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