType()) { |
|
768 add_if_condition(pushed, y, x, condition); |
|
769 add_if_condition(pushed, x, y, Instruction::mirror(condition)); |
|
770 } |
|
771 } |
|
772 } |
|
773 |
|
774 // Process access indexed |
|
775 void RangeCheckEliminator::process_access_indexed(BlockBegin *loop_header, BlockBegin *block, AccessIndexed *ai) { |
|
776 TRACE_RANGE_CHECK_ELIMINATION( |
|
777 tty->fill_to(block->dominator_depth()*2) |
|
778 ); |
|
779 TRACE_RANGE_CHECK_ELIMINATION( |
|
780 tty->print_cr("Access indexed: index=%d length=%d", ai->index()->id(), ai->length()->id()) |
|
781 ); |
|
782 |
|
783 if (ai->check_flag(Instruction::NeedsRangeCheckFlag)) { |
|
784 Bound *index_bound = get_bound(ai->index()); |
|
785 if (!index_bound->has_lower() || !index_bound->has_upper()) { |
|
786 TRACE_RANGE_CHECK_ELIMINATION( |
|
787 tty->fill_to(block->dominator_depth()*2); |
|
788 tty->print_cr("Index instruction %d has no lower and/or no upper bound!", ai->index()->id()) |
|
789 ); |
|
790 return; |
|
791 } |
|
792 |
|
793 Bound *array_bound; |
|
794 if (ai->length()) { |
|
795 array_bound = get_bound(ai->length()); |
|
796 } else { |
|
797 array_bound = get_bound(ai->array()); |
|
798 } |
|
799 |
|
800 if (in_array_bound(index_bound, ai->array()) || |
|
801 (index_bound && array_bound && index_bound->is_smaller(array_bound) && !index_bound->lower_instr() && index_bound->lower() >= 0)) { |
|
802 TRACE_RANGE_CHECK_ELIMINATION( |
|
803 tty->fill_to(block->dominator_depth()*2); |
|
804 tty->print_cr("Bounds check for instruction %d in block B%d can be fully eliminated!", ai->id(), ai->block()->block_id()) |
|
805 ); |
|
806 |
|
807 remove_range_check(ai); |
|
808 } else if (_optimistic && loop_header) { |
|
809 assert(ai->array(), "Array must not be null!"); |
|
810 assert(ai->index(), "Index must not be null!"); |
|
811 |
|
812 // Array instruction |
|
813 Instruction *array_instr = ai->array(); |
|
814 if (!loop_invariant(loop_header, array_instr)) { |
|
815 TRACE_RANGE_CHECK_ELIMINATION( |
|
816 tty->fill_to(block->dominator_depth()*2); |
|
817 tty->print_cr("Array %d is not loop invariant to header B%d", ai->array()->id(), loop_header->block_id()) |
|
818 ); |
|
819 return; |
|
820 } |
|
821 |
|
822 // Lower instruction |
|
823 Value index_instr = ai->index(); |
|
824 Value lower_instr = index_bound->lower_instr(); |
|
825 if (!loop_invariant(loop_header, lower_instr)) { |
|
826 TRACE_RANGE_CHECK_ELIMINATION( |
|
827 tty->fill_to(block->dominator_depth()*2); |
|
828 tty->print_cr("Lower instruction %d not loop invariant!", lower_instr->id()) |
|
829 ); |
|
830 return; |
|
831 } |
|
832 if (!lower_instr && index_bound->lower() < 0) { |
|
833 TRACE_RANGE_CHECK_ELIMINATION( |
|
834 tty->fill_to(block->dominator_depth()*2); |
|
835 tty->print_cr("Lower bound smaller than 0 (%d)!", index_bound->lower()) |
|
836 ); |
|
837 return; |
|
838 } |
|
839 |
|
840 // Upper instruction |
|
841 Value upper_instr = index_bound->upper_instr(); |
|
842 if (!loop_invariant(loop_header, upper_instr)) { |
|
843 TRACE_RANGE_CHECK_ELIMINATION( |
|
844 tty->fill_to(block->dominator_depth()*2); |
|
845 tty->print_cr("Upper instruction %d not loop invariant!", upper_instr->id()) |
|
846 ); |
|
847 return; |
|
848 } |
|
849 |
|
850 // Length instruction |
|
851 Value length_instr = ai->length(); |
|
852 if (!loop_invariant(loop_header, length_instr)) { |
|
853 // Generate length instruction yourself! |
|
854 length_instr = NULL; |
|
855 } |
|
856 |
|
857 TRACE_RANGE_CHECK_ELIMINATION( |
|
858 tty->fill_to(block->dominator_depth()*2); |
|
859 tty->print_cr("LOOP INVARIANT access indexed %d found in block B%d!", ai->id(), ai->block()->block_id()) |
