1 /*
2 * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2016, 2024 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 // Major contributions by AHa, AS, JL, ML.
27
28 #include "asm/macroAssembler.inline.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/barrierSetAssembler.hpp"
31 #include "interp_masm_s390.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/interpreterRuntime.hpp"
34 #include "oops/arrayOop.hpp"
35 #include "oops/markWord.hpp"
36 #include "oops/methodCounters.hpp"
37 #include "oops/methodData.hpp"
38 #include "oops/resolvedFieldEntry.hpp"
39 #include "oops/resolvedIndyEntry.hpp"
40 #include "oops/resolvedMethodEntry.hpp"
41 #include "prims/jvmtiExport.hpp"
42 #include "prims/jvmtiThreadState.hpp"
43 #include "runtime/basicLock.hpp"
44 #include "runtime/frame.inline.hpp"
45 #include "runtime/javaThread.hpp"
46 #include "runtime/safepointMechanism.hpp"
47 #include "runtime/sharedRuntime.hpp"
48 #include "utilities/macros.hpp"
49 #include "utilities/powerOfTwo.hpp"
50
51 // Implementation of InterpreterMacroAssembler.
52 // This file specializes the assembler with interpreter-specific macros.
53
54 #ifdef PRODUCT
55 #define BLOCK_COMMENT(str)
56 #define BIND(label) bind(label);
57 #else
58 #define BLOCK_COMMENT(str) block_comment(str)
59 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
60 #endif
61
62 void InterpreterMacroAssembler::jump_to_entry(address entry, Register Rscratch) {
63 assert(entry != nullptr, "Entry must have been generated by now");
64 assert(Rscratch != Z_R0, "Can't use R0 for addressing");
65 branch_optimized(Assembler::bcondAlways, entry);
66 }
67
68 void InterpreterMacroAssembler::empty_expression_stack(void) {
69 get_monitors(Z_R1_scratch);
70 add2reg(Z_esp, -Interpreter::stackElementSize, Z_R1_scratch);
71 }
72
73 // Dispatch code executed in the prolog of a bytecode which does not do it's
74 // own dispatch.
75 void InterpreterMacroAssembler::dispatch_prolog(TosState state, int bcp_incr) {
76 // On z/Architecture we are short on registers, therefore we do not preload the
77 // dispatch address of the next bytecode.
78 }
79
80 // Dispatch code executed in the epilog of a bytecode which does not do it's
81 // own dispatch.
82 void InterpreterMacroAssembler::dispatch_epilog(TosState state, int step) {
83 dispatch_next(state, step);
84 }
85
86 void InterpreterMacroAssembler::dispatch_next(TosState state, int bcp_incr, bool generate_poll) {
87 z_llgc(Z_bytecode, bcp_incr, Z_R0, Z_bcp); // Load next bytecode.
88 add2reg(Z_bcp, bcp_incr); // Advance bcp. Add2reg produces optimal code.
89 dispatch_base(state, Interpreter::dispatch_table(state), generate_poll);
90 }
91
92 // Common code to dispatch and dispatch_only.
93 // Dispatch value in Lbyte_code and increment Lbcp.
94
95 void InterpreterMacroAssembler::dispatch_base(TosState state, address* table, bool generate_poll) {
96 #ifdef ASSERT
97 address reentry = nullptr;
98 { Label OK;
99 // Check if the frame pointer in Z_fp is correct.
100 z_cg(Z_fp, 0, Z_SP);
101 z_bre(OK);
102 reentry = stop_chain_static(reentry, "invalid frame pointer Z_fp: " FILE_AND_LINE);
103 bind(OK);
104 }
105 { Label OK;
106 // check if the locals pointer in Z_locals is correct
107 z_cg(Z_locals, _z_ijava_state_neg(locals), Z_fp);
108 z_bre(OK);
109 reentry = stop_chain_static(reentry, "invalid locals pointer Z_locals: " FILE_AND_LINE);
110 bind(OK);
111 }
112 #endif
113
114 // TODO: Maybe implement +VerifyActivationFrameSize here.
115 verify_oop(Z_tos, state);
116
117 // Dispatch table to use.
118 load_absolute_address(Z_tmp_1, (address)table); // Z_tmp_1 = table;
119
120 if (generate_poll) {
121 address *sfpt_tbl = Interpreter::safept_table(state);
122 if (table != sfpt_tbl) {
123 Label dispatch;
124 const Address poll_byte_addr(Z_thread, in_bytes(JavaThread::polling_word_offset()) + 7 /* Big Endian */);
125 // Armed page has poll_bit set, if poll bit is cleared just continue.
126 z_tm(poll_byte_addr, SafepointMechanism::poll_bit());
127 z_braz(dispatch);
128 load_absolute_address(Z_tmp_1, (address)sfpt_tbl); // Z_tmp_1 = table;
129 bind(dispatch);
130 }
131 }
132
133 // 0 <= Z_bytecode < 256 => Use a 32 bit shift, because it is shorter than sllg.
134 // Z_bytecode must have been loaded zero-extended for this approach to be correct.
135 z_sll(Z_bytecode, LogBytesPerWord, Z_R0); // Multiply by wordSize.
136 z_lg(Z_tmp_1, 0, Z_bytecode, Z_tmp_1); // Get entry addr.
137
138 z_br(Z_tmp_1);
139 }
140
141 void InterpreterMacroAssembler::dispatch_only(TosState state, bool generate_poll) {
142 dispatch_base(state, Interpreter::dispatch_table(state), generate_poll);
143 }
144
145 void InterpreterMacroAssembler::dispatch_only_normal(TosState state) {
146 dispatch_base(state, Interpreter::normal_table(state));
147 }
148
149 void InterpreterMacroAssembler::dispatch_via(TosState state, address *table) {
150 // Load current bytecode.
151 z_llgc(Z_bytecode, Address(Z_bcp, (intptr_t)0));
152 dispatch_base(state, table);
153 }
154
155 // The following call_VM*_base() methods overload and mask the respective
156 // declarations/definitions in class MacroAssembler. They are meant as a "detour"
157 // to perform additional, template interpreter specific tasks before actually
158 // calling their MacroAssembler counterparts.
159
160 void InterpreterMacroAssembler::call_VM_leaf_base(address entry_point) {
161 bool allow_relocation = true; // Fenerally valid variant. Assume code is relocated.
162 // interpreter specific
163 // Note: No need to save/restore bcp (Z_R13) pointer since these are callee
164 // saved registers and no blocking/ GC can happen in leaf calls.
165
166 // super call
167 MacroAssembler::call_VM_leaf_base(entry_point, allow_relocation);
168 }
169
170 void InterpreterMacroAssembler::call_VM_leaf_base(address entry_point, bool allow_relocation) {
171 // interpreter specific
172 // Note: No need to save/restore bcp (Z_R13) pointer since these are callee
173 // saved registers and no blocking/ GC can happen in leaf calls.
174
175 // super call
176 MacroAssembler::call_VM_leaf_base(entry_point, allow_relocation);
177 }
178
179 void InterpreterMacroAssembler::call_VM_base(Register oop_result, Register last_java_sp,
180 address entry_point, bool check_exceptions) {
181 bool allow_relocation = true; // Fenerally valid variant. Assume code is relocated.
182 // interpreter specific
183
184 save_bcp();
185 save_esp();
186 // super call
187 MacroAssembler::call_VM_base(oop_result, last_java_sp,
188 entry_point, allow_relocation, check_exceptions);
189 restore_bcp();
190 }
191
192 void InterpreterMacroAssembler::call_VM_base(Register oop_result, Register last_java_sp,
193 address entry_point, bool allow_relocation,
194 bool check_exceptions) {
195 // interpreter specific
196
197 save_bcp();
198 save_esp();
199 // super call
200 MacroAssembler::call_VM_base(oop_result, last_java_sp,
201 entry_point, allow_relocation, check_exceptions);
202 restore_bcp();
203 }
204
205 void InterpreterMacroAssembler::check_and_handle_popframe(Register scratch_reg) {
206 if (JvmtiExport::can_pop_frame()) {
207 BLOCK_COMMENT("check_and_handle_popframe {");
208 Label L;
209 // Initiate popframe handling only if it is not already being
210 // processed. If the flag has the popframe_processing bit set, it
211 // means that this code is called *during* popframe handling - we
212 // don't want to reenter.
213 // TODO: Check if all four state combinations could be visible.
214 // If (processing and !pending) is an invisible/impossible state,
215 // there is optimization potential by testing both bits at once.
216 // Then, All_Zeroes and All_Ones means skip, Mixed means doit.
217 testbit(Address(Z_thread, JavaThread::popframe_condition_offset()),
218 exact_log2(JavaThread::popframe_pending_bit));
219 z_bfalse(L);
220 testbit(Address(Z_thread, JavaThread::popframe_condition_offset()),
221 exact_log2(JavaThread::popframe_processing_bit));
222 z_btrue(L);
223
224 // Call Interpreter::remove_activation_preserving_args_entry() to get the
225 // address of the same-named entrypoint in the generated interpreter code.
226 call_VM_leaf(CAST_FROM_FN_PTR(address, Interpreter::remove_activation_preserving_args_entry));
227 // The above call should (as its only effect) return the contents of the field
228 // _remove_activation_preserving_args_entry in Z_RET.
229 // We just jump there to have the work done.
230 z_br(Z_RET);
231 // There is no way for control to fall thru here.
232
233 bind(L);
234 BLOCK_COMMENT("} check_and_handle_popframe");
235 }
236 }
237
238
239 void InterpreterMacroAssembler::load_earlyret_value(TosState state) {
240 Register RjvmtiState = Z_R1_scratch;
241 int tos_off = in_bytes(JvmtiThreadState::earlyret_tos_offset());
242 int oop_off = in_bytes(JvmtiThreadState::earlyret_oop_offset());
243 int val_off = in_bytes(JvmtiThreadState::earlyret_value_offset());
244 int state_off = in_bytes(JavaThread::jvmti_thread_state_offset());
245
246 z_lg(RjvmtiState, state_off, Z_thread);
247
248 switch (state) {
249 case atos: z_lg(Z_tos, oop_off, RjvmtiState);
250 store_const(Address(RjvmtiState, oop_off), 0L, 8, 8, Z_R0_scratch);
251 break;
252 case ltos: z_lg(Z_tos, val_off, RjvmtiState); break;
253 case btos: // fall through
254 case ztos: // fall through
255 case ctos: // fall through
256 case stos: // fall through
257 case itos: z_llgf(Z_tos, val_off, RjvmtiState); break;
258 case ftos: z_le(Z_ftos, val_off, RjvmtiState); break;
259 case dtos: z_ld(Z_ftos, val_off, RjvmtiState); break;
260 case vtos: /* nothing to do */ break;
261 default : ShouldNotReachHere();
262 }
263
264 // Clean up tos value in the jvmti thread state.
265 store_const(Address(RjvmtiState, val_off), 0L, 8, 8, Z_R0_scratch);
266 // Set tos state field to illegal value.
267 store_const(Address(RjvmtiState, tos_off), ilgl, 4, 1, Z_R0_scratch);
268 }
269
270 void InterpreterMacroAssembler::check_and_handle_earlyret(Register scratch_reg) {
271 if (JvmtiExport::can_force_early_return()) {
272 BLOCK_COMMENT("check_and_handle_earlyret {");
273 Label L;
274 // arg regs are save, because we are just behind the call in call_VM_base
275 Register jvmti_thread_state = Z_ARG2;
276 Register tmp = Z_ARG3;
277 load_and_test_long(jvmti_thread_state, Address(Z_thread, JavaThread::jvmti_thread_state_offset()));
278 z_bre(L); // if (thread->jvmti_thread_state() == nullptr) exit;
279
280 // Initiate earlyret handling only if it is not already being processed.
281 // If the flag has the earlyret_processing bit set, it means that this code
282 // is called *during* earlyret handling - we don't want to reenter.
283
284 assert((JvmtiThreadState::earlyret_pending != 0) && (JvmtiThreadState::earlyret_inactive == 0),
285 "must fix this check, when changing the values of the earlyret enum");
286 assert(JvmtiThreadState::earlyret_pending == 1, "must fix this check, when changing the values of the earlyret enum");
287
288 load_and_test_int(tmp, Address(jvmti_thread_state, JvmtiThreadState::earlyret_state_offset()));
289 z_brz(L); // if (thread->jvmti_thread_state()->_earlyret_state != JvmtiThreadState::earlyret_pending) exit;
290
291 // Call Interpreter::remove_activation_early_entry() to get the address of the
292 // same-named entrypoint in the generated interpreter code.
