1 /*
2 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2018, 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 "registerSaver_s390.hpp"
29 #include "gc/g1/g1CardTable.hpp"
30 #include "gc/g1/g1BarrierSet.hpp"
31 #include "gc/g1/g1BarrierSetAssembler.hpp"
32 #include "gc/g1/g1BarrierSetRuntime.hpp"
33 #include "gc/g1/g1DirtyCardQueue.hpp"
34 #include "gc/g1/g1SATBMarkQueueSet.hpp"
35 #include "gc/g1/g1ThreadLocalData.hpp"
36 #include "gc/g1/heapRegion.hpp"
37 #include "interpreter/interp_masm.hpp"
38 #include "runtime/sharedRuntime.hpp"
39 #ifdef COMPILER1
40 #include "c1/c1_LIRAssembler.hpp"
41 #include "c1/c1_MacroAssembler.hpp"
42 #include "gc/g1/c1/g1BarrierSetC1.hpp"
43 #endif
44
45 #define __ masm->
46
47 #define BLOCK_COMMENT(str) if (PrintAssembly) __ block_comment(str)
48
49 void G1BarrierSetAssembler::gen_write_ref_array_pre_barrier(MacroAssembler* masm, DecoratorSet decorators,
50 Register addr, Register count) {
51 bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
52
53 // With G1, don't generate the call if we statically know that the target is uninitialized.
54 if (!dest_uninitialized) {
55 // Is marking active?
56 Label filtered;
57 assert_different_registers(addr, Z_R0_scratch); // would be destroyed by push_frame()
58 assert_different_registers(count, Z_R0_scratch); // would be destroyed by push_frame()
59 Register Rtmp1 = Z_R0_scratch;
60 const int active_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset());
61 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
62 __ load_and_test_int(Rtmp1, Address(Z_thread, active_offset));
63 } else {
64 guarantee(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
65 __ load_and_test_byte(Rtmp1, Address(Z_thread, active_offset));
66 }
67 __ z_bre(filtered); // Activity indicator is zero, so there is no marking going on currently.
68
69 RegisterSaver::save_live_registers(masm, RegisterSaver::arg_registers); // Creates frame.
70
71 if (UseCompressedOops) {
72 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_narrow_oop_entry), addr, count);
73 } else {
74 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_oop_entry), addr, count);
75 }
76
77 RegisterSaver::restore_live_registers(masm, RegisterSaver::arg_registers);
78
79 __ bind(filtered);
80 }
81 }
82
83 void G1BarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
84 Register addr, Register count, bool do_return) {
85 address entry_point = CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_post_entry);
86 if (!do_return) {
87 assert_different_registers(addr, Z_R0_scratch); // would be destroyed by push_frame()
88 assert_different_registers(count, Z_R0_scratch); // would be destroyed by push_frame()
89 RegisterSaver::save_live_registers(masm, RegisterSaver::arg_registers); // Creates frame.
90 __ call_VM_leaf(entry_point, addr, count);
91 RegisterSaver::restore_live_registers(masm, RegisterSaver::arg_registers);
92 } else {
93 // Tail call: call c and return to stub caller.
94 __ lgr_if_needed(Z_ARG1, addr);
95 __ lgr_if_needed(Z_ARG2, count);
96 __ load_const(Z_R1, entry_point);
97 __ z_br(Z_R1); // Branch without linking, callee will return to stub caller.
98 }
99 }
100
101 void G1BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
102 const Address& src, Register dst, Register tmp1, Register tmp2, Label *L_handle_null) {
103 bool on_oop = type == T_OBJECT || type == T_ARRAY;
104 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
105 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
106 bool on_reference = on_weak || on_phantom;
107 Label done;
108 if (on_oop && on_reference && L_handle_null == NULL) { L_handle_null = &done; }
109 ModRefBarrierSetAssembler::load_at(masm, decorators, type, src, dst, tmp1, tmp2, L_handle_null);
110 if (on_oop && on_reference) {
111 // Generate the G1 pre-barrier code to log the value of
112 // the referent field in an SATB buffer.
