1 /*
  2  * Copyright (c) 1999, 2023, 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 "classfile/javaClasses.hpp"
 32 #include "nativeInst_x86.hpp"
 33 #include "runtime/objectMonitor.hpp"
 34 #include "runtime/sharedRuntime.hpp"
 35 #include "utilities/align.hpp"
 36 #include "utilities/macros.hpp"
 37 #include "vmreg_x86.inline.hpp"
 38 
 39 
 40 #define __ ce->masm()->
 41 
 42 #ifndef _LP64
 43 float ConversionStub::float_zero = 0.0;
 44 double ConversionStub::double_zero = 0.0;
 45 
 46 void ConversionStub::emit_code(LIR_Assembler* ce) {
 47   __ bind(_entry);
 48   assert(bytecode() == Bytecodes::_f2i || bytecode() == Bytecodes::_d2i, "other conversions do not require stub");
 49 
 50 
 51   if (input()->is_single_xmm()) {
 52     __ comiss(input()->as_xmm_float_reg(),
 53               ExternalAddress((address)&float_zero));
 54   } else if (input()->is_double_xmm()) {
 55     __ comisd(input()->as_xmm_double_reg(),
 56               ExternalAddress((address)&double_zero));
 57   } else {
 58     __ push(rax);
 59     __ ftst();
 60     __ fnstsw_ax();
 61     __ sahf();
 62     __ pop(rax);
 63   }
 64 
 65   Label NaN, do_return;
 66   __ jccb(Assembler::parity, NaN);
 67   __ jccb(Assembler::below, do_return);
 68 
 69   // input is > 0 -> return maxInt
 70   // result register already contains 0x80000000, so subtracting 1 gives 0x7fffffff
 71   __ decrement(result()->as_register());
 72   __ jmpb(do_return);
 73 
 74   // input is NaN -> return 0
 75   __ bind(NaN);
 76   __ xorptr(result()->as_register(), result()->as_register());
 77 
 78   __ bind(do_return);
 79   __ jmp(_continuation);
 80 }
 81 #endif // !_LP64
 82 
 83 void C1SafepointPollStub::emit_code(LIR_Assembler* ce) {
 84   __ bind(_entry);
 85   InternalAddress safepoint_pc(ce->masm()->pc() - ce->masm()->offset() + safepoint_offset());
 86 #ifdef _LP64
 87   __ lea(rscratch1, safepoint_pc);
 88   __ movptr(Address(r15_thread, JavaThread::saved_exception_pc_offset()), rscratch1);
 89 #else
 90   const Register tmp1 = rcx;
 91   const Register tmp2 = rdx;
 92   __ push(tmp1);
 93   __ push(tmp2);
 94 
 95   __ lea(tmp1, safepoint_pc);
 96   __ get_thread(tmp2);
 97   __ movptr(Address(tmp2, JavaThread::saved_exception_pc_offset()), tmp1);
 98 
 99   __ pop(tmp2);
100   __ pop(tmp1);
101 #endif /* _LP64 */
102   assert(SharedRuntime::polling_page_return_handler_blob() != nullptr,
103          "polling page return stub not created yet");
104 
105   address stub = SharedRuntime::polling_page_return_handler_blob()->entry_point();
106   __ jump(RuntimeAddress(stub));
107 }
108 
109 void CounterOverflowStub::emit_code(LIR_Assembler* ce) {
110   __ bind(_entry);
111   Metadata *m = _method->as_constant_ptr()->as_metadata();
112   ce->store_parameter(m, 1);
113   ce->store_parameter(_bci, 0);
114   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::counter_overflow_id)));
115   ce->add_call_info_here(_info);
116   ce->verify_oop_map(_info);
117   __ jmp(_continuation);
118 }
119 
120 void RangeCheckStub::emit_code(LIR_Assembler* ce) {
121   __ bind(_entry);
122   if (_info->deoptimize_on_exception()) {
123     address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
124     __ call(RuntimeAddress(a));
125     ce->add_call_info_here(_info);
126     ce->verify_oop_map(_info);
127     debug_only(__ should_not_reach_here());
128     return;
129   }
130 
131   // pass the array index on stack because all registers must be preserved
132   if (_index->is_cpu_register()) {
133     ce->store_parameter(_index->as_register(), 0);
