1 /*
2 * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2014, 2021, Red Hat Inc. 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.
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24 */
25
26 #include "c1/c1_MacroAssembler.hpp"
27 #include "c1/c1_Runtime1.hpp"
28 #include "gc/shared/barrierSetAssembler.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "gc/shared/barrierSet.hpp"
31 #include "gc/shared/barrierSetAssembler.hpp"
32 #include "gc/shared/tlab_globals.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "oops/arrayOop.hpp"
35 #include "oops/markWord.hpp"
36 #include "runtime/basicLock.hpp"
37 #include "runtime/os.hpp"
38 #include "runtime/sharedRuntime.hpp"
39 #include "runtime/stubRoutines.hpp"
40
41 void C1_MacroAssembler::float_cmp(bool is_float, int unordered_result,
42 FloatRegister f0, FloatRegister f1,
43 Register result)
44 {
45 Label done;
46 if (is_float) {
47 fcmps(f0, f1);
48 } else {
49 fcmpd(f0, f1);
50 }
51 if (unordered_result < 0) {
52 // we want -1 for unordered or less than, 0 for equal and 1 for
53 // greater than.
54 cset(result, NE); // Not equal or unordered
55 cneg(result, result, LT); // Less than or unordered
56 } else {
57 // we want -1 for less than, 0 for equal and 1 for unordered or
58 // greater than.
59 cset(result, NE); // Not equal or unordered
60 cneg(result, result, LO); // Less than
61 }
62 }
63
64 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register temp, Label& slow_case) {
65 const int aligned_mask = BytesPerWord -1;
66 const int hdr_offset = oopDesc::mark_offset_in_bytes();
67 assert_different_registers(hdr, obj, disp_hdr, temp, rscratch2);
68 int null_check_offset = -1;
69
70 verify_oop(obj);
71
72 // save object being locked into the BasicObjectLock
73 str(obj, Address(disp_hdr, BasicObjectLock::obj_offset()));
74
75 null_check_offset = offset();
76
77 if (LockingMode == LM_LIGHTWEIGHT) {
78 lightweight_lock(disp_hdr, obj, hdr, temp, rscratch2, slow_case);
79 } else if (LockingMode == LM_LEGACY) {
80
81 if (DiagnoseSyncOnValueBasedClasses != 0) {
82 load_klass(hdr, obj);
83 ldrb(hdr, Address(hdr, Klass::misc_flags_offset()));
84 tst(hdr, KlassFlags::_misc_is_value_based_class);
85 br(Assembler::NE, slow_case);
86 }
87
88 Label done;
89 // Load object header
90 ldr(hdr, Address(obj, hdr_offset));
91 // and mark it as unlocked
92 orr(hdr, hdr, markWord::unlocked_value);
93
94 if (EnableValhalla) {
95 // Mask always_locked bit such that we go to the slow path if object is an inline type
96 andr(hdr, hdr, ~markWord::inline_type_bit_in_place);
97 }
98
99 // save unlocked object header into the displaced header location on the stack
100 str(hdr, Address(disp_hdr, 0));
101 // test if object header is still the same (i.e. unlocked), and if so, store the
102 // displaced header address in the object header - if it is not the same, get the
103 // object header instead
104 lea(rscratch2, Address(obj, hdr_offset));
105 cmpxchgptr(hdr, disp_hdr, rscratch2, rscratch1, done, /*fallthough*/nullptr);
106 // if the object header was the same, we're done
107 // if the object header was not the same, it is now in the hdr register
108 // => test if it is a stack pointer into the same stack (recursive locking), i.e.:
109 //
110 // 1) (hdr & aligned_mask) == 0
111 // 2) sp <= hdr
112 // 3) hdr <= sp + page_size
113 //
114 // these 3 tests can be done by evaluating the following expression:
115 //
116 // (hdr - sp) & (aligned_mask - page_size)
117 //
118 // assuming both the stack pointer and page_size have their least
119 // significant 2 bits cleared and page_size is a power of 2
120 mov(rscratch1, sp);
121 sub(hdr, hdr, rscratch1);
122 ands(hdr, hdr, aligned_mask - (int)os::vm_page_size());
123 // for recursive locking, the result is zero => save it in the displaced header
124 // location (null in the displaced hdr location indicates recursive locking)
125 str(hdr, Address(disp_hdr, 0));
126 // otherwise we don't care about the result and handle locking via runtime call
