1 /*
2 * Copyright (c) 1999, 2023, 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.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "c1/c1_MacroAssembler.hpp"
28 #include "c1/c1_Runtime1.hpp"
29 #include "gc/shared/barrierSetAssembler.hpp"
30 #include "gc/shared/collectedHeap.hpp"
31 #include "gc/shared/tlab_globals.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "oops/arrayOop.hpp"
34 #include "oops/markWord.hpp"
35 #include "runtime/basicLock.hpp"
36 #include "runtime/os.hpp"
37 #include "runtime/sharedRuntime.hpp"
38 #include "runtime/stubRoutines.hpp"
39
40 void C1_MacroAssembler::float_cmp(bool is_float, int unordered_result,
41 FloatRegister f0, FloatRegister f1,
42 Register result)
43 {
44 Label done;
45 if (is_float) {
46 fcmps(f0, f1);
47 } else {
48 fcmpd(f0, f1);
49 }
50 if (unordered_result < 0) {
51 // we want -1 for unordered or less than, 0 for equal and 1 for
52 // greater than.
53 cset(result, NE); // Not equal or unordered
54 cneg(result, result, LT); // Less than or unordered
55 } else {
56 // we want -1 for less than, 0 for equal and 1 for unordered or
57 // greater than.
58 cset(result, NE); // Not equal or unordered
59 cneg(result, result, LO); // Less than
60 }
61 }
62
63 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
64 const int aligned_mask = BytesPerWord -1;
65 const int hdr_offset = oopDesc::mark_offset_in_bytes();
66 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
67 Label done;
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_in_bytes()));
74
75 null_check_offset = offset();
76
77 if (DiagnoseSyncOnValueBasedClasses != 0) {
78 load_klass(hdr, obj);
79 ldrw(hdr, Address(hdr, Klass::access_flags_offset()));
80 tstw(hdr, JVM_ACC_IS_VALUE_BASED_CLASS);
81 br(Assembler::NE, slow_case);
82 }
83
84 // Load object header
85 ldr(hdr, Address(obj, hdr_offset));
86 if (UseFastLocking) {
87 fast_lock(obj, hdr, rscratch1, rscratch2, slow_case, false);
88 } else {
89 // and mark it as unlocked
90 orr(hdr, hdr, markWord::unlocked_value);
91 // save unlocked object header into the displaced header location on the stack
92 str(hdr, Address(disp_hdr, 0));
93 // test if object header is still the same (i.e. unlocked), and if so, store the
94 // displaced header address in the object header - if it is not the same, get the
95 // object header instead
96 lea(rscratch2, Address(obj, hdr_offset));
97 cmpxchgptr(hdr, disp_hdr, rscratch2, rscratch1, done, /*fallthough*/NULL);
98 // if the object header was the same, we're done
99 // if the object header was not the same, it is now in the hdr register
100 // => test if it is a stack pointer into the same stack (recursive locking), i.e.:
101 //
102 // 1) (hdr & aligned_mask) == 0
103 // 2) sp <= hdr
104 // 3) hdr <= sp + page_size
105 //
106 // these 3 tests can be done by evaluating the following expression:
107 //
108 // (hdr - sp) & (aligned_mask - page_size)
109 //
110 // assuming both the stack pointer and page_size have their least
111 // significant 2 bits cleared and page_size is a power of 2
112 mov(rscratch1, sp);
113 sub(hdr, hdr, rscratch1);
114 ands(hdr, hdr, aligned_mask - (int)os::vm_page_size());
115 // for recursive locking, the result is zero => save it in the displaced header
116 // location (NULL in the displaced hdr location indicates recursive locking)
117 str(hdr, Address(disp_hdr, 0));
118 // otherwise we don't care about the result and handle locking via runtime call
119 cbnz(hdr, slow_case);
120 }
121 // done
122 bind(done);
123 increment(Address(rthread, JavaThread::held_monitor_count_offset()));
124 return null_check_offset;
125 }
126
127
128 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