134   } else {
135     ce->store_parameter(_index->as_jint(), 0);
136   }
137   Runtime1::StubID stub_id;
138   if (_throw_index_out_of_bounds_exception) {
139     stub_id = Runtime1::throw_index_exception_id;
140   } else {
141     stub_id = Runtime1::throw_range_check_failed_id;
142     ce->store_parameter(_array->as_pointer_register(), 1);
143   }
144   __ call(RuntimeAddress(Runtime1::entry_for(stub_id)));
145   ce->add_call_info_here(_info);
146   ce->verify_oop_map(_info);
147   debug_only(__ should_not_reach_here());
148 }
149 
150 PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) {
151   _info = new CodeEmitInfo(info);
152 }
153 
154 void PredicateFailedStub::emit_code(LIR_Assembler* ce) {
155   __ bind(_entry);
156   address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
157   __ call(RuntimeAddress(a));
158   ce->add_call_info_here(_info);
159   ce->verify_oop_map(_info);
160   debug_only(__ should_not_reach_here());
161 }
162 
163 void DivByZeroStub::emit_code(LIR_Assembler* ce) {
164   if (_offset != -1) {
165     ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
166   }
167   __ bind(_entry);
168   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::throw_div0_exception_id)));
169   ce->add_call_info_here(_info);
170   debug_only(__ should_not_reach_here());
171 }
172 
173 
174 // Implementation of NewInstanceStub
175 
176 NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {
177   _result = result;
178   _klass = klass;
179   _klass_reg = klass_reg;
180   _info = new CodeEmitInfo(info);
181   assert(stub_id == Runtime1::new_instance_id                 ||
182          stub_id == Runtime1::fast_new_instance_id            ||
183          stub_id == Runtime1::fast_new_instance_init_check_id,
184          "need new_instance id");
185   _stub_id   = stub_id;
186 }
187 
188 
189 void NewInstanceStub::emit_code(LIR_Assembler* ce) {
190   assert(__ rsp_offset() == 0, "frame size should be fixed");
191   __ bind(_entry);
192   __ movptr(rdx, _klass_reg->as_register());
193   __ call(RuntimeAddress(Runtime1::entry_for(_stub_id)));
194   ce->add_call_info_here(_info);
195   ce->verify_oop_map(_info);
196   assert(_result->as_register() == rax, "result must in rax,");
197   __ jmp(_continuation);
198 }
199 
200 
201 // Implementation of NewTypeArrayStub
202 
203 NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
204   _klass_reg = klass_reg;
205   _length = length;
206   _result = result;
207   _info = new CodeEmitInfo(info);
208 }
209 
210 
211 void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {
212   assert(__ rsp_offset() == 0, "frame size should be fixed");
213   __ bind(_entry);
214   assert(_length->as_register() == rbx, "length must in rbx,");
215   assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
216   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_type_array_id)));
217   ce->add_call_info_here(_info);
218   ce->verify_oop_map(_info);
219   assert(_result->as_register() == rax, "result must in rax,");
220   __ jmp(_continuation);
221 }
222 
223 
224 // Implementation of NewObjectArrayStub
225 
226 NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
227   _klass_reg = klass_reg;
228   _result = result;
229   _length = length;
230   _info = new CodeEmitInfo(info);
231 }
232 
233 
234 void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {
235   assert(__ rsp_offset() == 0, "frame size should be fixed");
236   __ bind(_entry);
237   assert(_length->as_register() == rbx, "length must in rbx,");