127 cbnz(hdr, slow_case);
128 // done
129 bind(done);
130 inc_held_monitor_count(rscratch1);
131 }
132 return null_check_offset;
133 }
134
135
136 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Register temp, Label& slow_case) {
137 const int aligned_mask = BytesPerWord -1;
138 const int hdr_offset = oopDesc::mark_offset_in_bytes();
139 assert_different_registers(hdr, obj, disp_hdr, temp, rscratch2);
140 Label done;
141
142 if (LockingMode != LM_LIGHTWEIGHT) {
143 // load displaced header
144 ldr(hdr, Address(disp_hdr, 0));
145 // if the loaded hdr is null we had recursive locking
146 // if we had recursive locking, we are done
147 cbz(hdr, done);
148 }
149
150 // load object
151 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset()));
152 verify_oop(obj);
153
154 if (LockingMode == LM_LIGHTWEIGHT) {
155 lightweight_unlock(obj, hdr, temp, rscratch2, slow_case);
156 } else if (LockingMode == LM_LEGACY) {
157 // test if object header is pointing to the displaced header, and if so, restore
158 // the displaced header in the object - if the object header is not pointing to
159 // the displaced header, get the object header instead
160 // if the object header was not pointing to the displaced header,
161 // we do unlocking via runtime call
162 if (hdr_offset) {
163 lea(rscratch1, Address(obj, hdr_offset));
164 cmpxchgptr(disp_hdr, hdr, rscratch1, rscratch2, done, &slow_case);
165 } else {
166 cmpxchgptr(disp_hdr, hdr, obj, rscratch2, done, &slow_case);
167 }
168 // done
169 bind(done);
170 dec_held_monitor_count(rscratch1);
171 }
172 }
173
174
175 // Defines obj, preserves var_size_in_bytes
176 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
177 if (UseTLAB) {
178 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
179 } else {
180 b(slow_case);
181 }
182 }
183
184 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
185 assert_different_registers(obj, klass, len);
186
187 if (UseCompactObjectHeaders || EnableValhalla) {
188 ldr(t1, Address(klass, Klass::prototype_header_offset()));
189 str(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
190 } else {
191 mov(t1, checked_cast<int32_t>(markWord::prototype().value()));
192 str(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
193 }
194
195 if (!UseCompactObjectHeaders) {
196 if (UseCompressedClassPointers) { // Take care not to kill klass
197 encode_klass_not_null(t1, klass);
198 strw(t1, Address(obj, oopDesc::klass_offset_in_bytes()));
199 } else {
200 str(klass, Address(obj, oopDesc::klass_offset_in_bytes()));
201 }
202 }
203
204 if (len->is_valid()) {
205 strw(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
206 int base_offset = arrayOopDesc::length_offset_in_bytes() + BytesPerInt;
207 if (!is_aligned(base_offset, BytesPerWord)) {
208 assert(is_aligned(base_offset, BytesPerInt), "must be 4-byte aligned");
209 // Clear gap/first 4 bytes following the length field.
210 strw(zr, Address(obj, base_offset));
211 }
212 } else if (UseCompressedClassPointers && !UseCompactObjectHeaders) {
213 store_klass_gap(obj, zr);
214 }
215 }
216
217 // preserves obj, destroys len_in_bytes
218 //
219 // Scratch registers: t1 = r10, t2 = r11
220 //
221 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1, Register t2) {
222 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0");
223 assert(t1 == r10 && t2 == r11, "must be");
224
225 Label done;
226
227 // len_in_bytes is positive and ptr sized
228 subs(len_in_bytes, len_in_bytes, hdr_size_in_bytes);
229 br(Assembler::EQ, done);
230
231 // zero_words() takes ptr in r10 and count in words in r11
232 mov(rscratch1, len_in_bytes);
233 lea(t1, Address(obj, hdr_size_in_bytes));
234 lsr(t2, rscratch1, LogBytesPerWord);
235 address tpc = zero_words(t1, t2);
236
237 bind(done);
238 if (tpc == nullptr) {
239 Compilation::current()->bailout("no space for trampoline stub");
240 }
241 }
242
243
244 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
245 assert_different_registers(obj, t1, t2); // XXX really?
