114 __ add(start, start, scratch);
115
116 __ bind(loop);
117 if (UseCondCardMark) {
118 __ ldrb(scratch, Address(start, count));
119 // Instead of loading clean_card_val and comparing, we exploit the fact that
120 // the LSB of non-clean cards is always 0, and the LSB of clean cards 1.
121 __ tbz(scratch, 0, next);
122 }
123 static_assert(G1CardTable::dirty_card_val() == 0, "must be to use zr");
124 __ strb(zr, Address(start, count));
125 __ bind(next);
126 __ subs(count, count, 1);
127 __ br(Assembler::GE, loop);
128
129 __ bind(done);
130 }
131
132 static void generate_queue_test_and_insertion(MacroAssembler* masm, ByteSize index_offset, ByteSize buffer_offset, Label& runtime,
133 const Register thread, const Register value, const Register temp1, const Register temp2) {
134 // Can we store a value in the given thread's buffer?
135 // (The index field is typed as size_t.)
136 __ ldr(temp1, Address(thread, in_bytes(index_offset))); // temp1 := *(index address)
137 __ cbz(temp1, runtime); // jump to runtime if index == 0 (full buffer)
138 // The buffer is not full, store value into it.
139 __ sub(temp1, temp1, wordSize); // temp1 := next index
140 __ str(temp1, Address(thread, in_bytes(index_offset))); // *(index address) := next index
141 __ ldr(temp2, Address(thread, in_bytes(buffer_offset))); // temp2 := buffer address
142 __ str(value, Address(temp2, temp1)); // *(buffer address + next index) := value
143 }
144
145 static void generate_pre_barrier_fast_path(MacroAssembler* masm,
146 const Register thread,
147 const Register tmp1) {
148 Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()));
149 // Is marking active?
150 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
151 __ ldrw(tmp1, in_progress);
152 } else {
153 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
187 bool expand_call) {
188 // If expand_call is true then we expand the call_VM_leaf macro
189 // directly to skip generating the check by
190 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
191
192 assert(thread == rthread, "must be");
193
194 Label done;
195 Label runtime;
196
197 assert_different_registers(obj, pre_val, tmp1, tmp2);
198 assert(pre_val != noreg && tmp1 != noreg && tmp2 != noreg, "expecting a register");
199
200 generate_pre_barrier_fast_path(masm, thread, tmp1);
201 // If marking is not active (*(mark queue active address) == 0), jump to done
202 __ cbzw(tmp1, done);
203 generate_pre_barrier_slow_path(masm, obj, pre_val, thread, tmp1, tmp2, done, runtime);
204
205 __ bind(runtime);
206
207 __ push_call_clobbered_registers();
208
209 // Calling the runtime using the regular call_VM_leaf mechanism generates
210 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
211 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == nullptr.
212 //
213 // If we care generating the pre-barrier without a frame (e.g. in the
214 // intrinsified Reference.get() routine) then rfp might be pointing to
215 // the caller frame and so this check will most likely fail at runtime.
216 //
217 // Expanding the call directly bypasses the generation of the check.
218 // So when we do not have have a full interpreter frame on the stack
219 // expand_call should be passed true.
220
221 if (expand_call) {
222 assert(pre_val != c_rarg1, "smashed arg");
223 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread);
224 } else {
225 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread);
226 }
227
228 __ pop_call_clobbered_registers();
229
230 __ bind(done);
231
232 }
233
234 static void generate_post_barrier(MacroAssembler* masm,
235 const Register store_addr,
236 const Register new_val,
237 const Register thread,
238 const Register tmp1,
239 const Register tmp2,
240 Label& done,
241 bool new_val_may_be_null) {
242 assert(thread == rthread, "must be");
243 assert_different_registers(store_addr, new_val, thread, tmp1, tmp2, noreg, rscratch1);
244
245 // Does store cross heap regions?
246 __ eor(tmp1, store_addr, new_val); // tmp1 := store address ^ new value
247 __ lsr(tmp1, tmp1, G1HeapRegion::LogOfHRGrainBytes); // tmp1 := ((store address ^ new value) >> LogOfHRGrainBytes)
248 __ cbz(tmp1, done);
349 CardTableBarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp2);
350 if (on_oop && on_reference) {
351 // LR is live. It must be saved around calls.
352 __ enter(/*strip_ret_addr*/true); // barrier may call runtime
353 // Generate the G1 pre-barrier code to log the value of
354 // the referent field in an SATB buffer.
