1 /*
2 * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25 #include "precompiled.hpp"
26 #include "c1/c1_MacroAssembler.hpp"
27 #include "c1/c1_Runtime1.hpp"
28 #include "code/compiledIC.hpp"
29 #include "compiler/compilerDefinitions.inline.hpp"
30 #include "gc/shared/barrierSet.hpp"
31 #include "gc/shared/barrierSetAssembler.hpp"
32 #include "gc/shared/collectedHeap.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/frame.inline.hpp"
39 #include "runtime/globals.hpp"
40 #include "runtime/os.hpp"
41 #include "runtime/sharedRuntime.hpp"
42 #include "runtime/stubRoutines.hpp"
43 #include "utilities/checkedCast.hpp"
44 #include "utilities/globalDefinitions.hpp"
45
46 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register tmp, Label& slow_case) {
47 const int aligned_mask = BytesPerWord -1;
48 const int hdr_offset = oopDesc::mark_offset_in_bytes();
49 assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
50 assert_different_registers(hdr, obj, disp_hdr, tmp);
51 int null_check_offset = -1;
52
53 verify_oop(obj);
54
55 // save object being locked into the BasicObjectLock
56 movptr(Address(disp_hdr, BasicObjectLock::obj_offset()), obj);
57
58 null_check_offset = offset();
59
60 if (DiagnoseSyncOnValueBasedClasses != 0) {
61 load_klass(hdr, obj, rscratch1);
62 movl(hdr, Address(hdr, Klass::access_flags_offset()));
63 testl(hdr, JVM_ACC_IS_VALUE_BASED_CLASS);
64 jcc(Assembler::notZero, slow_case);
65 }
66
67 if (LockingMode == LM_LIGHTWEIGHT) {
68 #ifdef _LP64
69 const Register thread = r15_thread;
70 #else
71 const Register thread = disp_hdr;
72 get_thread(thread);
73 #endif
74 lightweight_lock(obj, hdr, thread, tmp, slow_case);
75 } else if (LockingMode == LM_LEGACY) {
76 Label done;
77 // Load object header
78 movptr(hdr, Address(obj, hdr_offset));
79 // and mark it as unlocked
80 orptr(hdr, markWord::unlocked_value);
81 if (EnableValhalla) {
82 // Mask inline_type bit such that we go to the slow path if object is an inline type
83 andptr(hdr, ~((int) markWord::inline_type_bit_in_place));
84 }
85 // save unlocked object header into the displaced header location on the stack
86 movptr(Address(disp_hdr, 0), hdr);
87 // test if object header is still the same (i.e. unlocked), and if so, store the
88 // displaced header address in the object header - if it is not the same, get the
89 // object header instead
90 MacroAssembler::lock(); // must be immediately before cmpxchg!
91 cmpxchgptr(disp_hdr, Address(obj, hdr_offset));
92 // if the object header was the same, we're done
93 jcc(Assembler::equal, done);
94 // if the object header was not the same, it is now in the hdr register
95 // => test if it is a stack pointer into the same stack (recursive locking), i.e.:
96 //
97 // 1) (hdr & aligned_mask) == 0
98 // 2) rsp <= hdr
99 // 3) hdr <= rsp + page_size
100 //
101 // these 3 tests can be done by evaluating the following expression:
102 //
103 // (hdr - rsp) & (aligned_mask - page_size)
104 //
105 // assuming both the stack pointer and page_size have their least
106 // significant 2 bits cleared and page_size is a power of 2
107 subptr(hdr, rsp);
108 andptr(hdr, aligned_mask - (int)os::vm_page_size());
109 // for recursive locking, the result is zero => save it in the displaced header
110 // location (null in the displaced hdr location indicates recursive locking)
111 movptr(Address(disp_hdr, 0), hdr);
112 // otherwise we don't care about the result and handle locking via runtime call
113 jcc(Assembler::notZero, slow_case);
114 // done
115 bind(done);
116 }
117
118 inc_held_monitor_count();
119
120 return null_check_offset;
121 }
122
123 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
124 const int aligned_mask = BytesPerWord -1;
125 const int hdr_offset = oopDesc::mark_offset_in_bytes();
126 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction");
127 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
128 Label done;
129
130 if (LockingMode != LM_LIGHTWEIGHT) {
131 // load displaced header
132 movptr(hdr, Address(disp_hdr, 0));
133 // if the loaded hdr is null we had recursive locking
134 testptr(hdr, hdr);
135 // if we had recursive locking, we are done
136 jcc(Assembler::zero, done);
137 }
138
139 // load object
140 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset()));
141 verify_oop(obj);
142
143 if (LockingMode == LM_LIGHTWEIGHT) {
144 #ifdef _LP64
145 lightweight_unlock(obj, disp_hdr, r15_thread, hdr, slow_case);
146 #else
147 // This relies on the implementation of lightweight_unlock being able to handle
148 // that the reg_rax and thread Register parameters may alias each other.