|
860 ); |
|
861 |
|
862 BlockBegin *pred_block = loop_header->dominator(); |
|
863 assert(pred_block != NULL, "Every loop header has a dominator!"); |
|
864 BlockEnd *pred_block_end = pred_block->end(); |
|
865 Instruction *insert_position = pred_block_end->prev(); |
|
866 ValueStack *state = pred_block_end->state_before(); |
|
867 if (pred_block_end->as_Goto() && state == NULL) state = pred_block_end->state(); |
|
868 assert(state, "State must not be null"); |
|
869 |
|
870 // Add deoptimization to dominator of loop header |
|
871 TRACE_RANGE_CHECK_ELIMINATION( |
|
872 tty->fill_to(block->dominator_depth()*2); |
|
873 tty->print_cr("Inserting deopt at bci %d in block B%d!", state->bci(), insert_position->block()->block_id()) |
|
874 ); |
|
875 |
|
876 if (!is_ok_for_deoptimization(insert_position, array_instr, length_instr, lower_instr, index_bound->lower(), upper_instr, index_bound->upper())) { |
|
877 TRACE_RANGE_CHECK_ELIMINATION( |
|
878 tty->fill_to(block->dominator_depth()*2); |
|
879 tty->print_cr("Could not eliminate because of static analysis!") |
|
880 ); |
|
881 return; |
|
882 } |
|
883 |
|
884 insert_deoptimization(state, insert_position, array_instr, length_instr, lower_instr, index_bound->lower(), upper_instr, index_bound->upper(), ai); |
|
885 |
|
886 // Finally remove the range check! |
|
887 remove_range_check(ai); |
|
888 } |
|
889 } |
|
890 } |
|
891 |
|
892 void RangeCheckEliminator::remove_range_check(AccessIndexed *ai) { |
|
893 ai->set_flag(Instruction::NeedsRangeCheckFlag, false); |
|
894 // no range check, no need for the length instruction anymore |
|
895 ai->clear_length(); |
|
896 |
|
897 TRACE_RANGE_CHECK_ELIMINATION( |
|
898 tty->fill_to(ai->dominator_depth()*2); |
|
899 tty->print_cr("Range check for instruction %d eliminated!", ai->id()); |
|
900 ); |
|
901 |
|
902 ASSERT_RANGE_CHECK_ELIMINATION( |
|
903 Value array_length = ai->length(); |
|
904 if (!array_length) { |
|
905 array_length = ai->array(); |
|
906 assert(array_length->type()->as_ObjectType(), "Has to be object type!"); |
|
907 } |
|
908 int cur_constant = -1; |
|
909 Value cur_value = array_length; |
|
910 if (cur_value->type()->as_IntConstant()) { |
|
911 cur_constant += cur_value->type()->as_IntConstant()->value(); |
|
912 cur_value = NULL; |
|
913 } |
|
914 Bound *new_index_bound = new Bound(0, NULL, cur_constant, cur_value); |
|
915 add_assertions(new_index_bound, ai->index(), ai); |
|
916 ); |
|
917 } |
|
918 |
|
919 // Calculate bounds for instruction in this block and children blocks in the dominator tree |
|
920 void RangeCheckEliminator::calc_bounds(BlockBegin *block, BlockBegin *loop_header) { |
|
921 // Ensures a valid loop_header |
|
922 assert(!loop_header || loop_header->is_set(BlockBegin::linear_scan_loop_header_flag), "Loop header has to be real !"); |
|
923 |
|
924 // Tracing output |
|
925 TRACE_RANGE_CHECK_ELIMINATION( |
|
926 tty->fill_to(block->dominator_depth()*2); |
|
927 tty->print_cr("Block B%d", block->block_id()); |
|
928 ); |
|
929 |
|
930 // Pushed stack for conditions |
|
931 IntegerStack pushed; |
|
932 // Process If |
|
933 BlockBegin *parent = block->dominator(); |
|
934 if (parent != NULL) { |
|
935 If *cond = parent->end()->as_If(); |
|
936 if (cond != NULL) { |
|
937 process_if(pushed, block, cond); |
|
938 } |
|
939 } |
|
940 |
|
941 // Interate over current block |
|
942 InstructionList arrays; |
|
943 AccessIndexedList accessIndexed; |
|
944 Instruction *cur = block; |
|
945 |
|
946 while (cur) { |
|
947 // Ensure cur wasn't inserted during the elimination |
|
948 if (cur->id() < this->_bounds.length()) { |