129 const int aligned_mask = BytesPerWord -1;
130 const int hdr_offset = oopDesc::mark_offset_in_bytes();
131 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
132 Label done;
133
134 if (!UseFastLocking) {
135 // load displaced header
136 ldr(hdr, Address(disp_hdr, 0));
137 // if the loaded hdr is NULL we had recursive locking
138 // if we had recursive locking, we are done
139 cbz(hdr, done);
140 }
141
142 // load object
143 ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
144 verify_oop(obj);
145
146 if (UseFastLocking) {
147 ldr(hdr, Address(obj, oopDesc::mark_offset_in_bytes()));
148 fast_unlock(obj, hdr, rscratch1, rscratch2, slow_case);
149 } else {
150 // test if object header is pointing to the displaced header, and if so, restore
151 // the displaced header in the object - if the object header is not pointing to
152 // the displaced header, get the object header instead
153 // if the object header was not pointing to the displaced header,
154 // we do unlocking via runtime call
155 if (hdr_offset) {
156 lea(rscratch1, Address(obj, hdr_offset));
157 cmpxchgptr(disp_hdr, hdr, rscratch1, rscratch2, done, &slow_case);
158 } else {
159 cmpxchgptr(disp_hdr, hdr, obj, rscratch2, done, &slow_case);
160 }
161 // done
162 bind(done);
163 }
164 decrement(Address(rthread, JavaThread::held_monitor_count_offset()));
165 }
166
167
168 // Defines obj, preserves var_size_in_bytes
169 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
170 if (UseTLAB) {
171 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
172 } else {
173 b(slow_case);
174 }
175 }
176
177 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
178 assert_different_registers(obj, klass, len);
179 if (UseCompactObjectHeaders) {
180 ldr(t1, Address(klass, Klass::prototype_header_offset()));
181 str(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
182 } else {
183 // This assumes that all prototype bits fit in an int32_t
184 mov(t1, (int32_t)(intptr_t)markWord::prototype().value());
185 str(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
186
187 if (UseCompressedClassPointers) { // Take care not to kill klass
188 encode_klass_not_null(t1, klass);
189 strw(t1, Address(obj, oopDesc::klass_offset_in_bytes()));
190 } else {
191 str(klass, Address(obj, oopDesc::klass_offset_in_bytes()));
192 }
193 }
194
195 if (len->is_valid()) {
196 strw(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
197 } else if (UseCompressedClassPointers && !UseCompactObjectHeaders) {
198 store_klass_gap(obj, zr);
199 }
200 }
201
202 // preserves obj, destroys len_in_bytes
203 //
204 // Scratch registers: t1 = r10, t2 = r11
205 //
206 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1, Register t2) {
207 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0");
208 assert(t1 == r10 && t2 == r11, "must be");
209
210 Label done;
211
212 // len_in_bytes is positive and ptr sized
213 subs(len_in_bytes, len_in_bytes, hdr_size_in_bytes);
214 br(Assembler::EQ, done);
215
216 // Zero first 4 bytes, if start offset is not word aligned.
217 if (!is_aligned(hdr_size_in_bytes, BytesPerWord)) {
218 strw(zr, Address(obj, hdr_size_in_bytes));
219 hdr_size_in_bytes += BytesPerInt;
220 }
221
222 // zero_words() takes ptr in r10 and count in words in r11
223 mov(rscratch1, len_in_bytes);
224 lea(t1, Address(obj, hdr_size_in_bytes));
225 lsr(t2, rscratch1, LogBytesPerWord);
226 address tpc = zero_words(t1, t2);
227
228 bind(done);
229 if (tpc == nullptr) {
230 Compilation::current()->bailout("no space for trampoline stub");
231 }
232 }
233
234
235 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
236 assert_different_registers(obj, t1, t2); // XXX really?
