1 /*
2 * Copyright (c) 2018, 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 "asm/macroAssembler.inline.hpp"
27 #include "gc/g1/g1BarrierSet.hpp"
28 #include "gc/g1/g1BarrierSetAssembler.hpp"
29 #include "gc/g1/g1CardTable.hpp"
30 #include "gc/g1/g1ThreadLocalData.hpp"
31 #include "gc/g1/heapRegion.hpp"
32 #include "interpreter/interp_masm.hpp"
33 #include "runtime/sharedRuntime.hpp"
34
35 #define __ masm->
36
37 void G1BarrierSetAssembler::gen_write_ref_array_pre_barrier(MacroAssembler* masm, DecoratorSet decorators,
38 Register addr, Register count, RegSet saved_regs) {
39 bool dest_uninitialized = (decorators & AS_DEST_NOT_INITIALIZED) != 0;
40 if (!dest_uninitialized) {
41 __ push(saved_regs, sp);
42 if (count == c_rarg0) {
43 if (addr == c_rarg1) {
44 // exactly backwards!!
45 __ mov(rscratch1, c_rarg0);
46 __ mov(c_rarg0, c_rarg1);
47 __ mov(c_rarg1, rscratch1);
48 } else {
49 __ mov(c_rarg1, count);
50 __ mov(c_rarg0, addr);
51 }
52 } else {
53 __ mov(c_rarg0, addr);
54 __ mov(c_rarg1, count);
55 }
56 if (UseCompressedOops) {
57 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_pre_narrow_oop_entry), 2);
58 } else {
59 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_pre_oop_entry), 2);
60 }
61 __ pop(saved_regs, sp);
62 }
63 }
64
65 void G1BarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
66 Register start, Register end, Register scratch, RegSet saved_regs) {
67 __ push(saved_regs, sp);
68 // must compute element count unless barrier set interface is changed (other platforms supply count)
69 assert_different_registers(start, end, scratch);
70 __ lea(scratch, Address(end, BytesPerHeapOop));
71 __ sub(scratch, scratch, start); // subtract start to get #bytes
72 __ lsr(scratch, scratch, LogBytesPerHeapOop); // convert to element count
73 __ mov(c_rarg0, start);
74 __ mov(c_rarg1, scratch);
75 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_post_entry), 2);
76 __ pop(saved_regs, sp);
77 }
78
79 void G1BarrierSetAssembler::g1_write_barrier_pre(MacroAssembler* masm,
80 Register obj,
81 Register pre_val,
82 Register thread,
83 Register tmp,
84 bool tosca_live,
85 bool expand_call) {
86 // If expand_call is true then we expand the call_VM_leaf macro
87 // directly to skip generating the check by
88 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
89
90 assert(thread == rthread, "must be");
91
92 Label done;
93 Label runtime;
94
95 assert_different_registers(obj, pre_val, tmp, rscratch1);
96 assert(pre_val != noreg && tmp != noreg, "expecting a register");
97
98 Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()));
99 Address index(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_index_offset()));
100 Address buffer(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset()));
101
102 // Is marking active?
103 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
104 __ ldrw(tmp, in_progress);
105 } else {
106 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
107 __ ldrb(tmp, in_progress);
108 }
109 __ cbzw(tmp, done);
110
111 // Do we need to load the previous value?
112 if (obj != noreg) {
113 __ load_heap_oop(pre_val, Address(obj, 0));
114 }
115
116 // Is the previous value null?
117 __ cbz(pre_val, done);
118
119 // Can we store original value in the thread's buffer?
120 // Is index == 0?
121 // (The index field is typed as size_t.)
122
123 __ ldr(tmp, index); // tmp := *index_adr
124 __ cbz(tmp, runtime); // tmp == 0?
125 // If yes, goto runtime
126
127 __ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize
128 __ str(tmp, index); // *index_adr := tmp
129 __ ldr(rscratch1, buffer);
130 __ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr
131
132 // Record the previous value
133 __ str(pre_val, Address(tmp, 0));
134 __ b(done);
135
136 __ bind(runtime);
137 // save the live input values
138 RegSet saved = RegSet::of(pre_val);
139 if (tosca_live) saved += RegSet::of(r0);
140 if (obj != noreg) saved += RegSet::of(obj);
141
142 __ push(saved, sp);
143
144 // Calling the runtime using the regular call_VM_leaf mechanism generates
145 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
146 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
147 //
148 // If we care generating the pre-barrier without a frame (e.g. in the
149 // intrinsified Reference.get() routine) then ebp might be pointing to
150 // the caller frame and so this check will most likely fail at runtime.
151 //
152 // Expanding the call directly bypasses the generation of the check.
153 // So when we do not have have a full interpreter frame on the stack
154 // expand_call should be passed true.