149 get_thread(disp_hdr);
150 lightweight_unlock(obj, disp_hdr, disp_hdr, hdr, slow_case);
151 #endif
152 } else if (LockingMode == LM_LEGACY) {
153 // test if object header is pointing to the displaced header, and if so, restore
154 // the displaced header in the object - if the object header is not pointing to
155 // the displaced header, get the object header instead
156 MacroAssembler::lock(); // must be immediately before cmpxchg!
157 cmpxchgptr(hdr, Address(obj, hdr_offset));
158 // if the object header was not pointing to the displaced header,
159 // we do unlocking via runtime call
160 jcc(Assembler::notEqual, slow_case);
161 // done
162 }
163 bind(done);
164 dec_held_monitor_count();
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(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
172 } else {
173 jmp(slow_case);
174 }
175 }
176
177
178 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
179 assert_different_registers(obj, klass, len);
180 if (EnableValhalla) {
181 // Need to copy markWord::prototype header for klass
182 assert_different_registers(obj, klass, len, t1, t2);
183 movptr(t1, Address(klass, Klass::prototype_header_offset()));
184 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
185 } else {
186 // This assumes that all prototype bits fit in an int32_t
187 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value()));
188 }
189 #ifdef _LP64
190 if (UseCompressedClassPointers) { // Take care not to kill klass
191 movptr(t1, klass);
192 encode_klass_not_null(t1, rscratch1);
193 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
194 } else
195 #endif
196 {
197 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
198 }
199
200 if (len->is_valid()) {
201 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
202 #ifdef _LP64
203 int base_offset = arrayOopDesc::length_offset_in_bytes() + BytesPerInt;
204 if (!is_aligned(base_offset, BytesPerWord)) {
205 assert(is_aligned(base_offset, BytesPerInt), "must be 4-byte aligned");
206 // Clear gap/first 4 bytes following the length field.
207 xorl(t1, t1);
208 movl(Address(obj, base_offset), t1);
209 }
210 #endif
211 }
212 #ifdef _LP64
213 else if (UseCompressedClassPointers) {
214 xorptr(t1, t1);
215 store_klass_gap(obj, t1);
216 }
217 #endif
218 }
219
220
221 // preserves obj, destroys len_in_bytes
222 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
223 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0");
224 Label done;
225
226 // len_in_bytes is positive and ptr sized
227 subptr(len_in_bytes, hdr_size_in_bytes);
228 zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1);
229 bind(done);
230 }
231
232
233 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
234 assert(obj == rax, "obj must be in rax, for cmpxchg");
235 assert_different_registers(obj, t1, t2); // XXX really?