|
949 // Process only if it is an access indexed instruction |
|
950 AccessIndexed *ai = cur->as_AccessIndexed(); |
|
951 if (ai != NULL) { |
|
952 process_access_indexed(loop_header, block, ai); |
|
953 accessIndexed.append(ai); |
|
954 if (!arrays.contains(ai->array())) { |
|
955 arrays.append(ai->array()); |
|
956 } |
|
957 Bound *b = get_bound(ai->index()); |
|
958 if (!b->lower_instr()) { |
|
959 // Lower bound is constant |
|
960 update_bound(pushed, ai->index(), Instruction::geq, NULL, 0); |
|
961 } |
|
962 if (!b->has_upper()) { |
|
963 if (ai->length() && ai->length()->type()->as_IntConstant()) { |
|
964 int value = ai->length()->type()->as_IntConstant()->value(); |
|
965 update_bound(pushed, ai->index(), Instruction::lss, NULL, value); |
|
966 } else { |
|
967 // Has no upper bound |
|
968 Instruction *instr = ai->length(); |
|
969 if (instr != NULL) instr = ai->array(); |
|
970 update_bound(pushed, ai->index(), Instruction::lss, instr, 0); |
|
971 } |
|
972 } |
|
973 } |
|
974 } |
|
975 cur = cur->next(); |
|
976 } |
|
977 |
|
978 // Output current condition stack |
|
979 TRACE_RANGE_CHECK_ELIMINATION(dump_condition_stack(block)); |
|
980 |
|
981 // Do in block motion of range checks |
|
982 in_block_motion(block, accessIndexed, arrays); |
|
983 |
|
984 // Call all dominated blocks |
|
985 for (int i=0; i<block->dominates()->length(); i++) { |
|
986 BlockBegin *next = block->dominates()->at(i); |
|
987 if (!next->is_set(BlockBegin::donot_eliminate_range_checks)) { |
|
988 // if current block is a loop header and: |
|
989 // - next block belongs to the same loop |
|
990 // or |
|
991 // - next block belongs to an inner loop |
|
992 // then current block is the loop header for next block |
|
993 if (block->is_set(BlockBegin::linear_scan_loop_header_flag) && (block->loop_index() == next->loop_index() || next->loop_depth() > block->loop_depth())) { |
|
994 calc_bounds(next, block); |
|
995 } else { |
|
996 calc_bounds(next, loop_header); |
|
997 } |
|
998 } |
|
999 } |
|
1000 |
|
1001 // Reset stack |
|
1002 for (int i=0; i<pushed.length(); i++) { |
|
1003 _bounds[pushed[i]]->pop(); |
|
1004 } |
|
1005 } |
|
1006 |
|
1007 #ifndef PRODUCT |
|
1008 // Dump condition stack |
|
1009 void RangeCheckEliminator::dump_condition_stack(BlockBegin *block) { |
|
1010 for (int i=0; i<_ir->linear_scan_order()->length(); i++) { |
|
1011 BlockBegin *cur_block = _ir->linear_scan_order()->at(i); |
|
1012 Instruction *instr = cur_block; |
|
1013 for_each_phi_fun(cur_block, phi, |
|
1014 BoundStack *bound_stack = _bounds.at(phi->id()); |
|
1015 if (bound_stack && bound_stack->length() > 0) { |
|
1016 Bound *bound = bound_stack->top(); |
|
1017 if ((bound->has_lower() || bound->has_upper()) && (bound->lower_instr() != phi || bound->upper_instr() != phi || bound->lower() != 0 || bound->upper() != 0)) { |
|
1018 TRACE_RANGE_CHECK_ELIMINATION(tty->fill_to(2*block->dominator_depth()); |
|
1019 tty->print("i%d", phi->id()); |
|
1020 tty->print(": "); |
|
1021 bound->print(); |
|
1022 tty->print_cr(""); |
|
1023 ); |
|
1024 } |
|
1025 }); |
|
1026 |
|
1027 while (!instr->as_BlockEnd()) { |
|
1028 if (instr->id() < _bounds.length()) { |
|
1029 BoundStack *bound_stack = _bounds.at(instr->id()); |
|
1030 if (bound_stack && bound_stack->length() > 0) { |
|
1031 Bound *bound = bound_stack->top(); |
|
1032 if ((bound->has_lower() || bound->has_upper()) && (bound->lower_instr() != instr || bound->upper_instr() != instr || bound->lower() != 0 || bound->upper() != 0)) { |
|
1033 TRACE_RANGE_CHECK_ELIMINATION(tty->fill_to(2*block->dominator_depth()); |
|
1034 tty->print("i%d", instr->id()); |
|
