1 /*
  2  * Copyright (c) 1999, 2020, 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/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 #ifndef _LP64
 42 float ConversionStub::float_zero = 0.0;
 43 double ConversionStub::double_zero = 0.0;
 44 
 45 void ConversionStub::emit_code(LIR_Assembler* ce) {
 46   __ bind(_entry);
 47   assert(bytecode() == Bytecodes::_f2i || bytecode() == Bytecodes::_d2i, "other conversions do not require stub");
 48 
 49 
 50   if (input()->is_single_xmm()) {
 51     __ comiss(input()->as_xmm_float_reg(),
 52               ExternalAddress((address)&float_zero));
 53   } else if (input()->is_double_xmm()) {
 54     __ comisd(input()->as_xmm_double_reg(),
 55               ExternalAddress((address)&double_zero));
 56   } else {
 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 #endif // !_LP64
 81 
 82 void CounterOverflowStub::emit_code(LIR_Assembler* ce) {
 83   __ bind(_entry);
 84   Metadata *m = _method->as_constant_ptr()->as_metadata();
 85   ce->store_parameter(m, 1);
 86   ce->store_parameter(_bci, 0);
 87   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::counter_overflow_id)));
 88   ce->add_call_info_here(_info);
 89   ce->verify_oop_map(_info);
 90   __ jmp(_continuation);
 91 }
 92 
 93 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index, LIR_Opr array)
 94   : _index(index), _array(array), _throw_index_out_of_bounds_exception(false) {
 95   assert(info != NULL, "must have info");
 96   _info = new CodeEmitInfo(info);
 97 }
 98 
 99 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index)
100   : _index(index), _array(NULL), _throw_index_out_of_bounds_exception(true) {
101   assert(info != NULL, "must have info");
102   _info = new CodeEmitInfo(info);
103 }
104 
105 void RangeCheckStub::emit_code(LIR_Assembler* ce) {
106   __ bind(_entry);
107   if (_info->deoptimize_on_exception()) {
108     address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
109     __ call(RuntimeAddress(a));
110     ce->add_call_info_here(_info);
111     ce->verify_oop_map(_info);
112     debug_only(__ should_not_reach_here());
113     return;
114   }
115 
116   // pass the array index on stack because all registers must be preserved
117   if (_index->is_cpu_register()) {
118     ce->store_parameter(_index->as_register(), 0);
119   } else {
120     ce->store_parameter(_index->as_jint(), 0);
121   }
122   Runtime1::StubID stub_id;
123   if (_throw_index_out_of_bounds_exception) {
124     stub_id = Runtime1::throw_index_exception_id;
125   } else {
126     stub_id = Runtime1::throw_range_check_failed_id;
127     ce->store_parameter(_array->as_pointer_register(), 1);
128   }
129   __ call(RuntimeAddress(Runtime1::entry_for(stub_id)));
130   ce->add_call_info_here(_info);
131   ce->verify_oop_map(_info);
132   debug_only(__ should_not_reach_here());
133 }
134 
135 PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) {
136   _info = new CodeEmitInfo(info);
137 }
138 
139 void PredicateFailedStub::emit_code(LIR_Assembler* ce) {
140   __ bind(_entry);
141   address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
142   __ call(RuntimeAddress(a));
143   ce->add_call_info_here(_info);
144   ce->verify_oop_map(_info);
145   debug_only(__ should_not_reach_here());
146 }
147 
148 void DivByZeroStub::emit_code(LIR_Assembler* ce) {
149   if (_offset != -1) {
150     ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
151   }
152   __ bind(_entry);
153   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::throw_div0_exception_id)));
154   ce->add_call_info_here(_info);
155   debug_only(__ should_not_reach_here());
156 }
157 
158 
159 // Implementation of NewInstanceStub
160 
161 NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {
162   _result = result;
163   _klass = klass;
164   _klass_reg = klass_reg;
165   _info = new CodeEmitInfo(info);
166   assert(stub_id == Runtime1::new_instance_id                 ||
167          stub_id == Runtime1::fast_new_instance_id            ||
168          stub_id == Runtime1::fast_new_instance_init_check_id,
169          "need new_instance id");
170   _stub_id   = stub_id;
171 }
172 
173 
174 void NewInstanceStub::emit_code(LIR_Assembler* ce) {
175   assert(__ rsp_offset() == 0, "frame size should be fixed");
176   __ bind(_entry);
177   __ movptr(rdx, _klass_reg->as_register());