236 assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
237
238 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
239
240 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB);
241 }
242
243 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) {
244 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
245 "con_size_in_bytes is not multiple of alignment");
246 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
247
248 initialize_header(obj, klass, noreg, t1, t2);
249
250 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
251 // clear rest of allocated space
252 const Register t1_zero = t1;
253 const Register index = t2;
254 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below)
255 if (var_size_in_bytes != noreg) {
256 mov(index, var_size_in_bytes);
257 initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
258 } else if (con_size_in_bytes <= threshold) {
259 // use explicit null stores
260 // code size = 2 + 3*n bytes (n = number of fields to clear)
261 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
262 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
263 movptr(Address(obj, i), t1_zero);
264 } else if (con_size_in_bytes > hdr_size_in_bytes) {
265 // use loop to null out the fields
266 // code size = 16 bytes for even n (n = number of fields to clear)
267 // initialize last object field first if odd number of fields
268 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
269 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3);
270 // initialize last object field if constant size is odd
271 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
272 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
273 // initialize remaining object fields: rdx is a multiple of 2
274 { Label loop;
275 bind(loop);
276 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)),
277 t1_zero);
278 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)),
279 t1_zero);)
280 decrement(index);
281 jcc(Assembler::notZero, loop);
282 }
283 }
284 }
285
286 if (CURRENT_ENV->dtrace_alloc_probes()) {
287 assert(obj == rax, "must be");
288 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
289 }
290
291 verify_oop(obj);
292 }
293
294 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int base_offset_in_bytes, Address::ScaleFactor f, Register klass, Label& slow_case, bool zero_array) {
295 assert(obj == rax, "obj must be in rax, for cmpxchg");
296 assert_different_registers(obj, len, t1, t2, klass);
297
298 // determine alignment mask
299 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
300
301 // check for negative or excessive length
302 cmpptr(len, checked_cast<int32_t>(max_array_allocation_length));
303 jcc(Assembler::above, slow_case);
304
305 const Register arr_size = t2; // okay to be the same
306 // align object end
307 movptr(arr_size, base_offset_in_bytes + MinObjAlignmentInBytesMask);
308 lea(arr_size, Address(arr_size, len, f));
309 andptr(arr_size, ~MinObjAlignmentInBytesMask);
310
311 try_allocate(obj, arr_size, 0, t1, t2, slow_case);
312
313 initialize_header(obj, klass, len, t1, t2);
314
315 // clear rest of allocated space
316 if (zero_array) {
317 const Register len_zero = len;
318 // Align-up to word boundary, because we clear the 4 bytes potentially
319 // following the length field in initialize_header().
320 int base_offset = align_up(base_offset_in_bytes, BytesPerWord);
321 initialize_body(obj, arr_size, base_offset, len_zero);
322 }
323
324 if (CURRENT_ENV->dtrace_alloc_probes()) {
325 assert(obj == rax, "must be");
326 call(RuntimeAddress(Runtime1::entry_for(Runtime1::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 push(rbp);
334 if (PreserveFramePointer) {
335 mov(rbp, rsp);
336 }
337 #if !defined(_LP64) && defined(COMPILER2)
338 if (UseSSE < 2 && !CompilerConfig::is_c1_only_no_jvmci()) {
339 // c2 leaves fpu stack dirty. Clean it on entry
340 empty_FPU_stack();
341 }
342 #endif // !_LP64 && COMPILER2
343 decrement(rsp, frame_size_in_bytes);
344
345 if (needs_stack_repair) {
346 // Save stack increment (also account for fixed framesize and rbp)
347 assert((sp_inc & (StackAlignmentInBytes-1)) == 0, "stack increment not aligned");
348 int real_frame_size = sp_inc + frame_size_in_bytes + wordSize;
349 movptr(Address(rsp, frame_size_in_bytes - wordSize), real_frame_size);
350 }
351 if (reset_orig_pc) {
352 // Zero orig_pc to detect deoptimization during buffering in the entry points
353 movptr(Address(rsp, sp_offset_for_orig_pc), 0);
354 }
355 }
356
357 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) {
358 // Make sure there is enough stack space for this method's activation.
359 // Note that we do this before doing an enter(). This matches the
360 // ordering of C2's stack overflow check / rsp decrement and allows
361 // the SharedRuntime stack overflow handling to be consistent
362 // between the two compilers.
363 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
364 generate_stack_overflow_check(bang_size_in_bytes);
365
366 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, has_scalarized_args, needs_stack_repair);
367
368 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
369 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub
370 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */);
371
372 if (verified_inline_entry_label != nullptr) {
373 // Jump here from the scalarized entry points that already created the frame.
