1 /*
   2  * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2012, 2015 SAP SE. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #include "precompiled.hpp"
  27 #include "c1/c1_CodeStubs.hpp"
  28 #include "c1/c1_FrameMap.hpp"
  29 #include "c1/c1_LIRAssembler.hpp"
  30 #include "c1/c1_MacroAssembler.hpp"
  31 #include "c1/c1_Runtime1.hpp"
  32 #include "nativeInst_ppc.hpp"
  33 #include "runtime/sharedRuntime.hpp"
  34 #include "utilities/macros.hpp"
  35 #include "vmreg_ppc.inline.hpp"
  36 #if INCLUDE_ALL_GCS
  37 #include "gc/g1/g1BarrierSet.hpp"
  38 #endif // INCLUDE_ALL_GCS
  39 
  40 #define __ ce->masm()->
  41 
  42 
  43 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index,
  44                                bool throw_index_out_of_bounds_exception)
  45   : _throw_index_out_of_bounds_exception(throw_index_out_of_bounds_exception)
  46   , _index(index) {
  47   assert(info != NULL, "must have info");
  48   _info = new CodeEmitInfo(info);
  49 }
  50 
  51 void RangeCheckStub::emit_code(LIR_Assembler* ce) {
  52   __ bind(_entry);
  53 
  54   if (_info->deoptimize_on_exception()) {
  55     address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
  56     // May be used by optimizations like LoopInvariantCodeMotion or RangeCheckEliminator.
  57     DEBUG_ONLY( __ untested("RangeCheckStub: predicate_failed_trap_id"); )
  58     //__ load_const_optimized(R0, a);
  59     __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(a));
  60     __ mtctr(R0);
  61     __ bctrl();
  62     ce->add_call_info_here(_info);
  63     ce->verify_oop_map(_info);
  64     debug_only(__ illtrap());
  65     return;
  66   }
  67 
  68   address stub = _throw_index_out_of_bounds_exception ? Runtime1::entry_for(Runtime1::throw_index_exception_id)
  69                                                       : Runtime1::entry_for(Runtime1::throw_range_check_failed_id);
  70   //__ load_const_optimized(R0, stub);
  71   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(stub));
  72   __ mtctr(R0);
  73 
  74   Register index = R0; // pass in R0
  75   if (_index->is_register()) {
  76     __ extsw(index, _index->as_register());
  77   } else {
  78     __ load_const_optimized(index, _index->as_jint());
  79   }
  80 
  81   __ bctrl();
  82   ce->add_call_info_here(_info);
  83   ce->verify_oop_map(_info);
  84   debug_only(__ illtrap());
  85 }
  86 
  87 
  88 PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) {
  89   _info = new CodeEmitInfo(info);
  90 }
  91 
  92 void PredicateFailedStub::emit_code(LIR_Assembler* ce) {
  93   __ bind(_entry);
  94   address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
  95   //__ load_const_optimized(R0, a);
  96   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(a));
  97   __ mtctr(R0);
  98   __ bctrl();
  99   ce->add_call_info_here(_info);
 100   ce->verify_oop_map(_info);
 101   debug_only(__ illtrap());
 102 }
 103 
 104 
 105 void CounterOverflowStub::emit_code(LIR_Assembler* ce) {
 106   __ bind(_entry);
 107 
 108   // Parameter 1: bci
 109   __ load_const_optimized(R0, _bci);
 110   __ std(R0, -16, R1_SP);
 111 
 112   // Parameter 2: Method*
 113   Metadata *m = _method->as_constant_ptr()->as_metadata();
 114   AddressLiteral md = __ constant_metadata_address(m); // Notify OOP recorder (don't need the relocation).
 115   __ load_const_optimized(R0, md.value());
 116   __ std(R0, -8, R1_SP);
 117 
 118   address a = Runtime1::entry_for(Runtime1::counter_overflow_id);
 119   //__ load_const_optimized(R0, a);
 120   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(a));
 121   __ mtctr(R0);
 122   __ bctrl();
 123   ce->add_call_info_here(_info);
 124   ce->verify_oop_map(_info);
 125 
 126   __ b(_continuation);
 127 }
 128 
 129 
 130 void DivByZeroStub::emit_code(LIR_Assembler* ce) {
 131   if (_offset != -1) {
 132     ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
 133   }
 134   __ bind(_entry);
 135   address stub = Runtime1::entry_for(Runtime1::throw_div0_exception_id);
 136   //__ load_const_optimized(R0, stub);
 137   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(stub));
 138   __ mtctr(R0);
 139   __ bctrl();
 140   ce->add_call_info_here(_info);
 141   ce->verify_oop_map(_info);
 142   debug_only(__ illtrap());
 143 }
 144 
 145 
 146 void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
 147   address a;
 148   if (_info->deoptimize_on_exception()) {
 149     // Deoptimize, do not throw the exception, because it is probably wrong to do it here.