293 assert(sizeof(TosState) == 4, "unexpected size");
294 z_l(Z_ARG1, Address(jvmti_thread_state, JvmtiThreadState::earlyret_tos_offset()));
295 call_VM_leaf(CAST_FROM_FN_PTR(address, Interpreter::remove_activation_early_entry), Z_ARG1);
296 // The above call should (as its only effect) return the contents of the field
297 // _remove_activation_preserving_args_entry in Z_RET.
298 // We just jump there to have the work done.
299 z_br(Z_RET);
300 // There is no way for control to fall thru here.
301
302 bind(L);
303 BLOCK_COMMENT("} check_and_handle_earlyret");
304 }
305 }
306
307 void InterpreterMacroAssembler::super_call_VM_leaf(address entry_point, Register arg_1, Register arg_2) {
308 lgr_if_needed(Z_ARG1, arg_1);
309 assert(arg_2 != Z_ARG1, "smashed argument");
310 lgr_if_needed(Z_ARG2, arg_2);
311 MacroAssembler::call_VM_leaf_base(entry_point, true);
312 }
313
314 void InterpreterMacroAssembler::get_cache_index_at_bcp(Register index, int bcp_offset, size_t index_size) {
315 Address param(Z_bcp, bcp_offset);
316
317 BLOCK_COMMENT("get_cache_index_at_bcp {");
318 assert(bcp_offset > 0, "bcp is still pointing to start of bytecode");
319 if (index_size == sizeof(u2)) {
320 load_sized_value(index, param, 2, false /*signed*/);
321 } else if (index_size == sizeof(u4)) {
322
323 load_sized_value(index, param, 4, false);
324 } else if (index_size == sizeof(u1)) {
325 z_llgc(index, param);
326 } else {
327 ShouldNotReachHere();
328 }
329 BLOCK_COMMENT("}");
330 }
331
332 void InterpreterMacroAssembler::load_resolved_indy_entry(Register cache, Register index) {
333 // Get index out of bytecode pointer.
334 get_cache_index_at_bcp(index, 1, sizeof(u4));
335
336 // Get the address of the ResolvedIndyEntry array
337 get_constant_pool_cache(cache);
338 z_lg(cache, Address(cache, in_bytes(ConstantPoolCache::invokedynamic_entries_offset())));
339
340 // Scale the index to form a byte offset into the ResolvedIndyEntry array
341 size_t entry_size = sizeof(ResolvedIndyEntry);
342 if (is_power_of_2(entry_size)) {
343 z_sllg(index, index, exact_log2(entry_size));
344 } else {
345 z_mghi(index, entry_size);
346 }
347
348 // Calculate the final field address.
349 z_la(cache, Array<ResolvedIndyEntry>::base_offset_in_bytes(), index, cache);
350 }
351
352 void InterpreterMacroAssembler::load_field_entry(Register cache, Register index, int bcp_offset) {
353 // Get field index out of bytecode pointer.
354 get_cache_index_at_bcp(index, bcp_offset, sizeof(u2));
355
356 // Get the address of the ResolvedFieldEntry array.
357 get_constant_pool_cache(cache);
358 z_lg(cache, Address(cache, in_bytes(ConstantPoolCache::field_entries_offset())));
359
360 // Scale the index to form a byte offset into the ResolvedFieldEntry array
361 size_t entry_size = sizeof(ResolvedFieldEntry);
362 if (is_power_of_2(entry_size)) {
363 z_sllg(index, index, exact_log2(entry_size));
364 } else {
365 z_mghi(index, entry_size);
366 }
367
368 // Calculate the final field address.
369 z_la(cache, Array<ResolvedFieldEntry>::base_offset_in_bytes(), index, cache);
370 }
371
372 void InterpreterMacroAssembler::load_method_entry(Register cache, Register index, int bcp_offset) {
373 // Get field index out of bytecode pointer.
374 get_cache_index_at_bcp(index, bcp_offset, sizeof(u2));
375
376 // Get the address of the ResolvedMethodEntry array.
377 get_constant_pool_cache(cache);
378 z_lg(cache, Address(cache, in_bytes(ConstantPoolCache::method_entries_offset())));
379
380 // Scale the index to form a byte offset into the ResolvedMethodEntry array
381 size_t entry_size = sizeof(ResolvedMethodEntry);
382 if (is_power_of_2(entry_size)) {
383 z_sllg(index, index, exact_log2(entry_size));
384 } else {
385 z_mghi(index, entry_size);
386 }
387
388 // Calculate the final field address.
389 z_la(cache, Array<ResolvedMethodEntry>::base_offset_in_bytes(), index, cache);
390 }
391
392 // Load object from cpool->resolved_references(index).
393 void InterpreterMacroAssembler::load_resolved_reference_at_index(Register result, Register index) {
394 assert_different_registers(result, index);
395 get_constant_pool(result);
396
397 // Convert
398 // - from field index to resolved_references() index and
399 // - from word index to byte offset.
400 // Since this is a java object, it is potentially compressed.
401 Register tmp = index; // reuse
402 z_sllg(index, index, LogBytesPerHeapOop); // Offset into resolved references array.
403 // Load pointer for resolved_references[] objArray.
404 z_lg(result, in_bytes(ConstantPool::cache_offset()), result);
405 z_lg(result, in_bytes(ConstantPoolCache::resolved_references_offset()), result);
406 resolve_oop_handle(result); // Load resolved references array itself.
407 #ifdef ASSERT
408 NearLabel index_ok;
409 z_lgf(Z_R0, Address(result, arrayOopDesc::length_offset_in_bytes()));
410 z_sllg(Z_R0, Z_R0, LogBytesPerHeapOop);
411 compare64_and_branch(tmp, Z_R0, Assembler::bcondLow, index_ok);
412 stop("resolved reference index out of bounds", 0x09256);
413 bind(index_ok);
414 #endif
415 z_agr(result, index); // Address of indexed array element.
416 load_heap_oop(result, Address(result, arrayOopDesc::base_offset_in_bytes(T_OBJECT)), tmp, noreg);
417 }
418
419 // load cpool->resolved_klass_at(index)
420 void InterpreterMacroAssembler::load_resolved_klass_at_offset(Register cpool, Register offset, Register iklass) {
421 // int value = *(Rcpool->int_at_addr(which));
422 // int resolved_klass_index = extract_low_short_from_int(value);
423 z_llgh(offset, Address(cpool, offset, sizeof(ConstantPool) + 2)); // offset = resolved_klass_index (s390 is big-endian)
424 z_sllg(offset, offset, LogBytesPerWord); // Convert 'index' to 'offset'
425 z_lg(iklass, Address(cpool, ConstantPool::resolved_klasses_offset())); // iklass = cpool->_resolved_klasses
426 z_lg(iklass, Address(iklass, offset, Array<Klass*>::base_offset_in_bytes()));
427 }
428
429 // Generate a subtype check: branch to ok_is_subtype if sub_klass is
430 // a subtype of super_klass. Blows registers Rsuper_klass, Rsub_klass, tmp1, tmp2.
431 void InterpreterMacroAssembler::gen_subtype_check(Register Rsub_klass,
432 Register Rsuper_klass,
433 Register Rtmp1,
434 Register Rtmp2,
435 Label &ok_is_subtype) {
436 // Profile the not-null value's klass.
437 profile_typecheck(Rtmp1, Rsub_klass, Rtmp2);
438
439 // Do the check.
440 check_klass_subtype(Rsub_klass, Rsuper_klass, Rtmp1, Rtmp2, ok_is_subtype);
441 }
442
443 // Pop topmost element from stack. It just disappears.
444 // Useful if consumed previously by access via stackTop().
445 void InterpreterMacroAssembler::popx(int len) {
446 add2reg(Z_esp, len*Interpreter::stackElementSize);
447 debug_only(verify_esp(Z_esp, Z_R1_scratch));
448 }
449
450 // Get Address object of stack top. No checks. No pop.
451 // Purpose: - Provide address of stack operand to exploit reg-mem operations.
452 // - Avoid RISC-like mem2reg - reg-reg-op sequence.
453 Address InterpreterMacroAssembler::stackTop() {
454 return Address(Z_esp, Interpreter::expr_offset_in_bytes(0));
455 }
456
457 void InterpreterMacroAssembler::pop_i(Register r) {
458 z_l(r, Interpreter::expr_offset_in_bytes(0), Z_esp);
459 add2reg(Z_esp, Interpreter::stackElementSize);
460 assert_different_registers(r, Z_R1_scratch);
461 debug_only(verify_esp(Z_esp, Z_R1_scratch));
462 }
463
464 void InterpreterMacroAssembler::pop_ptr(Register r) {
465 z_lg(r, Interpreter::expr_offset_in_bytes(0), Z_esp);
466 add2reg(Z_esp, Interpreter::stackElementSize);
467 assert_different_registers(r, Z_R1_scratch);
468 debug_only(verify_esp(Z_esp, Z_R1_scratch));
469 }
470
471 void InterpreterMacroAssembler::pop_l(Register r) {
472 z_lg(r, Interpreter::expr_offset_in_bytes(0), Z_esp);
473 add2reg(Z_esp, 2*Interpreter::stackElementSize);
474 assert_different_registers(r, Z_R1_scratch);
475 debug_only(verify_esp(Z_esp, Z_R1_scratch));
476 }
477
478 void InterpreterMacroAssembler::pop_f(FloatRegister f) {
479 mem2freg_opt(f, Address(Z_esp, Interpreter::expr_offset_in_bytes(0)), false);
480 add2reg(Z_esp, Interpreter::stackElementSize);
481 debug_only(verify_esp(Z_esp, Z_R1_scratch));
482 }
483
484 void InterpreterMacroAssembler::pop_d(FloatRegister f) {
485 mem2freg_opt(f, Address(Z_esp, Interpreter::expr_offset_in_bytes(0)), true);
486 add2reg(Z_esp, 2*Interpreter::stackElementSize);
487 debug_only(verify_esp(Z_esp, Z_R1_scratch));
488 }
489
490 void InterpreterMacroAssembler::push_i(Register r) {
491 assert_different_registers(r, Z_R1_scratch);
492 debug_only(verify_esp(Z_esp, Z_R1_scratch));
493 z_st(r, Address(Z_esp));
494 add2reg(Z_esp, -Interpreter::stackElementSize);
495 }
496
497 void InterpreterMacroAssembler::push_ptr(Register r) {
498 z_stg(r, Address(Z_esp));
499 add2reg(Z_esp, -Interpreter::stackElementSize);
500 }
501
502 void InterpreterMacroAssembler::push_l(Register r) {
503 assert_different_registers(r, Z_R1_scratch);
504 debug_only(verify_esp(Z_esp, Z_R1_scratch));
505 int offset = -Interpreter::stackElementSize;
506 z_stg(r, Address(Z_esp, offset));
507 clear_mem(Address(Z_esp), Interpreter::stackElementSize);
508 add2reg(Z_esp, 2 * offset);
509 }
510
511 void InterpreterMacroAssembler::push_f(FloatRegister f) {
512 debug_only(verify_esp(Z_esp, Z_R1_scratch));
513 freg2mem_opt(f, Address(Z_esp), false);
514 add2reg(Z_esp, -Interpreter::stackElementSize);
515 }
516
517 void InterpreterMacroAssembler::push_d(FloatRegister d) {
518 debug_only(verify_esp(Z_esp, Z_R1_scratch));
519 int offset = -Interpreter::stackElementSize;
520 freg2mem_opt(d, Address(Z_esp, offset));
521 add2reg(Z_esp, 2 * offset);
522 }
523
524 void InterpreterMacroAssembler::push(TosState state) {
525 verify_oop(Z_tos, state);
526 switch (state) {
527 case atos: push_ptr(); break;
528 case btos: push_i(); break;
529 case ztos:
530 case ctos:
531 case stos: push_i(); break;
532 case itos: push_i(); break;
533 case ltos: push_l(); break;
534 case ftos: push_f(); break;
535 case dtos: push_d(); break;
536 case vtos: /* nothing to do */ break;
537 default : ShouldNotReachHere();
538 }
539 }
540
541 void InterpreterMacroAssembler::pop(TosState state) {
542 switch (state) {
543 case atos: pop_ptr(Z_tos); break;
544 case btos: pop_i(Z_tos); break;
545 case ztos:
546 case ctos:
547 case stos: pop_i(Z_tos); break;
548 case itos: pop_i(Z_tos); break;
549 case ltos: pop_l(Z_tos); break;
550 case ftos: pop_f(Z_ftos); break;
551 case dtos: pop_d(Z_ftos); break;
552 case vtos: /* nothing to do */ break;
553 default : ShouldNotReachHere();
554 }
555 verify_oop(Z_tos, state);
556 }
557
558 // Helpers for swap and dup.
