1 /*
  2  * Copyright (c) 2018, 2023, Red Hat, Inc. All rights reserved.
  3  * Copyright (c) 2012, 2023 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 "asm/macroAssembler.inline.hpp"
 28 #include "c1/c1_LIRAssembler.hpp"
 29 #include "c1/c1_MacroAssembler.hpp"
 30 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
 31 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
 32 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
 33 
 34 #define __ masm->masm()->
 35 
 36 void LIR_OpShenandoahCompareAndSwap::emit_code(LIR_Assembler *masm) {
 37   __ block_comment("LIR_OpShenandoahCompareAndSwap (shenandaohgc) {");
 38 
 39   Register addr = _addr->as_register_lo();
 40   Register new_val = _new_value->as_register();
 41   Register cmp_val = _cmp_value->as_register();
 42   Register tmp1 = _tmp1->as_register();
 43   Register tmp2 = _tmp2->as_register();
 44   Register result = result_opr()->as_register();
 45 
 46   if (UseCompressedOops) {
 47     __ encode_heap_oop(cmp_val, cmp_val);
 48     __ encode_heap_oop(new_val, new_val);
 49   }
 50 
 51   // There might be a volatile load before this Unsafe CAS.
 52   if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
 53     __ sync();
 54   } else {
 55     __ lwsync();
 56   }
 57 
 58   ShenandoahBarrierSet::assembler()->cmpxchg_oop(masm->masm(), addr, cmp_val, new_val, tmp1, tmp2,
 59                                                  false, result);
 60 
 61   if (UseCompressedOops) {
 62     __ decode_heap_oop(cmp_val);
 63     __ decode_heap_oop(new_val);
 64   }
 65 
 66   if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
 67     __ isync();
 68   } else {
 69     __ sync();
 70   }
 71 
 72   __ block_comment("} LIR_OpShenandoahCompareAndSwap (shenandaohgc)");
 73 }
 74 
 75 #undef __
 76 
 77 #ifdef ASSERT
 78 #define __ gen->lir(__FILE__, __LINE__)->
 79 #else
 80 #define __ gen->lir()->
 81 #endif
 82 
 83 LIR_Opr ShenandoahBarrierSetC1::atomic_cmpxchg_at_resolved(LIRAccess &access, LIRItem &cmp_value, LIRItem &new_value) {
 84   BasicType bt = access.type();
 85 
 86   if (access.is_oop()) {
 87     LIRGenerator* gen = access.gen();
 88 
 89     if (ShenandoahSATBBarrier) {
 90       pre_barrier(gen, access.access_emit_info(), access.decorators(), access.resolved_addr(),
 91                   LIR_OprFact::illegalOpr);
 92     }
 93 
 94     if (ShenandoahCASBarrier) {
 95       cmp_value.load_item();
 96       new_value.load_item();
 97 
 98       LIR_Opr t1 = gen->new_register(T_OBJECT);
 99       LIR_Opr t2 = gen->new_register(T_OBJECT);
100       LIR_Opr addr = access.resolved_addr()->as_address_ptr()->base();
101       LIR_Opr result = gen->new_register(T_INT);
102 
103       __ append(new LIR_OpShenandoahCompareAndSwap(addr, cmp_value.result(), new_value.result(), t1, t2, result));
104 
105       if (ShenandoahCardBarrier) {
106         post_barrier(access, access.resolved_addr(), new_value.result());
107       }
108 
109       return result;
110     }
111   }
112 
113   return BarrierSetC1::atomic_cmpxchg_at_resolved(access, cmp_value, new_value);
114 }
115 
116 LIR_Opr ShenandoahBarrierSetC1::atomic_xchg_at_resolved(LIRAccess &access, LIRItem &value) {
117   LIRGenerator* gen = access.gen();
118   BasicType type = access.type();
119 
120   LIR_Opr result = gen->new_register(type);
121   value.load_item();
122   LIR_Opr value_opr = value.result();
123 
124   assert(type == T_INT || is_reference_type(type) LP64_ONLY( || type == T_LONG ), "unexpected type");
125   LIR_Opr tmp_xchg = gen->new_register(T_INT);
126   __ xchg(access.resolved_addr(), value_opr, result, tmp_xchg);
127 
128   if (access.is_oop()) {
129     result = load_reference_barrier_impl(access.gen(), result, LIR_OprFact::addressConst(0),
130                                          access.decorators());
131 
132     LIR_Opr tmp_barrier = gen->new_register(type);
133     __ move(result, tmp_barrier);
134     result = tmp_barrier;
135 
136     if (ShenandoahSATBBarrier) {
137       pre_barrier(access.gen(), access.access_emit_info(), access.decorators(), LIR_OprFact::illegalOpr, result);
138     }
139 
140     if (ShenandoahCardBarrier) {
141       post_barrier(access, access.resolved_addr(), result);
142     }
143   }
144 
145   return result;
146 }