1 /*
  2  * Copyright (c) 2020, 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 "opto/c2_MacroAssembler.hpp"
 27 #include "opto/c2_CodeStubs.hpp"
 28 #include "runtime/objectMonitor.hpp"
 29 #include "runtime/sharedRuntime.hpp"
 30 #include "runtime/stubRoutines.hpp"
 31 
 32 #define __ masm.
 33 
 34 int C2SafepointPollStub::max_size() const {
 35   return 20;
 36 }
 37 
 38 void C2SafepointPollStub::emit(C2_MacroAssembler& masm) {
 39   assert(SharedRuntime::polling_page_return_handler_blob() != nullptr,
 40          "polling page return stub not created yet");
 41   address stub = SharedRuntime::polling_page_return_handler_blob()->entry_point();
 42 
 43   RuntimeAddress callback_addr(stub);
 44 
 45   __ bind(entry());
 46   InternalAddress safepoint_pc(masm.pc() - masm.offset() + _safepoint_offset);
 47   __ adr(rscratch1, safepoint_pc);
 48   __ str(rscratch1, Address(rthread, JavaThread::saved_exception_pc_offset()));
 49   __ far_jump(callback_addr);
 50 }
 51 
 52 int C2EntryBarrierStub::max_size() const {
 53   return 24;
 54 }
 55 
 56 void C2EntryBarrierStub::emit(C2_MacroAssembler& masm) {
 57   __ bind(entry());
 58   __ lea(rscratch1, RuntimeAddress(StubRoutines::method_entry_barrier()));
 59   __ blr(rscratch1);
 60   __ b(continuation());
 61 
 62   __ bind(guard());
 63   __ relocate(entry_guard_Relocation::spec());
 64   __ emit_int32(0);   // nmethod guard value
 65 }
 66 
 67 int C2HandleAnonOMOwnerStub::max_size() const {
 68   // Max size of stub has been determined by testing with 0, in which case
 69   // C2CodeStubList::emit() will throw an assertion and report the actual size that
 70   // is needed.
 71   return 24;
 72 }
 73 
 74 void C2HandleAnonOMOwnerStub::emit(C2_MacroAssembler& masm) {
 75   __ bind(entry());
 76   Register mon = monitor();
 77   Register t = tmp();
 78   assert(t != noreg, "need tmp register");
 79 
 80   // Fix owner to be the current thread.
 81   __ str(rthread, Address(mon, ObjectMonitor::owner_offset()));
 82 
 83   // Pop owner object from lock-stack.
 84   __ ldrw(t, Address(rthread, JavaThread::lock_stack_top_offset()));
 85   __ subw(t, t, oopSize);
 86 #ifdef ASSERT
 87   __ str(zr, Address(rthread, t));
 88 #endif
 89   __ strw(t, Address(rthread, JavaThread::lock_stack_top_offset()));
 90 
 91   __ b(continuation());
 92 }
 93 
 94 int C2LoadNKlassStub::max_size() const {
 95   return 8;
 96 }
 97 
 98 void C2LoadNKlassStub::emit(C2_MacroAssembler& masm) {
 99   __ bind(entry());
100   Register d = dst();
101   __ ldr(d, Address(d, OM_OFFSET_NO_MONITOR_VALUE_TAG(header)));
102   __ b(continuation());
103 }
104 
105 #undef __