1 /*
   2  * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "c1/c1_CodeStubs.hpp"
  27 #include "c1/c1_FrameMap.hpp"
  28 #include "c1/c1_LIRAssembler.hpp"
  29 #include "c1/c1_MacroAssembler.hpp"
  30 #include "c1/c1_Runtime1.hpp"
  31 #include "nativeInst_x86.hpp"
  32 #include "oops/objArrayKlass.hpp"
  33 #include "runtime/sharedRuntime.hpp"
  34 #include "utilities/align.hpp"
  35 #include "utilities/macros.hpp"
  36 #include "vmreg_x86.inline.hpp"
  37 
  38 
  39 #define __ ce->masm()->
  40 
  41 float ConversionStub::float_zero = 0.0;
  42 double ConversionStub::double_zero = 0.0;
  43 
  44 void ConversionStub::emit_code(LIR_Assembler* ce) {
  45   __ bind(_entry);
  46   assert(bytecode() == Bytecodes::_f2i || bytecode() == Bytecodes::_d2i, "other conversions do not require stub");
  47 
  48 
  49   if (input()->is_single_xmm()) {
  50     __ comiss(input()->as_xmm_float_reg(),
  51               ExternalAddress((address)&float_zero));
  52   } else if (input()->is_double_xmm()) {
  53     __ comisd(input()->as_xmm_double_reg(),
  54               ExternalAddress((address)&double_zero));
  55   } else {
  56     LP64_ONLY(ShouldNotReachHere());
  57     __ push(rax);
  58     __ ftst();
  59     __ fnstsw_ax();
  60     __ sahf();
  61     __ pop(rax);
  62   }
  63 
  64   Label NaN, do_return;
  65   __ jccb(Assembler::parity, NaN);
  66   __ jccb(Assembler::below, do_return);
  67 
  68   // input is > 0 -> return maxInt
  69   // result register already contains 0x80000000, so subtracting 1 gives 0x7fffffff
  70   __ decrement(result()->as_register());
  71   __ jmpb(do_return);
  72 
  73   // input is NaN -> return 0
  74   __ bind(NaN);
  75   __ xorptr(result()->as_register(), result()->as_register());
  76 
  77   __ bind(do_return);
  78   __ jmp(_continuation);
  79 }
  80 
  81 void CounterOverflowStub::emit_code(LIR_Assembler* ce) {
  82   __ bind(_entry);
  83   Metadata *m = _method->as_constant_ptr()->as_metadata();
  84   ce->store_parameter(m, 1);
  85   ce->store_parameter(_bci, 0);
  86   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::counter_overflow_id)));
  87   ce->add_call_info_here(_info);
  88   ce->verify_oop_map(_info);
  89   __ jmp(_continuation);
  90 }
  91 
  92 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index, LIR_Opr array)
  93   : _index(index), _array(array), _throw_index_out_of_bounds_exception(false) {
  94   assert(info != NULL, "must have info");
  95   _info = new CodeEmitInfo(info);
  96 }
  97 
  98 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index)
  99   : _index(index), _array(NULL), _throw_index_out_of_bounds_exception(true) {
 100   assert(info != NULL, "must have info");
 101   _info = new CodeEmitInfo(info);
 102 }
 103 
 104 void RangeCheckStub::emit_code(LIR_Assembler* ce) {
 105   __ bind(_entry);
 106   if (_info->deoptimize_on_exception()) {
 107     address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
 108     __ call(RuntimeAddress(a));
 109     ce->add_call_info_here(_info);
 110     ce->verify_oop_map(_info);
 111     debug_only(__ should_not_reach_here());
 112     return;
 113   }
 114 
 115   // pass the array index on stack because all registers must be preserved
 116   if (_index->is_cpu_register()) {
 117     ce->store_parameter(_index->as_register(), 0);
 118   } else {
 119     ce->store_parameter(_index->as_jint(), 0);
