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1 /* |
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2 * Copyright (c) 1997, 2014, 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 "asm/macroAssembler.hpp" |
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27 #include "code/vtableStubs.hpp" |
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28 #include "interp_masm_x86.hpp" |
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29 #include "memory/resourceArea.hpp" |
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30 #include "oops/instanceKlass.hpp" |
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31 #include "oops/klassVtable.hpp" |
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32 #include "runtime/sharedRuntime.hpp" |
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33 #include "vmreg_x86.inline.hpp" |
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34 #ifdef COMPILER2 |
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35 #include "opto/runtime.hpp" |
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36 #endif |
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37 |
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38 // machine-dependent part of VtableStubs: create VtableStub of correct size and |
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39 // initialize its code |
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40 |
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41 #define __ masm-> |
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42 |
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43 #ifndef PRODUCT |
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44 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index); |
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45 #endif |
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46 |
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47 // These stubs are used by the compiler only. |
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48 // Argument registers, which must be preserved: |
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49 // rcx - receiver (always first argument) |
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50 // rdx - second argument (if any) |
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51 // Other registers that might be usable: |
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52 // rax - inline cache register (is interface for itable stub) |
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53 // rbx - method (used when calling out to interpreter) |
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54 // Available now, but may become callee-save at some point: |
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55 // rsi, rdi |
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56 // Note that rax and rdx are also used for return values. |
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57 // |
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58 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) { |
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59 const int i486_code_length = VtableStub::pd_code_size_limit(true); |
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60 VtableStub* s = new(i486_code_length) VtableStub(true, vtable_index); |
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61 // Can be NULL if there is no free space in the code cache. |
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62 if (s == NULL) { |
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63 return NULL; |
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64 } |
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65 |
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66 ResourceMark rm; |
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67 CodeBuffer cb(s->entry_point(), i486_code_length); |
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68 MacroAssembler* masm = new MacroAssembler(&cb); |
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69 |
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70 #ifndef PRODUCT |
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71 |
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72 if (CountCompiledCalls) { |
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73 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr())); |
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74 } |
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75 #endif /* PRODUCT */ |
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76 |
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77 // get receiver (need to skip return address on top of stack) |
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78 assert(VtableStub::receiver_location() == rcx->as_VMReg(), "receiver expected in rcx"); |
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79 |
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80 // get receiver klass |
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81 address npe_addr = __ pc(); |
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82 __ movptr(rax, Address(rcx, oopDesc::klass_offset_in_bytes())); |
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83 |
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84 #ifndef PRODUCT |
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85 if (DebugVtables) { |
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86 Label L; |
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87 // check offset vs vtable length |
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88 __ cmpl(Address(rax, InstanceKlass::vtable_length_offset()*wordSize), vtable_index*vtableEntry::size()); |
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89 __ jcc(Assembler::greater, L); |
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90 __ movl(rbx, vtable_index); |
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91 __ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), rcx, rbx); |
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92 __ bind(L); |
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93 } |
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94 #endif // PRODUCT |
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95 |
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96 const Register method = rbx; |
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97 |
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98 // load Method* and target address |
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99 __ lookup_virtual_method(rax, vtable_index, method); |
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100 |
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101 if (DebugVtables) { |
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102 Label L; |
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103 __ cmpptr(method, (int32_t)NULL_WORD); |
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104 __ jcc(Assembler::equal, L); |
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105 __ cmpptr(Address(method, Method::from_compiled_offset()), (int32_t)NULL_WORD); |
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106 __ jcc(Assembler::notZero, L); |
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107 __ stop("Vtable entry is NULL"); |
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108 __ bind(L); |
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109 } |
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110 |
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111 // rax,: receiver klass |
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112 // method (rbx): Method* |
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113 // rcx: receiver |
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114 address ame_addr = __ pc(); |
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115 __ jmp( Address(method, Method::from_compiled_offset())); |
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116 |
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117 masm->flush(); |
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118 |
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119 if (PrintMiscellaneous && (WizardMode || Verbose)) { |
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120 tty->print_cr("vtable #%d at "PTR_FORMAT"[%d] left over: %d", |
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121 vtable_index, p2i(s->entry_point()), |
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122 (int)(s->code_end() - s->entry_point()), |
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123 (int)(s->code_end() - __ pc())); |
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124 } |
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125 guarantee(__ pc() <= s->code_end(), "overflowed buffer"); |
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126 // shut the door on sizing bugs |
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127 int slop = 3; // 32-bit offset is this much larger than an 8-bit one |
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128 assert(vtable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset"); |
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129 |
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130 s->set_exception_points(npe_addr, ame_addr); |
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131 return s; |
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132 } |
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133 |
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134 |
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135 VtableStub* VtableStubs::create_itable_stub(int itable_index) { |
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136 // Note well: pd_code_size_limit is the absolute minimum we can get away with. If you |
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137 // add code here, bump the code stub size returned by pd_code_size_limit! |
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138 const int i486_code_length = VtableStub::pd_code_size_limit(false); |
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139 VtableStub* s = new(i486_code_length) VtableStub(false, itable_index); |
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140 // Can be NULL if there is no free space in the code cache. |
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141 if (s == NULL) { |
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142 return NULL; |
