1 /*
  2  * Copyright (c) 2016, 2018, 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 
 38 #define __ ce->masm()->
 39 #undef  CHECK_BAILOUT
 40 #define CHECK_BAILOUT() { if (ce->compilation()->bailed_out()) return; }
 41 
 42 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index,
 43                                bool throw_index_out_of_bounds_exception) :
 44   _throw_index_out_of_bounds_exception(throw_index_out_of_bounds_exception),
 45   _index(index) {
 46   assert(info != NULL, "must have info");
 47   _info = new CodeEmitInfo(info);
 48 }
 49 
 50 void RangeCheckStub::emit_code(LIR_Assembler* ce) {
 51   __ bind(_entry);
 52   if (_info->deoptimize_on_exception()) {
 53     address a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);
 54     ce->emit_call_c(a);
 55     CHECK_BAILOUT();
 56     ce->add_call_info_here(_info);
 57     ce->verify_oop_map(_info);
 58     debug_only(__ should_not_reach_here());
 59     return;
 60   }
 61 
 62   // Pass the array index in Z_R1_scratch which is not managed by linear scan.
 63   if (_index->is_cpu_register()) {
 64     __ lgr_if_needed(Z_R1_scratch, _index->as_register());
 65   } else {
 66     __ load_const_optimized(Z_R1_scratch, _index->as_jint());
 67   }
 68 
 69   Runtime1::StubID stub_id;
 70   if (_throw_index_out_of_bounds_exception) {
 71     stub_id = Runtime1::throw_index_exception_id;
 72   } else {
 73     stub_id = Runtime1::throw_range_check_failed_id;
 74   }
 75   ce->emit_call_c(Runtime1::entry_for (stub_id));
 76   CHECK_BAILOUT();
 77   ce->add_call_info_here(_info);
 78   ce->verify_oop_map(_info);
 79   debug_only(__ should_not_reach_here());
 80 }
 81 
 82 PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) {
 83   _info = new CodeEmitInfo(info);
 84 }
 85 
 86 void PredicateFailedStub::emit_code(LIR_Assembler* ce) {
 87   __ bind(_entry);
 88   address a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);
 89   ce->emit_call_c(a);
 90   CHECK_BAILOUT();
 91   ce->add_call_info_here(_info);
 92   ce->verify_oop_map(_info);
 93   debug_only(__ should_not_reach_here());
 94 }
 95 
 96 void CounterOverflowStub::emit_code(LIR_Assembler* ce) {
 97   __ bind(_entry);
 98   Metadata *m = _method->as_constant_ptr()->as_metadata();
 99   bool success = __ set_metadata_constant(m, Z_R1_scratch);
100   if (!success) {
101     ce->compilation()->bailout("const section overflow");
102     return;
103   }
104   ce->store_parameter(/*_method->as_register()*/ Z_R1_scratch, 1);
105   ce->store_parameter(_bci, 0);
106   ce->emit_call_c(Runtime1::entry_for (Runtime1::counter_overflow_id));
107   CHECK_BAILOUT();
108   ce->add_call_info_here(_info);
109   ce->verify_oop_map(_info);
110   __ branch_optimized(Assembler::bcondAlways, _continuation);
111 }
112 
113 void DivByZeroStub::emit_code(LIR_Assembler* ce) {
114   if (_offset != -1) {
115     ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
116   }
117   __ bind(_entry);
118   ce->emit_call_c(Runtime1::entry_for (Runtime1::throw_div0_exception_id));
119   CHECK_BAILOUT();
120   ce->add_call_info_here(_info);
121   debug_only(__ should_not_reach_here());
122 }
123 
124 void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
125   address a;
126   if (_info->deoptimize_on_exception()) {
127     // Deoptimize, do not throw the exception, because it is probably wrong to do it here.