559 void InterpreterMacroAssembler::load_ptr(int n, Register val) {
560 z_lg(val, Address(Z_esp, Interpreter::expr_offset_in_bytes(n)));
561 }
562
563 void InterpreterMacroAssembler::store_ptr(int n, Register val) {
564 z_stg(val, Address(Z_esp, Interpreter::expr_offset_in_bytes(n)));
565 }
566
567 void InterpreterMacroAssembler::prepare_to_jump_from_interpreted(Register method) {
568 // Satisfy interpreter calling convention (see generate_normal_entry()).
569 z_lgr(Z_R10, Z_SP); // Set sender sp (aka initial caller sp, aka unextended sp).
570 // Record top_frame_sp, because the callee might modify it, if it's compiled.
571 z_stg(Z_SP, _z_ijava_state_neg(top_frame_sp), Z_fp);
572 save_bcp();
573 save_esp();
574 z_lgr(Z_method, method); // Set Z_method (kills Z_fp!).
575 }
576
577 // Jump to from_interpreted entry of a call unless single stepping is possible
578 // in this thread in which case we must call the i2i entry.
579 void InterpreterMacroAssembler::jump_from_interpreted(Register method, Register temp) {
580 assert_different_registers(method, Z_R10 /*used for initial_caller_sp*/, temp);
581 prepare_to_jump_from_interpreted(method);
582
583 if (JvmtiExport::can_post_interpreter_events()) {
584 // JVMTI events, such as single-stepping, are implemented partly by avoiding running
585 // compiled code in threads for which the event is enabled. Check here for
586 // interp_only_mode if these events CAN be enabled.
587 z_lg(Z_R1_scratch, Address(method, Method::from_interpreted_offset()));
588 MacroAssembler::load_and_test_int(Z_R0_scratch, Address(Z_thread, JavaThread::interp_only_mode_offset()));
589 z_bcr(bcondEqual, Z_R1_scratch); // Run compiled code if zero.
590 // Run interpreted.
591 z_lg(Z_R1_scratch, Address(method, Method::interpreter_entry_offset()));
592 z_br(Z_R1_scratch);
593 } else {
594 // Run compiled code.
595 z_lg(Z_R1_scratch, Address(method, Method::from_interpreted_offset()));
596 z_br(Z_R1_scratch);
597 }
598 }
599
600 #ifdef ASSERT
601 void InterpreterMacroAssembler::verify_esp(Register Resp, Register Rtemp) {
602 // About to read or write Resp[0].
603 // Make sure it is not in the monitors or the TOP_IJAVA_FRAME_ABI.
604 address reentry = nullptr;
605
606 {
607 // Check if the frame pointer in Z_fp is correct.
608 NearLabel OK;
609 z_cg(Z_fp, 0, Z_SP);
610 z_bre(OK);
611 reentry = stop_chain_static(reentry, "invalid frame pointer Z_fp");
612 bind(OK);
613 }
614 {
615 // Resp must not point into or below the operand stack,
616 // i.e. IJAVA_STATE.monitors > Resp.
617 NearLabel OK;
618 Register Rmonitors = Rtemp;
619 z_lg(Rmonitors, _z_ijava_state_neg(monitors), Z_fp);
620 compareU64_and_branch(Rmonitors, Resp, bcondHigh, OK);
621 reentry = stop_chain_static(reentry, "too many pops: Z_esp points into monitor area");
622 bind(OK);
623 }
624 {
625 // Resp may point to the last word of TOP_IJAVA_FRAME_ABI, but not below
626 // i.e. !(Z_SP + frame::z_top_ijava_frame_abi_size - Interpreter::stackElementSize > Resp).
627 NearLabel OK;
628 Register Rabi_bottom = Rtemp;
629 add2reg(Rabi_bottom, frame::z_top_ijava_frame_abi_size - Interpreter::stackElementSize, Z_SP);
630 compareU64_and_branch(Rabi_bottom, Resp, bcondNotHigh, OK);
631 reentry = stop_chain_static(reentry, "too many pushes: Z_esp points into TOP_IJAVA_FRAME_ABI");
632 bind(OK);
633 }
634 }
635
636 void InterpreterMacroAssembler::asm_assert_ijava_state_magic(Register tmp) {
637 Label magic_ok;
638 load_const_optimized(tmp, frame::z_istate_magic_number);
639 z_cg(tmp, Address(Z_fp, _z_ijava_state_neg(magic)));
640 z_bre(magic_ok);
641 stop_static("error: wrong magic number in ijava_state access");
642 bind(magic_ok);
643 }
644 #endif // ASSERT
645
646 void InterpreterMacroAssembler::save_bcp() {
647 z_stg(Z_bcp, Address(Z_fp, _z_ijava_state_neg(bcp)));
648 asm_assert_ijava_state_magic(Z_bcp);
649 NOT_PRODUCT(z_lg(Z_bcp, Address(Z_fp, _z_ijava_state_neg(bcp))));
650 }
651
652 void InterpreterMacroAssembler::restore_bcp() {
653 asm_assert_ijava_state_magic(Z_bcp);
654 z_lg(Z_bcp, Address(Z_fp, _z_ijava_state_neg(bcp)));
655 }
656
657 void InterpreterMacroAssembler::save_esp() {
658 z_stg(Z_esp, Address(Z_fp, _z_ijava_state_neg(esp)));
659 }
660
661 void InterpreterMacroAssembler::restore_esp() {
662 asm_assert_ijava_state_magic(Z_esp);
663 z_lg(Z_esp, Address(Z_fp, _z_ijava_state_neg(esp)));
664 }
665
666 void InterpreterMacroAssembler::get_monitors(Register reg) {
667 asm_assert_ijava_state_magic(reg);
668 mem2reg_opt(reg, Address(Z_fp, _z_ijava_state_neg(monitors)));
669 }
670
671 void InterpreterMacroAssembler::save_monitors(Register reg) {
672 reg2mem_opt(reg, Address(Z_fp, _z_ijava_state_neg(monitors)));
673 }
674
675 void InterpreterMacroAssembler::get_mdp(Register mdp) {
676 z_lg(mdp, _z_ijava_state_neg(mdx), Z_fp);
677 }
678
679 void InterpreterMacroAssembler::save_mdp(Register mdp) {
680 z_stg(mdp, _z_ijava_state_neg(mdx), Z_fp);
681 }
682
683 // Values that are only read (besides initialization).
684 void InterpreterMacroAssembler::restore_locals() {
685 asm_assert_ijava_state_magic(Z_locals);
686 z_lg(Z_locals, Address(Z_fp, _z_ijava_state_neg(locals)));
687 }
688
689 void InterpreterMacroAssembler::get_method(Register reg) {
690 asm_assert_ijava_state_magic(reg);
691 z_lg(reg, Address(Z_fp, _z_ijava_state_neg(method)));
692 }
693
694 void InterpreterMacroAssembler::get_2_byte_integer_at_bcp(Register Rdst, int bcp_offset,
695 signedOrNot is_signed) {
696 // Rdst is an 8-byte return value!!!
697
698 // Unaligned loads incur only a small penalty on z/Architecture. The penalty
699 // is a few (2..3) ticks, even when the load crosses a cache line
700 // boundary. In case of a cache miss, the stall could, of course, be
701 // much longer.
702
703 switch (is_signed) {
704 case Signed:
705 z_lgh(Rdst, bcp_offset, Z_R0, Z_bcp);
706 break;
707 case Unsigned:
708 z_llgh(Rdst, bcp_offset, Z_R0, Z_bcp);
709 break;
710 default:
711 ShouldNotReachHere();
712 }
713 }
714
715
716 void InterpreterMacroAssembler::get_4_byte_integer_at_bcp(Register Rdst, int bcp_offset,
717 setCCOrNot set_cc) {
718 // Rdst is an 8-byte return value!!!
719
720 // Unaligned loads incur only a small penalty on z/Architecture. The penalty
721 // is a few (2..3) ticks, even when the load crosses a cache line
722 // boundary. In case of a cache miss, the stall could, of course, be
723 // much longer.
724
725 // Both variants implement a sign-extending int2long load.
726 if (set_cc == set_CC) {
727 load_and_test_int2long(Rdst, Address(Z_bcp, (intptr_t)bcp_offset));
728 } else {
729 mem2reg_signed_opt( Rdst, Address(Z_bcp, (intptr_t)bcp_offset));
730 }
731 }
732
733 void InterpreterMacroAssembler::get_constant_pool(Register Rdst) {
734 get_method(Rdst);
735 mem2reg_opt(Rdst, Address(Rdst, Method::const_offset()));
736 mem2reg_opt(Rdst, Address(Rdst, ConstMethod::constants_offset()));
737 }
738
739 void InterpreterMacroAssembler::get_constant_pool_cache(Register Rdst) {
740 get_constant_pool(Rdst);
741 mem2reg_opt(Rdst, Address(Rdst, ConstantPool::cache_offset()));
742 }
743
744 void InterpreterMacroAssembler::get_cpool_and_tags(Register Rcpool, Register Rtags) {
745 get_constant_pool(Rcpool);
746 mem2reg_opt(Rtags, Address(Rcpool, ConstantPool::tags_offset()));
747 }
748
749 // Unlock if synchronized method.
750 //
751 // Unlock the receiver if this is a synchronized method.
752 // Unlock any Java monitors from synchronized blocks.
753 //
754 // If there are locked Java monitors
755 // If throw_monitor_exception
756 // throws IllegalMonitorStateException
757 // Else if install_monitor_exception
758 // installs IllegalMonitorStateException
759 // Else
760 // no error processing
761 void InterpreterMacroAssembler::unlock_if_synchronized_method(TosState state,
762 bool throw_monitor_exception,
763 bool install_monitor_exception) {
764 NearLabel unlocked, unlock, no_unlock;
765
766 {
767 Register R_method = Z_ARG2;
768 Register R_do_not_unlock_if_synchronized = Z_ARG3;
769
770 // Get the value of _do_not_unlock_if_synchronized into G1_scratch.
771 const Address do_not_unlock_if_synchronized(Z_thread,
772 JavaThread::do_not_unlock_if_synchronized_offset());
773 load_sized_value(R_do_not_unlock_if_synchronized, do_not_unlock_if_synchronized, 1, false /*unsigned*/);
774 z_mvi(do_not_unlock_if_synchronized, false); // Reset the flag.
775
776 // Check if synchronized method.
777 get_method(R_method);
778 verify_oop(Z_tos, state);
779 push(state); // Save tos/result.
780 testbit_ushort(method2_(R_method, access_flags), JVM_ACC_SYNCHRONIZED_BIT);
781 z_bfalse(unlocked);
782
783 // Don't unlock anything if the _do_not_unlock_if_synchronized flag
784 // is set.
785 compareU64_and_branch(R_do_not_unlock_if_synchronized, (intptr_t)0L, bcondNotEqual, no_unlock);
786 }
787
788 // unlock monitor
789
790 // BasicObjectLock will be first in list, since this is a
791 // synchronized method. However, need to check that the object has
792 // not been unlocked by an explicit monitorexit bytecode.
793 const Address monitor(Z_fp, -(frame::z_ijava_state_size + (int) sizeof(BasicObjectLock)));
794 // We use Z_ARG2 so that if we go slow path it will be the correct
795 // register for unlock_object to pass to VM directly.
796 load_address(Z_ARG2, monitor); // Address of first monitor.
797 z_lg(Z_ARG3, Address(Z_ARG2, BasicObjectLock::obj_offset()));
798 compareU64_and_branch(Z_ARG3, (intptr_t)0L, bcondNotEqual, unlock);
799
800 if (throw_monitor_exception) {
801 // Entry already unlocked need to throw an exception.