113 g1_write_barrier_pre(masm, decorators | IS_NOT_NULL,
114 NULL /* obj */,
115 dst /* pre_val */,
116 noreg/* preserve */ ,
117 tmp1, tmp2 /* tmp */,
118 true /* pre_val_needed */);
119 }
120 __ bind(done);
121 }
122
123 void G1BarrierSetAssembler::g1_write_barrier_pre(MacroAssembler* masm, DecoratorSet decorators,
124 const Address* obj,
125 Register Rpre_val, // Ideally, this is a non-volatile register.
126 Register Rval, // Will be preserved.
127 Register Rtmp1, // If Rpre_val is volatile, either Rtmp1
128 Register Rtmp2, // or Rtmp2 has to be non-volatile.
129 bool pre_val_needed // Save Rpre_val across runtime call, caller uses it.
130 ) {
131
132 bool not_null = (decorators & IS_NOT_NULL) != 0,
133 preloaded = obj == NULL;
134
135 const Register Robj = obj ? obj->base() : noreg,
136 Roff = obj ? obj->index() : noreg;
137 const int active_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset());
138 const int buffer_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset());
139 const int index_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_index_offset());
140 assert_different_registers(Rtmp1, Rtmp2, Z_R0_scratch); // None of the Rtmp<i> must be Z_R0!!
141 assert_different_registers(Robj, Z_R0_scratch); // Used for addressing. Furthermore, push_frame destroys Z_R0!!
142 assert_different_registers(Rval, Z_R0_scratch); // push_frame destroys Z_R0!!
143
144 Label callRuntime, filtered;
145
146 BLOCK_COMMENT("g1_write_barrier_pre {");
147
148 // Is marking active?
149 // Note: value is loaded for test purposes only. No further use here.
150 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
151 __ load_and_test_int(Rtmp1, Address(Z_thread, active_offset));
152 } else {
153 guarantee(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
154 __ load_and_test_byte(Rtmp1, Address(Z_thread, active_offset));
155 }
156 __ z_bre(filtered); // Activity indicator is zero, so there is no marking going on currently.
157
158 assert(Rpre_val != noreg, "must have a real register");
159
160
161 // If an object is given, we need to load the previous value into Rpre_val.
162 if (obj) {
163 // Load the previous value...
164 if (UseCompressedOops) {
165 __ z_llgf(Rpre_val, *obj);
166 } else {
167 __ z_lg(Rpre_val, *obj);
168 }
169 }
170
171 // Is the previous value NULL?
172 // If so, we don't need to record it and we're done.
173 // Note: pre_val is loaded, decompressed and stored (directly or via runtime call).
174 // Register contents is preserved across runtime call if caller requests to do so.
175 if (preloaded && not_null) {
176 #ifdef ASSERT
177 __ z_ltgr(Rpre_val, Rpre_val);
178 __ asm_assert_ne("null oop not allowed (G1 pre)", 0x321); // Checked by caller.
179 #endif
180 } else {
181 __ z_ltgr(Rpre_val, Rpre_val);
182 __ z_bre(filtered); // previous value is NULL, so we don't need to record it.
183 }
184
185 // Decode the oop now. We know it's not NULL.
186 if (Robj != noreg && UseCompressedOops) {
187 __ oop_decoder(Rpre_val, Rpre_val, /*maybeNULL=*/false);
188 }
189
190 // OK, it's not filtered, so we'll need to call enqueue.
191
192 // We can store the original value in the thread's buffer
193 // only if index > 0. Otherwise, we need runtime to handle.
194 // (The index field is typed as size_t.)
195 Register Rbuffer = Rtmp1, Rindex = Rtmp2;
196 assert_different_registers(Rbuffer, Rindex, Rpre_val);
197
198 __ z_lg(Rbuffer, buffer_offset, Z_thread);
199
200 __ load_and_test_long(Rindex, Address(Z_thread, index_offset));
201 __ z_bre(callRuntime); // If index == 0, goto runtime.