128     a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);
129   } else {
130     a = Runtime1::entry_for (Runtime1::throw_null_pointer_exception_id);
131   }
132 
133   ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
134   __ bind(_entry);
135   ce->emit_call_c(a);
136   CHECK_BAILOUT();
137   ce->add_call_info_here(_info);
138   ce->verify_oop_map(_info);
139   debug_only(__ should_not_reach_here());
140 }
141 
142 // Note: pass object in Z_R1_scratch
143 void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {
144   __ bind(_entry);
145   if (_obj->is_valid()) {
146     __ z_lgr(Z_R1_scratch, _obj->as_register()); // _obj contains the optional argument to the stub
147   }
148   address a = Runtime1::entry_for (_stub);
149   ce->emit_call_c(a);
150   CHECK_BAILOUT();
151   ce->add_call_info_here(_info);
152   debug_only(__ should_not_reach_here());
153 }
154 
155 NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {
156   _result = result;
157   _klass = klass;
158   _klass_reg = klass_reg;
159   _info = new CodeEmitInfo(info);
160   assert(stub_id == Runtime1::new_instance_id                 ||
161          stub_id == Runtime1::fast_new_instance_id            ||
162          stub_id == Runtime1::fast_new_instance_init_check_id,
163          "need new_instance id");
164   _stub_id = stub_id;
165 }
166 
167 void NewInstanceStub::emit_code(LIR_Assembler* ce) {
168   __ bind(_entry);
169   assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");
170   address a = Runtime1::entry_for (_stub_id);
171   ce->emit_call_c(a);
172   CHECK_BAILOUT();
173   ce->add_call_info_here(_info);
174   ce->verify_oop_map(_info);
175   assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");
176   __ z_brul(_continuation);
177 }
178 
179 NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
180   _klass_reg = klass_reg;
181   _length = length;
182   _result = result;
183   _info = new CodeEmitInfo(info);
184 }
185 
186 void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {
187   __ bind(_entry);
188   assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");
189   __ lgr_if_needed(Z_R13, _length->as_register());
190   address a = Runtime1::entry_for (Runtime1::new_type_array_id);
191   ce->emit_call_c(a);
192   CHECK_BAILOUT();
193   ce->add_call_info_here(_info);
194   ce->verify_oop_map(_info);
195   assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");
196   __ z_brul(_continuation);
197 }
198 
199 NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
200   _klass_reg = klass_reg;
201   _length = length;
202   _result = result;
203   _info = new CodeEmitInfo(info);
204 }
205 
206 void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {
207   __ bind(_entry);
208   assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");
209   __ lgr_if_needed(Z_R13, _length->as_register());
210   address a = Runtime1::entry_for (Runtime1::new_object_array_id);
211   ce->emit_call_c(a);
212   CHECK_BAILOUT();
213   ce->add_call_info_here(_info);
214   ce->verify_oop_map(_info);
215   assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");
216   __ z_brul(_continuation);
217 }
218 
219 MonitorEnterStub::MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info)
220   : MonitorAccessStub(obj_reg, lock_reg) {
221   _info = new CodeEmitInfo(info);
222 }
223 
224 void MonitorEnterStub::emit_code(LIR_Assembler* ce) {
225   __ bind(_entry);
226   Runtime1::StubID enter_id;
227   if (ce->compilation()->has_fpu_code()) {
228     enter_id = Runtime1::monitorenter_id;
229   } else {
230     enter_id = Runtime1::monitorenter_nofpu_id;
231   }
232   __ lgr_if_needed(Z_R1_scratch, _obj_reg->as_register());
233   __ lgr_if_needed(Z_R13, _lock_reg->as_register()); // See LIRGenerator::syncTempOpr().
234   ce->emit_call_c(Runtime1::entry_for (enter_id));
235   CHECK_BAILOUT();
236   ce->add_call_info_here(_info);
237   ce->verify_oop_map(_info);
238   __ branch_optimized(Assembler::bcondAlways, _continuation);
239 }
240 
241 void MonitorExitStub::emit_code(LIR_Assembler* ce) {
242   __ bind(_entry);
243   // Move address of the BasicObjectLock into Z_R1_scratch.
244   if (_compute_lock) {
245     // Lock_reg was destroyed by fast unlocking attempt => recompute it.
246     ce->monitor_address(_monitor_ix, FrameMap::as_opr(Z_R1_scratch));
247   } else {
248     __ lgr_if_needed(Z_R1_scratch, _lock_reg->as_register());
249   }
250   // Note: non-blocking leaf routine => no call info needed.
251   Runtime1::StubID exit_id;
252   if (ce->compilation()->has_fpu_code()) {
253     exit_id = Runtime1::monitorexit_id;
254   } else {
255     exit_id = Runtime1::monitorexit_nofpu_id;
256   }
257   ce->emit_call_c(Runtime1::entry_for (exit_id));
258   CHECK_BAILOUT();
259   __ branch_optimized(Assembler::bcondAlways, _continuation);
260 }
261 
262 // Implementation of patching:
263 // - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes).
