1 /*
  2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
  3  * Copyright (c) 2016 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_s390.hpp"
 33 #include "runtime/sharedRuntime.hpp"
 34 #include "utilities/align.hpp"
 35 #include "utilities/macros.hpp"
 36 #include "vmreg_s390.inline.hpp"
 37 #if INCLUDE_ALL_GCS
 38 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
 39 #endif // INCLUDE_ALL_GCS
 40 
 41 #define __ ce->masm()->
 42 #undef  CHECK_BAILOUT
 43 #define CHECK_BAILOUT() { if (ce->compilation()->bailed_out()) return; }
 44 
 45 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index,
 46                                bool throw_index_out_of_bounds_exception) :
 47   _throw_index_out_of_bounds_exception(throw_index_out_of_bounds_exception),
 48   _index(index) {
 49   assert(info != NULL, "must have info");
 50   _info = new CodeEmitInfo(info);
 51 }
 52 
 53 void RangeCheckStub::emit_code(LIR_Assembler* ce) {
 54   __ bind(_entry);
 55   if (_info->deoptimize_on_exception()) {
 56     address a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);
 57     ce->emit_call_c(a);
 58     CHECK_BAILOUT();
 59     ce->add_call_info_here(_info);
 60     ce->verify_oop_map(_info);
 61     debug_only(__ should_not_reach_here());
 62     return;
 63   }
 64 
 65   // Pass the array index in Z_R1_scratch which is not managed by linear scan.
 66   if (_index->is_cpu_register()) {
 67     __ lgr_if_needed(Z_R1_scratch, _index->as_register());
 68   } else {
 69     __ load_const_optimized(Z_R1_scratch, _index->as_jint());
 70   }
 71 
 72   Runtime1::StubID stub_id;
 73   if (_throw_index_out_of_bounds_exception) {
 74     stub_id = Runtime1::throw_index_exception_id;
 75   } else {
 76     stub_id = Runtime1::throw_range_check_failed_id;
 77   }
 78   ce->emit_call_c(Runtime1::entry_for (stub_id));
 79   CHECK_BAILOUT();
 80   ce->add_call_info_here(_info);
 81   ce->verify_oop_map(_info);
 82   debug_only(__ should_not_reach_here());
 83 }
 84 
 85 PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) {
 86   _info = new CodeEmitInfo(info);
 87 }
 88 
 89 void PredicateFailedStub::emit_code(LIR_Assembler* ce) {
 90   __ bind(_entry);
 91   address a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);
 92   ce->emit_call_c(a);
 93   CHECK_BAILOUT();
 94   ce->add_call_info_here(_info);
 95   ce->verify_oop_map(_info);
 96   debug_only(__ should_not_reach_here());
 97 }
 98 
 99 void CounterOverflowStub::emit_code(LIR_Assembler* ce) {
100   __ bind(_entry);
101   Metadata *m = _method->as_constant_ptr()->as_metadata();
102   bool success = __ set_metadata_constant(m, Z_R1_scratch);
103   if (!success) {
104     ce->compilation()->bailout("const section overflow");
105     return;
106   }
107   ce->store_parameter(/*_method->as_register()*/ Z_R1_scratch, 1);
108   ce->store_parameter(_bci, 0);
109   ce->emit_call_c(Runtime1::entry_for (Runtime1::counter_overflow_id));
110   CHECK_BAILOUT();
111   ce->add_call_info_here(_info);
112   ce->verify_oop_map(_info);
113   __ branch_optimized(Assembler::bcondAlways, _continuation);
114 }
115 
116 void DivByZeroStub::emit_code(LIR_Assembler* ce) {
117   if (_offset != -1) {
118     ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
119   }
120   __ bind(_entry);
121   ce->emit_call_c(Runtime1::entry_for (Runtime1::throw_div0_exception_id));
122   CHECK_BAILOUT();
123   ce->add_call_info_here(_info);
124   debug_only(__ should_not_reach_here());
125 }
126 
127 void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
128   address a;
129   if (_info->deoptimize_on_exception()) {
130     // Deoptimize, do not throw the exception, because it is probably wrong to do it here.