355 g1_write_barrier_pre(masm /* masm */,
356 noreg /* obj */,
357 dst /* pre_val */,
358 rthread /* thread */,
359 tmp1 /* tmp1 */,
360 tmp2 /* tmp2 */,
361 true /* tosca_live */,
362 true /* expand_call */);
363 __ leave();
364 }
365 }
366
367 void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
368 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
369 // flatten object address if needed
370 if (dst.index() == noreg && dst.offset() == 0) {
371 if (dst.base() != tmp3) {
372 __ mov(tmp3, dst.base());
373 }
374 } else {
375 __ lea(tmp3, dst);
376 }
377
378 g1_write_barrier_pre(masm,
379 tmp3 /* obj */,
380 tmp2 /* pre_val */,
381 rthread /* thread */,
382 tmp1 /* tmp1 */,
383 rscratch2 /* tmp2 */,
384 val != noreg /* tosca_live */,
385 false /* expand_call */);
386
387 if (val == noreg) {
388 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp3, 0), noreg, noreg, noreg, noreg);
389 } else {
390 // G1 barrier needs uncompressed oop for region cross check.
391 Register new_val = val;
392 if (UseCompressedOops) {
393 new_val = rscratch2;
394 __ mov(new_val, val);
395 }
396 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp3, 0), val, noreg, noreg, noreg);
397 g1_write_barrier_post(masm,
398 tmp3 /* store_adr */,
399 new_val /* new_val */,
400 rthread /* thread */,
401 tmp1 /* tmp1 */,
402 tmp2 /* tmp2 */);
403 }
404
405 }
406
407 #ifdef COMPILER1
408
409 #undef __
410 #define __ ce->masm()->
411
412 void G1BarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, G1PreBarrierStub* stub) {
413 G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
414 // At this point we know that marking is in progress.
415 // If do_load() is true then we have to emit the
416 // load of the previous value; otherwise it has already
417 // been loaded into _pre_val.
418
419 __ bind(*stub->entry());
420
421 assert(stub->pre_val()->is_register(), "Precondition.");
422
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114 __ add(start, start, scratch);
115
116 __ bind(loop);
117 if (UseCondCardMark) {
118 __ ldrb(scratch, Address(start, count));
119 // Instead of loading clean_card_val and comparing, we exploit the fact that
120 // the LSB of non-clean cards is always 0, and the LSB of clean cards 1.
121 __ tbz(scratch, 0, next);
122 }
123 static_assert(G1CardTable::dirty_card_val() == 0, "must be to use zr");
124 __ strb(zr, Address(start, count));
125 __ bind(next);
126 __ subs(count, count, 1);
127 __ br(Assembler::GE, loop);
128
129 __ bind(done);
130 }
131
132 static void generate_queue_test_and_insertion(MacroAssembler* masm, ByteSize index_offset, ByteSize buffer_offset, Label& runtime,
133 const Register thread, const Register value, const Register temp1, const Register temp2) {
134 assert_different_registers(value, temp1, temp2);
135 // Can we store a value in the given thread's buffer?
136 // (The index field is typed as size_t.)
137 __ ldr(temp1, Address(thread, in_bytes(index_offset))); // temp1 := *(index address)
138 __ cbz(temp1, runtime); // jump to runtime if index == 0 (full buffer)
139 // The buffer is not full, store value into it.
140 __ sub(temp1, temp1, wordSize); // temp1 := next index
141 __ str(temp1, Address(thread, in_bytes(index_offset))); // *(index address) := next index
142 __ ldr(temp2, Address(thread, in_bytes(buffer_offset))); // temp2 := buffer address
143 __ str(value, Address(temp2, temp1)); // *(buffer address + next index) := value
144 }
145
146 static void generate_pre_barrier_fast_path(MacroAssembler* masm,
147 const Register thread,
148 const Register tmp1) {
149 Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()));
150 // Is marking active?
151 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
152 __ ldrw(tmp1, in_progress);
153 } else {
154 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
188 bool expand_call) {
189 // If expand_call is true then we expand the call_VM_leaf macro
190 // directly to skip generating the check by
191 // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
192
193 assert(thread == rthread, "must be");
194
195 Label done;
196 Label runtime;
197
198 assert_different_registers(obj, pre_val, tmp1, tmp2);
199 assert(pre_val != noreg && tmp1 != noreg && tmp2 != noreg, "expecting a register");
200
201 generate_pre_barrier_fast_path(masm, thread, tmp1);
202 // If marking is not active (*(mark queue active address) == 0), jump to done
203 __ cbzw(tmp1, done);
204 generate_pre_barrier_slow_path(masm, obj, pre_val, thread, tmp1, tmp2, done, runtime);
205
206 __ bind(runtime);
207
208 // save the live input values
209 RegSet saved = RegSet::of(pre_val);
210 FloatRegSet fsaved;
211
212 // Barriers might be emitted when converting between (scalarized) calling
213 // conventions for inline types. Save all argument registers before calling
214 // into the runtime.