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143 } |
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144 |
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145 ResourceMark rm; |
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146 CodeBuffer cb(s->entry_point(), i486_code_length); |
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147 MacroAssembler* masm = new MacroAssembler(&cb); |
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148 |
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149 // Entry arguments: |
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150 // rax,: Interface |
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151 // rcx: Receiver |
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152 |
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153 #ifndef PRODUCT |
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154 if (CountCompiledCalls) { |
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155 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr())); |
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156 } |
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157 #endif /* PRODUCT */ |
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158 // get receiver (need to skip return address on top of stack) |
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159 |
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160 assert(VtableStub::receiver_location() == rcx->as_VMReg(), "receiver expected in rcx"); |
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161 |
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162 // get receiver klass (also an implicit null-check) |
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163 address npe_addr = __ pc(); |
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164 __ movptr(rsi, Address(rcx, oopDesc::klass_offset_in_bytes())); |
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165 |
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166 // Most registers are in use; we'll use rax, rbx, rsi, rdi |
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167 // (If we need to make rsi, rdi callee-save, do a push/pop here.) |
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168 const Register method = rbx; |
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169 Label throw_icce; |
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170 |
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171 // Get Method* and entrypoint for compiler |
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172 __ lookup_interface_method(// inputs: rec. class, interface, itable index |
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173 rsi, rax, itable_index, |
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174 // outputs: method, scan temp. reg |
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175 method, rdi, |
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176 throw_icce); |
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177 |
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178 // method (rbx): Method* |
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179 // rcx: receiver |
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180 |
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181 #ifdef ASSERT |
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182 if (DebugVtables) { |
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183 Label L1; |
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184 __ cmpptr(method, (int32_t)NULL_WORD); |
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185 __ jcc(Assembler::equal, L1); |
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186 __ cmpptr(Address(method, Method::from_compiled_offset()), (int32_t)NULL_WORD); |
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187 __ jcc(Assembler::notZero, L1); |
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188 __ stop("Method* is null"); |
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189 __ bind(L1); |
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190 } |
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191 #endif // ASSERT |
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192 |
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193 address ame_addr = __ pc(); |
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194 __ jmp(Address(method, Method::from_compiled_offset())); |
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195 |
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196 __ bind(throw_icce); |
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197 __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry())); |
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198 masm->flush(); |
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199 |
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200 if (PrintMiscellaneous && (WizardMode || Verbose)) { |
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201 tty->print_cr("itable #%d at "PTR_FORMAT"[%d] left over: %d", |
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202 itable_index, p2i(s->entry_point()), |
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203 (int)(s->code_end() - s->entry_point()), |
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204 (int)(s->code_end() - __ pc())); |
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205 } |
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206 guarantee(__ pc() <= s->code_end(), "overflowed buffer"); |
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207 // shut the door on sizing bugs |
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208 int slop = 3; // 32-bit offset is this much larger than an 8-bit one |
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209 assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset"); |
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210 |
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211 s->set_exception_points(npe_addr, ame_addr); |
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212 return s; |
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213 } |
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214 |
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215 |
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216 |
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217 int VtableStub::pd_code_size_limit(bool is_vtable_stub) { |
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218 if (is_vtable_stub) { |
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219 // Vtable stub size |
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220 return (DebugVtables ? 210 : 16) + (CountCompiledCalls ? 6 : 0); |
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221 } else { |
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222 // Itable stub size |
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223 return (DebugVtables ? 256 : 66) + (CountCompiledCalls ? 6 : 0); |
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224 } |
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225 // In order to tune these parameters, run the JVM with VM options |
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226 // +PrintMiscellaneous and +WizardMode to see information about |
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227 // actual itable stubs. Look for lines like this: |
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228 // itable #1 at 0x5551212[65] left over: 3 |
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229 // Reduce the constants so that the "left over" number is >=3 |
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230 // for the common cases. |
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231 // Do not aim at a left-over number of zero, because a |
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232 // large vtable or itable index (> 16) will require a 32-bit |
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233 // immediate displacement instead of an 8-bit one. |
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234 // |
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235 // The JVM98 app. _202_jess has a megamorphic interface call. |
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236 // The itable code looks like this: |
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237 // Decoding VtableStub itbl[1]@1 |
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238 // mov 0x4(%ecx),%esi |
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239 // mov 0xe8(%esi),%edi |
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240 // lea 0x130(%esi,%edi,4),%edi |
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241 // add $0x7,%edi |
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242 // and $0xfffffff8,%edi |
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243 // lea 0x4(%esi),%esi |
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244 // mov (%edi),%ebx |
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245 // cmp %ebx,%eax |
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246 // je success |
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247 // loop: |
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248 // test %ebx,%ebx |
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249 // je throw_icce |
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250 // add $0x8,%edi |
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251 // mov (%edi),%ebx |
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252 // cmp %ebx,%eax |
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253 // jne loop |
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254 // success: |
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255 // mov 0x4(%edi),%edi |
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256 // mov (%esi,%edi,1),%ebx |
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257 // jmp *0x44(%ebx) |
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258 // throw_icce: |
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259 // jmp throw_ICCE_entry |
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260 } |
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261 |
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262 int VtableStub::pd_code_alignment() { |
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263 return wordSize; |
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264 } |