155
156 if (expand_call) {
157 assert(pre_val != c_rarg1, "smashed arg");
158 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), pre_val, thread);
159 } else {
160 __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), pre_val, thread);
161 }
162
163 __ pop(saved, sp);
164
165 __ bind(done);
166
167 }
168
169 void G1BarrierSetAssembler::g1_write_barrier_post(MacroAssembler* masm,
170 Register store_addr,
171 Register new_val,
172 Register thread,
173 Register tmp,
174 Register tmp2) {
175 assert(thread == rthread, "must be");
176 assert_different_registers(store_addr, new_val, thread, tmp, tmp2,
177 rscratch1);
178 assert(store_addr != noreg && new_val != noreg && tmp != noreg
179 && tmp2 != noreg, "expecting a register");
180
181 Address queue_index(thread, in_bytes(G1ThreadLocalData::dirty_card_queue_index_offset()));
182 Address buffer(thread, in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset()));
183
184 BarrierSet* bs = BarrierSet::barrier_set();
185 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
186 CardTable* ct = ctbs->card_table();
187 assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
188
189 Label done;
190 Label runtime;
191
192 // Does store cross heap regions?
193
194 __ eor(tmp, store_addr, new_val);
195 __ lsr(tmp, tmp, HeapRegion::LogOfHRGrainBytes);
196 __ cbz(tmp, done);
197
198 // crosses regions, storing NULL?
199
200 __ cbz(new_val, done);
201
202 // storing region crossing non-NULL, is card already dirty?
203
204 ExternalAddress cardtable((address) ct->byte_map_base());
205 assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
206 const Register card_addr = tmp;
207
208 __ lsr(card_addr, store_addr, CardTable::card_shift);
209
210 // get the address of the card
211 __ load_byte_map_base(tmp2);
212 __ add(card_addr, card_addr, tmp2);
213 __ ldrb(tmp2, Address(card_addr));
214 __ cmpw(tmp2, (int)G1CardTable::g1_young_card_val());
215 __ br(Assembler::EQ, done);
216
217 assert((int)CardTable::dirty_card_val() == 0, "must be 0");
218
219 __ membar(Assembler::StoreLoad);
220
221 __ ldrb(tmp2, Address(card_addr));
222 __ cbzw(tmp2, done);
223
224 // storing a region crossing, non-NULL oop, card is clean.
225 // dirty card and log.
226
227 __ strb(zr, Address(card_addr));
228
229 __ ldr(rscratch1, queue_index);
230 __ cbz(rscratch1, runtime);
231 __ sub(rscratch1, rscratch1, wordSize);
232 __ str(rscratch1, queue_index);
233
234 __ ldr(tmp2, buffer);
235 __ str(card_addr, Address(tmp2, rscratch1));
236 __ b(done);
237
238 __ bind(runtime);
239 // save the live input values
240 RegSet saved = RegSet::of(store_addr, new_val);
241 __ push(saved, sp);
242 __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), card_addr, thread);
243 __ pop(saved, sp);
244
245 __ bind(done);
246 }
247
248 void G1BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
249 Register dst, Address src, Register tmp1, Register tmp_thread) {
250 bool on_oop = type == T_OBJECT || type == T_ARRAY;
251 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
252 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
253 bool on_reference = on_weak || on_phantom;
254 ModRefBarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
255 if (on_oop && on_reference) {
256 // Generate the G1 pre-barrier code to log the value of
257 // the referent field in an SATB buffer.
258 g1_write_barrier_pre(masm /* masm */,
259 noreg /* obj */,
260 dst /* pre_val */,
261 rthread /* thread */,
262 tmp1 /* tmp */,
263 true /* tosca_live */,
264 true /* expand_call */);
265 }
266 }
267
268 void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
269 Address dst, Register val, Register tmp1, Register tmp2) {
270 // flatten object address if needed
271 if (dst.index() == noreg && dst.offset() == 0) {
272 if (dst.base() != r3) {
273 __ mov(r3, dst.base());
274 }
275 } else {
276 __ lea(r3, dst);
277 }
278
279 g1_write_barrier_pre(masm,
280 r3 /* obj */,
281 tmp2 /* pre_val */,
282 rthread /* thread */,
283 tmp1 /* tmp */,
284 val != noreg /* tosca_live */,
285 false /* expand_call */);
286
287 if (val == noreg) {
288 __ store_heap_oop_null(Address(r3, 0));
289 } else {
290 // G1 barrier needs uncompressed oop for region cross check.
291 Register new_val = val;
292 if (UseCompressedOops) {
293 new_val = rscratch2;
294 __ mov(new_val, val);
295 }
296 __ store_heap_oop(Address(r3, 0), val);
297 g1_write_barrier_post(masm,
298 r3 /* store_adr */,
299 new_val /* new_val */,
300 rthread /* thread */,
301 tmp1 /* tmp */,
302 tmp2 /* tmp2 */);
303 }
304
305 }
306
307 #undef __