205 __ flush(); 206 207 if (PrintMiscellaneous && (WizardMode || Verbose)) { 208 tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d", 209 itable_index, s->entry_point(), 210 (int)(s->code_end() - s->entry_point()), 211 (int)(s->code_end() - __ pc())); 212 } 213 guarantee(__ pc() <= s->code_end(), "overflowed buffer"); 214 // shut the door on sizing bugs 215 int slop = 3; // 32-bit offset is this much larger than an 8-bit one 216 assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset"); 217 218 s->set_exception_points(npe_addr, ame_addr); 219 return s; 220 } 221 222 int VtableStub::pd_code_size_limit(bool is_vtable_stub) { 223 if (is_vtable_stub) { 224 // Vtable stub size 225 return (DebugVtables ? 512 : 24) + (CountCompiledCalls ? 13 : 0) + 226 (UseCompressedClassPointers ? MacroAssembler::instr_size_for_decode_klass_not_null() : 0); 227 } else { 228 // Itable stub size 229 return (DebugVtables ? 512 : 74) + (CountCompiledCalls ? 13 : 0) + 230 (UseCompressedClassPointers ? MacroAssembler::instr_size_for_decode_klass_not_null() : 0); 231 } 232 // In order to tune these parameters, run the JVM with VM options 233 // +PrintMiscellaneous and +WizardMode to see information about 234 // actual itable stubs. Look for lines like this: 235 // itable #1 at 0x5551212[71] left over: 3 236 // Reduce the constants so that the "left over" number is >=3 237 // for the common cases. 238 // Do not aim at a left-over number of zero, because a 239 // large vtable or itable index (>= 32) will require a 32-bit 240 // immediate displacement instead of an 8-bit one. 241 // 242 // The JVM98 app. _202_jess has a megamorphic interface call. 243 // The itable code looks like this: 244 // Decoding VtableStub itbl[1]@12 245 // mov 0x8(%rsi),%r10 246 // mov 0x198(%r10),%r11d 247 // lea 0x218(%r10,%r11,8),%r11 248 // lea 0x8(%r10),%r10 249 // mov (%r11),%rbx | 205 __ flush(); 206 207 if (PrintMiscellaneous && (WizardMode || Verbose)) { 208 tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d", 209 itable_index, s->entry_point(), 210 (int)(s->code_end() - s->entry_point()), 211 (int)(s->code_end() - __ pc())); 212 } 213 guarantee(__ pc() <= s->code_end(), "overflowed buffer"); 214 // shut the door on sizing bugs 215 int slop = 3; // 32-bit offset is this much larger than an 8-bit one 216 assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset"); 217 218 s->set_exception_points(npe_addr, ame_addr); 219 return s; 220 } 221 222 int VtableStub::pd_code_size_limit(bool is_vtable_stub) { 223 if (is_vtable_stub) { 224 // Vtable stub size 225 return (ShenandoahVerifyReadsToFromSpace ? 512 : 0) + 226 (DebugVtables ? 512 : 24) + (CountCompiledCalls ? 13 : 0) + 227 (UseCompressedClassPointers ? MacroAssembler::instr_size_for_decode_klass_not_null() : 0); 228 } else { 229 // Itable stub size 230 return (ShenandoahVerifyReadsToFromSpace ? 512 : 0) + 231 (DebugVtables ? 512 : 74) + (CountCompiledCalls ? 13 : 0) + 232 (UseCompressedClassPointers ? MacroAssembler::instr_size_for_decode_klass_not_null() : 0); 233 } 234 // In order to tune these parameters, run the JVM with VM options 235 // +PrintMiscellaneous and +WizardMode to see information about 236 // actual itable stubs. Look for lines like this: 237 // itable #1 at 0x5551212[71] left over: 3 238 // Reduce the constants so that the "left over" number is >=3 239 // for the common cases. 240 // Do not aim at a left-over number of zero, because a 241 // large vtable or itable index (>= 32) will require a 32-bit 242 // immediate displacement instead of an 8-bit one. 243 // 244 // The JVM98 app. _202_jess has a megamorphic interface call. 245 // The itable code looks like this: 246 // Decoding VtableStub itbl[1]@12 247 // mov 0x8(%rsi),%r10 248 // mov 0x198(%r10),%r11d 249 // lea 0x218(%r10,%r11,8),%r11 250 // lea 0x8(%r10),%r10 251 // mov (%r11),%rbx |