238   assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
239   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_object_array_id)));
240   ce->add_call_info_here(_info);
241   ce->verify_oop_map(_info);
242   assert(_result->as_register() == rax, "result must in rax,");
243   __ jmp(_continuation);
244 }
245 
246 void MonitorEnterStub::emit_code(LIR_Assembler* ce) {
247   assert(__ rsp_offset() == 0, "frame size should be fixed");
248   __ bind(_entry);
249   ce->store_parameter(_obj_reg->as_register(),  1);
250   ce->store_parameter(_lock_reg->as_register(), 0);
251   Runtime1::StubID enter_id;
252   if (ce->compilation()->has_fpu_code()) {
253     enter_id = Runtime1::monitorenter_id;
254   } else {
255     enter_id = Runtime1::monitorenter_nofpu_id;
256   }
257   __ call(RuntimeAddress(Runtime1::entry_for(enter_id)));
258   ce->add_call_info_here(_info);
259   ce->verify_oop_map(_info);
260   __ jmp(_continuation);
261 }
262 
263 
264 void MonitorExitStub::emit_code(LIR_Assembler* ce) {
265   __ bind(_entry);
266   if (_compute_lock) {
267     // lock_reg was destroyed by fast unlocking attempt => recompute it
268     ce->monitor_address(_monitor_ix, _lock_reg);
269   }
270   ce->store_parameter(_lock_reg->as_register(), 0);
271   // note: non-blocking leaf routine => no call info needed
272   Runtime1::StubID exit_id;
273   if (ce->compilation()->has_fpu_code()) {
274     exit_id = Runtime1::monitorexit_id;
275   } else {
276     exit_id = Runtime1::monitorexit_nofpu_id;
277   }
278   __ call(RuntimeAddress(Runtime1::entry_for(exit_id)));
279   __ jmp(_continuation);
280 }
281 
282 void LoadKlassStub::emit_code(LIR_Assembler* ce) {
283   assert(UseCompactObjectHeaders, "only with compact headers");
284   __ bind(_entry);
285 #ifdef _LP64
286   Register d = _result->as_register();
287   __ movq(d, Address(d, OM_OFFSET_NO_MONITOR_VALUE_TAG(header)));
288   __ jmp(_continuation);
289 #else
290   __ should_not_reach_here();
291 #endif
292 }
293 
294 // Implementation of patching:
295 // - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes)
296 // - Replace original code with a call to the stub
297 // At Runtime:
298 // - call to stub, jump to runtime
299 // - in runtime: preserve all registers (rspecially objects, i.e., source and destination object)
300 // - in runtime: after initializing class, restore original code, reexecute instruction
301 
302 int PatchingStub::_patch_info_offset = -NativeGeneralJump::instruction_size;
303 
304 void PatchingStub::align_patch_site(MacroAssembler* masm) {
305   // We're patching a 5-7 byte instruction on intel and we need to
306   // make sure that we don't see a piece of the instruction.  It
307   // appears mostly impossible on Intel to simply invalidate other
308   // processors caches and since they may do aggressive prefetch it's
309   // very hard to make a guess about what code might be in the icache.
310   // Force the instruction to be double word aligned so that it
311   // doesn't span a cache line.
312   masm->align(align_up((int)NativeGeneralJump::instruction_size, wordSize));
313 }
314 
315 void PatchingStub::emit_code(LIR_Assembler* ce) {
316   assert(NativeCall::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF, "not enough room for call");
317 
318   Label call_patch;
319 
320   // static field accesses have special semantics while the class
321   // initializer is being run so we emit a test which can be used to
322   // check that this code is being executed by the initializing
323   // thread.