131     a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);
132   } else {
133     a = Runtime1::entry_for (Runtime1::throw_null_pointer_exception_id);
134   }
135 
136   ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
137   __ bind(_entry);
138   ce->emit_call_c(a);
139   CHECK_BAILOUT();
140   ce->add_call_info_here(_info);
141   ce->verify_oop_map(_info);
142   debug_only(__ should_not_reach_here());
143 }
144 
145 // Note: pass object in Z_R1_scratch
146 void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {
147   __ bind(_entry);
148   if (_obj->is_valid()) {
149     __ z_lgr(Z_R1_scratch, _obj->as_register()); // _obj contains the optional argument to the stub
150   }
151   address a = Runtime1::entry_for (_stub);
152   ce->emit_call_c(a);
153   CHECK_BAILOUT();
154   ce->add_call_info_here(_info);
155   debug_only(__ should_not_reach_here());
156 }
157 
158 NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {
159   _result = result;
160   _klass = klass;
161   _klass_reg = klass_reg;
162   _info = new CodeEmitInfo(info);
163   assert(stub_id == Runtime1::new_instance_id                 ||
164          stub_id == Runtime1::fast_new_instance_id            ||
165          stub_id == Runtime1::fast_new_instance_init_check_id,
166          "need new_instance id");
167   _stub_id = stub_id;
168 }
169 
170 void NewInstanceStub::emit_code(LIR_Assembler* ce) {
171   __ bind(_entry);
172   assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");
173   address a = Runtime1::entry_for (_stub_id);
174   ce->emit_call_c(a);
175   CHECK_BAILOUT();
176   ce->add_call_info_here(_info);
177   ce->verify_oop_map(_info);
178   assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");
179   __ z_brul(_continuation);
180 }
181 
182 NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
183   _klass_reg = klass_reg;
184   _length = length;
185   _result = result;
186   _info = new CodeEmitInfo(info);
187 }
188 
189 void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {
190   __ bind(_entry);
191   assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");
192   __ lgr_if_needed(Z_R13, _length->as_register());
193   address a = Runtime1::entry_for (Runtime1::new_type_array_id);
194   ce->emit_call_c(a);
195   CHECK_BAILOUT();
196   ce->add_call_info_here(_info);
197   ce->verify_oop_map(_info);
198   assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");
199   __ z_brul(_continuation);
200 }
201 
202 NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
203   _klass_reg = klass_reg;
204   _length = length;
205   _result = result;
206   _info = new CodeEmitInfo(info);
207 }
208 
209 void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {
210   __ bind(_entry);
211   assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");
212   __ lgr_if_needed(Z_R13, _length->as_register());
213   address a = Runtime1::entry_for (Runtime1::new_object_array_id);
214   ce->emit_call_c(a);
215   CHECK_BAILOUT();
216   ce->add_call_info_here(_info);
217   ce->verify_oop_map(_info);
218   assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");
219   __ z_brul(_continuation);
220 }
221 
222 MonitorEnterStub::MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info)
223   : MonitorAccessStub(obj_reg, lock_reg) {
224   _info = new CodeEmitInfo(info);
225 }
226 
227 void MonitorEnterStub::emit_code(LIR_Assembler* ce) {
228   __ bind(_entry);
229   Runtime1::StubID enter_id;
230   if (ce->compilation()->has_fpu_code()) {
231     enter_id = Runtime1::monitorenter_id;
232   } else {
233     enter_id = Runtime1::monitorenter_nofpu_id;
234   }
235   __ lgr_if_needed(Z_R1_scratch, _obj_reg->as_register());
236   __ lgr_if_needed(Z_R13, _lock_reg->as_register()); // See LIRGenerator::syncTempOpr().