802 MacroAssembler::call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_illegal_monitor_state_exception));
803 should_not_reach_here();
804 } else {
805 // Monitor already unlocked during a stack unroll.
806 // If requested, install an illegal_monitor_state_exception.
807 // Continue with stack unrolling.
808 if (install_monitor_exception) {
809 MacroAssembler::call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::new_illegal_monitor_state_exception));
810 }
811 z_bru(unlocked);
812 }
813
814 bind(unlock);
815
816 unlock_object(Z_ARG2);
817
818 bind(unlocked);
819
820 // I0, I1: Might contain return value
821
822 // Check that all monitors are unlocked.
823 {
824 NearLabel loop, exception, entry, restart;
825 const int entry_size = frame::interpreter_frame_monitor_size_in_bytes();
826 // We use Z_ARG2 so that if we go slow path it will be the correct
827 // register for unlock_object to pass to VM directly.
828 Register R_current_monitor = Z_ARG2;
829 Register R_monitor_block_bot = Z_ARG1;
830 const Address monitor_block_top(Z_fp, _z_ijava_state_neg(monitors));
831 const Address monitor_block_bot(Z_fp, -frame::z_ijava_state_size);
832
833 bind(restart);
834 // Starting with top-most entry.
835 z_lg(R_current_monitor, monitor_block_top);
836 // Points to word before bottom of monitor block.
837 load_address(R_monitor_block_bot, monitor_block_bot);
838 z_bru(entry);
839
840 // Entry already locked, need to throw exception.
841 bind(exception);
842
843 if (throw_monitor_exception) {
844 // Throw exception.
845 MacroAssembler::call_VM(noreg,
846 CAST_FROM_FN_PTR(address, InterpreterRuntime::
847 throw_illegal_monitor_state_exception));
848 should_not_reach_here();
849 } else {
850 // Stack unrolling. Unlock object and install illegal_monitor_exception.
851 // Unlock does not block, so don't have to worry about the frame.
852 // We don't have to preserve c_rarg1 since we are going to throw an exception.
853 unlock_object(R_current_monitor);
854 if (install_monitor_exception) {
855 call_VM(noreg, CAST_FROM_FN_PTR(address,
856 InterpreterRuntime::
857 new_illegal_monitor_state_exception));
858 }
859 z_bru(restart);
860 }
861
862 bind(loop);
863 // Check if current entry is used.
864 load_and_test_long(Z_R0_scratch, Address(R_current_monitor, BasicObjectLock::obj_offset()));
865 z_brne(exception);
866
867 add2reg(R_current_monitor, entry_size); // Otherwise advance to next entry.
868 bind(entry);
869 compareU64_and_branch(R_current_monitor, R_monitor_block_bot, bcondNotEqual, loop);
870 }
871
872 bind(no_unlock);
873 pop(state);
874 verify_oop(Z_tos, state);
875 }
876
877 void InterpreterMacroAssembler::narrow(Register result, Register ret_type) {
878 get_method(ret_type);
879 z_lg(ret_type, Address(ret_type, in_bytes(Method::const_offset())));
880 z_lb(ret_type, Address(ret_type, in_bytes(ConstMethod::result_type_offset())));
881
882 Label notBool, notByte, notChar, done;
883
884 // common case first
885 compareU32_and_branch(ret_type, T_INT, bcondEqual, done);
886
887 compareU32_and_branch(ret_type, T_BOOLEAN, bcondNotEqual, notBool);
888 z_nilf(result, 0x1);
889 z_bru(done);
890
891 bind(notBool);
892 compareU32_and_branch(ret_type, T_BYTE, bcondNotEqual, notByte);
893 z_lbr(result, result);
894 z_bru(done);
895
896 bind(notByte);
897 compareU32_and_branch(ret_type, T_CHAR, bcondNotEqual, notChar);
898 z_nilf(result, 0xffff);
899 z_bru(done);
900
901 bind(notChar);
902 // compareU32_and_branch(ret_type, T_SHORT, bcondNotEqual, notShort);
903 z_lhr(result, result);
904
905 // Nothing to do for T_INT
906 bind(done);
907 }
908
909 // remove activation
910 //
911 // Unlock the receiver if this is a synchronized method.
912 // Unlock any Java monitors from synchronized blocks.
913 // Remove the activation from the stack.
914 //
915 // If there are locked Java monitors
916 // If throw_monitor_exception
917 // throws IllegalMonitorStateException
918 // Else if install_monitor_exception
919 // installs IllegalMonitorStateException
920 // Else
921 // no error processing
922 void InterpreterMacroAssembler::remove_activation(TosState state,
923 Register return_pc,
924 bool throw_monitor_exception,
925 bool install_monitor_exception,
926 bool notify_jvmti) {
927 BLOCK_COMMENT("remove_activation {");
928 unlock_if_synchronized_method(state, throw_monitor_exception, install_monitor_exception);
929
930 // Save result (push state before jvmti call and pop it afterwards) and notify jvmti.
931 notify_method_exit(false, state, notify_jvmti ? NotifyJVMTI : SkipNotifyJVMTI);
932
933 if (StackReservedPages > 0) {
934 BLOCK_COMMENT("reserved_stack_check:");
935 // Test if reserved zone needs to be enabled.
936 Label no_reserved_zone_enabling;
937
938 // check if already enabled - if so no re-enabling needed
939 assert(sizeof(StackOverflow::StackGuardState) == 4, "unexpected size");
940 z_ly(Z_R0, Address(Z_thread, JavaThread::stack_guard_state_offset()));
941 compare32_and_branch(Z_R0, StackOverflow::stack_guard_enabled, bcondEqual, no_reserved_zone_enabling);
942
943 // Compare frame pointers. There is no good stack pointer, as with stack
944 // frame compression we can get different SPs when we do calls. A subsequent
945 // call could have a smaller SP, so that this compare succeeds for an
946 // inner call of the method annotated with ReservedStack.
947 z_lg(Z_R0, Address(Z_SP, (intptr_t)_z_abi(callers_sp)));
948 z_clg(Z_R0, Address(Z_thread, JavaThread::reserved_stack_activation_offset())); // Compare with frame pointer in memory.
949 z_brl(no_reserved_zone_enabling);
950
951 // Enable reserved zone again, throw stack overflow exception.
952 call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::enable_stack_reserved_zone), Z_thread);
953 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::throw_delayed_StackOverflowError));
954
955 should_not_reach_here();
956
957 bind(no_reserved_zone_enabling);
958 }
959
960 verify_oop(Z_tos, state);
961
962 pop_interpreter_frame(return_pc, Z_ARG2, Z_ARG3);
963 BLOCK_COMMENT("} remove_activation");
964 }
965
966 // lock object
967 //
968 // Registers alive
969 // monitor (Z_R10) - Address of the BasicObjectLock to be used for locking,
970 // which must be initialized with the object to lock.
971 // object (Z_R11, Z_R2) - Address of the object to be locked.
972 // templateTable (monitorenter) is using Z_R2 for object
973 void InterpreterMacroAssembler::lock_object(Register monitor, Register object) {
974
975 if (LockingMode == LM_MONITOR) {
976 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter), monitor);
977 return;
978 }
979
980 // template code: (for LM_LEGACY)
981 //
982 // markWord displaced_header = obj->mark().set_unlocked();
983 // monitor->lock()->set_displaced_header(displaced_header);
984 // if (Atomic::cmpxchg(/*addr*/obj->mark_addr(), /*cmp*/displaced_header, /*ex=*/monitor) == displaced_header) {
985 // // We stored the monitor address into the object's mark word.
986 // } else if (THREAD->is_lock_owned((address)displaced_header))
987 // // Simple recursive case.
988 // monitor->lock()->set_displaced_header(nullptr);
989 // } else {
990 // // Slow path.
991 // InterpreterRuntime::monitorenter(THREAD, monitor);
992 // }
993
994 const int hdr_offset = oopDesc::mark_offset_in_bytes();
995
996 const Register header = Z_ARG5;
997 const Register object_mark_addr = Z_ARG4;
998 const Register current_header = Z_ARG5;
999 const Register tmp = Z_R1_scratch;
1000
1001 NearLabel done, slow_case;
1002
1003 // markWord header = obj->mark().set_unlocked();
1004
1005 if (LockingMode == LM_LIGHTWEIGHT) {
1006 lightweight_lock(monitor, object, header, tmp, slow_case);
1007 } else if (LockingMode == LM_LEGACY) {
1008
1009 if (DiagnoseSyncOnValueBasedClasses != 0) {
1010 load_klass(tmp, object);
1011 z_tm(Address(tmp, Klass::misc_flags_offset()), KlassFlags::_misc_is_value_based_class);
1012 z_btrue(slow_case);
1013 }
1014
1015 // Load markWord from object into header.
1016 z_lg(header, hdr_offset, object);
1017
1018 // Set header to be (markWord of object | UNLOCK_VALUE).
1019 // This will not change anything if it was unlocked before.
1020 z_oill(header, markWord::unlocked_value);
1021
1022 // monitor->lock()->set_displaced_header(displaced_header);
1023 const int lock_offset = in_bytes(BasicObjectLock::lock_offset());
1024 const int mark_offset = lock_offset + BasicLock::displaced_header_offset_in_bytes();
1025
1026 // Initialize the box (Must happen before we update the object mark!).
1027 z_stg(header, mark_offset, monitor);
1028
1029 // if (Atomic::cmpxchg(/*addr*/obj->mark_addr(), /*cmp*/displaced_header, /*ex=*/monitor) == displaced_header) {
1030
1031 // not necessary, use offset in instruction directly.
1032 // add2reg(object_mark_addr, hdr_offset, object);
1033
1034 // Store stack address of the BasicObjectLock (this is monitor) into object.
1035 z_csg(header, monitor, hdr_offset, object);
1036 assert(current_header == header,
1037 "must be same register"); // Identified two registers from z/Architecture.
1038
1039 z_bre(done);
1040
1041 // } else if (THREAD->is_lock_owned((address)displaced_header))
1042 // // Simple recursive case.
1043 // monitor->lock()->set_displaced_header(nullptr);
1044
1045 // We did not see an unlocked object so try the fast recursive case.
1046
1047 // Check if owner is self by comparing the value in the markWord of object
1048 // (current_header) with the stack pointer.
1049 z_sgr(current_header, Z_SP);
1050
1051 assert(os::vm_page_size() > 0xfff, "page size too small - change the constant");
1052
1053 // The prior sequence "LGR, NGR, LTGR" can be done better
1054 // (Z_R1 is temp and not used after here).
1055 load_const_optimized(Z_R0, (~(os::vm_page_size() - 1) | markWord::lock_mask_in_place));
1056 z_ngr(Z_R0, current_header); // AND sets CC (result eq/ne 0)
1057
1058 // If condition is true we are done and hence we can store 0 in the displaced
1059 // header indicating it is a recursive lock and be done.
1060 z_brne(slow_case);
1061 z_release(); // Member unnecessary on zarch AND because the above csg does a sync before and after.
1062 z_stg(Z_R0/*==0!*/, mark_offset, monitor);
1063 }
1064 z_bru(done);
1065 // } else {
1066 // // Slow path.
1067 // InterpreterRuntime::monitorenter(THREAD, monitor);
1068
1069 // None of the above fast optimizations worked so we have to get into the
1070 // slow case of monitor enter.
1071 bind(slow_case);
1072 call_VM(noreg,
1073 CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
1074 monitor);
1075 // }
1076
1077 bind(done);
1078 }
1079
1080 // Unlocks an object. Used in monitorexit bytecode and remove_activation.
1081 //
1082 // Registers alive
1083 // monitor - address of the BasicObjectLock to be used for locking,
1084 // which must be initialized with the object to lock.
1085 //
1086 // Throw IllegalMonitorException if object is not locked by current thread.
1087 void InterpreterMacroAssembler::unlock_object(Register monitor, Register object) {
1088
1089 if (LockingMode == LM_MONITOR) {
1090 call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit), monitor);
1091 return;
1092 }
1093
1094 // else {
1095 // template code: (for LM_LEGACY):
1096 //
1097 // if ((displaced_header = monitor->displaced_header()) == nullptr) {
1098 // // Recursive unlock. Mark the monitor unlocked by setting the object field to null.