202
203 __ add2reg(Rindex, -wordSize); // Decrement index.
204 __ z_stg(Rindex, index_offset, Z_thread);
205
206 // Record the previous value.
207 __ z_stg(Rpre_val, 0, Rbuffer, Rindex);
208 __ z_bru(filtered); // We are done.
209
210 Rbuffer = noreg; // end of life
211 Rindex = noreg; // end of life
212
213 __ bind(callRuntime);
214
215 // Save some registers (inputs and result) over runtime call
216 // by spilling them into the top frame.
217 if (Robj != noreg && Robj->is_volatile()) {
218 __ z_stg(Robj, Robj->encoding()*BytesPerWord, Z_SP);
219 }
220 if (Roff != noreg && Roff->is_volatile()) {
221 __ z_stg(Roff, Roff->encoding()*BytesPerWord, Z_SP);
222 }
223 if (Rval != noreg && Rval->is_volatile()) {
224 __ z_stg(Rval, Rval->encoding()*BytesPerWord, Z_SP);
225 }
226
227 // Save Rpre_val (result) over runtime call.
228 Register Rpre_save = Rpre_val;
229 if ((Rpre_val == Z_R0_scratch) || (pre_val_needed && Rpre_val->is_volatile())) {
230 guarantee(!Rtmp1->is_volatile() || !Rtmp2->is_volatile(), "oops!");
231 Rpre_save = !Rtmp1->is_volatile() ? Rtmp1 : Rtmp2;
232 }
233 __ lgr_if_needed(Rpre_save, Rpre_val);
234
235 // Push frame to protect top frame with return pc and spilled register values.
236 __ save_return_pc();
237 __ push_frame_abi160(0); // Will use Z_R0 as tmp.
238
239 // Rpre_val may be destroyed by push_frame().
240 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), Rpre_save, Z_thread);
241
242 __ pop_frame();
243 __ restore_return_pc();
244
245 // Restore spilled values.
246 if (Robj != noreg && Robj->is_volatile()) {
247 __ z_lg(Robj, Robj->encoding()*BytesPerWord, Z_SP);
248 }
249 if (Roff != noreg && Roff->is_volatile()) {
250 __ z_lg(Roff, Roff->encoding()*BytesPerWord, Z_SP);
251 }
252 if (Rval != noreg && Rval->is_volatile()) {
253 __ z_lg(Rval, Rval->encoding()*BytesPerWord, Z_SP);
254 }
255 if (pre_val_needed && Rpre_val->is_volatile()) {
256 __ lgr_if_needed(Rpre_val, Rpre_save);
257 }
258
259 __ bind(filtered);
260 BLOCK_COMMENT("} g1_write_barrier_pre");
261 }
262
263 void G1BarrierSetAssembler::g1_write_barrier_post(MacroAssembler* masm, DecoratorSet decorators, Register Rstore_addr, Register Rnew_val,
264 Register Rtmp1, Register Rtmp2, Register Rtmp3) {
265 bool not_null = (decorators & IS_NOT_NULL) != 0;
266
267 assert_different_registers(Rstore_addr, Rnew_val, Rtmp1, Rtmp2); // Most probably, Rnew_val == Rtmp3.
268
269 Label callRuntime, filtered;
270
271 CardTableBarrierSet* ct = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
272
273 BLOCK_COMMENT("g1_write_barrier_post {");
274
275 // Does store cross heap regions?
276 // It does if the two addresses specify different grain addresses.
277 if (VM_Version::has_DistinctOpnds()) {
278 __ z_xgrk(Rtmp1, Rstore_addr, Rnew_val);
279 } else {
280 __ z_lgr(Rtmp1, Rstore_addr);
281 __ z_xgr(Rtmp1, Rnew_val);
282 }
283 __ z_srag(Rtmp1, Rtmp1, HeapRegion::LogOfHRGrainBytes);
284 __ z_bre(filtered);
285
286 // Crosses regions, storing NULL?