 150     a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
 151   } else {
 152     a = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);
 153   }
 154 
 155   if (ImplicitNullChecks || TrapBasedNullChecks) {
 156     ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
 157   }
 158   __ bind(_entry);
 159   //__ load_const_optimized(R0, a);
 160   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(a));
 161   __ mtctr(R0);
 162   __ bctrl();
 163   ce->add_call_info_here(_info);
 164   ce->verify_oop_map(_info);
 165   debug_only(__ illtrap());
 166 }
 167 
 168 
 169 // Implementation of SimpleExceptionStub
 170 void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {
 171   __ bind(_entry);
 172   address stub = Runtime1::entry_for(_stub);
 173   //__ load_const_optimized(R0, stub);
 174   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(stub));
 175   if (_obj->is_valid()) { __ mr_if_needed(/*tmp1 in do_CheckCast*/ R4_ARG2, _obj->as_register()); }
 176   __ mtctr(R0);
 177   __ bctrl();
 178   ce->add_call_info_here(_info);
 179   debug_only( __ illtrap(); )
 180 }
 181 
 182 
 183 // Implementation of NewInstanceStub
 184 NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {
 185   _result = result;
 186   _klass = klass;
 187   _klass_reg = klass_reg;
 188   _info = new CodeEmitInfo(info);
 189   assert(stub_id == Runtime1::new_instance_id                 ||
 190          stub_id == Runtime1::fast_new_instance_id            ||
 191          stub_id == Runtime1::fast_new_instance_init_check_id,
 192          "need new_instance id");
 193   _stub_id = stub_id;
 194 }
 195 
 196 void NewInstanceStub::emit_code(LIR_Assembler* ce) {
 197   __ bind(_entry);
 198 
 199   address entry = Runtime1::entry_for(_stub_id);
 200   //__ load_const_optimized(R0, entry);
 201   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(entry));
 202   __ mtctr(R0);
 203   __ bctrl();
 204   ce->add_call_info_here(_info);
 205   ce->verify_oop_map(_info);
 206   __ b(_continuation);
 207 }
 208 
 209 
 210 // Implementation of NewTypeArrayStub
 211 NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
 212   _klass_reg = klass_reg;
 213   _length = length;
 214   _result = result;
 215   _info = new CodeEmitInfo(info);
 216 }
 217 
 218 void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {
 219   __ bind(_entry);
 220 
 221   address entry = Runtime1::entry_for(Runtime1::new_type_array_id);
 222   //__ load_const_optimized(R0, entry);
 223   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(entry));
 224   __ mr_if_needed(/*op->tmp1()->as_register()*/ R5_ARG3, _length->as_register()); // already sign-extended
 225   __ mtctr(R0);
 226   __ bctrl();
 227   ce->add_call_info_here(_info);
 228   ce->verify_oop_map(_info);
 229   __ b(_continuation);
 230 }
 231 
 232 
 233 // Implementation of NewObjectArrayStub
 234 NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
 235   _klass_reg = klass_reg;
 236   _length = length;
 237   _result = result;
 238   _info = new CodeEmitInfo(info);
 239 }
 240 
 241 void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {
 242   __ bind(_entry);
 243 
 244   address entry = Runtime1::entry_for(Runtime1::new_object_array_id);
 245   //__ load_const_optimized(R0, entry);
 246   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(entry));
 247   __ mr_if_needed(/*op->tmp1()->as_register()*/ R5_ARG3, _length->as_register()); // already sign-extended
 248   __ mtctr(R0);
 249   __ bctrl();
 250   ce->add_call_info_here(_info);
 251   ce->verify_oop_map(_info);
 252   __ b(_continuation);
 253 }
 254 
 255 
 256 // Implementation of MonitorAccessStubs