1099 // monitor->set_obj(nullptr);
1100 // } else if (Atomic::cmpxchg(obj->mark_addr(), monitor, displaced_header) == monitor) {
1101 // // We swapped the unlocked mark in displaced_header into the object's mark word.
1102 // monitor->set_obj(nullptr);
1103 // } else {
1104 // // Slow path.
1105 // InterpreterRuntime::monitorexit(monitor);
1106 // }
1107
1108 const int hdr_offset = oopDesc::mark_offset_in_bytes();
1109
1110 const Register header = Z_ARG4;
1111 const Register current_header = Z_R1_scratch;
1112 Address obj_entry(monitor, BasicObjectLock::obj_offset());
1113 Label done, slow_case;
1114
1115 if (object == noreg) {
1116 // In the template interpreter, we must assure that the object
1117 // entry in the monitor is cleared on all paths. Thus we move
1118 // loading up to here, and clear the entry afterwards.
1119 object = Z_ARG3; // Use Z_ARG3 if caller didn't pass object.
1120 z_lg(object, obj_entry);
1121 }
1122
1123 assert_different_registers(monitor, object, header, current_header);
1124
1125 // if ((displaced_header = monitor->displaced_header()) == nullptr) {
1126 // // Recursive unlock. Mark the monitor unlocked by setting the object field to null.
1127 // monitor->set_obj(nullptr);
1128
1129 // monitor->lock()->set_displaced_header(displaced_header);
1130 const int lock_offset = in_bytes(BasicObjectLock::lock_offset());
1131 const int mark_offset = lock_offset + BasicLock::displaced_header_offset_in_bytes();
1132
1133 clear_mem(obj_entry, sizeof(oop));
1134 if (LockingMode != LM_LIGHTWEIGHT) {
1135 // Test first if we are in the fast recursive case.
1136 MacroAssembler::load_and_test_long(header, Address(monitor, mark_offset));
1137 z_bre(done); // header == 0 -> goto done
1138 }
1139
1140 // } else if (Atomic::cmpxchg(obj->mark_addr(), monitor, displaced_header) == monitor) {
1141 // // We swapped the unlocked mark in displaced_header into the object's mark word.
1142 // monitor->set_obj(nullptr);
1143
1144 // If we still have a lightweight lock, unlock the object and be done.
1145 if (LockingMode == LM_LIGHTWEIGHT) {
1146
1147 lightweight_unlock(object, header, current_header, slow_case);
1148
1149 z_bru(done);
1150 } else {
1151 // The markword is expected to be at offset 0.
1152 // This is not required on s390, at least not here.
1153 assert(hdr_offset == 0, "unlock_object: review code below");
1154
1155 // We have the displaced header in header. If the lock is still
1156 // lightweight, it will contain the monitor address and we'll store the
1157 // displaced header back into the object's mark word.
1158 z_lgr(current_header, monitor);
1159 z_csg(current_header, header, hdr_offset, object);
1160 z_bre(done);
1161 }
1162
1163 // } else {
1164 // // Slow path.
1165 // InterpreterRuntime::monitorexit(monitor);
1166
1167 // The lock has been converted into a heavy lock and hence
1168 // we need to get into the slow case.
1169 bind(slow_case);
1170 z_stg(object, obj_entry); // Restore object entry, has been cleared above.
1171 call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit), monitor);
1172
1173 // }
1174
1175 bind(done);
1176 }
1177
1178 void InterpreterMacroAssembler::test_method_data_pointer(Register mdp, Label& zero_continue) {
1179 assert(ProfileInterpreter, "must be profiling interpreter");
1180 load_and_test_long(mdp, Address(Z_fp, _z_ijava_state_neg(mdx)));
1181 z_brz(zero_continue);
1182 }
1183
1184 // Set the method data pointer for the current bcp.
1185 void InterpreterMacroAssembler::set_method_data_pointer_for_bcp() {
1186 assert(ProfileInterpreter, "must be profiling interpreter");
1187 Label set_mdp;
1188 Register mdp = Z_ARG4;
1189 Register method = Z_ARG5;
1190
1191 get_method(method);
1192 // Test MDO to avoid the call if it is null.
1193 load_and_test_long(mdp, method2_(method, method_data));
1194 z_brz(set_mdp);
1195
1196 call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::bcp_to_di), method, Z_bcp);
1197 // Z_RET: mdi
1198 // Mdo is guaranteed to be non-zero here, we checked for it before the call.
1199 assert(method->is_nonvolatile(), "choose nonvolatile reg or reload from frame");
1200 z_lg(mdp, method2_(method, method_data)); // Must reload, mdp is volatile reg.
1201 add2reg_with_index(mdp, in_bytes(MethodData::data_offset()), Z_RET, mdp);
1202
1203 bind(set_mdp);
1204 save_mdp(mdp);
1205 }
1206
1207 void InterpreterMacroAssembler::verify_method_data_pointer() {
1208 assert(ProfileInterpreter, "must be profiling interpreter");
1209 #ifdef ASSERT
1210 NearLabel verify_continue;
1211 Register bcp_expected = Z_ARG3;
1212 Register mdp = Z_ARG4;
1213 Register method = Z_ARG5;
1214
1215 test_method_data_pointer(mdp, verify_continue); // If mdp is zero, continue
1216 get_method(method);
1217
1218 // If the mdp is valid, it will point to a DataLayout header which is
1219 // consistent with the bcp. The converse is highly probable also.
1220 load_sized_value(bcp_expected, Address(mdp, DataLayout::bci_offset()), 2, false /*signed*/);
1221 z_ag(bcp_expected, Address(method, Method::const_offset()));
1222 load_address(bcp_expected, Address(bcp_expected, ConstMethod::codes_offset()));
1223 compareU64_and_branch(bcp_expected, Z_bcp, bcondEqual, verify_continue);
1224 call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::verify_mdp), method, Z_bcp, mdp);
1225 bind(verify_continue);
1226 #endif // ASSERT
1227 }
1228
1229 void InterpreterMacroAssembler::set_mdp_data_at(Register mdp_in, int constant, Register value) {
1230 assert(ProfileInterpreter, "must be profiling interpreter");
1231 z_stg(value, constant, mdp_in);
1232 }
1233
1234 void InterpreterMacroAssembler::increment_mdp_data_at(Register mdp_in,
1235 int constant,
1236 Register tmp,
1237 bool decrement) {
1238 assert_different_registers(mdp_in, tmp);
1239 // counter address
1240 Address data(mdp_in, constant);
1241 const int delta = decrement ? -DataLayout::counter_increment : DataLayout::counter_increment;
1242 add2mem_64(Address(mdp_in, constant), delta, tmp);
1243 }
1244
1245 void InterpreterMacroAssembler::set_mdp_flag_at(Register mdp_in,
1246 int flag_byte_constant) {
1247 assert(ProfileInterpreter, "must be profiling interpreter");
1248 // Set the flag.
1249 z_oi(Address(mdp_in, DataLayout::flags_offset()), flag_byte_constant);
1250 }
1251
1252 void InterpreterMacroAssembler::test_mdp_data_at(Register mdp_in,
1253 int offset,
1254 Register value,
1255 Register test_value_out,
1256 Label& not_equal_continue) {
1257 assert(ProfileInterpreter, "must be profiling interpreter");
1258 if (test_value_out == noreg) {
1259 z_cg(value, Address(mdp_in, offset));
1260 z_brne(not_equal_continue);
1261 } else {
1262 // Put the test value into a register, so caller can use it:
1263 z_lg(test_value_out, Address(mdp_in, offset));
1264 compareU64_and_branch(test_value_out, value, bcondNotEqual, not_equal_continue);
1265 }
1266 }
1267
1268 void InterpreterMacroAssembler::update_mdp_by_offset(Register mdp_in, int offset_of_disp) {
1269 update_mdp_by_offset(mdp_in, noreg, offset_of_disp);
1270 }
1271
1272 void InterpreterMacroAssembler::update_mdp_by_offset(Register mdp_in,
1273 Register dataidx,
1274 int offset_of_disp) {
1275 assert(ProfileInterpreter, "must be profiling interpreter");
1276 Address disp_address(mdp_in, dataidx, offset_of_disp);
1277 Assembler::z_ag(mdp_in, disp_address);
1278 save_mdp(mdp_in);
1279 }
1280
1281 void InterpreterMacroAssembler::update_mdp_by_constant(Register mdp_in, int constant) {
1282 assert(ProfileInterpreter, "must be profiling interpreter");
1283 add2reg(mdp_in, constant);
1284 save_mdp(mdp_in);
1285 }
1286
1287 void InterpreterMacroAssembler::update_mdp_for_ret(Register return_bci) {
1288 assert(ProfileInterpreter, "must be profiling interpreter");
1289 assert(return_bci->is_nonvolatile(), "choose nonvolatile reg or save/restore");
1290 call_VM(noreg,
1291 CAST_FROM_FN_PTR(address, InterpreterRuntime::update_mdp_for_ret),
1292 return_bci);
1293 }
1294
1295 void InterpreterMacroAssembler::profile_taken_branch(Register mdp, Register bumped_count) {
1296 if (ProfileInterpreter) {
1297 Label profile_continue;
1298
1299 // If no method data exists, go to profile_continue.
1300 // Otherwise, assign to mdp.
1301 test_method_data_pointer(mdp, profile_continue);
1302
1303 // We are taking a branch. Increment the taken count.
1304 // We inline increment_mdp_data_at to return bumped_count in a register
1305 //increment_mdp_data_at(mdp, in_bytes(JumpData::taken_offset()));
1306 Address data(mdp, JumpData::taken_offset());
1307 z_lg(bumped_count, data);
1308 // 64-bit overflow is very unlikely. Saturation to 32-bit values is
1309 // performed when reading the counts.
1310 add2reg(bumped_count, DataLayout::counter_increment);
1311 z_stg(bumped_count, data); // Store back out
1312
1313 // The method data pointer needs to be updated to reflect the new target.
1314 update_mdp_by_offset(mdp, in_bytes(JumpData::displacement_offset()));
1315 bind(profile_continue);
1316 }
1317 }
1318
1319 // Kills Z_R1_scratch.
1320 void InterpreterMacroAssembler::profile_not_taken_branch(Register mdp) {
1321 if (ProfileInterpreter) {
1322 Label profile_continue;
1323
1324 // If no method data exists, go to profile_continue.
1325 test_method_data_pointer(mdp, profile_continue);
1326
1327 // We are taking a branch. Increment the not taken count.
1328 increment_mdp_data_at(mdp, in_bytes(BranchData::not_taken_offset()), Z_R1_scratch);
1329
1330 // The method data pointer needs to be updated to correspond to
1331 // the next bytecode.
1332 update_mdp_by_constant(mdp, in_bytes(BranchData::branch_data_size()));
1333 bind(profile_continue);
1334 }
1335 }
1336
1337 // Kills: Z_R1_scratch.
1338 void InterpreterMacroAssembler::profile_call(Register mdp) {
1339 if (ProfileInterpreter) {
1340 Label profile_continue;
1341
1342 // If no method data exists, go to profile_continue.
1343 test_method_data_pointer(mdp, profile_continue);
1344
1345 // We are making a call. Increment the count.
1346 increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1347
1348 // The method data pointer needs to be updated to reflect the new target.
1349 update_mdp_by_constant(mdp, in_bytes(CounterData::counter_data_size()));
1350 bind(profile_continue);
1351 }
1352 }
1353
1354 void InterpreterMacroAssembler::profile_final_call(Register mdp) {
1355 if (ProfileInterpreter) {
1356 Label profile_continue;
1357
1358 // If no method data exists, go to profile_continue.
1359 test_method_data_pointer(mdp, profile_continue);
1360
1361 // We are making a call. Increment the count.
1362 increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1363
1364 // The method data pointer needs to be updated to reflect the new target.
1365 update_mdp_by_constant(mdp, in_bytes(VirtualCallData::virtual_call_data_size()));
1366 bind(profile_continue);
1367 }
1368 }
1369
1370 void InterpreterMacroAssembler::profile_virtual_call(Register receiver,
1371 Register mdp,
1372 Register reg2,
1373 bool receiver_can_be_null) {
1374 if (ProfileInterpreter) {
1375 NearLabel profile_continue;
1376
1377 // If no method data exists, go to profile_continue.