324   address being_initialized_entry = __ pc();
325   if (CommentedAssembly) {
326     __ block_comment(" patch template");
327   }
328   if (_id == load_klass_id) {
329     // produce a copy of the load klass instruction for use by the being initialized case
330 #ifdef ASSERT
331     address start = __ pc();
332 #endif
333     Metadata* o = nullptr;
334     __ mov_metadata(_obj, o);
335 #ifdef ASSERT
336     for (int i = 0; i < _bytes_to_copy; i++) {
337       address ptr = (address)(_pc_start + i);
338       int a_byte = (*ptr) & 0xFF;
339       assert(a_byte == *start++, "should be the same code");
340     }
341 #endif
342   } else if (_id == load_mirror_id) {
343     // produce a copy of the load mirror instruction for use by the being
344     // initialized case
345 #ifdef ASSERT
346     address start = __ pc();
347 #endif
348     jobject o = nullptr;
349     __ movoop(_obj, o);
350 #ifdef ASSERT
351     for (int i = 0; i < _bytes_to_copy; i++) {
352       address ptr = (address)(_pc_start + i);
353       int a_byte = (*ptr) & 0xFF;
354       assert(a_byte == *start++, "should be the same code");
355     }
356 #endif
357   } else {
358     // make a copy the code which is going to be patched.
359     for (int i = 0; i < _bytes_to_copy; i++) {
360       address ptr = (address)(_pc_start + i);
361       int a_byte = (*ptr) & 0xFF;
362       __ emit_int8(a_byte);
363       *ptr = 0x90; // make the site look like a nop
364     }
365   }
366 
367   address end_of_patch = __ pc();
368   int bytes_to_skip = 0;
369   if (_id == load_mirror_id) {
370     int offset = __ offset();
371     if (CommentedAssembly) {
372       __ block_comment(" being_initialized check");
373     }
374     assert(_obj != noreg, "must be a valid register");
375     Register tmp = rax;
376     Register tmp2 = rbx;
377     __ push(tmp);
378     __ push(tmp2);
379     // Load without verification to keep code size small. We need it because
380     // begin_initialized_entry_offset has to fit in a byte. Also, we know it's not null.
381     __ movptr(tmp2, Address(_obj, java_lang_Class::klass_offset()));
382     __ get_thread(tmp);
383     __ cmpptr(tmp, Address(tmp2, InstanceKlass::init_thread_offset()));
384     __ pop(tmp2);
385     __ pop(tmp);
386     __ jcc(Assembler::notEqual, call_patch);
387 
388     // access_field patches may execute the patched code before it's
389     // copied back into place so we need to jump back into the main
390     // code of the nmethod to continue execution.
391     __ jmp(_patch_site_continuation);
392 
393     // make sure this extra code gets skipped
394     bytes_to_skip += __ offset() - offset;
395   }
396   if (CommentedAssembly) {
397     __ block_comment("patch data encoded as movl");
398   }
399   // Now emit the patch record telling the runtime how to find the
400   // pieces of the patch.  We only need 3 bytes but for readability of
401   // the disassembly we make the data look like a movl reg, imm32,
402   // which requires 5 bytes
403   int sizeof_patch_record = 5;
404   bytes_to_skip += sizeof_patch_record;
405 
406   // emit the offsets needed to find the code to patch
407   int being_initialized_entry_offset = __ pc() - being_initialized_entry + sizeof_patch_record;
408 
409   __ emit_int8((unsigned char)0xB8);
410   __ emit_int8(0);
411   __ emit_int8(being_initialized_entry_offset);
412   __ emit_int8(bytes_to_skip);
413   __ emit_int8(_bytes_to_copy);
414   address patch_info_pc = __ pc();
415   assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
416 
417   address entry = __ pc();
418   NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
419   address target = nullptr;
420   relocInfo::relocType reloc_type = relocInfo::none;
421   switch (_id) {
422     case access_field_id:  target = Runtime1::entry_for(Runtime1::access_field_patching_id); break;
423     case load_klass_id:    target = Runtime1::entry_for(Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;
424     case load_mirror_id:   target = Runtime1::entry_for(Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;
425     case load_appendix_id:      target = Runtime1::entry_for(Runtime1::load_appendix_patching_id); reloc_type = relocInfo::oop_type; break;
426     default: ShouldNotReachHere();
427   }
428   __ bind(call_patch);
429 
430   if (CommentedAssembly) {
431     __ block_comment("patch entry point");
432   }
433   __ call(RuntimeAddress(target));
434   assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
435   ce->add_call_info_here(_info);
436   int jmp_off = __ offset();
437   __ jmp(_patch_site_entry);
438   // Add enough nops so deoptimization can overwrite the jmp above with a call
439   // and not destroy the world. We cannot use fat nops here, since the concurrent
440   // code rewrite may transiently create the illegal instruction sequence.