 257 MonitorEnterStub::MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info)
 258   : MonitorAccessStub(obj_reg, lock_reg) {
 259   _info = new CodeEmitInfo(info);
 260 }
 261 
 262 void MonitorEnterStub::emit_code(LIR_Assembler* ce) {
 263   __ bind(_entry);
 264   address stub = Runtime1::entry_for(ce->compilation()->has_fpu_code() ? Runtime1::monitorenter_id : Runtime1::monitorenter_nofpu_id);
 265   //__ load_const_optimized(R0, stub);
 266   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(stub));
 267   __ mr_if_needed(/*scratch_opr()->as_register()*/ R4_ARG2, _obj_reg->as_register());
 268   assert(_lock_reg->as_register() == R5_ARG3, "");
 269   __ mtctr(R0);
 270   __ bctrl();
 271   ce->add_call_info_here(_info);
 272   ce->verify_oop_map(_info);
 273   __ b(_continuation);
 274 }
 275 
 276 void MonitorExitStub::emit_code(LIR_Assembler* ce) {
 277   __ bind(_entry);
 278   if (_compute_lock) {
 279     ce->monitor_address(_monitor_ix, _lock_reg);
 280   }
 281   address stub = Runtime1::entry_for(ce->compilation()->has_fpu_code() ? Runtime1::monitorexit_id : Runtime1::monitorexit_nofpu_id);
 282   //__ load_const_optimized(R0, stub);
 283   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(stub));
 284   assert(_lock_reg->as_register() == R4_ARG2, "");
 285   __ mtctr(R0);
 286   __ bctrl();
 287   __ b(_continuation);
 288 }
 289 
 290 
 291 // Implementation of patching:
 292 // - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes).
 293 // - Replace original code with a call to the stub.
 294 // At Runtime:
 295 // - call to stub, jump to runtime
 296 // - in runtime: preserve all registers (especially objects, i.e., source and destination object)
 297 // - in runtime: after initializing class, restore original code, reexecute instruction
 298 
 299 int PatchingStub::_patch_info_offset = -(5 * BytesPerInstWord);
 300 
 301 void PatchingStub::align_patch_site(MacroAssembler* ) {
 302   // Patch sites on ppc are always properly aligned.
 303 }
 304 
 305 #ifdef ASSERT
 306 inline void compare_with_patch_site(address template_start, address pc_start, int bytes_to_copy) {
 307   address start = template_start;
 308   for (int i = 0; i < bytes_to_copy; i++) {
 309     address ptr = (address)(pc_start + i);
 310     int a_byte = (*ptr) & 0xFF;
 311     assert(a_byte == *start++, "should be the same code");
 312   }
 313 }
 314 #endif
 315 
 316 void PatchingStub::emit_code(LIR_Assembler* ce) {
 317   // copy original code here
 318   assert(NativeGeneralJump::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF,
 319          "not enough room for call");
 320   assert((_bytes_to_copy & 0x3) == 0, "must copy a multiple of four bytes");
 321 
 322   Label call_patch;
 323 
 324   int being_initialized_entry = __ offset();
 325 
 326   if (_id == load_klass_id) {
 327     // Produce a copy of the load klass instruction for use by the being initialized case.
 328     AddressLiteral addrlit((address)NULL, metadata_Relocation::spec(_index));
 329     __ load_const(_obj, addrlit, R0);
 330     DEBUG_ONLY( compare_with_patch_site(__ code_section()->start() + being_initialized_entry, _pc_start, _bytes_to_copy); )
 331   } else if (_id == load_mirror_id || _id == load_appendix_id) {
 332     // Produce a copy of the load mirror instruction for use by the being initialized case.
 333     AddressLiteral addrlit((address)NULL, oop_Relocation::spec(_index));
 334     __ load_const(_obj, addrlit, R0);
 335     DEBUG_ONLY( compare_with_patch_site(__ code_section()->start() + being_initialized_entry, _pc_start, _bytes_to_copy); )
 336   } else {
 337     // Make a copy the code which is going to be patched.