237   ce->emit_call_c(Runtime1::entry_for (enter_id));
238   CHECK_BAILOUT();
239   ce->add_call_info_here(_info);
240   ce->verify_oop_map(_info);
241   __ branch_optimized(Assembler::bcondAlways, _continuation);
242 }
243 
244 void MonitorExitStub::emit_code(LIR_Assembler* ce) {
245   __ bind(_entry);
246   // Move address of the BasicObjectLock into Z_R1_scratch.
247   if (_compute_lock) {
248     // Lock_reg was destroyed by fast unlocking attempt => recompute it.
249     ce->monitor_address(_monitor_ix, FrameMap::as_opr(Z_R1_scratch));
250   } else {
251     __ lgr_if_needed(Z_R1_scratch, _lock_reg->as_register());
252   }
253   // Note: non-blocking leaf routine => no call info needed.
254   Runtime1::StubID exit_id;
255   if (ce->compilation()->has_fpu_code()) {
256     exit_id = Runtime1::monitorexit_id;
257   } else {
258     exit_id = Runtime1::monitorexit_nofpu_id;
259   }
260   ce->emit_call_c(Runtime1::entry_for (exit_id));
261   CHECK_BAILOUT();
262   __ branch_optimized(Assembler::bcondAlways, _continuation);
263 }
264 
265 // Implementation of patching:
266 // - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes).
267 // - Replace original code with a call to the stub.
268 // At Runtime:
269 // - call to stub, jump to runtime.
270 // - in runtime: Preserve all registers (especially objects, i.e., source and destination object).
271 // - in runtime: After initializing class, restore original code, reexecute instruction.
272 
273 int PatchingStub::_patch_info_offset = - (12 /* load const */ + 2 /*BASR*/);
274 
275 void PatchingStub::align_patch_site(MacroAssembler* masm) {
276 #ifndef PRODUCT
277   const char* bc;
278   switch (_id) {
279   case access_field_id: bc = "patch site (access_field)"; break;
280   case load_klass_id: bc = "patch site (load_klass)"; break;
281   case load_mirror_id: bc = "patch site (load_mirror)"; break;
282   case load_appendix_id: bc = "patch site (load_appendix)"; break;
283   default: bc = "patch site (unknown patch id)"; break;
284   }
285   masm->block_comment(bc);
286 #endif
287 
288   masm->align(align_up((int)NativeGeneralJump::instruction_size, wordSize));
289 }
290 
291 void PatchingStub::emit_code(LIR_Assembler* ce) {
292   // Copy original code here.
293   assert(NativeGeneralJump::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF,
294          "not enough room for call");
295 
296   NearLabel call_patch;
297 
298   int being_initialized_entry = __ offset();
299 
300   if (_id == load_klass_id) {
301     // Produce a copy of the load klass instruction for use by the case being initialized.
302 #ifdef ASSERT
303     address start = __ pc();
304 #endif
305     AddressLiteral addrlit((intptr_t)0, metadata_Relocation::spec(_index));
306     __ load_const(_obj, addrlit);
307 
308 #ifdef ASSERT
309     for (int i = 0; i < _bytes_to_copy; i++) {
310       address ptr = (address)(_pc_start + i);
311       int a_byte = (*ptr) & 0xFF;
312       assert(a_byte == *start++, "should be the same code");
313     }
314 #endif
315   } else if (_id == load_mirror_id || _id == load_appendix_id) {
316     // Produce a copy of the load mirror instruction for use by the case being initialized.
317 #ifdef ASSERT
318     address start = __ pc();
319 #endif
320     AddressLiteral addrlit((intptr_t)0, oop_Relocation::spec(_index));
321     __ load_const(_obj, addrlit);
322 
323 #ifdef ASSERT
324     for (int i = 0; i < _bytes_to_copy; i++) {
325       address ptr = (address)(_pc_start + i);
326       int a_byte = (*ptr) & 0xFF;
327       assert(a_byte == *start++, "should be the same code");
328     }
329 #endif
330   } else {
331     // Make a copy the code which is going to be patched.