178   __ call(RuntimeAddress(Runtime1::entry_for(_stub_id)));
179   ce->add_call_info_here(_info);
180   ce->verify_oop_map(_info);
181   assert(_result->as_register() == rax, "result must in rax,");
182   __ jmp(_continuation);
183 }
184 
185 
186 // Implementation of NewTypeArrayStub
187 
188 NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
189   _klass_reg = klass_reg;
190   _length = length;
191   _result = result;
192   _info = new CodeEmitInfo(info);
193 }
194 
195 
196 void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {
197   assert(__ rsp_offset() == 0, "frame size should be fixed");
198   __ bind(_entry);
199   assert(_length->as_register() == rbx, "length must in rbx,");
200   assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
201   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_type_array_id)));
202   ce->add_call_info_here(_info);
203   ce->verify_oop_map(_info);
204   assert(_result->as_register() == rax, "result must in rax,");
205   __ jmp(_continuation);
206 }
207 
208 
209 // Implementation of NewObjectArrayStub
210 
211 NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
212   _klass_reg = klass_reg;
213   _result = result;
214   _length = length;
215   _info = new CodeEmitInfo(info);
216 }
217 
218 
219 void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {
220   assert(__ rsp_offset() == 0, "frame size should be fixed");
221   __ bind(_entry);
222   assert(_length->as_register() == rbx, "length must in rbx,");
223   assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
224   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_object_array_id)));
225   ce->add_call_info_here(_info);
226   ce->verify_oop_map(_info);
227   assert(_result->as_register() == rax, "result must in rax,");
228   __ jmp(_continuation);
229 }
230 
231 
232 // Implementation of MonitorAccessStubs
233 
234 MonitorEnterStub::MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info)
235 : MonitorAccessStub(obj_reg, lock_reg)
236 {
237   _info = new CodeEmitInfo(info);
238 }
239 
240 
241 void MonitorEnterStub::emit_code(LIR_Assembler* ce) {
242   assert(__ rsp_offset() == 0, "frame size should be fixed");
243   __ bind(_entry);
244   ce->store_parameter(_obj_reg->as_register(),  1);
245   ce->store_parameter(_lock_reg->as_register(), 0);
246   Runtime1::StubID enter_id;
247   if (ce->compilation()->has_fpu_code()) {
248     enter_id = Runtime1::monitorenter_id;
249   } else {
250     enter_id = Runtime1::monitorenter_nofpu_id;
251   }
252   __ call(RuntimeAddress(Runtime1::entry_for(enter_id)));
253   ce->add_call_info_here(_info);
254   ce->verify_oop_map(_info);
255   __ jmp(_continuation);
256 }
257 
258 
259 void MonitorExitStub::emit_code(LIR_Assembler* ce) {
260   __ bind(_entry);
261   if (_compute_lock) {
262     // lock_reg was destroyed by fast unlocking attempt => recompute it
263     ce->monitor_address(_monitor_ix, _lock_reg);
264   }
265   ce->store_parameter(_lock_reg->as_register(), 0);
266   // note: non-blocking leaf routine => no call info needed
267   Runtime1::StubID exit_id;
268   if (ce->compilation()->has_fpu_code()) {
269     exit_id = Runtime1::monitorexit_id;
270   } else {
271     exit_id = Runtime1::monitorexit_nofpu_id;
272   }
273   __ call(RuntimeAddress(Runtime1::entry_for(exit_id)));
274   __ jmp(_continuation);
275 }
276 
277 
278 // Implementation of patching:
279 // - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes)
280 // - Replace original code with a call to the stub
281 // At Runtime:
282 // - call to stub, jump to runtime
283 // - in runtime: preserve all registers (rspecially objects, i.e., source and destination object)
284 // - in runtime: after initializing class, restore original code, reexecute instruction
285 
286 int PatchingStub::_patch_info_offset = -NativeGeneralJump::instruction_size;
287 
288 void PatchingStub::align_patch_site(MacroAssembler* masm) {
289   // We're patching a 5-7 byte instruction on intel and we need to
290   // make sure that we don't see a piece of the instruction.  It
291   // appears mostly impossible on Intel to simply invalidate other
292   // processors caches and since they may do aggressive prefetch it's
293   // very hard to make a guess about what code might be in the icache.
294   // Force the instruction to be double word aligned so that it
295   // doesn't span a cache line.