 120   }
 121   Runtime1::StubID stub_id;
 122   if (_throw_index_out_of_bounds_exception) {
 123     stub_id = Runtime1::throw_index_exception_id;
 124   } else {
 125     stub_id = Runtime1::throw_range_check_failed_id;
 126     ce->store_parameter(_array->as_pointer_register(), 1);
 127   }
 128   __ call(RuntimeAddress(Runtime1::entry_for(stub_id)));
 129   ce->add_call_info_here(_info);
 130   ce->verify_oop_map(_info);
 131   debug_only(__ should_not_reach_here());
 132 }
 133 
 134 PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) {
 135   _info = new CodeEmitInfo(info);
 136 }
 137 
 138 void PredicateFailedStub::emit_code(LIR_Assembler* ce) {
 139   __ bind(_entry);
 140   address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
 141   __ call(RuntimeAddress(a));
 142   ce->add_call_info_here(_info);
 143   ce->verify_oop_map(_info);
 144   debug_only(__ should_not_reach_here());
 145 }
 146 
 147 void DivByZeroStub::emit_code(LIR_Assembler* ce) {
 148   if (_offset != -1) {
 149     ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
 150   }
 151   __ bind(_entry);
 152   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::throw_div0_exception_id)));
 153   ce->add_call_info_here(_info);
 154   debug_only(__ should_not_reach_here());
 155 }
 156 
 157 
 158 // Implementation of LoadFlattenedArrayStub
 159 
 160 LoadFlattenedArrayStub::LoadFlattenedArrayStub(LIR_Opr array, LIR_Opr index, LIR_Opr result, CodeEmitInfo* info) {
 161   _array = array;
 162   _index = index;
 163   _result = result;









 164   // Tell the register allocator that the runtime call will scratch rax.
 165   _scratch_reg = FrameMap::rax_oop_opr;
 166   _info = new CodeEmitInfo(info);
 167 }
 168 
 169 void LoadFlattenedArrayStub::emit_code(LIR_Assembler* ce) {
 170   assert(__ rsp_offset() == 0, "frame size should be fixed");
 171   __ bind(_entry);
 172   ce->store_parameter(_array->as_register(), 1);
 173   ce->store_parameter(_index->as_register(), 0);
 174   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::load_flattened_array_id)));
 175   ce->add_call_info_here(_info);
 176   ce->verify_oop_map(_info);
 177   if (_result->as_register() != rax) {
 178     __ movptr(_result->as_register(), rax);
 179   }
 180   __ jmp(_continuation);
 181 }
 182 
 183 
 184 // Implementation of StoreFlattenedArrayStub
 185 
 186 StoreFlattenedArrayStub::StoreFlattenedArrayStub(LIR_Opr array, LIR_Opr index, LIR_Opr value, CodeEmitInfo* info) {
 187   _array = array;
 188   _index = index;
 189   _value = value;
 190   _info = new CodeEmitInfo(info);
 191 }
 192 
 193 
 194 void StoreFlattenedArrayStub::emit_code(LIR_Assembler* ce) {
 195   assert(__ rsp_offset() == 0, "frame size should be fixed");
 196   __ bind(_entry);
 197   ce->store_parameter(_array->as_register(), 2);
 198   ce->store_parameter(_index->as_register(), 1);
 199   ce->store_parameter(_value->as_register(), 0);
 200   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::store_flattened_array_id)));
 201   ce->add_call_info_here(_info);
 202   ce->verify_oop_map(_info);
 203   __ jmp(_continuation);
 204 }
 205 
 206 
 207 // Implementation of NewInstanceStub
 208 
 209 NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {
 210   _result = result;
 211   _klass = klass;
 212   _klass_reg = klass_reg;
 213   _info = new CodeEmitInfo(info);
