1 /*
2 * Copyright (c) 2018, 2021, 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 "classfile/classLoaderData.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shared/barrierSetAssembler.hpp"
29 #include "gc/shared/barrierSetNMethod.hpp"
30 #include "gc/shared/collectedHeap.hpp"
31 #include "interpreter/interp_masm.hpp"
32 #include "memory/universe.hpp"
33 #include "runtime/javaThread.hpp"
34 #include "runtime/jniHandles.hpp"
35 #include "runtime/sharedRuntime.hpp"
36 #include "runtime/stubRoutines.hpp"
37
38 #define __ masm->
39
40 void BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
41 Register dst, Address src, Register tmp1, Register tmp_thread) {
42 bool in_heap = (decorators & IN_HEAP) != 0;
43 bool in_native = (decorators & IN_NATIVE) != 0;
44 bool is_not_null = (decorators & IS_NOT_NULL) != 0;
45 bool atomic = (decorators & MO_RELAXED) != 0;
46
47 switch (type) {
48 case T_OBJECT:
49 case T_ARRAY: {
50 if (in_heap) {
51 #ifdef _LP64
52 if (UseCompressedOops) {
53 __ movl(dst, src);
54 if (is_not_null) {
55 __ decode_heap_oop_not_null(dst);
56 } else {
57 __ decode_heap_oop(dst);
58 }
59 } else
60 #endif
61 {
62 __ movptr(dst, src);
63 }
64 } else {
65 assert(in_native, "why else?");
66 __ movptr(dst, src);
67 }
68 break;
69 }
70 case T_BOOLEAN: __ load_unsigned_byte(dst, src); break;
71 case T_BYTE: __ load_signed_byte(dst, src); break;
72 case T_CHAR: __ load_unsigned_short(dst, src); break;
73 case T_SHORT: __ load_signed_short(dst, src); break;
74 case T_INT: __ movl (dst, src); break;
75 case T_ADDRESS: __ movptr(dst, src); break;
76 case T_FLOAT:
77 assert(dst == noreg, "only to ftos");
78 __ load_float(src);
79 break;
80 case T_DOUBLE:
81 assert(dst == noreg, "only to dtos");
82 __ load_double(src);
83 break;
84 case T_LONG:
85 assert(dst == noreg, "only to ltos");
86 #ifdef _LP64
87 __ movq(rax, src);
88 #else
89 if (atomic) {
90 __ fild_d(src); // Must load atomically
91 __ subptr(rsp,2*wordSize); // Make space for store
92 __ fistp_d(Address(rsp,0));
93 __ pop(rax);
94 __ pop(rdx);
95 } else {
96 __ movl(rax, src);
97 __ movl(rdx, src.plus_disp(wordSize));
98 }
99 #endif
100 break;
101 default: Unimplemented();
102 }
103 }
104
105 void BarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
106 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
107 bool in_heap = (decorators & IN_HEAP) != 0;
108 bool in_native = (decorators & IN_NATIVE) != 0;
109 bool is_not_null = (decorators & IS_NOT_NULL) != 0;
110 bool atomic = (decorators & MO_RELAXED) != 0;
111
112 switch (type) {
113 case T_OBJECT:
114 case T_ARRAY: {
115 if (in_heap) {
116 if (val == noreg) {
117 assert(!is_not_null, "inconsistent access");
118 #ifdef _LP64
119 if (UseCompressedOops) {
120 __ movl(dst, NULL_WORD);
121 } else {
122 __ movslq(dst, NULL_WORD);
123 }
124 #else
125 __ movl(dst, NULL_WORD);
126 #endif
127 } else {
128 #ifdef _LP64
129 if (UseCompressedOops) {
130 assert(!dst.uses(val), "not enough registers");
131 if (is_not_null) {
132 __ encode_heap_oop_not_null(val);
133 } else {
134 __ encode_heap_oop(val);
135 }
136 __ movl(dst, val);
137 } else
138 #endif
139 {
140 __ movptr(dst, val);
141 }
142 }
143 } else {
144 assert(in_native, "why else?");
145 assert(val != noreg, "not supported");