246 assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
247
248 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
249
250 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB);
251 }
252
253 // Scratch registers: t1 = r10, t2 = r11
254 void C1_MacroAssembler::initialize_object(Register obj, Register klass, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, bool is_tlab_allocated) {
255 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
256 "con_size_in_bytes is not multiple of alignment");
257 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
258
259 initialize_header(obj, klass, noreg, t1, t2);
260
261 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
262 // clear rest of allocated space
263 const Register index = t2;
264 if (var_size_in_bytes != noreg) {
265 mov(index, var_size_in_bytes);
266 initialize_body(obj, index, hdr_size_in_bytes, t1, t2);
267 if (Compilation::current()->bailed_out()) {
268 return;
269 }
270 } else if (con_size_in_bytes > hdr_size_in_bytes) {
271 con_size_in_bytes -= hdr_size_in_bytes;
272 lea(t1, Address(obj, hdr_size_in_bytes));
273 address tpc = zero_words(t1, con_size_in_bytes / BytesPerWord);
274 if (tpc == nullptr) {
275 Compilation::current()->bailout("no space for trampoline stub");
276 return;
277 }
278 }
279 }
280
281 membar(StoreStore);
282
283 if (CURRENT_ENV->dtrace_alloc_probes()) {
284 assert(obj == r0, "must be");
285 far_call(RuntimeAddress(Runtime1::entry_for(C1StubId::dtrace_object_alloc_id)));
286 }
287
288 verify_oop(obj);
289 }
290 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int base_offset_in_bytes, int f, Register klass, Label& slow_case, bool zero_array) {
291 assert_different_registers(obj, len, t1, t2, klass);
292
293 // determine alignment mask
294 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
295
296 // check for negative or excessive length
297 mov(rscratch1, (int32_t)max_array_allocation_length);
298 cmp(len, rscratch1);
299 br(Assembler::HS, slow_case);
300
301 const Register arr_size = t2; // okay to be the same
302 // align object end
303 mov(arr_size, (int32_t)base_offset_in_bytes + MinObjAlignmentInBytesMask);
304 add(arr_size, arr_size, len, ext::uxtw, f);
305 andr(arr_size, arr_size, ~MinObjAlignmentInBytesMask);
306
307 try_allocate(obj, arr_size, 0, t1, t2, slow_case);
308
309 initialize_header(obj, klass, len, t1, t2);
310
311 // Align-up to word boundary, because we clear the 4 bytes potentially
312 // following the length field in initialize_header().
313 int base_offset = align_up(base_offset_in_bytes, BytesPerWord);
314 // clear rest of allocated space
315 if (zero_array) {
316 initialize_body(obj, arr_size, base_offset, t1, t2);
317 }
318 if (Compilation::current()->bailed_out()) {
319 return;
320 }
321
322 membar(StoreStore);
323
324 if (CURRENT_ENV->dtrace_alloc_probes()) {
325 assert(obj == r0, "must be");
326 far_call(RuntimeAddress(Runtime1::entry_for(C1StubId::dtrace_object_alloc_id)));
327 }
328
329 verify_oop(obj);
330 }
331
332 void C1_MacroAssembler::build_frame_helper(int frame_size_in_bytes, int sp_offset_for_orig_pc, int sp_inc, bool reset_orig_pc, bool needs_stack_repair) {
333 MacroAssembler::build_frame(frame_size_in_bytes);
334
335 if (needs_stack_repair) {
336 save_stack_increment(sp_inc, frame_size_in_bytes);
337 }
338 if (reset_orig_pc) {
339 // Zero orig_pc to detect deoptimization during buffering in the entry points
340 str(zr, Address(sp, sp_offset_for_orig_pc));
341 }
342 }
343
344 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes, int sp_offset_for_orig_pc, bool needs_stack_repair, bool has_scalarized_args, Label* verified_inline_entry_label) {
345 // Make sure there is enough stack space for this method's activation.
346 // Note that we do this before creating a frame.
347 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
348 generate_stack_overflow_check(bang_size_in_bytes);
349
350 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, has_scalarized_args, needs_stack_repair);
351
352 // Insert nmethod entry barrier into frame.
353 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
354 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */, nullptr /* guard */);
355
356 if (verified_inline_entry_label != nullptr) {
357 // Jump here from the scalarized entry points that already created the frame.