332     for (int i = 0; i < _bytes_to_copy; i++) {
333       address ptr = (address)(_pc_start + i);
334       int a_byte = (*ptr) & 0xFF;
335       __ emit_int8 (a_byte);
336     }
337   }
338 
339   address end_of_patch = __ pc();
340   int bytes_to_skip = 0;
341   if (_id == load_mirror_id) {
342     int offset = __ offset();
343     if (CommentedAssembly) {
344       __ block_comment(" being_initialized check");
345     }
346 
347     // Static field accesses have special semantics while the class
348     // initializer is being run, so we emit a test which can be used to
349     // check that this code is being executed by the initializing
350     // thread.
351     assert(_obj != noreg, "must be a valid register");
352     assert(_index >= 0, "must have oop index");
353     __ z_lg(Z_R1_scratch, java_lang_Class::klass_offset_in_bytes(), _obj);
354     __ z_cg(Z_thread, Address(Z_R1_scratch, InstanceKlass::init_thread_offset()));
355     __ branch_optimized(Assembler::bcondNotEqual, call_patch);
356 
357     // Load_klass patches may execute the patched code before it's
358     // copied back into place so we need to jump back into the main
359     // code of the nmethod to continue execution.
360     __ branch_optimized(Assembler::bcondAlways, _patch_site_continuation);
361 
362     // Make sure this extra code gets skipped.
363     bytes_to_skip += __ offset() - offset;
364   }
365 
366   // Now emit the patch record telling the runtime how to find the
367   // pieces of the patch. We only need 3 bytes but to help the disassembler
368   // we make the data look like a the following add instruction:
369   //   A R1, D2(X2, B2)
370   // which requires 4 bytes.
371   int sizeof_patch_record = 4;
372   bytes_to_skip += sizeof_patch_record;
373 
374   // Emit the offsets needed to find the code to patch.
375   int being_initialized_entry_offset = __ offset() - being_initialized_entry + sizeof_patch_record;
376 
377   // Emit the patch record: opcode of the add followed by 3 bytes patch record data.
378   __ emit_int8((int8_t)(A_ZOPC>>24));
379   __ emit_int8(being_initialized_entry_offset);
380   __ emit_int8(bytes_to_skip);
381   __ emit_int8(_bytes_to_copy);
382   address patch_info_pc = __ pc();
383   assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
384 
385   address entry = __ pc();
386   NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
387   address target = NULL;
388   relocInfo::relocType reloc_type = relocInfo::none;
389   switch (_id) {
390     case access_field_id:  target = Runtime1::entry_for (Runtime1::access_field_patching_id); break;
391     case load_klass_id:    target = Runtime1::entry_for (Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;
392     case load_mirror_id:   target = Runtime1::entry_for (Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;
393     case load_appendix_id: target = Runtime1::entry_for (Runtime1::load_appendix_patching_id); reloc_type = relocInfo::oop_type; break;
394     default: ShouldNotReachHere();
395   }
396   __ bind(call_patch);
397 
398   if (CommentedAssembly) {
399     __ block_comment("patch entry point");
400   }
401   // Cannot use call_c_opt() because its size is not constant.
402   __ load_const(Z_R1_scratch, target); // Must not optimize in order to keep constant _patch_info_offset constant.
403   __ z_basr(Z_R14, Z_R1_scratch);
404   assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
405   ce->add_call_info_here(_info);
406   __ z_brcl(Assembler::bcondAlways, _patch_site_entry);
407   if (_id == load_klass_id || _id == load_mirror_id || _id == load_appendix_id) {
408     CodeSection* cs = __ code_section();
409     address pc = (address)_pc_start;
410     RelocIterator iter(cs, pc, pc + 1);
411     relocInfo::change_reloc_info_for_address(&iter, (address) pc, reloc_type, relocInfo::none);
412   }
413 }
414 
415 void DeoptimizeStub::emit_code(LIR_Assembler* ce) {
416   __ bind(_entry);
417   __ load_const_optimized(Z_R1_scratch, _trap_request); // Pass trap request in Z_R1_scratch.