1035 tty->print(": "); |
|
1036 bound->print(); |
|
1037 tty->print_cr(""); |
|
1038 ); |
|
1039 } |
|
1040 } |
|
1041 } |
|
1042 instr = instr->next(); |
|
1043 } |
|
1044 } |
|
1045 } |
|
1046 #endif |
|
1047 |
|
1048 // Verification or the IR |
|
1049 RangeCheckEliminator::Verification::Verification(IR *ir) : _used(BlockBegin::number_of_blocks(), false) { |
|
1050 this->_ir = ir; |
|
1051 ir->iterate_linear_scan_order(this); |
|
1052 } |
|
1053 |
|
1054 // Verify this block |
|
1055 void RangeCheckEliminator::Verification::block_do(BlockBegin *block) { |
|
1056 If *cond = block->end()->as_If(); |
|
1057 // Watch out: tsux and fsux can be the same! |
|
1058 if (block->number_of_sux() > 1) { |
|
1059 for (int i=0; i<block->number_of_sux(); i++) { |
|
1060 BlockBegin *sux = block->sux_at(i); |
|
1061 BlockBegin *pred = NULL; |
|
1062 for (int j=0; j<sux->number_of_preds(); j++) { |
|
1063 BlockBegin *cur = sux->pred_at(j); |
|
1064 assert(cur != NULL, "Predecessor must not be null"); |
|
1065 if (!pred) { |
|
1066 pred = cur; |
|
1067 } |
|
1068 assert(cur == pred, "Block must not have more than one predecessor if its predecessor has more than one successor"); |
|
1069 } |
|
1070 assert(sux->number_of_preds() >= 1, "Block must have at least one predecessor"); |
|
1071 assert(sux->pred_at(0) == block, "Wrong successor"); |
|
1072 } |
|
1073 } |
|
1074 |
|
1075 BlockBegin *dominator = block->dominator(); |
|
1076 if (dominator) { |
|
1077 assert(block != _ir->start(), "Start block must not have a dominator!"); |
|
1078 assert(can_reach(dominator, block), "Dominator can't reach his block !"); |
|
1079 assert(can_reach(_ir->start(), dominator), "Dominator is unreachable !"); |
|
1080 assert(!can_reach(_ir->start(), block, dominator), "Wrong dominator ! Block can be reached anyway !"); |
|
1081 BlockList *all_blocks = _ir->linear_scan_order(); |
|
1082 for (int i=0; i<all_blocks->length(); i++) { |
|
1083 BlockBegin *cur = all_blocks->at(i); |
|
1084 if (cur != dominator && cur != block) { |
|
1085 assert(can_reach(dominator, block, cur), "There has to be another dominator!"); |
|
1086 } |
|
1087 } |
|
1088 } else { |
|
1089 assert(block == _ir->start(), "Only start block must not have a dominator"); |
|
1090 } |
|
1091 |
|
1092 if (block->is_set(BlockBegin::linear_scan_loop_header_flag)) { |
|
1093 int loop_index = block->loop_index(); |
|
1094 BlockList *all_blocks = _ir->linear_scan_order(); |
|
1095 assert(block->number_of_preds() >= 1, "Block must have at least one predecessor"); |
|
1096 assert(!block->is_set(BlockBegin::exception_entry_flag), "Loop header must not be exception handler!"); |
|
1097 // Sometimes, the backbranch comes from an exception handler. In |
|
1098 // this case, loop indexes/loop depths may not appear correct. |
|
1099 bool loop_through_xhandler = false; |
|
1100 for (int i = 0; i < block->number_of_exception_handlers(); i++) { |
|
1101 BlockBegin *xhandler = block->exception_handler_at(i); |
|
1102 for (int j = 0; j < block->number_of_preds(); j++) { |
|
1103 if (dominates(xhandler, block->pred_at(j)) || xhandler == block->pred_at(j)) { |
|
1104 loop_through_xhandler = true; |
|
1105 } |
|
1106 } |
|
1107 } |
|
1108 |
|
1109 for (int i=0; i<block->number_of_sux(); i++) { |
|
1110 BlockBegin *sux = block->sux_at(i); |
|
1111 assert(sux->loop_depth() != block->loop_depth() || sux->loop_index() == block->loop_index() || loop_through_xhandler, "Loop index has to be same"); |
|
1112 assert(sux->loop_depth() == block->loop_depth() || sux->loop_index() != block->loop_index(), "Loop index has to be different"); |
|
1113 } |
|
1114 |
|