 214   assert(stub_id == Runtime1::new_instance_id                 ||
 215          stub_id == Runtime1::fast_new_instance_id            ||
 216          stub_id == Runtime1::fast_new_instance_init_check_id,
 217          "need new_instance id");
 218   _stub_id   = stub_id;
 219 }
 220 
 221 
 222 void NewInstanceStub::emit_code(LIR_Assembler* ce) {
 223   assert(__ rsp_offset() == 0, "frame size should be fixed");
 224   __ bind(_entry);
 225   __ movptr(rdx, _klass_reg->as_register());
 226   __ call(RuntimeAddress(Runtime1::entry_for(_stub_id)));
 227   ce->add_call_info_here(_info);
 228   ce->verify_oop_map(_info);
 229   assert(_result->as_register() == rax, "result must in rax,");
 230   __ jmp(_continuation);
 231 }
 232 
 233 
 234 // Implementation of NewTypeArrayStub
 235 
 236 NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
 237   _klass_reg = klass_reg;
 238   _length = length;
 239   _result = result;
 240   _info = new CodeEmitInfo(info);
 241 }
 242 
 243 
 244 void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {
 245   assert(__ rsp_offset() == 0, "frame size should be fixed");
 246   __ bind(_entry);
 247   assert(_length->as_register() == rbx, "length must in rbx,");
 248   assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
 249   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_type_array_id)));
 250   ce->add_call_info_here(_info);
 251   ce->verify_oop_map(_info);
 252   assert(_result->as_register() == rax, "result must in rax,");
 253   __ jmp(_continuation);
 254 }
 255 
 256 
 257 // Implementation of NewObjectArrayStub
 258 
 259 NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result,
 260                                        CodeEmitInfo* info, bool is_value_type) {
 261   _klass_reg = klass_reg;
 262   _result = result;
 263   _length = length;
 264   _info = new CodeEmitInfo(info);
 265   _is_value_type = is_value_type;
 266 }
 267 
 268 
 269 void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {
 270   assert(__ rsp_offset() == 0, "frame size should be fixed");
 271   __ bind(_entry);
 272   assert(_length->as_register() == rbx, "length must in rbx,");
 273   assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
 274   if (_is_value_type) {
 275     __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_value_array_id)));
 276   } else {
 277     __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_object_array_id)));
 278   }
 279   ce->add_call_info_here(_info);
 280   ce->verify_oop_map(_info);
 281   assert(_result->as_register() == rax, "result must in rax,");
 282   __ jmp(_continuation);
 283 }
 284 
 285 
 286 // Implementation of MonitorAccessStubs
 287 
 288 MonitorEnterStub::MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info, CodeStub* throw_imse_stub, LIR_Opr scratch_reg)
 289 : MonitorAccessStub(obj_reg, lock_reg)
 290 {
 291   _info = new CodeEmitInfo(info);
 292   _throw_imse_stub = throw_imse_stub;
 293   _scratch_reg = scratch_reg;
 294   if (_throw_imse_stub != NULL) {
 295     assert(_scratch_reg != LIR_OprFact::illegalOpr, "must be");
 296   }
 297 }
 298 
 299 
 300 void MonitorEnterStub::emit_code(LIR_Assembler* ce) {
 301   assert(__ rsp_offset() == 0, "frame size should be fixed");
 302   __ bind(_entry);
 303   if (_throw_imse_stub != NULL) {
 304     // When we come here, _obj_reg has already been checked to be non-null.