146 __ movptr(dst, val);
147 }
148 break;
149 }
150 case T_BOOLEAN:
151 __ andl(val, 0x1); // boolean is true if LSB is 1
152 __ movb(dst, val);
153 break;
154 case T_BYTE:
155 __ movb(dst, val);
156 break;
157 case T_SHORT:
158 __ movw(dst, val);
159 break;
160 case T_CHAR:
161 __ movw(dst, val);
162 break;
163 case T_INT:
164 __ movl(dst, val);
165 break;
166 case T_LONG:
167 assert(val == noreg, "only tos");
168 #ifdef _LP64
169 __ movq(dst, rax);
170 #else
171 if (atomic) {
172 __ push(rdx);
173 __ push(rax); // Must update atomically with FIST
174 __ fild_d(Address(rsp,0)); // So load into FPU register
175 __ fistp_d(dst); // and put into memory atomically
176 __ addptr(rsp, 2*wordSize);
177 } else {
178 __ movptr(dst, rax);
179 __ movptr(dst.plus_disp(wordSize), rdx);
180 }
181 #endif
182 break;
183 case T_FLOAT:
184 assert(val == noreg, "only tos");
185 __ store_float(dst);
186 break;
187 case T_DOUBLE:
188 assert(val == noreg, "only tos");
189 __ store_double(dst);
190 break;
191 case T_ADDRESS:
192 __ movptr(dst, val);
193 break;
194 default: Unimplemented();
195 }
196 }
197
198 void BarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env,
199 Register obj, Register tmp, Label& slowpath) {
200 __ clear_jweak_tag(obj);
201 __ movptr(obj, Address(obj, 0));
202 }
203
204 void BarrierSetAssembler::tlab_allocate(MacroAssembler* masm,
205 Register thread, Register obj,
206 Register var_size_in_bytes,
207 int con_size_in_bytes,
208 Register t1,
209 Register t2,
210 Label& slow_case) {
211 assert_different_registers(obj, t1, t2);
212 assert_different_registers(obj, var_size_in_bytes, t1);
213 Register end = t2;
214 if (!thread->is_valid()) {
215 #ifdef _LP64
216 thread = r15_thread;
217 #else
218 assert(t1->is_valid(), "need temp reg");
219 thread = t1;
220 __ get_thread(thread);
221 #endif
222 }
223
224 __ verify_tlab();
225
226 __ movptr(obj, Address(thread, JavaThread::tlab_top_offset()));
227 if (var_size_in_bytes == noreg) {
228 __ lea(end, Address(obj, con_size_in_bytes));
229 } else {
230 __ lea(end, Address(obj, var_size_in_bytes, Address::times_1));
231 }
232 __ cmpptr(end, Address(thread, JavaThread::tlab_end_offset()));
233 __ jcc(Assembler::above, slow_case);
234
235 // update the tlab top pointer
236 __ movptr(Address(thread, JavaThread::tlab_top_offset()), end);
237
238 // recover var_size_in_bytes if necessary
239 if (var_size_in_bytes == end) {
240 __ subptr(var_size_in_bytes, obj);
241 }
242 __ verify_tlab();
243 }
244
245 void BarrierSetAssembler::incr_allocated_bytes(MacroAssembler* masm, Register thread,
246 Register var_size_in_bytes,
247 int con_size_in_bytes,
248 Register t1) {
249 if (!thread->is_valid()) {
250 #ifdef _LP64
251 thread = r15_thread;
252 #else
253 assert(t1->is_valid(), "need temp reg");
254 thread = t1;
255 __ get_thread(thread);
256 #endif
257 }
258
259 #ifdef _LP64
260 if (var_size_in_bytes->is_valid()) {
261 __ addq(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())), var_size_in_bytes);
262 } else {
263 __ addq(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())), con_size_in_bytes);
264 }
265 #else
266 if (var_size_in_bytes->is_valid()) {
267 __ addl(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())), var_size_in_bytes);