1115 for (int i=0; i<all_blocks->length(); i++) { |
|
1116 BlockBegin *cur = all_blocks->at(i); |
|
1117 if (cur->loop_index() == loop_index && cur != block) { |
|
1118 assert(dominates(block->dominator(), cur), "Dominator of loop header must dominate all loop blocks"); |
|
1119 } |
|
1120 } |
|
1121 } |
|
1122 |
|
1123 Instruction *cur = block; |
|
1124 while (cur) { |
|
1125 assert(cur->block() == block, "Block begin has to be set correctly!"); |
|
1126 cur = cur->next(); |
|
1127 } |
|
1128 } |
|
1129 |
|
1130 // Loop header must dominate all loop blocks |
|
1131 bool RangeCheckEliminator::Verification::dominates(BlockBegin *dominator, BlockBegin *block) { |
|
1132 BlockBegin *cur = block->dominator(); |
|
1133 while (cur && cur != dominator) { |
|
1134 cur = cur->dominator(); |
|
1135 } |
|
1136 return cur == dominator; |
|
1137 } |
|
1138 |
|
1139 // Try to reach Block end beginning in Block start and not using Block dont_use |
|
1140 bool RangeCheckEliminator::Verification::can_reach(BlockBegin *start, BlockBegin *end, BlockBegin *dont_use /* = NULL */) { |
|
1141 if (start == end) return start != dont_use; |
|
1142 // Simple BSF from start to end |
|
1143 // BlockBeginList _current; |
|
1144 for (int i=0; i<_used.length(); i++) { |
|
1145 _used[i] = false; |
|
1146 } |
|
1147 _current.truncate(0); |
|
1148 _successors.truncate(0); |
|
1149 if (start != dont_use) { |
|
1150 _current.push(start); |
|
1151 _used[start->block_id()] = true; |
|
1152 } |
|
1153 |
|
1154 // BlockBeginList _successors; |
|
1155 while (_current.length() > 0) { |
|
1156 BlockBegin *cur = _current.pop(); |
|
1157 // Add exception handlers to list |
|
1158 for (int i=0; i<cur->number_of_exception_handlers(); i++) { |
|
1159 BlockBegin *xhandler = cur->exception_handler_at(i); |
|
1160 _successors.push(xhandler); |
|
1161 // Add exception handlers of _successors to list |
|
1162 for (int j=0; j<xhandler->number_of_exception_handlers(); j++) { |
|
1163 BlockBegin *sux_xhandler = xhandler->exception_handler_at(j); |
|
1164 _successors.push(sux_xhandler); |
|
1165 } |
|
1166 } |
|
1167 // Add normal _successors to list |
|
1168 for (int i=0; i<cur->number_of_sux(); i++) { |
|
1169 BlockBegin *sux = cur->sux_at(i); |
|
1170 _successors.push(sux); |
|
1171 // Add exception handlers of _successors to list |
|
1172 for (int j=0; j<sux->number_of_exception_handlers(); j++) { |
|
1173 BlockBegin *xhandler = sux->exception_handler_at(j); |
|
1174 _successors.push(xhandler); |
|
1175 } |
|
1176 } |
|
1177 for (int i=0; i<_successors.length(); i++) { |
|
1178 BlockBegin *sux = _successors[i]; |
|
1179 assert(sux != NULL, "Successor must not be NULL!"); |
|
1180 if (sux == end) { |
|
1181 return true; |
|
1182 } |
|
1183 if (sux != dont_use && !_used[sux->block_id()]) { |
|
1184 _used[sux->block_id()] = true; |
|
1185 _current.push(sux); |
|
1186 } |
|
1187 } |
|
1188 _successors.truncate(0); |
|
1189 } |
|
1190 |
|
1191 return false; |
|
1192 } |
|
1193 |
|
1194 // Bound |
|
1195 RangeCheckEliminator::Bound::~Bound() { |
|
1196 } |
|
1197 |
|
1198 // Bound constructor |
|
1199 RangeCheckEliminator::Bound::Bound() { |
|
1200 init(); |
|
1201 this->_lower = min_jint; |
|
1202 this->_upper = max_jint; |
|
1203 this->_lower_instr = NULL; |
|
1204 this->_upper_instr = NULL; |
|
1205 } |
|
1206 |
|
1207 // Bound constructor |
|
1208 RangeCheckEliminator::Bound::Bound(int lower, Value lower_instr, int upper, Value upper_instr) { |
|
1209 init(); |
|
1210 assert(!lower_instr || !lower_instr->as_Constant() || !lower_instr->type()->as_IntConstant(), "Must not be constant!"); |
|