374 bind(*verified_inline_entry_label);
375 }
376 }
377
378 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
379 if (breakAtEntry || VerifyFPU) {
380 // Verified Entry first instruction should be 5 bytes long for correct
381 // patching by patch_verified_entry().
382 //
383 // Breakpoint and VerifyFPU have one byte first instruction.
384 // Also first instruction will be one byte "push(rbp)" if stack banging
385 // code is not generated (see build_frame() above).
386 // For all these cases generate long instruction first.
387 fat_nop();
388 }
389 if (breakAtEntry) int3();
390 // build frame
391 IA32_ONLY( verify_FPU(0, "method_entry"); )
392 }
393
394 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) {
395 assert(InlineTypePassFieldsAsArgs, "sanity");
396 // Make sure there is enough stack space for this method's activation.
397 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
398 generate_stack_overflow_check(bang_size_in_bytes);
399
400 GrowableArray<SigEntry>* sig = ces->sig();
401 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? ces->sig_cc_ro() : ces->sig_cc();
402 VMRegPair* regs = ces->regs();
403 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc();
404 int args_on_stack = ces->args_on_stack();
405 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc();
406
407 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!");
408 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length());
409 int args_passed = sig->length();
410 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt);
411
412 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC.
413 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, true, ces->c1_needs_stack_repair());
414
415 // The runtime call might safepoint, make sure nmethod entry barrier is executed
416 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
417 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub
418 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */);
419
420 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args.
421 movptr(rbx, (intptr_t)(ces->method()));
422 if (is_inline_ro_entry) {
423 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_no_receiver_id)));
424 } else {
425 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_id)));
426 }
427 int rt_call_offset = offset();
428
429 // Remove the temp frame
430 addptr(rsp, frame_size_in_bytes);
431 pop(rbp);
432
433 // Check if we need to extend the stack for packing
434 int sp_inc = 0;
435 if (args_on_stack > args_on_stack_cc) {
436 sp_inc = extend_stack_for_inline_args(args_on_stack);
437 }
438
439 shuffle_inline_args(true, is_inline_ro_entry, sig_cc,
440 args_passed_cc, args_on_stack_cc, regs_cc, // from
441 args_passed, args_on_stack, regs, // to
442 sp_inc, rax);
443
444 // Create the real frame. Below jump will then skip over the stack banging and frame
445 // setup code in the verified_inline_entry (which has a different real_frame_size).
446 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, sp_inc, false, ces->c1_needs_stack_repair());
447
448 jmp(verified_inline_entry_label);
449 return rt_call_offset;
450 }
451
452 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) {
453 // rbp, + 0: link
454 // + 1: return address
455 // + 2: argument with offset 0
456 // + 3: argument with offset 1
457 // + 4: ...
458
459 movptr(reg, Address(rbp, (offset_in_words + 2) * BytesPerWord));
460 }
461
462 #ifndef PRODUCT
463
464 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
465 if (!VerifyOops) return;
466 verify_oop_addr(Address(rsp, stack_offset));
467 }
468
469 void C1_MacroAssembler::verify_not_null_oop(Register r) {
470 if (!VerifyOops) return;
471 Label not_null;
472 testptr(r, r);
473 jcc(Assembler::notZero, not_null);
474 stop("non-null oop required");
475 bind(not_null);
476 verify_oop(r);
477 }
478
479 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) {
480 #ifdef ASSERT
481 if (inv_rax) movptr(rax, 0xDEAD);
482 if (inv_rbx) movptr(rbx, 0xDEAD);
483 if (inv_rcx) movptr(rcx, 0xDEAD);
484 if (inv_rdx) movptr(rdx, 0xDEAD);
485 if (inv_rsi) movptr(rsi, 0xDEAD);
486 if (inv_rdi) movptr(rdi, 0xDEAD);
487 #endif
488 }
489
490 #endif // ifndef PRODUCT