268 } else {
269 __ addl(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())), con_size_in_bytes);
270 }
271 __ adcl(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())+4), 0);
272 #endif
273 }
274
275 #ifdef _LP64
276 void BarrierSetAssembler::nmethod_entry_barrier(MacroAssembler* masm, Label* slow_path, Label* continuation) {
277 BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
278 if (bs_nm == NULL) {
279 return;
280 }
281 Register thread = r15_thread;
282 Address disarmed_addr(thread, in_bytes(bs_nm->thread_disarmed_guard_value_offset()));
283 // The immediate is the last 4 bytes, so if we align the start of the cmp
284 // instruction to 4 bytes, we know that the second half of it is also 4
285 // byte aligned, which means that the immediate will not cross a cache line
286 __ align(4);
287 uintptr_t before_cmp = (uintptr_t)__ pc();
288 __ cmpl_imm32(disarmed_addr, 0);
289 uintptr_t after_cmp = (uintptr_t)__ pc();
290 guarantee(after_cmp - before_cmp == 8, "Wrong assumed instruction length");
291
292 if (slow_path != NULL) {
293 __ jcc(Assembler::notEqual, *slow_path);
294 __ bind(*continuation);
295 } else {
296 Label done;
297 __ jccb(Assembler::equal, done);
298 __ call(RuntimeAddress(StubRoutines::x86::method_entry_barrier()));
299 __ bind(done);
300 }
301 }
302 #else
303 void BarrierSetAssembler::nmethod_entry_barrier(MacroAssembler* masm, Label*, Label*) {
304 BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
305 if (bs_nm == NULL) {
306 return;
307 }
308
309 Label continuation;
310
311 Register tmp = rdi;
312 __ push(tmp);
313 __ movptr(tmp, (intptr_t)bs_nm->disarmed_guard_value_address());
314 Address disarmed_addr(tmp, 0);
315 __ align(4);
316 __ cmpl_imm32(disarmed_addr, 0);
317 __ pop(tmp);
318 __ jcc(Assembler::equal, continuation);
319 __ call(RuntimeAddress(StubRoutines::x86::method_entry_barrier()));
320 __ bind(continuation);
321 }
322 #endif
323
324 void BarrierSetAssembler::c2i_entry_barrier(MacroAssembler* masm) {
325 BarrierSetNMethod* bs = BarrierSet::barrier_set()->barrier_set_nmethod();
326 if (bs == NULL) {
327 return;
328 }
329
330 Label bad_call;
331 __ cmpptr(rbx, 0); // rbx contains the incoming method for c2i adapters.
332 __ jcc(Assembler::equal, bad_call);
333
334 Register tmp1 = LP64_ONLY( rscratch1 ) NOT_LP64( rax );
335 Register tmp2 = LP64_ONLY( rscratch2 ) NOT_LP64( rcx );
336 #ifndef _LP64
337 __ push(tmp1);
338 __ push(tmp2);
339 #endif // !_LP64
340
341 // Pointer chase to the method holder to find out if the method is concurrently unloading.
342 Label method_live;
343 __ load_method_holder_cld(tmp1, rbx);
344
345 // Is it a strong CLD?
346 __ cmpl(Address(tmp1, ClassLoaderData::keep_alive_offset()), 0);
347 __ jcc(Assembler::greater, method_live);
348
349 // Is it a weak but alive CLD?
350 __ movptr(tmp1, Address(tmp1, ClassLoaderData::holder_offset()));
351 __ resolve_weak_handle(tmp1, tmp2);
352 __ cmpptr(tmp1, 0);
353 __ jcc(Assembler::notEqual, method_live);
354
355 #ifndef _LP64
356 __ pop(tmp2);
357 __ pop(tmp1);
358 #endif
359
360 __ bind(bad_call);
361 __ jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub()));
362 __ bind(method_live);
363
364 #ifndef _LP64
365 __ pop(tmp2);
366 __ pop(tmp1);
367 #endif
368 }