1211 assert(!upper_instr || !upper_instr->as_Constant() || !upper_instr->type()->as_IntConstant(), "Must not be constant!"); |
|
1212 this->_lower = lower; |
|
1213 this->_upper = upper; |
|
1214 this->_lower_instr = lower_instr; |
|
1215 this->_upper_instr = upper_instr; |
|
1216 } |
|
1217 |
|
1218 // Bound constructor |
|
1219 RangeCheckEliminator::Bound::Bound(Instruction::Condition cond, Value v, int constant) { |
|
1220 assert(!v || (v->type() && (v->type()->as_IntType() || v->type()->as_ObjectType())), "Type must be array or integer!"); |
|
1221 assert(!v || !v->as_Constant() || !v->type()->as_IntConstant(), "Must not be constant!"); |
|
1222 |
|
1223 init(); |
|
1224 if (cond == Instruction::eql) { |
|
1225 _lower = constant; |
|
1226 _lower_instr = v; |
|
1227 _upper = constant; |
|
1228 _upper_instr = v; |
|
1229 } else if (cond == Instruction::neq) { |
|
1230 _lower = min_jint; |
|
1231 _upper = max_jint; |
|
1232 _lower_instr = NULL; |
|
1233 _upper_instr = NULL; |
|
1234 if (v == NULL) { |
|
1235 if (constant == min_jint) { |
|
1236 _lower++; |
|
1237 } |
|
1238 if (constant == max_jint) { |
|
1239 _upper--; |
|
1240 } |
|
1241 } |
|
1242 } else if (cond == Instruction::geq) { |
|
1243 _lower = constant; |
|
1244 _lower_instr = v; |
|
1245 _upper = max_jint; |
|
1246 _upper_instr = NULL; |
|
1247 } else if (cond == Instruction::leq) { |
|
1248 _lower = min_jint; |
|
1249 _lower_instr = NULL; |
|
1250 _upper = constant; |
|
1251 _upper_instr = v; |
|
1252 } else { |
|
1253 ShouldNotReachHere(); |
|
1254 } |
|
1255 } |
|
1256 |
|
1257 // Set lower |
|
1258 void RangeCheckEliminator::Bound::set_lower(int value, Value v) { |
|
1259 assert(!v || !v->as_Constant() || !v->type()->as_IntConstant(), "Must not be constant!"); |
|
1260 this->_lower = value; |
|
1261 this->_lower_instr = v; |
|
1262 } |
|
1263 |
|
1264 // Set upper |
|
1265 void RangeCheckEliminator::Bound::set_upper(int value, Value v) { |
|
1266 assert(!v || !v->as_Constant() || !v->type()->as_IntConstant(), "Must not be constant!"); |
|
1267 this->_upper = value; |
|
1268 this->_upper_instr = v; |
|
1269 } |
|
1270 |
|
1271 // Add constant -> no overflow may occur |
|
1272 void RangeCheckEliminator::Bound::add_constant(int value) { |
|
1273 this->_lower += value; |
|
1274 this->_upper += value; |
|
1275 } |
|
1276 |
|
1277 // Init |
|
1278 void RangeCheckEliminator::Bound::init() { |
|
1279 } |
|
1280 |
|
1281 // or |
|
1282 void RangeCheckEliminator::Bound::or_op(Bound *b) { |
|
1283 // Watch out, bound is not guaranteed not to overflow! |
|
1284 // Update lower bound |
|
1285 if (_lower_instr != b->_lower_instr || (_lower_instr && _lower != b->_lower)) { |
|
1286 _lower_instr = NULL; |
|
1287 _lower = min_jint; |
|
1288 } else { |
|
1289 _lower = MIN2(_lower, b->_lower); |
|
1290 } |
|
1291 // Update upper bound |
|
1292 if (_upper_instr != b->_upper_instr || (_upper_instr && _upper != b->_upper)) { |
|
1293 _upper_instr = NULL; |
|
1294 _upper = max_jint; |
|
1295 } else { |
|
1296 _upper = MAX2(_upper, b->_upper); |
|
1297 } |
|
1298 } |
|
1299 |
|
1300 // and |
|
1301 void RangeCheckEliminator::Bound::and_op(Bound *b) { |
|
1302 // Update lower bound |
|
1303 if (_lower_instr == b->_lower_instr) { |
|
1304 _lower = MAX2(_lower, b->_lower); |
|
1305 } |
|
1306 if (b->has_lower()) { |
|
1307 bool set = true; |
|
1308 if (_lower_instr != NULL && b->_lower_instr != NULL) { |
|
1309 set = (_lower_instr->dominator_depth() > b->_lower_instr->dominator_depth()); |
|
1310 } |
|
1311 if (set) { |
|
1312 _lower = b->_lower; |
|
1313 _lower_instr = b->_lower_instr; |
|
1314 } |
|
1315 } |
|
1316 // Update upper bound |
|
1317 if (_upper_instr == b->_upper_instr) { |