287 if (not_null) {
288 #ifdef ASSERT
289 __ z_ltgr(Rnew_val, Rnew_val);
290 __ asm_assert_ne("null oop not allowed (G1 post)", 0x322); // Checked by caller.
291 #endif
292 } else {
293 __ z_ltgr(Rnew_val, Rnew_val);
294 __ z_bre(filtered);
295 }
296
297 Rnew_val = noreg; // end of lifetime
298
299 // Storing region crossing non-NULL, is card already dirty?
300 assert_different_registers(Rtmp1, Rtmp2, Rtmp3);
301 // Make sure not to use Z_R0 for any of these registers.
302 Register Rcard_addr = (Rtmp1 != Z_R0_scratch) ? Rtmp1 : Rtmp3;
303 Register Rbase = (Rtmp2 != Z_R0_scratch) ? Rtmp2 : Rtmp3;
304
305 // calculate address of card
306 __ load_const_optimized(Rbase, (address)ct->card_table()->byte_map_base()); // Card table base.
307 __ z_srlg(Rcard_addr, Rstore_addr, CardTable::card_shift); // Index into card table.
308 __ z_algr(Rcard_addr, Rbase); // Explicit calculation needed for cli.
309 Rbase = noreg; // end of lifetime
310
311 // Filter young.
312 assert((unsigned int)G1CardTable::g1_young_card_val() <= 255, "otherwise check this code");
313 __ z_cli(0, Rcard_addr, G1CardTable::g1_young_card_val());
314 __ z_bre(filtered);
315
316 // Check the card value. If dirty, we're done.
317 // This also avoids false sharing of the (already dirty) card.
318 __ z_sync(); // Required to support concurrent cleaning.
319 assert((unsigned int)G1CardTable::dirty_card_val() <= 255, "otherwise check this code");
320 __ z_cli(0, Rcard_addr, G1CardTable::dirty_card_val()); // Reload after membar.
321 __ z_bre(filtered);
322
323 // Storing a region crossing, non-NULL oop, card is clean.
324 // Dirty card and log.
325 __ z_mvi(0, Rcard_addr, G1CardTable::dirty_card_val());
326
327 Register Rcard_addr_x = Rcard_addr;
328 Register Rqueue_index = (Rtmp2 != Z_R0_scratch) ? Rtmp2 : Rtmp1;
329 Register Rqueue_buf = (Rtmp3 != Z_R0_scratch) ? Rtmp3 : Rtmp1;
330 const int qidx_off = in_bytes(G1ThreadLocalData::dirty_card_queue_index_offset());
331 const int qbuf_off = in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset());
332 if ((Rcard_addr == Rqueue_buf) || (Rcard_addr == Rqueue_index)) {
333 Rcard_addr_x = Z_R0_scratch; // Register shortage. We have to use Z_R0.
334 }
335 __ lgr_if_needed(Rcard_addr_x, Rcard_addr);
336
337 __ load_and_test_long(Rqueue_index, Address(Z_thread, qidx_off));
338 __ z_bre(callRuntime); // Index == 0 then jump to runtime.
339
340 __ z_lg(Rqueue_buf, qbuf_off, Z_thread);
341
342 __ add2reg(Rqueue_index, -wordSize); // Decrement index.
343 __ z_stg(Rqueue_index, qidx_off, Z_thread);
344
345 __ z_stg(Rcard_addr_x, 0, Rqueue_index, Rqueue_buf); // Store card.
346 __ z_bru(filtered);
347
348 __ bind(callRuntime);
349
350 // TODO: do we need a frame? Introduced to be on the safe side.
351 bool needs_frame = true;
352 __ lgr_if_needed(Rcard_addr, Rcard_addr_x); // copy back asap. push_frame will destroy Z_R0_scratch!
353
354 // VM call need frame to access(write) O register.