 338     for (int i = 0; i < _bytes_to_copy; i++) {
 339       address ptr = (address)(_pc_start + i);
 340       int a_byte = (*ptr) & 0xFF;
 341       __ emit_int8 (a_byte);
 342     }
 343   }
 344 
 345   address end_of_patch = __ pc();
 346   int bytes_to_skip = 0;
 347   if (_id == load_mirror_id) {
 348     int offset = __ offset();
 349     __ block_comment(" being_initialized check");
 350 
 351     // Static field accesses have special semantics while the class
 352     // initializer is being run so we emit a test which can be used to
 353     // check that this code is being executed by the initializing
 354     // thread.
 355     assert(_obj != noreg, "must be a valid register");
 356     assert(_index >= 0, "must have oop index");
 357     __ mr(R0, _obj); // spill
 358     __ ld(_obj, java_lang_Class::klass_offset_in_bytes(), _obj);
 359     __ ld(_obj, in_bytes(InstanceKlass::init_thread_offset()), _obj);
 360     __ cmpd(CCR0, _obj, R16_thread);
 361     __ mr(_obj, R0); // restore
 362     __ bne(CCR0, call_patch);
 363 
 364     // Load_klass patches may execute the patched code before it's
 365     // copied back into place so we need to jump back into the main
 366     // code of the nmethod to continue execution.
 367     __ b(_patch_site_continuation);
 368 
 369     // Make sure this extra code gets skipped.
 370     bytes_to_skip += __ offset() - offset;
 371   }
 372 
 373   // Now emit the patch record telling the runtime how to find the
 374   // pieces of the patch.  We only need 3 bytes but it has to be
 375   // aligned as an instruction so emit 4 bytes.
 376   int sizeof_patch_record = 4;
 377   bytes_to_skip += sizeof_patch_record;
 378 
 379   // Emit the offsets needed to find the code to patch.
 380   int being_initialized_entry_offset = __ offset() - being_initialized_entry + sizeof_patch_record;
 381 
 382   // Emit the patch record.  We need to emit a full word, so emit an extra empty byte.
 383   __ emit_int8(0);
 384   __ emit_int8(being_initialized_entry_offset);
 385   __ emit_int8(bytes_to_skip);
 386   __ emit_int8(_bytes_to_copy);
 387   address patch_info_pc = __ pc();
 388   assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
 389 
 390   address entry = __ pc();
 391   NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
 392   address target = NULL;
 393   relocInfo::relocType reloc_type = relocInfo::none;
 394   switch (_id) {
 395     case access_field_id:  target = Runtime1::entry_for(Runtime1::access_field_patching_id); break;
 396     case load_klass_id:    target = Runtime1::entry_for(Runtime1::load_klass_patching_id);
 397                            reloc_type = relocInfo::metadata_type; break;
 398     case load_mirror_id:   target = Runtime1::entry_for(Runtime1::load_mirror_patching_id);
 399                            reloc_type = relocInfo::oop_type; break;
 400     case load_appendix_id: target = Runtime1::entry_for(Runtime1::load_appendix_patching_id);
 401                            reloc_type = relocInfo::oop_type; break;
 402     default: ShouldNotReachHere();
 403   }
 404   __ bind(call_patch);
 405 
 406   __ block_comment("patch entry point");
 407   //__ load_const(R0, target); + mtctr + bctrl must have size -_patch_info_offset
 408   __ load_const32(R0, MacroAssembler::offset_to_global_toc(target));
 409   __ add(R0, R29_TOC, R0);
 410   __ mtctr(R0);
 411   __ bctrl();
 412   assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
 413   ce->add_call_info_here(_info);
 414   __ b(_patch_site_entry);
 415   if (_id == load_klass_id || _id == load_mirror_id || _id == load_appendix_id) {
 416     CodeSection* cs = __ code_section();
 417     address pc = (address)_pc_start;
 418     RelocIterator iter(cs, pc, pc + 1);
 419     relocInfo::change_reloc_info_for_address(&iter, (address) pc, reloc_type, relocInfo::none);
 420   }
 421 }
 422 
 423 
 424 void DeoptimizeStub::emit_code(LIR_Assembler* ce) {
 425   __ bind(_entry);
 426   address stub = Runtime1::entry_for(Runtime1::deoptimize_id);
 427   //__ load_const_optimized(R0, stub);
 428   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(stub));
 429   __ mtctr(R0);
 430 
 431   __ load_const_optimized(R0, _trap_request); // Pass trap request in R0.