264 // - Replace original code with a call to the stub.
265 // At Runtime:
266 // - call to stub, jump to runtime.
267 // - in runtime: Preserve all registers (especially objects, i.e., source and destination object).
268 // - in runtime: After initializing class, restore original code, reexecute instruction.
269 
270 int PatchingStub::_patch_info_offset = - (12 /* load const */ + 2 /*BASR*/);
271 
272 void PatchingStub::align_patch_site(MacroAssembler* masm) {
273 #ifndef PRODUCT
274   const char* bc;
275   switch (_id) {
276   case access_field_id: bc = "patch site (access_field)"; break;
277   case load_klass_id: bc = "patch site (load_klass)"; break;
278   case load_mirror_id: bc = "patch site (load_mirror)"; break;
279   case load_appendix_id: bc = "patch site (load_appendix)"; break;
280   default: bc = "patch site (unknown patch id)"; break;
281   }
282   masm->block_comment(bc);
283 #endif
284 
285   masm->align(align_up((int)NativeGeneralJump::instruction_size, wordSize));
286 }
287 
288 void PatchingStub::emit_code(LIR_Assembler* ce) {
289   // Copy original code here.
290   assert(NativeGeneralJump::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF,
291          "not enough room for call");
292 
293   NearLabel call_patch;
294 
295   int being_initialized_entry = __ offset();
296 
297   if (_id == load_klass_id) {
298     // Produce a copy of the load klass instruction for use by the case being initialized.
299 #ifdef ASSERT
300     address start = __ pc();
301 #endif
302     AddressLiteral addrlit((intptr_t)0, metadata_Relocation::spec(_index));
303     __ load_const(_obj, addrlit);
304 
305 #ifdef ASSERT
306     for (int i = 0; i < _bytes_to_copy; i++) {
307       address ptr = (address)(_pc_start + i);
308       int a_byte = (*ptr) & 0xFF;
309       assert(a_byte == *start++, "should be the same code");
310     }
311 #endif
312   } else if (_id == load_mirror_id || _id == load_appendix_id) {
313     // Produce a copy of the load mirror instruction for use by the case being initialized.
314 #ifdef ASSERT
315     address start = __ pc();
316 #endif
317     AddressLiteral addrlit((intptr_t)0, oop_Relocation::spec(_index));
318     __ load_const(_obj, addrlit);
319 
320 #ifdef ASSERT
321     for (int i = 0; i < _bytes_to_copy; i++) {
322       address ptr = (address)(_pc_start + i);
323       int a_byte = (*ptr) & 0xFF;
324       assert(a_byte == *start++, "should be the same code");
325     }
326 #endif
327   } else {
328     // Make a copy the code which is going to be patched.
329     for (int i = 0; i < _bytes_to_copy; i++) {
330       address ptr = (address)(_pc_start + i);
331       int a_byte = (*ptr) & 0xFF;
332       __ emit_int8 (a_byte);
333     }
334   }
335 
336   address end_of_patch = __ pc();
337   int bytes_to_skip = 0;
338   if (_id == load_mirror_id) {
339     int offset = __ offset();
340     if (CommentedAssembly) {
341       __ block_comment(" being_initialized check");
342     }
343 
344     // Static field accesses have special semantics while the class
345     // initializer is being run, so we emit a test which can be used to
346     // check that this code is being executed by the initializing
347     // thread.
348     assert(_obj != noreg, "must be a valid register");
349     assert(_index >= 0, "must have oop index");
350     __ z_lg(Z_R1_scratch, java_lang_Class::klass_offset_in_bytes(), _obj);
351     __ z_cg(Z_thread, Address(Z_R1_scratch, InstanceKlass::init_thread_offset()));
352     __ branch_optimized(Assembler::bcondNotEqual, call_patch);
353 
354     // Load_klass patches may execute the patched code before it's
355     // copied back into place so we need to jump back into the main
356     // code of the nmethod to continue execution.
357     __ branch_optimized(Assembler::bcondAlways, _patch_site_continuation);
358 
359     // Make sure this extra code gets skipped.