358 bind(*verified_inline_entry_label);
359 }
360 }
361
362 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
363 // If we have to make this method not-entrant we'll overwrite its
364 // first instruction with a jump. For this action to be legal we
365 // must ensure that this first instruction is a B, BL, NOP, BKPT,
366 // SVC, HVC, or SMC. Make it a NOP.
367 nop();
368 if (C1Breakpoint) brk(1);
369 }
370
371 int C1_MacroAssembler::scalarized_entry(const CompiledEntrySignature* ces, int frame_size_in_bytes, int bang_size_in_bytes, int sp_offset_for_orig_pc, Label& verified_inline_entry_label, bool is_inline_ro_entry) {
372 assert(InlineTypePassFieldsAsArgs, "sanity");
373 // Make sure there is enough stack space for this method's activation.
374 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
375 generate_stack_overflow_check(bang_size_in_bytes);
376
377 GrowableArray<SigEntry>* sig = ces->sig();
378 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? ces->sig_cc_ro() : ces->sig_cc();
379 VMRegPair* regs = ces->regs();
380 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc();
381 int args_on_stack = ces->args_on_stack();
382 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc();
383
384 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!");
385 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length());
386 int args_passed = sig->length();
387 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt);
388
389 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC.
390 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, true, ces->c1_needs_stack_repair());
391
392 // The runtime call might safepoint, make sure nmethod entry barrier is executed
393 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
394 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub
395 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */, nullptr /* guard */);
396
397 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args.
398 mov(r19, (intptr_t) ces->method());
399 if (is_inline_ro_entry) {
400 far_call(RuntimeAddress(Runtime1::entry_for(C1StubId::buffer_inline_args_no_receiver_id)));
401 } else {
402 far_call(RuntimeAddress(Runtime1::entry_for(C1StubId::buffer_inline_args_id)));
403 }
404 int rt_call_offset = offset();
405
406 // The runtime call returns the new array in r20 instead of the usual r0
407 // because r0 is also j_rarg7 which may be holding a live argument here.
408 Register val_array = r20;
409
410 // Remove the temp frame
411 MacroAssembler::remove_frame(frame_size_in_bytes);
412
413 // Check if we need to extend the stack for packing
414 int sp_inc = 0;
415 if (args_on_stack > args_on_stack_cc) {
416 sp_inc = extend_stack_for_inline_args(args_on_stack);
417 }
418
419 shuffle_inline_args(true, is_inline_ro_entry, sig_cc,
420 args_passed_cc, args_on_stack_cc, regs_cc, // from
421 args_passed, args_on_stack, regs, // to
422 sp_inc, val_array);
423
424 // Create the real frame. Below jump will then skip over the stack banging and frame
425 // setup code in the verified_inline_entry (which has a different real_frame_size).
426 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, sp_inc, false, ces->c1_needs_stack_repair());
427
428 b(verified_inline_entry_label);
429 return rt_call_offset;
430 }
431
432
433 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) {
434 // rfp, + 0: link
435 // + 1: return address
436 // + 2: argument with offset 0
437 // + 3: argument with offset 1
438 // + 4: ...
439
440 ldr(reg, Address(rfp, (offset_in_words + 2) * BytesPerWord));
441 }
442
443 #ifndef PRODUCT
444
445 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
446 if (!VerifyOops) return;
447 verify_oop_addr(Address(sp, stack_offset));
448 }
449
450 void C1_MacroAssembler::verify_not_null_oop(Register r) {
451 if (!VerifyOops) return;
452 Label not_null;
453 cbnz(r, not_null);
454 stop("non-null oop required");
455 bind(not_null);
456 verify_oop(r);
457 }
458
459 void C1_MacroAssembler::invalidate_registers(bool inv_r0, bool inv_r19, bool inv_r2, bool inv_r3, bool inv_r4, bool inv_r5) {
460 #ifdef ASSERT
461 static int nn;
462 if (inv_r0) mov(r0, 0xDEAD);
463 if (inv_r19) mov(r19, 0xDEAD);
464 if (inv_r2) mov(r2, nn++);
465 if (inv_r3) mov(r3, 0xDEAD);
466 if (inv_r4) mov(r4, 0xDEAD);
467 if (inv_r5) mov(r5, 0xDEAD);
468 #endif
469 }
470 #endif // ifndef PRODUCT