355 if (needs_frame) {
356 __ save_return_pc();
357 __ push_frame_abi160(0); // Will use Z_R0 as tmp on old CPUs.
358 }
359
360 // Save the live input values.
361 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_post_entry), Rcard_addr, Z_thread);
362
363 if (needs_frame) {
364 __ pop_frame();
365 __ restore_return_pc();
366 }
367
368 __ bind(filtered);
369
370 BLOCK_COMMENT("} g1_write_barrier_post");
371 }
372
373 void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
374 const Address& dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
375 bool is_array = (decorators & IS_ARRAY) != 0;
376 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
377 bool precise = is_array || on_anonymous;
378 // Load and record the previous value.
379 g1_write_barrier_pre(masm, decorators, &dst, tmp3, val, tmp1, tmp2, false);
380
381 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2, tmp3);
382
383 // No need for post barrier if storing NULL
384 if (val != noreg) {
385 const Register base = dst.base(),
386 idx = dst.index();
387 const intptr_t disp = dst.disp();
388 if (precise && (disp != 0 || idx != noreg)) {
389 __ add2reg_with_index(base, disp, idx, base);
390 }
391 g1_write_barrier_post(masm, decorators, base, val, tmp1, tmp2, tmp3);
392 }
393 }
394
395 void G1BarrierSetAssembler::resolve_jobject(MacroAssembler* masm, Register value, Register tmp1, Register tmp2) {
396 NearLabel Ldone, Lnot_weak;
397 __ z_ltgr(tmp1, value);
398 __ z_bre(Ldone); // Use NULL result as-is.
399
400 __ z_nill(value, ~JNIHandles::weak_tag_mask);
401 __ z_lg(value, 0, value); // Resolve (untagged) jobject.
402
403 __ z_tmll(tmp1, JNIHandles::weak_tag_mask); // Test for jweak tag.
404 __ z_braz(Lnot_weak);
405 __ verify_oop(value);
406 DecoratorSet decorators = IN_NATIVE | ON_PHANTOM_OOP_REF;
407 g1_write_barrier_pre(masm, decorators, (const Address*)NULL, value, noreg, tmp1, tmp2, true);
408 __ bind(Lnot_weak);
409 __ verify_oop(value);
410 __ bind(Ldone);
411 }
412
413 #ifdef COMPILER1
414
415 #undef __
416 #define __ ce->masm()->
417
418 void G1BarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, G1PreBarrierStub* stub) {
419 G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
420 // At this point we know that marking is in progress.
421 // If do_load() is true then we have to emit the
422 // load of the previous value; otherwise it has already
423 // been loaded into _pre_val.
424 __ bind(*stub->entry());
425 ce->check_reserved_argument_area(16); // RT stub needs 2 spill slots.
426 assert(stub->pre_val()->is_register(), "Precondition.");
427
428 Register pre_val_reg = stub->pre_val()->as_register();
429
430 if (stub->do_load()) {
431 ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
432 }
433
434 __ z_ltgr(Z_R1_scratch, pre_val_reg); // Pass oop in Z_R1_scratch to Runtime1::g1_pre_barrier_slow_id.
435 __ branch_optimized(Assembler::bcondZero, *stub->continuation());
436 ce->emit_call_c(bs->pre_barrier_c1_runtime_code_blob()->code_begin());
437 __ branch_optimized(Assembler::bcondAlways, *stub->continuation());
438 }
439
440 void G1BarrierSetAssembler::gen_post_barrier_stub(LIR_Assembler* ce, G1PostBarrierStub* stub) {
441 G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
442 __ bind(*stub->entry());
443 ce->check_reserved_argument_area(16); // RT stub needs 2 spill slots.