 305     Register mark = _scratch_reg->as_register();
 306     __ movptr(mark, Address(_obj_reg->as_register(), oopDesc::mark_offset_in_bytes()));
 307     __ testl(mark, markOopDesc::always_locked_pattern);
 308     __ jcc(Assembler::notZero, *_throw_imse_stub->entry());
 309   }
 310   ce->store_parameter(_obj_reg->as_register(),  1);
 311   ce->store_parameter(_lock_reg->as_register(), 0);
 312   Runtime1::StubID enter_id;
 313   if (ce->compilation()->has_fpu_code()) {
 314     enter_id = Runtime1::monitorenter_id;
 315   } else {
 316     enter_id = Runtime1::monitorenter_nofpu_id;
 317   }
 318   __ call(RuntimeAddress(Runtime1::entry_for(enter_id)));
 319   ce->add_call_info_here(_info);
 320   ce->verify_oop_map(_info);
 321   __ jmp(_continuation);
 322 }
 323 
 324 
 325 void MonitorExitStub::emit_code(LIR_Assembler* ce) {
 326   __ bind(_entry);
 327   if (_compute_lock) {
 328     // lock_reg was destroyed by fast unlocking attempt => recompute it
 329     ce->monitor_address(_monitor_ix, _lock_reg);
 330   }
 331   ce->store_parameter(_lock_reg->as_register(), 0);
 332   // note: non-blocking leaf routine => no call info needed
 333   Runtime1::StubID exit_id;
 334   if (ce->compilation()->has_fpu_code()) {
 335     exit_id = Runtime1::monitorexit_id;
 336   } else {
 337     exit_id = Runtime1::monitorexit_nofpu_id;
 338   }
 339   __ call(RuntimeAddress(Runtime1::entry_for(exit_id)));
 340   __ jmp(_continuation);
 341 }
 342 
 343 
 344 // Implementation of patching:
 345 // - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes)
 346 // - Replace original code with a call to the stub
 347 // At Runtime:
 348 // - call to stub, jump to runtime
 349 // - in runtime: preserve all registers (rspecially objects, i.e., source and destination object)
 350 // - in runtime: after initializing class, restore original code, reexecute instruction
 351 
 352 int PatchingStub::_patch_info_offset = -NativeGeneralJump::instruction_size;
 353 
 354 void PatchingStub::align_patch_site(MacroAssembler* masm) {
 355   // We're patching a 5-7 byte instruction on intel and we need to
 356   // make sure that we don't see a piece of the instruction.  It
 357   // appears mostly impossible on Intel to simply invalidate other
 358   // processors caches and since they may do aggressive prefetch it's
 359   // very hard to make a guess about what code might be in the icache.
 360   // Force the instruction to be double word aligned so that it
 361   // doesn't span a cache line.
 362   masm->align(align_up((int)NativeGeneralJump::instruction_size, wordSize));
 363 }
 364 
 365 void PatchingStub::emit_code(LIR_Assembler* ce) {
 366   assert(NativeCall::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF, "not enough room for call");
 367 
 368   Label call_patch;
 369 
 370   // static field accesses have special semantics while the class
 371   // initializer is being run so we emit a test which can be used to
 372   // check that this code is being executed by the initializing
 373   // thread.
 374   address being_initialized_entry = __ pc();
 375   if (CommentedAssembly) {
 376     __ block_comment(" patch template");
 377   }
 378   if (_id == load_klass_id) {
 379     // produce a copy of the load klass instruction for use by the being initialized case
 380 #ifdef ASSERT
 381     address start = __ pc();
 382 #endif
 383     Metadata* o = NULL;
 384     __ mov_metadata(_obj, o);
 385 #ifdef ASSERT
 386     for (int i = 0; i < _bytes_to_copy; i++) {
 387       address ptr = (address)(_pc_start + i);
 388       int a_byte = (*ptr) & 0xFF;
 389       assert(a_byte == *start++, "should be the same code");
 390     }
 391 #endif
 392   } else if (_id == load_mirror_id) {
 393     // produce a copy of the load mirror instruction for use by the being
 394     // initialized case
 395 #ifdef ASSERT
 396     address start = __ pc();
 397 #endif
 398     jobject o = NULL;
 399     __ movoop(_obj, o);
 400 #ifdef ASSERT
 401     for (int i = 0; i < _bytes_to_copy; i++) {
 402       address ptr = (address)(_pc_start + i);
 403       int a_byte = (*ptr) & 0xFF;
 404       assert(a_byte == *start++, "should be the same code");
 405     }
 406 #endif
 407   } else {
 408     // make a copy the code which is going to be patched.