|
1318 _upper = MIN2(_upper, b->_upper); |
|
1319 } |
|
1320 if (b->has_upper()) { |
|
1321 bool set = true; |
|
1322 if (_upper_instr != NULL && b->_upper_instr != NULL) { |
|
1323 set = (_upper_instr->dominator_depth() > b->_upper_instr->dominator_depth()); |
|
1324 } |
|
1325 if (set) { |
|
1326 _upper = b->_upper; |
|
1327 _upper_instr = b->_upper_instr; |
|
1328 } |
|
1329 } |
|
1330 } |
|
1331 |
|
1332 // has_upper |
|
1333 bool RangeCheckEliminator::Bound::has_upper() { |
|
1334 return _upper_instr != NULL || _upper < max_jint; |
|
1335 } |
|
1336 |
|
1337 // is_smaller |
|
1338 bool RangeCheckEliminator::Bound::is_smaller(Bound *b) { |
|
1339 if (b->_lower_instr != _upper_instr) { |
|
1340 return false; |
|
1341 } |
|
1342 return _upper < b->_lower; |
|
1343 } |
|
1344 |
|
1345 // has_lower |
|
1346 bool RangeCheckEliminator::Bound::has_lower() { |
|
1347 return _lower_instr != NULL || _lower > min_jint; |
|
1348 } |
|
1349 |
|
1350 // in_array_bound |
|
1351 bool RangeCheckEliminator::in_array_bound(Bound *bound, Value array){ |
|
1352 if (!bound) return false; |
|
1353 assert(array != NULL, "Must not be null!"); |
|
1354 assert(bound != NULL, "Must not be null!"); |
|
1355 if (bound->lower() >=0 && bound->lower_instr() == NULL && bound->upper() < 0 && bound->upper_instr() != NULL) { |
|
1356 ArrayLength *len = bound->upper_instr()->as_ArrayLength(); |
|
1357 if (bound->upper_instr() == array || (len != NULL && len->array() == array)) { |
|
1358 return true; |
|
1359 } |
|
1360 } |
|
1361 return false; |
|
1362 } |
|
1363 |
|
1364 // remove_lower |
|
1365 void RangeCheckEliminator::Bound::remove_lower() { |
|
1366 _lower = min_jint; |
|
1367 _lower_instr = NULL; |
|
1368 } |
|
1369 |
|
1370 // remove_upper |
|
1371 void RangeCheckEliminator::Bound::remove_upper() { |
|
1372 _upper = max_jint; |
|
1373 _upper_instr = NULL; |
|
1374 } |
|
1375 |
|
1376 // upper |
|
1377 int RangeCheckEliminator::Bound::upper() { |
|
1378 return _upper; |
|
1379 } |
|
1380 |
|
1381 // lower |
|
1382 int RangeCheckEliminator::Bound::lower() { |
|
1383 return _lower; |
|
1384 } |
|
1385 |
|
1386 // upper_instr |
|
1387 Value RangeCheckEliminator::Bound::upper_instr() { |
|
1388 return _upper_instr; |
|
1389 } |
|
1390 |
|
1391 // lower_instr |
|
1392 Value RangeCheckEliminator::Bound::lower_instr() { |
|
1393 return _lower_instr; |
|
1394 } |
|
1395 |
|
1396 // print |
|
1397 void RangeCheckEliminator::Bound::print() { |
|
1398 tty->print(""); |
|
1399 if (this->_lower_instr || this->_lower != min_jint) { |
|
1400 if (this->_lower_instr) { |
|
1401 tty->print("i%d", this->_lower_instr->id()); |
|
1402 if (this->_lower > 0) { |
|
1403 tty->print("+%d", _lower); |
|
1404 } |
|
1405 if (this->_lower < 0) { |
|
1406 tty->print("%d", _lower); |
|
1407 } |
|
1408 } else { |
|
1409 tty->print("%d", _lower); |
|
1410 } |
|
1411 tty->print(" <= "); |
|
1412 } |
|
1413 tty->print("x"); |
|
1414 if (this->_upper_instr || this->_upper != max_jint) { |
|
1415 tty->print(" <= "); |
|
1416 if (this->_upper_instr) { |
|
1417 tty->print("i%d", this->_upper_instr->id()); |
|
1418 if (this->_upper > 0) { |
|
1419 tty->print("+%d", _upper); |
|
1420 } |
|
1421 if (this->_upper < 0) { |
|
1422 tty->print("%d", _upper); |
|
1423 } |
|
1424 } else { |
|
1425 tty->print("%d", _upper); |
|
1426 } |
|
1427 } |
|
1428 } |
|
1429 |
|
1430 // Copy |
|
1431 RangeCheckEliminator::Bound *RangeCheckEliminator::Bound::copy() { |
|
1432 Bound *b = new Bound(); |
|
1433 b->_lower = _lower; |
|
1434 b->_lower_instr = _lower_instr; |
|
1435 b->_upper = _upper; |
|
1436 b->_upper_instr = _upper_instr; |
|