296   masm->align(align_up((int)NativeGeneralJump::instruction_size, wordSize));
297 }
298 
299 void PatchingStub::emit_code(LIR_Assembler* ce) {
300   assert(NativeCall::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF, "not enough room for call");
301 
302   Label call_patch;
303 
304   // static field accesses have special semantics while the class
305   // initializer is being run so we emit a test which can be used to
306   // check that this code is being executed by the initializing
307   // thread.
308   address being_initialized_entry = __ pc();
309   if (CommentedAssembly) {
310     __ block_comment(" patch template");
311   }
312   if (_id == load_klass_id) {
313     // produce a copy of the load klass instruction for use by the being initialized case
314 #ifdef ASSERT
315     address start = __ pc();
316 #endif
317     Metadata* o = NULL;
318     __ mov_metadata(_obj, o);
319 #ifdef ASSERT
320     for (int i = 0; i < _bytes_to_copy; i++) {
321       address ptr = (address)(_pc_start + i);
322       int a_byte = (*ptr) & 0xFF;
323       assert(a_byte == *start++, "should be the same code");
324     }
325 #endif
326   } else if (_id == load_mirror_id) {
327     // produce a copy of the load mirror instruction for use by the being
328     // initialized case
329 #ifdef ASSERT
330     address start = __ pc();
331 #endif
332     jobject o = NULL;
333     __ movoop(_obj, o);
334 #ifdef ASSERT
335     for (int i = 0; i < _bytes_to_copy; i++) {
336       address ptr = (address)(_pc_start + i);
337       int a_byte = (*ptr) & 0xFF;
338       assert(a_byte == *start++, "should be the same code");
339     }
340 #endif
341   } else {
342     // make a copy the code which is going to be patched.
343     for (int i = 0; i < _bytes_to_copy; i++) {
344       address ptr = (address)(_pc_start + i);
345       int a_byte = (*ptr) & 0xFF;
346       __ emit_int8(a_byte);
347       *ptr = 0x90; // make the site look like a nop
348     }
349   }
350 
351   address end_of_patch = __ pc();
352   int bytes_to_skip = 0;
353   if (_id == load_mirror_id) {
354     int offset = __ offset();
355     if (CommentedAssembly) {
356       __ block_comment(" being_initialized check");
357     }
358     assert(_obj != noreg, "must be a valid register");
359     Register tmp = rax;
360     Register tmp2 = rbx;
361     __ push(tmp);
362     __ push(tmp2);
363     // Load without verification to keep code size small. We need it because
364     // begin_initialized_entry_offset has to fit in a byte. Also, we know it's not null.
365     __ movptr(tmp2, Address(_obj, java_lang_Class::klass_offset()));
366     __ get_thread(tmp);
367     __ cmpptr(tmp, Address(tmp2, InstanceKlass::init_thread_offset()));
368     __ pop(tmp2);
369     __ pop(tmp);
370     __ jcc(Assembler::notEqual, call_patch);
371 
372     // access_field patches may execute the patched code before it's
373     // copied back into place so we need to jump back into the main
374     // code of the nmethod to continue execution.
375     __ jmp(_patch_site_continuation);
376 
377     // make sure this extra code gets skipped
378     bytes_to_skip += __ offset() - offset;
379   }
380   if (CommentedAssembly) {
381     __ block_comment("patch data encoded as movl");
382   }
383   // Now emit the patch record telling the runtime how to find the
384   // pieces of the patch.  We only need 3 bytes but for readability of
385   // the disassembly we make the data look like a movl reg, imm32,
386   // which requires 5 bytes
387   int sizeof_patch_record = 5;
388   bytes_to_skip += sizeof_patch_record;
389 
390   // emit the offsets needed to find the code to patch
391   int being_initialized_entry_offset = __ pc() - being_initialized_entry + sizeof_patch_record;
392 
393   __ emit_int8((unsigned char)0xB8);
394   __ emit_int8(0);
395   __ emit_int8(being_initialized_entry_offset);
396   __ emit_int8(bytes_to_skip);
397   __ emit_int8(_bytes_to_copy);
398   address patch_info_pc = __ pc();
399   assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
400 
401   address entry = __ pc();
402   NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
403   address target = NULL;
404   relocInfo::relocType reloc_type = relocInfo::none;
405   switch (_id) {
406     case access_field_id:  target = Runtime1::entry_for(Runtime1::access_field_patching_id); break;
407     case load_klass_id:    target = Runtime1::entry_for(Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;
408     case load_mirror_id:   target = Runtime1::entry_for(Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;
409     case load_appendix_id:      target = Runtime1::entry_for(Runtime1::load_appendix_patching_id); reloc_type = relocInfo::oop_type; break;
410     default: ShouldNotReachHere();
411   }
412   __ bind(call_patch);
413 
414   if (CommentedAssembly) {
415     __ block_comment("patch entry point");
416   }
417   __ call(RuntimeAddress(target));
418   assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
419   ce->add_call_info_here(_info);
420   int jmp_off = __ offset();
421   __ jmp(_patch_site_entry);
422   // Add enough nops so deoptimization can overwrite the jmp above with a call
423   // and not destroy the world. We cannot use fat nops here, since the concurrent
424   // code rewrite may transiently create the illegal instruction sequence.