1378 test_method_data_pointer(mdp, profile_continue);
1379
1380 NearLabel skip_receiver_profile;
1381 if (receiver_can_be_null) {
1382 NearLabel not_null;
1383 compareU64_and_branch(receiver, (intptr_t)0L, bcondNotEqual, not_null);
1384 // We are making a call. Increment the count for null receiver.
1385 increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1386 z_bru(skip_receiver_profile);
1387 bind(not_null);
1388 }
1389
1390 // Record the receiver type.
1391 record_klass_in_profile(receiver, mdp, reg2);
1392 bind(skip_receiver_profile);
1393
1394 // The method data pointer needs to be updated to reflect the new target.
1395 update_mdp_by_constant(mdp, in_bytes(VirtualCallData::virtual_call_data_size()));
1396 bind(profile_continue);
1397 }
1398 }
1399
1400 // This routine creates a state machine for updating the multi-row
1401 // type profile at a virtual call site (or other type-sensitive bytecode).
1402 // The machine visits each row (of receiver/count) until the receiver type
1403 // is found, or until it runs out of rows. At the same time, it remembers
1404 // the location of the first empty row. (An empty row records null for its
1405 // receiver, and can be allocated for a newly-observed receiver type.)
1406 // Because there are two degrees of freedom in the state, a simple linear
1407 // search will not work; it must be a decision tree. Hence this helper
1408 // function is recursive, to generate the required tree structured code.
1409 // It's the interpreter, so we are trading off code space for speed.
1410 // See below for example code.
1411 void InterpreterMacroAssembler::record_klass_in_profile_helper(
1412 Register receiver, Register mdp,
1413 Register reg2, int start_row,
1414 Label& done) {
1415 if (TypeProfileWidth == 0) {
1416 increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1417 return;
1418 }
1419
1420 int last_row = VirtualCallData::row_limit() - 1;
1421 assert(start_row <= last_row, "must be work left to do");
1422 // Test this row for both the receiver and for null.
1423 // Take any of three different outcomes:
1424 // 1. found receiver => increment count and goto done
1425 // 2. found null => keep looking for case 1, maybe allocate this cell
1426 // 3. found something else => keep looking for cases 1 and 2
1427 // Case 3 is handled by a recursive call.
1428 for (int row = start_row; row <= last_row; row++) {
1429 NearLabel next_test;
1430 bool test_for_null_also = (row == start_row);
1431
1432 // See if the receiver is receiver[n].
1433 int recvr_offset = in_bytes(VirtualCallData::receiver_offset(row));
1434 test_mdp_data_at(mdp, recvr_offset, receiver,
1435 (test_for_null_also ? reg2 : noreg),
1436 next_test);
1437 // (Reg2 now contains the receiver from the CallData.)
1438
1439 // The receiver is receiver[n]. Increment count[n].
1440 int count_offset = in_bytes(VirtualCallData::receiver_count_offset(row));
1441 increment_mdp_data_at(mdp, count_offset);
1442 z_bru(done);
1443 bind(next_test);
1444
1445 if (test_for_null_also) {
1446 Label found_null;
1447 // Failed the equality check on receiver[n]... Test for null.
1448 z_ltgr(reg2, reg2);
1449 if (start_row == last_row) {
1450 // The only thing left to do is handle the null case.
1451 z_brz(found_null);
1452 // Receiver did not match any saved receiver and there is no empty row for it.
1453 // Increment total counter to indicate polymorphic case.
1454 increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1455 z_bru(done);
1456 bind(found_null);
1457 break;
1458 }
1459 // Since null is rare, make it be the branch-taken case.
1460 z_brz(found_null);
1461
1462 // Put all the "Case 3" tests here.
1463 record_klass_in_profile_helper(receiver, mdp, reg2, start_row + 1, done);
1464
1465 // Found a null. Keep searching for a matching receiver,
1466 // but remember that this is an empty (unused) slot.
1467 bind(found_null);
1468 }
1469 }
1470
1471 // In the fall-through case, we found no matching receiver, but we
1472 // observed the receiver[start_row] is null.
1473
1474 // Fill in the receiver field and increment the count.
1475 int recvr_offset = in_bytes(VirtualCallData::receiver_offset(start_row));
1476 set_mdp_data_at(mdp, recvr_offset, receiver);
1477 int count_offset = in_bytes(VirtualCallData::receiver_count_offset(start_row));
1478 load_const_optimized(reg2, DataLayout::counter_increment);
1479 set_mdp_data_at(mdp, count_offset, reg2);
1480 if (start_row > 0) {
1481 z_bru(done);
1482 }
1483 }
1484
1485 // Example state machine code for three profile rows:
1486 // // main copy of decision tree, rooted at row[1]
1487 // if (row[0].rec == rec) { row[0].incr(); goto done; }
1488 // if (row[0].rec != nullptr) {
1489 // // inner copy of decision tree, rooted at row[1]
1490 // if (row[1].rec == rec) { row[1].incr(); goto done; }
1491 // if (row[1].rec != nullptr) {
1492 // // degenerate decision tree, rooted at row[2]
1493 // if (row[2].rec == rec) { row[2].incr(); goto done; }
1494 // if (row[2].rec != nullptr) { count.incr(); goto done; } // overflow
1495 // row[2].init(rec); goto done;
1496 // } else {
1497 // // remember row[1] is empty
1498 // if (row[2].rec == rec) { row[2].incr(); goto done; }
1499 // row[1].init(rec); goto done;
1500 // }
1501 // } else {
1502 // // remember row[0] is empty
1503 // if (row[1].rec == rec) { row[1].incr(); goto done; }
1504 // if (row[2].rec == rec) { row[2].incr(); goto done; }
1505 // row[0].init(rec); goto done;
1506 // }
1507 // done:
1508
1509 void InterpreterMacroAssembler::record_klass_in_profile(Register receiver,
1510 Register mdp, Register reg2) {
1511 assert(ProfileInterpreter, "must be profiling");
1512 Label done;
1513
1514 record_klass_in_profile_helper(receiver, mdp, reg2, 0, done);
1515
1516 bind (done);
1517 }
1518
1519 void InterpreterMacroAssembler::profile_ret(Register return_bci, Register mdp) {
1520 if (ProfileInterpreter) {
1521 NearLabel profile_continue;
1522 uint row;
1523
1524 // If no method data exists, go to profile_continue.
1525 test_method_data_pointer(mdp, profile_continue);
1526
1527 // Update the total ret count.
1528 increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));
1529
1530 for (row = 0; row < RetData::row_limit(); row++) {
1531 NearLabel next_test;
1532
1533 // See if return_bci is equal to bci[n]:
1534 test_mdp_data_at(mdp,
1535 in_bytes(RetData::bci_offset(row)),
1536 return_bci, noreg,
1537 next_test);
1538
1539 // Return_bci is equal to bci[n]. Increment the count.
1540 increment_mdp_data_at(mdp, in_bytes(RetData::bci_count_offset(row)));
1541
1542 // The method data pointer needs to be updated to reflect the new target.
1543 update_mdp_by_offset(mdp, in_bytes(RetData::bci_displacement_offset(row)));
1544 z_bru(profile_continue);
1545 bind(next_test);
1546 }
1547
1548 update_mdp_for_ret(return_bci);
1549
1550 bind(profile_continue);
1551 }
1552 }
1553
1554 void InterpreterMacroAssembler::profile_null_seen(Register mdp) {
1555 if (ProfileInterpreter) {
1556 Label profile_continue;
1557
1558 // If no method data exists, go to profile_continue.
1559 test_method_data_pointer(mdp, profile_continue);
1560
1561 set_mdp_flag_at(mdp, BitData::null_seen_byte_constant());
1562
1563 // The method data pointer needs to be updated.
1564 int mdp_delta = in_bytes(BitData::bit_data_size());
1565 if (TypeProfileCasts) {
1566 mdp_delta = in_bytes(VirtualCallData::virtual_call_data_size());
1567 }
1568 update_mdp_by_constant(mdp, mdp_delta);
1569
1570 bind(profile_continue);
1571 }
1572 }
1573
1574 void InterpreterMacroAssembler::profile_typecheck(Register mdp, Register klass, Register reg2) {
1575 if (ProfileInterpreter) {
1576 Label profile_continue;
1577
1578 // If no method data exists, go to profile_continue.
1579 test_method_data_pointer(mdp, profile_continue);
1580
1581 // The method data pointer needs to be updated.
1582 int mdp_delta = in_bytes(BitData::bit_data_size());
1583 if (TypeProfileCasts) {
1584 mdp_delta = in_bytes(VirtualCallData::virtual_call_data_size());
1585
1586 // Record the object type.
1587 record_klass_in_profile(klass, mdp, reg2);
1588 }
1589 update_mdp_by_constant(mdp, mdp_delta);
1590
1591 bind(profile_continue);
1592 }
1593 }
1594
1595 void InterpreterMacroAssembler::profile_switch_default(Register mdp) {
1596 if (ProfileInterpreter) {
1597 Label profile_continue;
1598
1599 // If no method data exists, go to profile_continue.
1600 test_method_data_pointer(mdp, profile_continue);
1601
1602 // Update the default case count.
1603 increment_mdp_data_at(mdp, in_bytes(MultiBranchData::default_count_offset()));
1604
1605 // The method data pointer needs to be updated.
1606 update_mdp_by_offset(mdp, in_bytes(MultiBranchData::default_displacement_offset()));
1607
1608 bind(profile_continue);
1609 }
1610 }
1611
1612 // Kills: index, scratch1, scratch2.
1613 void InterpreterMacroAssembler::profile_switch_case(Register index,
1614 Register mdp,
1615 Register scratch1,
1616 Register scratch2) {
1617 if (ProfileInterpreter) {
1618 Label profile_continue;
1619 assert_different_registers(index, mdp, scratch1, scratch2);
1620
1621 // If no method data exists, go to profile_continue.
1622 test_method_data_pointer(mdp, profile_continue);
1623
1624 // Build the base (index * per_case_size_in_bytes()) +
1625 // case_array_offset_in_bytes().
1626 z_sllg(index, index, exact_log2(in_bytes(MultiBranchData::per_case_size())));
1627 add2reg(index, in_bytes(MultiBranchData::case_array_offset()));
1628
1629 // Add the calculated base to the mdp -> address of the case' data.
1630 Address case_data_addr(mdp, index);
1631 Register case_data = scratch1;
1632 load_address(case_data, case_data_addr);
1633
1634 // Update the case count.
1635 increment_mdp_data_at(case_data,
1636 in_bytes(MultiBranchData::relative_count_offset()),
1637 scratch2);
1638
1639 // The method data pointer needs to be updated.
1640 update_mdp_by_offset(mdp,
1641 index,
1642 in_bytes(MultiBranchData::relative_displacement_offset()));
1643
1644 bind(profile_continue);
1645 }
1646 }
1647
1648 // kills: R0, R1, flags, loads klass from obj (if not null)
1649 void InterpreterMacroAssembler::profile_obj_type(Register obj, Address mdo_addr, Register klass, bool cmp_done) {
1650 NearLabel null_seen, init_klass, do_nothing, do_update;
1651
1652 // Klass = obj is allowed.
1653 const Register tmp = Z_R1;
1654 assert_different_registers(obj, mdo_addr.base(), tmp, Z_R0);
1655 assert_different_registers(klass, mdo_addr.base(), tmp, Z_R0);
1656
1657 z_lg(tmp, mdo_addr);
1658 if (cmp_done) {
1659 z_brz(null_seen);
1660 } else {
1661 compareU64_and_branch(obj, (intptr_t)0, Assembler::bcondEqual, null_seen);
1662 }
1663
1664 MacroAssembler::verify_oop(obj, FILE_AND_LINE);
1665 load_klass(klass, obj);
1666
1667 // Klass seen before, nothing to do (regardless of unknown bit).
1668 z_lgr(Z_R0, tmp);
1669 assert(Immediate::is_uimm(~TypeEntries::type_klass_mask, 16), "or change following instruction");
1670 z_nill(Z_R0, TypeEntries::type_klass_mask & 0xFFFF);
1671 compareU64_and_branch(Z_R0, klass, Assembler::bcondEqual, do_nothing);
1672
1673 // Already unknown. Nothing to do anymore.
