1 /*
2 * Copyright (c) 2015, 2022, 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 #include "precompiled.hpp"
25 #include "c1/c1_LIR.hpp"
26 #include "c1/c1_LIRGenerator.hpp"
27 #include "c1/c1_CodeStubs.hpp"
28 #include "gc/z/c1/zBarrierSetC1.hpp"
29 #include "gc/z/zBarrierSet.hpp"
30 #include "gc/z/zBarrierSetAssembler.hpp"
31 #include "gc/z/zThreadLocalData.hpp"
32 #include "utilities/macros.hpp"
33
34 ZLoadBarrierStubC1::ZLoadBarrierStubC1(LIRAccess& access, LIR_Opr ref, address runtime_stub) :
35 _decorators(access.decorators()),
36 _ref_addr(access.resolved_addr()),
37 _ref(ref),
38 _tmp(LIR_OprFact::illegalOpr),
39 _runtime_stub(runtime_stub) {
40
41 assert(_ref_addr->is_address(), "Must be an address");
42 assert(_ref->is_register(), "Must be a register");
43
44 // Allocate tmp register if needed
45 if (_ref_addr->as_address_ptr()->index()->is_valid() ||
46 _ref_addr->as_address_ptr()->disp() != 0) {
47 // Has index or displacement, need tmp register to load address into
48 _tmp = access.gen()->new_pointer_register();
49 }
50 }
51
52 DecoratorSet ZLoadBarrierStubC1::decorators() const {
53 return _decorators;
54 }
55
56 LIR_Opr ZLoadBarrierStubC1::ref() const {
57 return _ref;
58 }
59
60 LIR_Opr ZLoadBarrierStubC1::ref_addr() const {
61 return _ref_addr;
62 }
63
64 LIR_Opr ZLoadBarrierStubC1::tmp() const {
65 return _tmp;
66 }
67
68 address ZLoadBarrierStubC1::runtime_stub() const {
69 return _runtime_stub;
70 }
71
72 void ZLoadBarrierStubC1::visit(LIR_OpVisitState* visitor) {
73 visitor->do_slow_case();
74 visitor->do_input(_ref_addr);
75 visitor->do_output(_ref);
76 if (_tmp->is_valid()) {
77 visitor->do_temp(_tmp);
78 }
79 }
80
81 void ZLoadBarrierStubC1::emit_code(LIR_Assembler* ce) {
82 ZBarrierSet::assembler()->generate_c1_load_barrier_stub(ce, this);
83 }
84
85 #ifndef PRODUCT
86 void ZLoadBarrierStubC1::print_name(outputStream* out) const {
87 out->print("ZLoadBarrierStubC1");
88 }
89 #endif // PRODUCT
90
91 class LIR_OpZLoadBarrierTest : public LIR_Op {
92 private:
93 LIR_Opr _opr;
94
95 public:
96 LIR_OpZLoadBarrierTest(LIR_Opr opr) :
97 #ifdef RISCV
98 LIR_Op(lir_zloadbarrier_test, LIR_OprFact::illegalOpr, NULL),
99 #else
100 LIR_Op(),
101 #endif
102 _opr(opr) {}
103
104 virtual void visit(LIR_OpVisitState* state) {
105 state->do_input(_opr);
106 }
107
108 virtual void emit_code(LIR_Assembler* ce) {
109 ZBarrierSet::assembler()->generate_c1_load_barrier_test(ce, _opr);
110 }
111
112 virtual void print_instr(outputStream* out) const {
113 _opr->print(out);
114 out->print(" ");
115 }
116
117 #ifndef PRODUCT
118 virtual const char* name() const {
119 return "lir_z_load_barrier_test";
120 }
121 #endif // PRODUCT
122 };
123
124 static bool barrier_needed(LIRAccess& access) {
125 return ZBarrierSet::barrier_needed(access.decorators(), access.type());
126 }
127
128 ZBarrierSetC1::ZBarrierSetC1() :
129 _load_barrier_on_oop_field_preloaded_runtime_stub(NULL),
130 _load_barrier_on_weak_oop_field_preloaded_runtime_stub(NULL) {}
131
132 address ZBarrierSetC1::load_barrier_on_oop_field_preloaded_runtime_stub(DecoratorSet decorators) const {
133 assert((decorators & ON_PHANTOM_OOP_REF) == 0, "Unsupported decorator");
134 //assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Unsupported decorator");
135
136 if ((decorators & ON_WEAK_OOP_REF) != 0) {
137 return _load_barrier_on_weak_oop_field_preloaded_runtime_stub;
138 } else {
139 return _load_barrier_on_oop_field_preloaded_runtime_stub;
140 }
141 }
142
143 #ifdef ASSERT
144 #define __ access.gen()->lir(__FILE__, __LINE__)->
145 #else
146 #define __ access.gen()->lir()->
147 #endif
148
149 void ZBarrierSetC1::load_barrier(LIRAccess& access, LIR_Opr result) const {
150 // Fast path
151 __ append(new LIR_OpZLoadBarrierTest(result));
152
153 // Slow path
154 const address runtime_stub = load_barrier_on_oop_field_preloaded_runtime_stub(access.decorators());
155 CodeStub* const stub = new ZLoadBarrierStubC1(access, result, runtime_stub);
156 __ branch(lir_cond_notEqual, stub);
157 __ branch_destination(stub->continuation());
158 }
159
160 LIR_Opr ZBarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) {
161 // We must resolve in register when patching. This is to avoid
162 // having a patch area in the load barrier stub, since the call
163 // into the runtime to patch will not have the proper oop map.