360     bytes_to_skip += __ offset() - offset;
361   }
362 
363   // Now emit the patch record telling the runtime how to find the
364   // pieces of the patch. We only need 3 bytes but to help the disassembler
365   // we make the data look like a the following add instruction:
366   //   A R1, D2(X2, B2)
367   // which requires 4 bytes.
368   int sizeof_patch_record = 4;
369   bytes_to_skip += sizeof_patch_record;
370 
371   // Emit the offsets needed to find the code to patch.
372   int being_initialized_entry_offset = __ offset() - being_initialized_entry + sizeof_patch_record;
373 
374   // Emit the patch record: opcode of the add followed by 3 bytes patch record data.
375   __ emit_int8((int8_t)(A_ZOPC>>24));
376   __ emit_int8(being_initialized_entry_offset);
377   __ emit_int8(bytes_to_skip);
378   __ emit_int8(_bytes_to_copy);
379   address patch_info_pc = __ pc();
380   assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
381 
382   address entry = __ pc();
383   NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
384   address target = NULL;
385   relocInfo::relocType reloc_type = relocInfo::none;
386   switch (_id) {
387     case access_field_id:  target = Runtime1::entry_for (Runtime1::access_field_patching_id); break;
388     case load_klass_id:    target = Runtime1::entry_for (Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;
389     case load_mirror_id:   target = Runtime1::entry_for (Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;
390     case load_appendix_id: target = Runtime1::entry_for (Runtime1::load_appendix_patching_id); reloc_type = relocInfo::oop_type; break;
391     default: ShouldNotReachHere();
392   }
393   __ bind(call_patch);
394 
395   if (CommentedAssembly) {
396     __ block_comment("patch entry point");
397   }
398   // Cannot use call_c_opt() because its size is not constant.
399   __ load_const(Z_R1_scratch, target); // Must not optimize in order to keep constant _patch_info_offset constant.
400   __ z_basr(Z_R14, Z_R1_scratch);
401   assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
402   ce->add_call_info_here(_info);
403   __ z_brcl(Assembler::bcondAlways, _patch_site_entry);
404   if (_id == load_klass_id || _id == load_mirror_id || _id == load_appendix_id) {
405     CodeSection* cs = __ code_section();
406     address pc = (address)_pc_start;
407     RelocIterator iter(cs, pc, pc + 1);
408     relocInfo::change_reloc_info_for_address(&iter, (address) pc, reloc_type, relocInfo::none);
409   }
410 }
411 
412 void DeoptimizeStub::emit_code(LIR_Assembler* ce) {
413   __ bind(_entry);
414   __ load_const_optimized(Z_R1_scratch, _trap_request); // Pass trap request in Z_R1_scratch.
415   ce->emit_call_c(Runtime1::entry_for (Runtime1::deoptimize_id));
416   CHECK_BAILOUT();
417   ce->add_call_info_here(_info);
418   DEBUG_ONLY(__ should_not_reach_here());
419 }
420 
421 void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
422   // Slow case: call to native.
423   __ bind(_entry);
424   __ lgr_if_needed(Z_ARG1, src()->as_register());
425   __ lgr_if_needed(Z_ARG2, src_pos()->as_register());
426   __ lgr_if_needed(Z_ARG3, dst()->as_register());
427   __ lgr_if_needed(Z_ARG4, dst_pos()->as_register());
428   __ lgr_if_needed(Z_ARG5, length()->as_register());
429 
430   // Must align calls sites, otherwise they can't be updated atomically on MP hardware.
431   ce->align_call(lir_static_call);
432 
433   assert((__ offset() + NativeCall::call_far_pcrelative_displacement_offset) % NativeCall::call_far_pcrelative_displacement_alignment == 0,
434          "must be aligned");
435 
436   ce->emit_static_call_stub();
437 
438   // Prepend each BRASL with a nop.
439   __ relocate(relocInfo::static_call_type);
440   __ z_nop();
441   __ z_brasl(Z_R14, SharedRuntime::get_resolve_static_call_stub());
442   ce->add_call_info_here(info());
443   ce->verify_oop_map(info());
444 
445 #ifndef PRODUCT
446   __ load_const_optimized(Z_R1_scratch, (address)&Runtime1::_arraycopy_slowcase_cnt);
447   __ add2mem_32(Address(Z_R1_scratch), 1, Z_R0_scratch);
448 #endif
449 
450   __ branch_optimized(Assembler::bcondAlways, _continuation);
451 }
452 
453 #undef __