1674 z_tmll(tmp, TypeEntries::type_unknown);
1675 z_brc(Assembler::bcondAllOne, do_nothing);
1676
1677 z_lgr(Z_R0, tmp);
1678 assert(Immediate::is_uimm(~TypeEntries::type_mask, 16), "or change following instruction");
1679 z_nill(Z_R0, TypeEntries::type_mask & 0xFFFF);
1680 compareU64_and_branch(Z_R0, (intptr_t)0, Assembler::bcondEqual, init_klass);
1681
1682 // Different than before. Cannot keep accurate profile.
1683 z_oill(tmp, TypeEntries::type_unknown);
1684 z_bru(do_update);
1685
1686 bind(init_klass);
1687 // Combine klass and null_seen bit (only used if (tmp & type_mask)==0).
1688 z_ogr(tmp, klass);
1689 z_bru(do_update);
1690
1691 bind(null_seen);
1692 // Set null_seen if obj is 0.
1693 z_oill(tmp, TypeEntries::null_seen);
1694 // fallthru: z_bru(do_update);
1695
1696 bind(do_update);
1697 z_stg(tmp, mdo_addr);
1698
1699 bind(do_nothing);
1700 }
1701
1702 void InterpreterMacroAssembler::profile_arguments_type(Register mdp, Register callee, Register tmp, bool is_virtual) {
1703 if (!ProfileInterpreter) {
1704 return;
1705 }
1706
1707 assert_different_registers(mdp, callee, tmp);
1708
1709 if (MethodData::profile_arguments() || MethodData::profile_return()) {
1710 Label profile_continue;
1711
1712 test_method_data_pointer(mdp, profile_continue);
1713
1714 int off_to_start = is_virtual ? in_bytes(VirtualCallData::virtual_call_data_size()) : in_bytes(CounterData::counter_data_size());
1715
1716 z_cliy(in_bytes(DataLayout::tag_offset()) - off_to_start, mdp,
1717 is_virtual ? DataLayout::virtual_call_type_data_tag : DataLayout::call_type_data_tag);
1718 z_brne(profile_continue);
1719
1720 if (MethodData::profile_arguments()) {
1721 NearLabel done;
1722 int off_to_args = in_bytes(TypeEntriesAtCall::args_data_offset());
1723 add2reg(mdp, off_to_args);
1724
1725 for (int i = 0; i < TypeProfileArgsLimit; i++) {
1726 if (i > 0 || MethodData::profile_return()) {
1727 // If return value type is profiled we may have no argument to profile.
1728 z_lg(tmp, in_bytes(TypeEntriesAtCall::cell_count_offset())-off_to_args, mdp);
1729 add2reg(tmp, -i*TypeStackSlotEntries::per_arg_count());
1730 compare64_and_branch(tmp, TypeStackSlotEntries::per_arg_count(), Assembler::bcondLow, done);
1731 }
1732 z_lg(tmp, Address(callee, Method::const_offset()));
1733 z_lgh(tmp, Address(tmp, ConstMethod::size_of_parameters_offset()));
1734 // Stack offset o (zero based) from the start of the argument
1735 // list. For n arguments translates into offset n - o - 1 from
1736 // the end of the argument list. But there is an extra slot at
1737 // the top of the stack. So the offset is n - o from Lesp.
1738 z_sg(tmp, Address(mdp, in_bytes(TypeEntriesAtCall::stack_slot_offset(i))-off_to_args));
1739 z_sllg(tmp, tmp, Interpreter::logStackElementSize);
1740 Address stack_slot_addr(tmp, Z_esp);
1741 z_ltg(tmp, stack_slot_addr);
1742
1743 Address mdo_arg_addr(mdp, in_bytes(TypeEntriesAtCall::argument_type_offset(i))-off_to_args);
1744 profile_obj_type(tmp, mdo_arg_addr, tmp, /*ltg did compare to 0*/ true);
1745
1746 int to_add = in_bytes(TypeStackSlotEntries::per_arg_size());
1747 add2reg(mdp, to_add);
1748 off_to_args += to_add;
1749 }
1750
1751 if (MethodData::profile_return()) {
1752 z_lg(tmp, in_bytes(TypeEntriesAtCall::cell_count_offset())-off_to_args, mdp);
1753 add2reg(tmp, -TypeProfileArgsLimit*TypeStackSlotEntries::per_arg_count());
1754 }
1755
1756 bind(done);
1757
1758 if (MethodData::profile_return()) {
1759 // We're right after the type profile for the last
1760 // argument. Tmp is the number of cells left in the
1761 // CallTypeData/VirtualCallTypeData to reach its end. Non null
1762 // if there's a return to profile.
1763 assert(ReturnTypeEntry::static_cell_count() < TypeStackSlotEntries::per_arg_count(), "can't move past ret type");
1764 z_sllg(tmp, tmp, exact_log2(DataLayout::cell_size));
1765 z_agr(mdp, tmp);
1766 }
1767 z_stg(mdp, _z_ijava_state_neg(mdx), Z_fp);
1768 } else {
1769 assert(MethodData::profile_return(), "either profile call args or call ret");
1770 update_mdp_by_constant(mdp, in_bytes(TypeEntriesAtCall::return_only_size()));
1771 }
1772
1773 // Mdp points right after the end of the
1774 // CallTypeData/VirtualCallTypeData, right after the cells for the
1775 // return value type if there's one.
1776 bind(profile_continue);
1777 }
1778 }
1779
1780 void InterpreterMacroAssembler::profile_return_type(Register mdp, Register ret, Register tmp) {
1781 assert_different_registers(mdp, ret, tmp);
1782 if (ProfileInterpreter && MethodData::profile_return()) {
1783 Label profile_continue;
1784
1785 test_method_data_pointer(mdp, profile_continue);
1786
1787 if (MethodData::profile_return_jsr292_only()) {
1788 // If we don't profile all invoke bytecodes we must make sure
1789 // it's a bytecode we indeed profile. We can't go back to the
1790 // beginning of the ProfileData we intend to update to check its
1791 // type because we're right after it and we don't known its
1792 // length.
1793 NearLabel do_profile;
1794 Address bc(Z_bcp);
1795 z_lb(tmp, bc);
1796 compare32_and_branch(tmp, Bytecodes::_invokedynamic, Assembler::bcondEqual, do_profile);
1797 compare32_and_branch(tmp, Bytecodes::_invokehandle, Assembler::bcondEqual, do_profile);
1798 get_method(tmp);
1799 // Supplement to 8139891: _intrinsic_id exceeded 1-byte size limit.
1800 if (Method::intrinsic_id_size_in_bytes() == 1) {
1801 z_cli(in_bytes(Method::intrinsic_id_offset()), tmp, static_cast<int>(vmIntrinsics::_compiledLambdaForm));
1802 } else {
1803 assert(Method::intrinsic_id_size_in_bytes() == 2, "size error: check Method::_intrinsic_id");
1804 z_lh(tmp, in_bytes(Method::intrinsic_id_offset()), Z_R0, tmp);
1805 z_chi(tmp, static_cast<int>(vmIntrinsics::_compiledLambdaForm));
1806 }
1807 z_brne(profile_continue);
1808
1809 bind(do_profile);
1810 }
1811
1812 Address mdo_ret_addr(mdp, -in_bytes(ReturnTypeEntry::size()));
1813 profile_obj_type(ret, mdo_ret_addr, tmp);
1814
1815 bind(profile_continue);
1816 }
1817 }
1818
1819 void InterpreterMacroAssembler::profile_parameters_type(Register mdp, Register tmp1, Register tmp2) {
1820 if (ProfileInterpreter && MethodData::profile_parameters()) {
1821 Label profile_continue, done;
1822
1823 test_method_data_pointer(mdp, profile_continue);
1824
1825 // Load the offset of the area within the MDO used for
1826 // parameters. If it's negative we're not profiling any parameters.
1827 Address parm_di_addr(mdp, in_bytes(MethodData::parameters_type_data_di_offset()) - in_bytes(MethodData::data_offset()));
1828 load_and_test_int2long(tmp1, parm_di_addr);
1829 z_brl(profile_continue);
1830
1831 // Compute a pointer to the area for parameters from the offset
1832 // and move the pointer to the slot for the last
1833 // parameters. Collect profiling from last parameter down.
1834 // mdo start + parameters offset + array length - 1
1835
1836 // Pointer to the parameter area in the MDO.
1837 z_agr(mdp, tmp1);
1838
1839 // Offset of the current profile entry to update.
1840 const Register entry_offset = tmp1;
1841 // entry_offset = array len in number of cells.
1842 z_lg(entry_offset, Address(mdp, ArrayData::array_len_offset()));
1843 // entry_offset (number of cells) = array len - size of 1 entry
1844 add2reg(entry_offset, -TypeStackSlotEntries::per_arg_count());
1845 // entry_offset in bytes
1846 z_sllg(entry_offset, entry_offset, exact_log2(DataLayout::cell_size));
1847
1848 Label loop;
1849 bind(loop);
1850
1851 Address arg_off(mdp, entry_offset, ParametersTypeData::stack_slot_offset(0));
1852 Address arg_type(mdp, entry_offset, ParametersTypeData::type_offset(0));
1853
1854 // Load offset on the stack from the slot for this parameter.
1855 z_lg(tmp2, arg_off);
1856 z_sllg(tmp2, tmp2, Interpreter::logStackElementSize);
1857 z_lcgr(tmp2); // Negate.
1858
1859 // Profile the parameter.
1860 z_ltg(tmp2, Address(Z_locals, tmp2));
1861 profile_obj_type(tmp2, arg_type, tmp2, /*ltg did compare to 0*/ true);
1862
1863 // Go to next parameter.
1864 z_aghi(entry_offset, -TypeStackSlotEntries::per_arg_count() * DataLayout::cell_size);
1865 z_brnl(loop);
1866
1867 bind(profile_continue);
1868 }
1869 }
1870
1871 // Jump if ((*counter_addr += increment) & mask) satisfies the condition.
1872 void InterpreterMacroAssembler::increment_mask_and_jump(Address counter_addr,
1873 int increment,
1874 Address mask,
1875 Register scratch,
1876 bool preloaded,
1877 branch_condition cond,
1878 Label *where) {
1879 assert_different_registers(counter_addr.base(), scratch);
1880 if (preloaded) {
1881 add2reg(scratch, increment);
1882 reg2mem_opt(scratch, counter_addr, false);
1883 } else {
1884 if (VM_Version::has_MemWithImmALUOps() && Immediate::is_simm8(increment) && counter_addr.is_RSYform()) {
1885 z_alsi(counter_addr.disp20(), counter_addr.base(), increment);
1886 mem2reg_signed_opt(scratch, counter_addr);
1887 } else {
1888 mem2reg_signed_opt(scratch, counter_addr);
1889 add2reg(scratch, increment);
1890 reg2mem_opt(scratch, counter_addr, false);
1891 }
1892 }
1893 z_n(scratch, mask);
1894 if (where) { z_brc(cond, *where); }
1895 }
1896
1897 // Get MethodCounters object for given method. Lazily allocated if necessary.
1898 // method - Ptr to Method object.
1899 // Rcounters - Ptr to MethodCounters object associated with Method object.
1900 // skip - Exit point if MethodCounters object can't be created (OOM condition).
1901 void InterpreterMacroAssembler::get_method_counters(Register Rmethod,
1902 Register Rcounters,
1903 Label& skip) {
1904 assert_different_registers(Rmethod, Rcounters);
1905
1906 BLOCK_COMMENT("get MethodCounters object {");
1907
1908 Label has_counters;
1909 load_and_test_long(Rcounters, Address(Rmethod, Method::method_counters_offset()));
1910 z_brnz(has_counters);
1911
1912 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::build_method_counters), Rmethod);
1913 z_ltgr(Rcounters, Z_RET); // Runtime call returns MethodCounters object.
1914 z_brz(skip); // No MethodCounters, out of memory.
1915
1916 bind(has_counters);
1917
1918 BLOCK_COMMENT("} get MethodCounters object");
1919 }
1920
1921 // Increment invocation counter in MethodCounters object.
1922 // Return (invocation_counter+backedge_counter) as "result" in RctrSum.
1923 // Counter values are all unsigned.