215
216 // TODO 8366717 This came with 8284161: Implementation of Virtual Threads (Preview) later in May 2022
217 // Check if it's sufficient
218 //__ push_call_clobbered_registers();
219 assert_different_registers(rscratch1, pre_val); // push_CPU_state trashes rscratch1
220 __ push_CPU_state(true);
221
222 // Calling the runtime using the regular call_VM_leaf mechanism generates
223 // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
224 // that checks that the *(rfp+frame::interpreter_frame_last_sp) == nullptr.
225 //
226 // If we care generating the pre-barrier without a frame (e.g. in the
227 // intrinsified Reference.get() routine) then rfp might be pointing to
228 // the caller frame and so this check will most likely fail at runtime.
229 //
230 // Expanding the call directly bypasses the generation of the check.
231 // So when we do not have have a full interpreter frame on the stack
232 // expand_call should be passed true.
233
234 if (expand_call) {
235 assert(pre_val != c_rarg1, "smashed arg");
236 __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread);
237 } else {
238 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread);
239 }
240
241 __ pop_CPU_state(true);
242
243 __ bind(done);
244
245 }
246
247 static void generate_post_barrier(MacroAssembler* masm,
248 const Register store_addr,
249 const Register new_val,
250 const Register thread,
251 const Register tmp1,
252 const Register tmp2,
253 Label& done,
254 bool new_val_may_be_null) {
255 assert(thread == rthread, "must be");
256 assert_different_registers(store_addr, new_val, thread, tmp1, tmp2, noreg, rscratch1);
257
258 // Does store cross heap regions?
259 __ eor(tmp1, store_addr, new_val); // tmp1 := store address ^ new value
260 __ lsr(tmp1, tmp1, G1HeapRegion::LogOfHRGrainBytes); // tmp1 := ((store address ^ new value) >> LogOfHRGrainBytes)
261 __ cbz(tmp1, done);
362 CardTableBarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp2);
363 if (on_oop && on_reference) {
364 // LR is live. It must be saved around calls.
365 __ enter(/*strip_ret_addr*/true); // barrier may call runtime
366 // Generate the G1 pre-barrier code to log the value of
367 // the referent field in an SATB buffer.
368 g1_write_barrier_pre(masm /* masm */,
369 noreg /* obj */,
370 dst /* pre_val */,
371 rthread /* thread */,
372 tmp1 /* tmp1 */,
373 tmp2 /* tmp2 */,
374 true /* tosca_live */,
375 true /* expand_call */);
376 __ leave();
377 }
378 }
379
380 void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
381 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
382
383 bool in_heap = (decorators & IN_HEAP) != 0;
384 bool as_normal = (decorators & AS_NORMAL) != 0;
385 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
386
387 bool needs_pre_barrier = as_normal && !dest_uninitialized;
388 bool needs_post_barrier = (val != noreg && in_heap);
389
390 assert_different_registers(val, tmp1, tmp2, tmp3);
391
392 // flatten object address if needed
393 if (dst.index() == noreg && dst.offset() == 0) {
394 if (dst.base() != tmp3) {
395 __ mov(tmp3, dst.base());
396 }
397 } else {
398 __ lea(tmp3, dst);
399 }
400
401 if (needs_pre_barrier) {
402 g1_write_barrier_pre(masm,
403 tmp3 /* obj */,
404 tmp2 /* pre_val */,
405 rthread /* thread */,
406 tmp1 /* tmp1 */,
407 rscratch2 /* tmp2 */,
408 val != noreg /* tosca_live */,
409 false /* expand_call */);
410 }
411
412 if (val == noreg) {
413 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp3, 0), noreg, noreg, noreg, noreg);
414 } else {
415 // G1 barrier needs uncompressed oop for region cross check.
416 Register new_val = val;
417 if (needs_post_barrier) {
418 if (UseCompressedOops) {
419 new_val = rscratch2;
420 __ mov(new_val, val);
421 }
422 }
423
424 BarrierSetAssembler::store_at(masm, decorators, type, Address(tmp3, 0), val, noreg, noreg, noreg);
425 if (needs_post_barrier) {
426 g1_write_barrier_post(masm,
427 tmp3 /* store_adr */,
428 new_val /* new_val */,
429 rthread /* thread */,
430 tmp1 /* tmp1 */,
431 tmp2 /* tmp2 */);
432 }
433 }
434
435 }
436
437 #ifdef COMPILER1
438
439 #undef __
440 #define __ ce->masm()->
441
442 void G1BarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, G1PreBarrierStub* stub) {
443 G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
444 // At this point we know that marking is in progress.
445 // If do_load() is true then we have to emit the
446 // load of the previous value; otherwise it has already
447 // been loaded into _pre_val.
448
449 __ bind(*stub->entry());
450
451 assert(stub->pre_val()->is_register(), "Precondition.");
452
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