441   for (int j = __ offset() ; j < jmp_off + 5 ; j++ ) {
442     __ nop();
443   }
444   if (_id == load_klass_id || _id == load_mirror_id || _id == load_appendix_id) {
445     CodeSection* cs = __ code_section();
446     RelocIterator iter(cs, (address)_pc_start, (address)(_pc_start + 1));
447     relocInfo::change_reloc_info_for_address(&iter, (address) _pc_start, reloc_type, relocInfo::none);
448   }
449 }
450 
451 
452 void DeoptimizeStub::emit_code(LIR_Assembler* ce) {
453   __ bind(_entry);
454   ce->store_parameter(_trap_request, 0);
455   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::deoptimize_id)));
456   ce->add_call_info_here(_info);
457   DEBUG_ONLY(__ should_not_reach_here());
458 }
459 
460 
461 void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
462   address a;
463   if (_info->deoptimize_on_exception()) {
464     // Deoptimize, do not throw the exception, because it is probably wrong to do it here.
465     a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
466   } else {
467     a = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);
468   }
469 
470   ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
471   __ bind(_entry);
472   __ call(RuntimeAddress(a));
473   ce->add_call_info_here(_info);
474   ce->verify_oop_map(_info);
475   debug_only(__ should_not_reach_here());
476 }
477 
478 
479 void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {
480   assert(__ rsp_offset() == 0, "frame size should be fixed");
481 
482   __ bind(_entry);
483   // pass the object on stack because all registers must be preserved
484   if (_obj->is_cpu_register()) {
485     ce->store_parameter(_obj->as_register(), 0);
486   }
487   __ call(RuntimeAddress(Runtime1::entry_for(_stub)));
488   ce->add_call_info_here(_info);
489   debug_only(__ should_not_reach_here());
490 }
491 
492 
493 void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
494   //---------------slow case: call to native-----------------
495   __ bind(_entry);
496   // Figure out where the args should go
497   // This should really convert the IntrinsicID to the Method* and signature
498   // but I don't know how to do that.
499   //
500   VMRegPair args[5];
501   BasicType signature[5] = { T_OBJECT, T_INT, T_OBJECT, T_INT, T_INT};
502   SharedRuntime::java_calling_convention(signature, args, 5);
503 
504   // push parameters
505   // (src, src_pos, dest, destPos, length)
506   Register r[5];
507   r[0] = src()->as_register();
508   r[1] = src_pos()->as_register();
509   r[2] = dst()->as_register();
510   r[3] = dst_pos()->as_register();
511   r[4] = length()->as_register();
512 
513   // next registers will get stored on the stack
514   for (int i = 0; i < 5 ; i++ ) {
515     VMReg r_1 = args[i].first();
516     if (r_1->is_stack()) {
517       int st_off = r_1->reg2stack() * wordSize;
518       __ movptr (Address(rsp, st_off), r[i]);
519     } else {
520       assert(r[i] == args[i].first()->as_Register(), "Wrong register for arg ");
521     }
522   }
523 
524   ce->align_call(lir_static_call);
525 
526   ce->emit_static_call_stub();
527   if (ce->compilation()->bailed_out()) {
528     return; // CodeCache is full
529   }
530   AddressLiteral resolve(SharedRuntime::get_resolve_static_call_stub(),
531                          relocInfo::static_call_type);
532   __ call(resolve);
533   ce->add_call_info_here(info());
534 
535 #ifndef PRODUCT
536   if (PrintC1Statistics) {
537     __ incrementl(ExternalAddress((address)&Runtime1::_arraycopy_slowcase_cnt), rscratch1);
538   }
539 #endif
540 
541   __ jmp(_continuation);
542 }
543 
544 #undef __