1924 void InterpreterMacroAssembler::increment_invocation_counter(Register Rcounters, Register RctrSum) {
1925 assert(UseCompiler, "incrementing must be useful");
1926 assert_different_registers(Rcounters, RctrSum);
1927
1928 int increment = InvocationCounter::count_increment;
1929 int inv_counter_offset = in_bytes(MethodCounters::invocation_counter_offset() + InvocationCounter::counter_offset());
1930 int be_counter_offset = in_bytes(MethodCounters::backedge_counter_offset() + InvocationCounter::counter_offset());
1931
1932 BLOCK_COMMENT("Increment invocation counter {");
1933
1934 if (VM_Version::has_MemWithImmALUOps() && Immediate::is_simm8(increment)) {
1935 // Increment the invocation counter in place,
1936 // then add the incremented value to the backedge counter.
1937 z_l(RctrSum, be_counter_offset, Rcounters);
1938 z_alsi(inv_counter_offset, Rcounters, increment); // Atomic increment @no extra cost!
1939 z_nilf(RctrSum, InvocationCounter::count_mask_value); // Mask off state bits.
1940 z_al(RctrSum, inv_counter_offset, Z_R0, Rcounters);
1941 } else {
1942 // This path is optimized for low register consumption
1943 // at the cost of somewhat higher operand delays.
1944 // It does not need an extra temp register.
1945
1946 // Update the invocation counter.
1947 z_l(RctrSum, inv_counter_offset, Rcounters);
1948 if (RctrSum == Z_R0) {
1949 z_ahi(RctrSum, increment);
1950 } else {
1951 add2reg(RctrSum, increment);
1952 }
1953 z_st(RctrSum, inv_counter_offset, Rcounters);
1954
1955 // Mask off the state bits.
1956 z_nilf(RctrSum, InvocationCounter::count_mask_value);
1957
1958 // Add the backedge counter to the updated invocation counter to
1959 // form the result.
1960 z_al(RctrSum, be_counter_offset, Z_R0, Rcounters);
1961 }
1962
1963 BLOCK_COMMENT("} Increment invocation counter");
1964
1965 // Note that this macro must leave the backedge_count + invocation_count in Rtmp!
1966 }
1967
1968
1969 // increment backedge counter in MethodCounters object.
1970 // return (invocation_counter+backedge_counter) as "result" in RctrSum
1971 // counter values are all unsigned!
1972 void InterpreterMacroAssembler::increment_backedge_counter(Register Rcounters, Register RctrSum) {
1973 assert(UseCompiler, "incrementing must be useful");
1974 assert_different_registers(Rcounters, RctrSum);
1975
1976 int increment = InvocationCounter::count_increment;
1977 int inv_counter_offset = in_bytes(MethodCounters::invocation_counter_offset() + InvocationCounter::counter_offset());
1978 int be_counter_offset = in_bytes(MethodCounters::backedge_counter_offset() + InvocationCounter::counter_offset());
1979
1980 BLOCK_COMMENT("Increment backedge counter {");
1981
1982 if (VM_Version::has_MemWithImmALUOps() && Immediate::is_simm8(increment)) {
1983 // Increment the invocation counter in place,
1984 // then add the incremented value to the backedge counter.
1985 z_l(RctrSum, inv_counter_offset, Rcounters);
1986 z_alsi(be_counter_offset, Rcounters, increment); // Atomic increment @no extra cost!
1987 z_nilf(RctrSum, InvocationCounter::count_mask_value); // Mask off state bits.
1988 z_al(RctrSum, be_counter_offset, Z_R0, Rcounters);
1989 } else {
1990 // This path is optimized for low register consumption
1991 // at the cost of somewhat higher operand delays.
1992 // It does not need an extra temp register.
1993
1994 // Update the invocation counter.
1995 z_l(RctrSum, be_counter_offset, Rcounters);
1996 if (RctrSum == Z_R0) {
1997 z_ahi(RctrSum, increment);
1998 } else {
1999 add2reg(RctrSum, increment);
2000 }
2001 z_st(RctrSum, be_counter_offset, Rcounters);
2002
2003 // Mask off the state bits.
2004 z_nilf(RctrSum, InvocationCounter::count_mask_value);
2005
2006 // Add the backedge counter to the updated invocation counter to
2007 // form the result.
2008 z_al(RctrSum, inv_counter_offset, Z_R0, Rcounters);
2009 }
2010
2011 BLOCK_COMMENT("} Increment backedge counter");
2012
2013 // Note that this macro must leave the backedge_count + invocation_count in Rtmp!
2014 }
2015
2016 // Add an InterpMonitorElem to stack (see frame_s390.hpp).
2017 void InterpreterMacroAssembler::add_monitor_to_stack(bool stack_is_empty,
2018 Register Rtemp1,
2019 Register Rtemp2,
2020 Register Rtemp3) {
2021
2022 const Register Rcurr_slot = Rtemp1;
2023 const Register Rlimit = Rtemp2;
2024 const jint delta = -frame::interpreter_frame_monitor_size_in_bytes();
2025
2026 assert((delta & LongAlignmentMask) == 0,
2027 "sizeof BasicObjectLock must be even number of doublewords");
2028 assert(2 * wordSize == -delta, "this works only as long as delta == -2*wordSize");
2029 assert(Rcurr_slot != Z_R0, "Register must be usable as base register");
2030 assert_different_registers(Rlimit, Rcurr_slot, Rtemp3);
2031
2032 get_monitors(Rlimit);
2033
2034 // Adjust stack pointer for additional monitor entry.
2035 resize_frame(RegisterOrConstant((intptr_t) delta), Z_fp, false);
2036
2037 if (!stack_is_empty) {
2038 // Must copy stack contents down.
2039 NearLabel next, done;
2040
2041 // Rtemp := addr(Tos), Z_esp is pointing below it!
2042 add2reg(Rcurr_slot, wordSize, Z_esp);
2043
2044 // Nothing to do, if already at monitor area.
2045 compareU64_and_branch(Rcurr_slot, Rlimit, bcondNotLow, done);
2046
2047 bind(next);
2048
2049 // Move one stack slot.
2050 mem2reg_opt(Rtemp3, Address(Rcurr_slot));
2051 reg2mem_opt(Rtemp3, Address(Rcurr_slot, delta));
2052 add2reg(Rcurr_slot, wordSize);
2053 compareU64_and_branch(Rcurr_slot, Rlimit, bcondLow, next); // Are we done?
2054
2055 bind(done);
2056 // Done copying stack.
2057 }
2058
2059 // Adjust expression stack and monitor pointers.
2060 add2reg(Z_esp, delta);
2061 add2reg(Rlimit, delta);
2062 save_monitors(Rlimit);
2063 }
2064
2065 // Note: Index holds the offset in bytes afterwards.
2066 // You can use this to store a new value (with Llocals as the base).
2067 void InterpreterMacroAssembler::access_local_int(Register index, Register dst) {
2068 z_sllg(index, index, LogBytesPerWord);
2069 mem2reg_opt(dst, Address(Z_locals, index), false);
2070 }
2071
2072 void InterpreterMacroAssembler::verify_oop(Register reg, TosState state) {
2073 if (state == atos) { MacroAssembler::verify_oop(reg, FILE_AND_LINE); }
2074 }
2075
2076 // Inline assembly for:
2077 //
2078 // if (thread is in interp_only_mode) {
2079 // InterpreterRuntime::post_method_entry();
2080 // }
2081
2082 void InterpreterMacroAssembler::notify_method_entry() {
2083
2084 // JVMTI
2085 // Whenever JVMTI puts a thread in interp_only_mode, method
2086 // entry/exit events are sent for that thread to track stack
2087 // depth. If it is possible to enter interp_only_mode we add
2088 // the code to check if the event should be sent.
2089 if (JvmtiExport::can_post_interpreter_events()) {
2090 Label jvmti_post_done;
2091 MacroAssembler::load_and_test_int(Z_R0, Address(Z_thread, JavaThread::interp_only_mode_offset()));
2092 z_bre(jvmti_post_done);
2093 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::post_method_entry));
2094 bind(jvmti_post_done);
2095 }
2096 }
2097
2098 // Inline assembly for:
2099 //
2100 // if (thread is in interp_only_mode) {
2101 // if (!native_method) save result
2102 // InterpreterRuntime::post_method_exit();
2103 // if (!native_method) restore result
2104 // }
2105 // if (DTraceMethodProbes) {
2106 // SharedRuntime::dtrace_method_exit(thread, method);
2107 // }
2108 //
2109 // For native methods their result is stored in z_ijava_state.lresult
2110 // and z_ijava_state.fresult before coming here.
2111 // Java methods have their result stored in the expression stack.
2112 //
2113 // Notice the dependency to frame::interpreter_frame_result().
2114 void InterpreterMacroAssembler::notify_method_exit(bool native_method,
2115 TosState state,
2116 NotifyMethodExitMode mode) {
2117 // JVMTI
2118 // Whenever JVMTI puts a thread in interp_only_mode, method
2119 // entry/exit events are sent for that thread to track stack
2120 // depth. If it is possible to enter interp_only_mode we add
2121 // the code to check if the event should be sent.
2122 if (mode == NotifyJVMTI && JvmtiExport::can_post_interpreter_events()) {
2123 Label jvmti_post_done;
2124 MacroAssembler::load_and_test_int(Z_R0, Address(Z_thread, JavaThread::interp_only_mode_offset()));
2125 z_bre(jvmti_post_done);
2126 if (!native_method) push(state); // see frame::interpreter_frame_result()
2127 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::post_method_exit));
2128 if (!native_method) pop(state);
2129 bind(jvmti_post_done);
2130 }
2131 }
2132
2133 void InterpreterMacroAssembler::skip_if_jvmti_mode(Label &Lskip, Register Rscratch) {
2134 if (!JvmtiExport::can_post_interpreter_events()) {
2135 return;
2136 }
2137
2138 load_and_test_int(Rscratch, Address(Z_thread, JavaThread::interp_only_mode_offset()));
2139 z_brnz(Lskip);
2140
2141 }
2142
2143 // Pop the topmost TOP_IJAVA_FRAME and set it's sender_sp as new Z_SP.
2144 // The return pc is loaded into the register return_pc.
2145 //
2146 // Registers updated:
2147 // return_pc - The return pc of the calling frame.
2148 // tmp1, tmp2 - scratch
2149 void InterpreterMacroAssembler::pop_interpreter_frame(Register return_pc, Register tmp1, Register tmp2) {
2150 // F0 Z_SP -> caller_sp (F1's)
2151 // ...
2152 // sender_sp (F1's)
2153 // ...
2154 // F1 Z_fp -> caller_sp (F2's)
2155 // return_pc (Continuation after return from F0.)
2156 // ...
2157 // F2 caller_sp
2158
2159 // Remove F0's activation. Restoring Z_SP to sender_sp reverts modifications
2160 // (a) by a c2i adapter and (b) by generate_fixed_frame().
2161 // In case (a) the new top frame F1 is an unextended compiled frame.
2162 // In case (b) F1 is converted from PARENT_IJAVA_FRAME to TOP_IJAVA_FRAME.
2163
2164 // Case (b) seems to be redundant when returning to a interpreted caller,
2165 // because then the caller's top_frame_sp is installed as sp (see
2166 // TemplateInterpreterGenerator::generate_return_entry_for ()). But
2167 // pop_interpreter_frame() is also used in exception handling and there the
2168 // frame type of the caller is unknown, therefore top_frame_sp cannot be used,
2169 // so it is important that sender_sp is the caller's sp as TOP_IJAVA_FRAME.
2170
2171 Register R_f1_sender_sp = tmp1;
2172 Register R_f2_sp = tmp2;
2173
2174 // First check for the interpreter frame's magic.
2175 asm_assert_ijava_state_magic(R_f2_sp/*tmp*/);
2176 z_lg(R_f2_sp, _z_parent_ijava_frame_abi(callers_sp), Z_fp);
2177 z_lg(R_f1_sender_sp, _z_ijava_state_neg(sender_sp), Z_fp);
2178 if (return_pc->is_valid())
2179 z_lg(return_pc, _z_parent_ijava_frame_abi(return_pc), Z_fp);
2180 // Pop F0 by resizing to R_f1_sender_sp and using R_f2_sp as fp.
2181 resize_frame_absolute(R_f1_sender_sp, R_f2_sp, false/*load fp*/);
2182
2183 #ifdef ASSERT
2184 // The return_pc in the new top frame is dead... at least that's my
2185 // current understanding; to assert this I overwrite it.
2186 load_const_optimized(Z_ARG3, 0xb00b1);
2187 z_stg(Z_ARG3, _z_parent_ijava_frame_abi(return_pc), Z_SP);
2188 #endif
2189 }