 409     for (int i = 0; i < _bytes_to_copy; i++) {
 410       address ptr = (address)(_pc_start + i);
 411       int a_byte = (*ptr) & 0xFF;
 412       __ emit_int8(a_byte);
 413       *ptr = 0x90; // make the site look like a nop
 414     }
 415   }
 416 
 417   address end_of_patch = __ pc();
 418   int bytes_to_skip = 0;
 419   if (_id == load_mirror_id) {
 420     int offset = __ offset();
 421     if (CommentedAssembly) {
 422       __ block_comment(" being_initialized check");
 423     }
 424     assert(_obj != noreg, "must be a valid register");
 425     Register tmp = rax;
 426     Register tmp2 = rbx;
 427     __ push(tmp);
 428     __ push(tmp2);
 429     // Load without verification to keep code size small. We need it because
 430     // begin_initialized_entry_offset has to fit in a byte. Also, we know it's not null.
 431     __ movptr(tmp2, Address(_obj, java_lang_Class::klass_offset_in_bytes()));
 432     __ get_thread(tmp);
 433     __ cmpptr(tmp, Address(tmp2, InstanceKlass::init_thread_offset()));
 434     __ pop(tmp2);
 435     __ pop(tmp);
 436     __ jcc(Assembler::notEqual, call_patch);
 437 
 438     // access_field patches may execute the patched code before it's
 439     // copied back into place so we need to jump back into the main
 440     // code of the nmethod to continue execution.
 441     __ jmp(_patch_site_continuation);
 442 
 443     // make sure this extra code gets skipped
 444     bytes_to_skip += __ offset() - offset;
 445   }
 446   if (CommentedAssembly) {
 447     __ block_comment("patch data encoded as movl");
 448   }
 449   // Now emit the patch record telling the runtime how to find the
 450   // pieces of the patch.  We only need 3 bytes but for readability of
 451   // the disassembly we make the data look like a movl reg, imm32,
 452   // which requires 5 bytes
 453   int sizeof_patch_record = 5;
 454   bytes_to_skip += sizeof_patch_record;
 455 
 456   // emit the offsets needed to find the code to patch
 457   int being_initialized_entry_offset = __ pc() - being_initialized_entry + sizeof_patch_record;
 458 
 459   __ emit_int8((unsigned char)0xB8);
 460   __ emit_int8(0);
 461   __ emit_int8(being_initialized_entry_offset);
 462   __ emit_int8(bytes_to_skip);
 463   __ emit_int8(_bytes_to_copy);
 464   address patch_info_pc = __ pc();
 465   assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
 466 
 467   address entry = __ pc();
 468   NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
 469   address target = NULL;
 470   relocInfo::relocType reloc_type = relocInfo::none;
 471   switch (_id) {
 472     case access_field_id:  target = Runtime1::entry_for(Runtime1::access_field_patching_id); break;
 473     case load_klass_id:    target = Runtime1::entry_for(Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;
 474     case load_mirror_id:   target = Runtime1::entry_for(Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;
 475     case load_appendix_id:      target = Runtime1::entry_for(Runtime1::load_appendix_patching_id); reloc_type = relocInfo::oop_type; break;
 476     default: ShouldNotReachHere();
 477   }
 478   __ bind(call_patch);
 479 
 480   if (CommentedAssembly) {
 481     __ block_comment("patch entry point");
 482   }
 483   __ call(RuntimeAddress(target));
 484   assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
 485   ce->add_call_info_here(_info);
 486   int jmp_off = __ offset();
 487   __ jmp(_patch_site_entry);
 488   // Add enough nops so deoptimization can overwrite the jmp above with a call
 489   // and not destroy the world. We cannot use fat nops here, since the concurrent
 490   // code rewrite may transiently create the illegal instruction sequence.