237 assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
238
239 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
240
241 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB);
242 }
243
244 // Scratch registers: t1 = r10, t2 = r11
245 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) {
246 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
247 "con_size_in_bytes is not multiple of alignment");
248 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
249
250 initialize_header(obj, klass, noreg, t1, t2);
251
252 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
253 // clear rest of allocated space
254 const Register index = t2;
255 if (var_size_in_bytes != noreg) {
256 mov(index, var_size_in_bytes);
257 initialize_body(obj, index, hdr_size_in_bytes, t1, t2);
258 if (Compilation::current()->bailed_out()) {
259 return;
260 }
261 } else if (con_size_in_bytes > hdr_size_in_bytes) {
262 con_size_in_bytes -= hdr_size_in_bytes;
263 lea(t1, Address(obj, hdr_size_in_bytes));
264 address tpc = zero_words(t1, con_size_in_bytes / BytesPerWord);
265 if (tpc == nullptr) {
266 Compilation::current()->bailout("no space for trampoline stub");
267 return;
268 }
269 }
270 }
271
272 membar(StoreStore);
273
274 if (CURRENT_ENV->dtrace_alloc_probes()) {
275 assert(obj == r0, "must be");
276 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
277 }
278
279 verify_oop(obj);
280 }
281 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) {
282 assert_different_registers(obj, len, t1, t2, klass);
283
284 // determine alignment mask
285 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
286
287 // check for negative or excessive length
288 mov(rscratch1, (int32_t)max_array_allocation_length);
289 cmp(len, rscratch1);
290 br(Assembler::HS, slow_case);
291
292 const Register arr_size = t2; // okay to be the same
293 // align object end
294 mov(arr_size, (int32_t)base_offset_in_bytes + MinObjAlignmentInBytesMask);
295 add(arr_size, arr_size, len, ext::uxtw, f);
296 andr(arr_size, arr_size, ~MinObjAlignmentInBytesMask);
297
298 try_allocate(obj, arr_size, 0, t1, t2, slow_case);
299
300 initialize_header(obj, klass, len, t1, t2);
301
302 // clear rest of allocated space
303 initialize_body(obj, arr_size, base_offset_in_bytes, t1, t2);
304 if (Compilation::current()->bailed_out()) {
305 return;
306 }
307
308 membar(StoreStore);
309
310 if (CURRENT_ENV->dtrace_alloc_probes()) {
311 assert(obj == r0, "must be");
312 far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
313 }
314
315 verify_oop(obj);
316 }
317
318
319 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
320 verify_oop(receiver);
321 // explicit NULL check not needed since load from [klass_offset] causes a trap
322 // check against inline cache
323 if (UseCompactObjectHeaders) {
324 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::mark_offset_in_bytes()), "must add explicit null check");
325 } else {
326 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check");
327 }
328
329 cmp_klass(receiver, iCache, rscratch1);
330 }
331
332
333 void C1_MacroAssembler::build_frame(int framesize, int bang_size_in_bytes, int max_monitors) {
334 assert(bang_size_in_bytes >= framesize, "stack bang size incorrect");
335 // Make sure there is enough stack space for this method's activation.
336 // Note that we do this before creating a frame.
337 generate_stack_overflow_check(bang_size_in_bytes);
338 MacroAssembler::build_frame(framesize);
339
340 if (UseFastLocking && max_monitors > 0) {
341 Label ok;
342 ldr(r9, Address(rthread, JavaThread::lock_stack_current_offset()));
343 ldr(r10, Address(rthread, JavaThread::lock_stack_limit_offset()));
344 add(r9, r9, max_monitors * oopSize);
345 cmp(r9, r10);
346 br(Assembler::LT, ok);
347 assert(StubRoutines::aarch64::check_lock_stack() != NULL, "need runtime call stub");
348 far_call(StubRoutines::aarch64::check_lock_stack());
349 bind(ok);
350 }
351
352 // Insert nmethod entry barrier into frame.
353 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
354 bs->nmethod_entry_barrier(this, NULL /* slow_path */, NULL /* continuation */, NULL /* guard */);
355 }
356
357 void C1_MacroAssembler::remove_frame(int framesize) {
358 MacroAssembler::remove_frame(framesize);
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 }
369
370 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) {
371 // rfp, + 0: link
372 // + 1: return address
373 // + 2: argument with offset 0
374 // + 3: argument with offset 1
375 // + 4: ...
376
377 ldr(reg, Address(rfp, (offset_in_words + 2) * BytesPerWord));
378 }
379
380 #ifndef PRODUCT
381
382 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
383 if (!VerifyOops) return;
384 verify_oop_addr(Address(sp, stack_offset));
385 }
386
387 void C1_MacroAssembler::verify_not_null_oop(Register r) {
388 if (!VerifyOops) return;
389 Label not_null;
390 cbnz(r, not_null);
391 stop("non-null oop required");
392 bind(not_null);
393 verify_oop(r);
394 }
395
396 void C1_MacroAssembler::invalidate_registers(bool inv_r0, bool inv_r19, bool inv_r2, bool inv_r3, bool inv_r4, bool inv_r5) {
397 #ifdef ASSERT
398 static int nn;
399 if (inv_r0) mov(r0, 0xDEAD);
400 if (inv_r19) mov(r19, 0xDEAD);
401 if (inv_r2) mov(r2, nn++);
402 if (inv_r3) mov(r3, 0xDEAD);
403 if (inv_r4) mov(r4, 0xDEAD);
404 if (inv_r5) mov(r5, 0xDEAD);
405 #endif
406 }
407 #endif // ifndef PRODUCT