444 assert(stub->addr()->is_register(), "Precondition.");
445 assert(stub->new_val()->is_register(), "Precondition.");
446 Register new_val_reg = stub->new_val()->as_register();
447 __ z_ltgr(new_val_reg, new_val_reg);
448 __ branch_optimized(Assembler::bcondZero, *stub->continuation());
449 __ z_lgr(Z_R1_scratch, stub->addr()->as_pointer_register());
450 ce->emit_call_c(bs->post_barrier_c1_runtime_code_blob()->code_begin());
451 __ branch_optimized(Assembler::bcondAlways, *stub->continuation());
452 }
453
454 #undef __
455
456 #define __ sasm->
457
458 static OopMap* save_volatile_registers(StubAssembler* sasm, Register return_pc = Z_R14) {
459 __ block_comment("save_volatile_registers");
460 RegisterSaver::RegisterSet reg_set = RegisterSaver::all_volatile_registers;
461 int frame_size_in_slots = RegisterSaver::live_reg_frame_size(reg_set) / VMRegImpl::stack_slot_size;
462 sasm->set_frame_size(frame_size_in_slots / VMRegImpl::slots_per_word);
463 return RegisterSaver::save_live_registers(sasm, reg_set, return_pc);
464 }
465
466 static void restore_volatile_registers(StubAssembler* sasm) {
467 __ block_comment("restore_volatile_registers");
468 RegisterSaver::RegisterSet reg_set = RegisterSaver::all_volatile_registers;
469 RegisterSaver::restore_live_registers(sasm, reg_set);
470 }
471
472 void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
473 // Z_R1_scratch: previous value of memory
474
475 BarrierSet* bs = BarrierSet::barrier_set();
476 __ set_info("g1_pre_barrier_slow_id", false);
477
478 Register pre_val = Z_R1_scratch;
479 Register tmp = Z_R6; // Must be non-volatile because it is used to save pre_val.
480 Register tmp2 = Z_R7;
481
482 Label refill, restart, marking_not_active;
483 int satb_q_active_byte_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset());
484 int satb_q_index_byte_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_index_offset());
485 int satb_q_buf_byte_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset());
486
487 // Save tmp registers (see assertion in G1PreBarrierStub::emit_code()).
488 __ z_stg(tmp, 0*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
489 __ z_stg(tmp2, 1*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
490
491 // Is marking still active?
492 if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
493 __ load_and_test_int(tmp, Address(Z_thread, satb_q_active_byte_offset));
494 } else {
495 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
496 __ load_and_test_byte(tmp, Address(Z_thread, satb_q_active_byte_offset));
497 }
498 __ z_bre(marking_not_active); // Activity indicator is zero, so there is no marking going on currently.
499
500 __ bind(restart);
501 // Load the index into the SATB buffer. SATBMarkQueue::_index is a
502 // size_t so ld_ptr is appropriate.
503 __ z_ltg(tmp, satb_q_index_byte_offset, Z_R0, Z_thread);
504
505 // index == 0?
506 __ z_brz(refill);
507
508 __ z_lg(tmp2, satb_q_buf_byte_offset, Z_thread);
509 __ add2reg(tmp, -oopSize);
510
511 __ z_stg(pre_val, 0, tmp, tmp2); // [_buf + index] := <address_of_card>
512 __ z_stg(tmp, satb_q_index_byte_offset, Z_thread);
513
514 __ bind(marking_not_active);
515 // Restore tmp registers (see assertion in G1PreBarrierStub::emit_code()).
516 __ z_lg(tmp, 0*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
517 __ z_lg(tmp2, 1*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
518 __ z_br(Z_R14);
519
520 __ bind(refill);
521 save_volatile_registers(sasm);
522 __ z_lgr(tmp, pre_val); // save pre_val
523 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1SATBMarkQueueSet::handle_zero_index_for_thread),
524 Z_thread);
525 __ z_lgr(pre_val, tmp); // restore pre_val
526 restore_volatile_registers(sasm);
527 __ z_bru(restart);
528 }
529
530 void G1BarrierSetAssembler::generate_c1_post_barrier_runtime_stub(StubAssembler* sasm) {
531 // Z_R1_scratch: oop address, address of updated memory slot
532
533 BarrierSet* bs = BarrierSet::barrier_set();
534 __ set_info("g1_post_barrier_slow_id", false);