418   ce->emit_call_c(Runtime1::entry_for (Runtime1::deoptimize_id));
419   CHECK_BAILOUT();
420   ce->add_call_info_here(_info);
421   DEBUG_ONLY(__ should_not_reach_here());
422 }
423 
424 void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
425   // Slow case: call to native.
426   __ bind(_entry);
427   __ lgr_if_needed(Z_ARG1, src()->as_register());
428   __ lgr_if_needed(Z_ARG2, src_pos()->as_register());
429   __ lgr_if_needed(Z_ARG3, dst()->as_register());
430   __ lgr_if_needed(Z_ARG4, dst_pos()->as_register());
431   __ lgr_if_needed(Z_ARG5, length()->as_register());
432 
433   // Must align calls sites, otherwise they can't be updated atomically on MP hardware.
434   ce->align_call(lir_static_call);
435 
436   assert((__ offset() + NativeCall::call_far_pcrelative_displacement_offset) % NativeCall::call_far_pcrelative_displacement_alignment == 0,
437          "must be aligned");
438 
439   ce->emit_static_call_stub();
440 
441   // Prepend each BRASL with a nop.
442   __ relocate(relocInfo::static_call_type);
443   __ z_nop();
444   __ z_brasl(Z_R14, SharedRuntime::get_resolve_static_call_stub());
445   ce->add_call_info_here(info());
446   ce->verify_oop_map(info());
447 
448 #ifndef PRODUCT
449   __ load_const_optimized(Z_R1_scratch, (address)&Runtime1::_arraycopy_slowcase_cnt);
450   __ add2mem_32(Address(Z_R1_scratch), 1, Z_R0_scratch);
451 #endif
452 
453   __ branch_optimized(Assembler::bcondAlways, _continuation);
454 }
455 
456 
457 ///////////////////////////////////////////////////////////////////////////////////
458 #if INCLUDE_ALL_GCS
459 
460 void G1PreBarrierStub::emit_code(LIR_Assembler* ce) {
461   // At this point we know that marking is in progress.
462   // If do_load() is true then we have to emit the
463   // load of the previous value; otherwise it has already
464   // been loaded into _pre_val.
465   __ bind(_entry);
466   ce->check_reserved_argument_area(16); // RT stub needs 2 spill slots.
467   assert(pre_val()->is_register(), "Precondition.");
468 
469   Register pre_val_reg = pre_val()->as_register();
470 
471   if (do_load()) {
472     ce->mem2reg(addr(), pre_val(), T_OBJECT, patch_code(), info(), false /*wide*/, false /*unaligned*/);
473   }
474 
475   __ z_ltgr(Z_R1_scratch, pre_val_reg); // Pass oop in Z_R1_scratch to Runtime1::g1_pre_barrier_slow_id.
476   __ branch_optimized(Assembler::bcondZero, _continuation);
477   ce->emit_call_c(Runtime1::entry_for (Runtime1::g1_pre_barrier_slow_id));
478   CHECK_BAILOUT();
479   __ branch_optimized(Assembler::bcondAlways, _continuation);
480 }
481 
482 void G1PostBarrierStub::emit_code(LIR_Assembler* ce) {
483   __ bind(_entry);
484   ce->check_reserved_argument_area(16); // RT stub needs 2 spill slots.
485   assert(addr()->is_register(), "Precondition.");
486   assert(new_val()->is_register(), "Precondition.");
487   Register new_val_reg = new_val()->as_register();
488   __ z_ltgr(new_val_reg, new_val_reg);
489   __ branch_optimized(Assembler::bcondZero, _continuation);
490   __ z_lgr(Z_R1_scratch, addr()->as_pointer_register());
491   ce->emit_call_c(Runtime1::entry_for (Runtime1::g1_post_barrier_slow_id));
492   CHECK_BAILOUT();
493   __ branch_optimized(Assembler::bcondAlways, _continuation);
494 }
495 
496 #endif // INCLUDE_ALL_GCS
497 
498 #undef __