1437 return b; |
|
1438 } |
|
1439 |
|
1440 #ifdef ASSERT |
|
1441 // Add assertion |
|
1442 void RangeCheckEliminator::Bound::add_assertion(Instruction *instruction, Instruction *position, int i, Value instr, Instruction::Condition cond) { |
|
1443 Instruction *result = position; |
|
1444 Instruction *compare_with = NULL; |
|
1445 ValueStack *state = position->state_before(); |
|
1446 if (position->as_BlockEnd() && !position->as_Goto()) { |
|
1447 state = position->as_BlockEnd()->state_before(); |
|
1448 } |
|
1449 Instruction *instruction_before = position->prev(); |
|
1450 if (position->as_Return() && Compilation::current()->method()->is_synchronized() && instruction_before->as_MonitorExit()) { |
|
1451 instruction_before = instruction_before->prev(); |
|
1452 } |
|
1453 result = instruction_before; |
|
1454 // Load constant only if needed |
|
1455 Constant *constant = NULL; |
|
1456 if (i != 0 || !instr) { |
|
1457 constant = new Constant(new IntConstant(i)); |
|
1458 NOT_PRODUCT(constant->set_printable_bci(position->printable_bci())); |
|
1459 result = result->insert_after(constant); |
|
1460 compare_with = constant; |
|
1461 } |
|
1462 |
|
1463 if (instr) { |
|
1464 assert(instr->type()->as_ObjectType() || instr->type()->as_IntType(), "Type must be array or integer!"); |
|
1465 compare_with = instr; |
|
1466 // Load array length if necessary |
|
1467 Instruction *op = instr; |
|
1468 if (instr->type()->as_ObjectType()) { |
|
1469 assert(state, "must not be null"); |
|
1470 ArrayLength *length = new ArrayLength(instr, state->copy()); |
|
1471 NOT_PRODUCT(length->set_printable_bci(position->printable_bci())); |
|
1472 length->set_exception_state(length->state_before()); |
|
1473 result = result->insert_after(length); |
|
1474 op = length; |
|
1475 compare_with = length; |
|
1476 } |
|
1477 // Add operation only if necessary |
|
1478 if (constant) { |
|
1479 ArithmeticOp *ao = new ArithmeticOp(Bytecodes::_iadd, constant, op, false, NULL); |
|
1480 NOT_PRODUCT(ao->set_printable_bci(position->printable_bci())); |
|
1481 result = result->insert_after(ao); |
|
1482 compare_with = ao; |
|
1483 // TODO: Check that add operation does not overflow! |
|
1484 } |
|
1485 } |
|
1486 assert(compare_with != NULL, "You have to compare with something!"); |
|
1487 assert(instruction != NULL, "Instruction must not be null!"); |
|
1488 |
|
1489 if (instruction->type()->as_ObjectType()) { |
|
1490 // Load array length if necessary |
|
1491 Instruction *op = instruction; |
|
1492 assert(state, "must not be null"); |
|
1493 ArrayLength *length = new ArrayLength(instruction, state->copy()); |
|
1494 length->set_exception_state(length->state_before()); |
|
1495 NOT_PRODUCT(length->set_printable_bci(position->printable_bci())); |
|
1496 result = result->insert_after(length); |
|
1497 instruction = length; |
|
1498 } |
|
1499 |
|
1500 Assert *assert = new Assert(instruction, cond, false, compare_with); |
|
1501 NOT_PRODUCT(assert->set_printable_bci(position->printable_bci())); |
|
1502 result->insert_after(assert); |
|
1503 } |
|
1504 |
|
1505 // Add assertions |
|
1506 void RangeCheckEliminator::add_assertions(Bound *bound, Instruction *instruction, Instruction *position) { |
|
1507 // Add lower bound assertion |
|
1508 if (bound->has_lower()) { |
|
1509 bound->add_assertion(instruction, position, bound->lower(), bound->lower_instr(), Instruction::geq); |
|
1510 } |
|
1511 // Add upper bound assertion |
|
1512 if (bound->has_upper()) { |
|
1513 bound->add_assertion(instruction, position, bound->upper(), bound->upper_instr(), Instruction::leq); |
|
1514 } |
|
1515 } |
|
1516 #endif |
|
1517 |