 432   __ bctrl();
 433   ce->add_call_info_here(_info);
 434   debug_only(__ illtrap());
 435 }
 436 
 437 
 438 void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
 439   //---------------slow case: call to native-----------------
 440   __ bind(_entry);
 441   __ mr(R3_ARG1, src()->as_register());
 442   __ extsw(R4_ARG2, src_pos()->as_register());
 443   __ mr(R5_ARG3, dst()->as_register());
 444   __ extsw(R6_ARG4, dst_pos()->as_register());
 445   __ extsw(R7_ARG5, length()->as_register());
 446 
 447   ce->emit_static_call_stub();
 448 
 449   bool success = ce->emit_trampoline_stub_for_call(SharedRuntime::get_resolve_static_call_stub());
 450   if (!success) { return; }
 451 
 452   __ relocate(relocInfo::static_call_type);
 453   // Note: At this point we do not have the address of the trampoline
 454   // stub, and the entry point might be too far away for bl, so __ pc()
 455   // serves as dummy and the bl will be patched later.
 456   __ code()->set_insts_mark();
 457   __ bl(__ pc());
 458   ce->add_call_info_here(info());
 459   ce->verify_oop_map(info());
 460 
 461 #ifndef PRODUCT
 462   const address counter = (address)&Runtime1::_arraycopy_slowcase_cnt;
 463   const Register tmp = R3, tmp2 = R4;
 464   int simm16_offs = __ load_const_optimized(tmp, counter, tmp2, true);
 465   __ lwz(tmp2, simm16_offs, tmp);
 466   __ addi(tmp2, tmp2, 1);
 467   __ stw(tmp2, simm16_offs, tmp);
 468 #endif
 469 
 470   __ b(_continuation);
 471 }
 472 
 473 
 474 ///////////////////////////////////////////////////////////////////////////////////
 475 #if INCLUDE_ALL_GCS
 476 
 477 void G1PreBarrierStub::emit_code(LIR_Assembler* ce) {
 478   // At this point we know that marking is in progress.
 479   // If do_load() is true then we have to emit the
 480   // load of the previous value; otherwise it has already
 481   // been loaded into _pre_val.
 482 
 483   __ bind(_entry);
 484 
 485   assert(pre_val()->is_register(), "Precondition.");
 486   Register pre_val_reg = pre_val()->as_register();
 487 
 488   if (do_load()) {
 489     ce->mem2reg(addr(), pre_val(), T_OBJECT, patch_code(), info(), false /*wide*/, false /*unaligned*/);
 490   }
 491 
 492   __ cmpdi(CCR0, pre_val_reg, 0);
 493   __ bc_far_optimized(Assembler::bcondCRbiIs1, __ bi0(CCR0, Assembler::equal), _continuation);
 494 
 495   address stub = Runtime1::entry_for(Runtime1::Runtime1::g1_pre_barrier_slow_id);
 496   //__ load_const_optimized(R0, stub);
 497   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(stub));
 498   __ std(pre_val_reg, -8, R1_SP); // Pass pre_val on stack.
 499   __ mtctr(R0);
 500   __ bctrl();
 501   __ b(_continuation);
 502 }
 503 
 504 void G1PostBarrierStub::emit_code(LIR_Assembler* ce) {
 505   __ bind(_entry);
 506 
 507   assert(addr()->is_register(), "Precondition.");
 508   assert(new_val()->is_register(), "Precondition.");
 509   Register addr_reg = addr()->as_pointer_register();
 510   Register new_val_reg = new_val()->as_register();
 511 
 512   __ cmpdi(CCR0, new_val_reg, 0);
 513   __ bc_far_optimized(Assembler::bcondCRbiIs1, __ bi0(CCR0, Assembler::equal), _continuation);
 514 
 515   address stub = Runtime1::entry_for(Runtime1::Runtime1::g1_post_barrier_slow_id);
 516   //__ load_const_optimized(R0, stub);
 517   __ add_const_optimized(R0, R29_TOC, MacroAssembler::offset_to_global_toc(stub));
 518   __ mtctr(R0);
 519   __ mr(R0, addr_reg); // Pass addr in R0.
 520   __ bctrl();
 521   __ b(_continuation);
 522 }
 523 
 524 #endif // INCLUDE_ALL_GCS
 525 ///////////////////////////////////////////////////////////////////////////////////
 526 
 527 #undef __