425   for (int j = __ offset() ; j < jmp_off + 5 ; j++ ) {
426     __ nop();
427   }
428   if (_id == load_klass_id || _id == load_mirror_id || _id == load_appendix_id) {
429     CodeSection* cs = __ code_section();
430     RelocIterator iter(cs, (address)_pc_start, (address)(_pc_start + 1));
431     relocInfo::change_reloc_info_for_address(&iter, (address) _pc_start, reloc_type, relocInfo::none);
432   }
433 }
434 
435 
436 void DeoptimizeStub::emit_code(LIR_Assembler* ce) {
437   __ bind(_entry);
438   ce->store_parameter(_trap_request, 0);
439   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::deoptimize_id)));
440   ce->add_call_info_here(_info);
441   DEBUG_ONLY(__ should_not_reach_here());
442 }
443 
444 
445 void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
446   address a;
447   if (_info->deoptimize_on_exception()) {
448     // Deoptimize, do not throw the exception, because it is probably wrong to do it here.
449     a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
450   } else {
451     a = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);
452   }
453 
454   ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
455   __ bind(_entry);
456   __ call(RuntimeAddress(a));
457   ce->add_call_info_here(_info);
458   ce->verify_oop_map(_info);
459   debug_only(__ should_not_reach_here());
460 }
461 
462 
463 void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {
464   assert(__ rsp_offset() == 0, "frame size should be fixed");
465 
466   __ bind(_entry);
467   // pass the object on stack because all registers must be preserved
468   if (_obj->is_cpu_register()) {
469     ce->store_parameter(_obj->as_register(), 0);
470   }
471   __ call(RuntimeAddress(Runtime1::entry_for(_stub)));
472   ce->add_call_info_here(_info);
473   debug_only(__ should_not_reach_here());
474 }
475 
476 
477 void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
478   //---------------slow case: call to native-----------------
479   __ bind(_entry);
480   // Figure out where the args should go
481   // This should really convert the IntrinsicID to the Method* and signature
482   // but I don't know how to do that.
483   //
484   VMRegPair args[5];
485   BasicType signature[5] = { T_OBJECT, T_INT, T_OBJECT, T_INT, T_INT};
486   SharedRuntime::java_calling_convention(signature, args, 5, true);
487 
488   // push parameters
489   // (src, src_pos, dest, destPos, length)
490   Register r[5];
491   r[0] = src()->as_register();
492   r[1] = src_pos()->as_register();
493   r[2] = dst()->as_register();
494   r[3] = dst_pos()->as_register();
495   r[4] = length()->as_register();
496 
497   // next registers will get stored on the stack
498   for (int i = 0; i < 5 ; i++ ) {
499     VMReg r_1 = args[i].first();
500     if (r_1->is_stack()) {
501       int st_off = r_1->reg2stack() * wordSize;
502       __ movptr (Address(rsp, st_off), r[i]);
503     } else {
504       assert(r[i] == args[i].first()->as_Register(), "Wrong register for arg ");
505     }
506   }
507 
508   ce->align_call(lir_static_call);
509 
510   ce->emit_static_call_stub();
511   if (ce->compilation()->bailed_out()) {
512     return; // CodeCache is full
513   }
514   AddressLiteral resolve(SharedRuntime::get_resolve_static_call_stub(),
515                          relocInfo::static_call_type);
516   __ call(resolve);
517   ce->add_call_info_here(info());
518 
519 #ifndef PRODUCT
520   __ incrementl(ExternalAddress((address)&Runtime1::_arraycopy_slowcase_cnt));
521 #endif
522 
523   __ jmp(_continuation);
524 }
525 
526 #undef __