535
536 Register addr_oop = Z_R1_scratch;
537 Register addr_card = Z_R1_scratch;
538 Register r1 = Z_R6; // Must be saved/restored.
539 Register r2 = Z_R7; // Must be saved/restored.
540 Register cardtable = r1; // Must be non-volatile, because it is used to save addr_card.
541 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
542 CardTable* ct = ctbs->card_table();
543 CardTable::CardValue* byte_map_base = ct->byte_map_base();
544
545 // Save registers used below (see assertion in G1PreBarrierStub::emit_code()).
546 __ z_stg(r1, 0*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
547
548 Label not_already_dirty, restart, refill, young_card;
549
550 // Calculate address of card corresponding to the updated oop slot.
551 AddressLiteral rs(byte_map_base);
552 __ z_srlg(addr_card, addr_oop, CardTable::card_shift);
553 addr_oop = noreg; // dead now
554 __ load_const_optimized(cardtable, rs); // cardtable := <card table base>
555 __ z_agr(addr_card, cardtable); // addr_card := addr_oop>>card_shift + cardtable
556
557 __ z_cli(0, addr_card, (int)G1CardTable::g1_young_card_val());
558 __ z_bre(young_card);
559
560 __ z_sync(); // Required to support concurrent cleaning.
561
562 __ z_cli(0, addr_card, (int)CardTable::dirty_card_val());
563 __ z_brne(not_already_dirty);
564
565 __ bind(young_card);
566 // We didn't take the branch, so we're already dirty: restore
567 // used registers and return.
568 __ z_lg(r1, 0*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
569 __ z_br(Z_R14);
570
571 // Not dirty.
572 __ bind(not_already_dirty);
573
574 // First, dirty it: [addr_card] := 0
575 __ z_mvi(0, addr_card, CardTable::dirty_card_val());
576
577 Register idx = cardtable; // Must be non-volatile, because it is used to save addr_card.
578 Register buf = r2;
579 cardtable = noreg; // now dead
580
581 // Save registers used below (see assertion in G1PreBarrierStub::emit_code()).
582 __ z_stg(r2, 1*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
583
584 ByteSize dirty_card_q_index_byte_offset = G1ThreadLocalData::dirty_card_queue_index_offset();
585 ByteSize dirty_card_q_buf_byte_offset = G1ThreadLocalData::dirty_card_queue_buffer_offset();
586
587 __ bind(restart);
588
589 // Get the index into the update buffer. G1DirtyCardQueue::_index is
590 // a size_t so z_ltg is appropriate here.
591 __ z_ltg(idx, Address(Z_thread, dirty_card_q_index_byte_offset));
592
593 // index == 0?
594 __ z_brz(refill);
595
596 __ z_lg(buf, Address(Z_thread, dirty_card_q_buf_byte_offset));
597 __ add2reg(idx, -oopSize);
598
599 __ z_stg(addr_card, 0, idx, buf); // [_buf + index] := <address_of_card>
600 __ z_stg(idx, Address(Z_thread, dirty_card_q_index_byte_offset));
601 // Restore killed registers and return.
602 __ z_lg(r1, 0*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
603 __ z_lg(r2, 1*BytesPerWord + FrameMap::first_available_sp_in_frame, Z_SP);
604 __ z_br(Z_R14);
605
606 __ bind(refill);
607 save_volatile_registers(sasm);
608 __ z_lgr(idx, addr_card); // Save addr_card, tmp3 must be non-volatile.
609 __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1DirtyCardQueueSet::handle_zero_index_for_thread),
610 Z_thread);
611 __ z_lgr(addr_card, idx);
612 restore_volatile_registers(sasm); // Restore addr_card.
613 __ z_bru(restart);
614 }
615
616 #undef __
617
618 #endif // COMPILER1