 491   for (int j = __ offset() ; j < jmp_off + 5 ; j++ ) {
 492     __ nop();
 493   }
 494   if (_id == load_klass_id || _id == load_mirror_id || _id == load_appendix_id) {
 495     CodeSection* cs = __ code_section();
 496     RelocIterator iter(cs, (address)_pc_start, (address)(_pc_start + 1));
 497     relocInfo::change_reloc_info_for_address(&iter, (address) _pc_start, reloc_type, relocInfo::none);
 498   }
 499 }
 500 
 501 
 502 void DeoptimizeStub::emit_code(LIR_Assembler* ce) {
 503   __ bind(_entry);
 504   ce->store_parameter(_trap_request, 0);
 505   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::deoptimize_id)));
 506   ce->add_call_info_here(_info);
 507   DEBUG_ONLY(__ should_not_reach_here());
 508 }
 509 
 510 
 511 void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
 512   address a;
 513   if (_info->deoptimize_on_exception()) {
 514     // Deoptimize, do not throw the exception, because it is probably wrong to do it here.
 515     a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
 516   } else {
 517     a = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);
 518   }
 519 
 520   ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
 521   __ bind(_entry);
 522   __ call(RuntimeAddress(a));
 523   ce->add_call_info_here(_info);
 524   ce->verify_oop_map(_info);
 525   debug_only(__ should_not_reach_here());
 526 }
 527 
 528 
 529 void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {
 530   assert(__ rsp_offset() == 0, "frame size should be fixed");
 531 
 532   __ bind(_entry);
 533   // pass the object on stack because all registers must be preserved
 534   if (_obj->is_cpu_register()) {
 535     ce->store_parameter(_obj->as_register(), 0);
 536   }
 537   __ call(RuntimeAddress(Runtime1::entry_for(_stub)));
 538   ce->add_call_info_here(_info);
 539   debug_only(__ should_not_reach_here());
 540 }
 541 
 542 
 543 void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
 544   //---------------slow case: call to native-----------------
 545   __ bind(_entry);
 546   // Figure out where the args should go
 547   // This should really convert the IntrinsicID to the Method* and signature
 548   // but I don't know how to do that.
 549   //
 550   VMRegPair args[5];
 551   BasicType signature[5] = { T_OBJECT, T_INT, T_OBJECT, T_INT, T_INT};
 552   SharedRuntime::java_calling_convention(signature, args, 5, true);
 553 
 554   // push parameters
 555   // (src, src_pos, dest, destPos, length)
 556   Register r[5];
 557   r[0] = src()->as_register();
 558   r[1] = src_pos()->as_register();
 559   r[2] = dst()->as_register();
 560   r[3] = dst_pos()->as_register();
 561   r[4] = length()->as_register();
 562 
 563   // next registers will get stored on the stack
 564   for (int i = 0; i < 5 ; i++ ) {
 565     VMReg r_1 = args[i].first();
 566     if (r_1->is_stack()) {
 567       int st_off = r_1->reg2stack() * wordSize;
 568       __ movptr (Address(rsp, st_off), r[i]);
 569     } else {
 570       assert(r[i] == args[i].first()->as_Register(), "Wrong register for arg ");
 571     }
 572   }
 573 
 574   ce->align_call(lir_static_call);
 575 
 576   ce->emit_static_call_stub();
 577   if (ce->compilation()->bailed_out()) {
 578     return; // CodeCache is full
 579   }
 580   AddressLiteral resolve(SharedRuntime::get_resolve_static_call_stub(),
 581                          relocInfo::static_call_type);
 582   __ call(resolve);
 583   ce->add_call_info_here(info());
 584 
 585 #ifndef PRODUCT
 586   __ incrementl(ExternalAddress((address)&Runtime1::_arraycopy_slowcase_cnt));
 587 #endif
 588 
 589   __ jmp(_continuation);
 590 }
 591 
 592 #undef __
--- EOF ---