164 const bool patch_before_barrier = barrier_needed(access) && (access.decorators() & C1_NEEDS_PATCHING) != 0;
165 return BarrierSetC1::resolve_address(access, resolve_in_register || patch_before_barrier);
166 }
167
168 #undef __
169
170 void ZBarrierSetC1::load_at_resolved(LIRAccess& access, LIR_Opr result) {
171 BarrierSetC1::load_at_resolved(access, result);
172
173 if (barrier_needed(access)) {
174 load_barrier(access, result);
175 }
176 }
177
178 static void pre_load_barrier(LIRAccess& access) {
179 DecoratorSet decorators = access.decorators();
180
181 // Downgrade access to MO_UNORDERED
182 decorators = (decorators & ~MO_DECORATOR_MASK) | MO_UNORDERED;
183
184 // Remove ACCESS_WRITE
185 decorators = (decorators & ~ACCESS_WRITE);
186
187 // Generate synthetic load at
188 access.gen()->access_load_at(decorators,
189 access.type(),
190 access.base().item(),
191 access.offset().opr(),
192 access.gen()->new_register(access.type()),
193 NULL /* patch_emit_info */,
194 NULL /* load_emit_info */);
195 }
196
197 LIR_Opr ZBarrierSetC1::atomic_xchg_at_resolved(LIRAccess& access, LIRItem& value) {
198 if (barrier_needed(access)) {
199 pre_load_barrier(access);
200 }
201
202 return BarrierSetC1::atomic_xchg_at_resolved(access, value);
203 }
204
205 LIR_Opr ZBarrierSetC1::atomic_cmpxchg_at_resolved(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) {
206 if (barrier_needed(access)) {
207 pre_load_barrier(access);
208 }
209
210 return BarrierSetC1::atomic_cmpxchg_at_resolved(access, cmp_value, new_value);
211 }
212
213 class ZLoadBarrierRuntimeStubCodeGenClosure : public StubAssemblerCodeGenClosure {
214 private:
215 const DecoratorSet _decorators;
216
217 public:
218 ZLoadBarrierRuntimeStubCodeGenClosure(DecoratorSet decorators) :
219 _decorators(decorators) {}
220
221 virtual OopMapSet* generate_code(StubAssembler* sasm) {
222 ZBarrierSet::assembler()->generate_c1_load_barrier_runtime_stub(sasm, _decorators);
223 return NULL;
224 }
225 };
226
227 static address generate_c1_runtime_stub(BufferBlob* blob, DecoratorSet decorators, const char* name) {
228 ZLoadBarrierRuntimeStubCodeGenClosure cl(decorators);
229 CodeBlob* const code_blob = Runtime1::generate_blob(blob, -1 /* stub_id */, name, false /* expect_oop_map*/, &cl);
230 return code_blob->code_begin();
231 }
232
233 void ZBarrierSetC1::generate_c1_runtime_stubs(BufferBlob* blob) {
234 _load_barrier_on_oop_field_preloaded_runtime_stub =
235 generate_c1_runtime_stub(blob, ON_STRONG_OOP_REF, "load_barrier_on_oop_field_preloaded_runtime_stub");
236 _load_barrier_on_weak_oop_field_preloaded_runtime_stub =
237 generate_c1_runtime_stub(blob, ON_WEAK_OOP_REF, "load_barrier_on_weak_oop_field_preloaded_runtime_stub");
238 }