1 /*
2 * Copyright (c) 1999, 2023, 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 "compiler/compilerDefinitions.inline.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/barrierSetAssembler.hpp"
31 #include "gc/shared/collectedHeap.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/frame.inline.hpp"
38 #include "runtime/os.hpp"
39 #include "runtime/sharedRuntime.hpp"
40 #include "runtime/stubRoutines.hpp"
41 #include "utilities/checkedCast.hpp"
42
43 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register tmp, Label& slow_case) {
44 const int aligned_mask = BytesPerWord -1;
45 const int hdr_offset = oopDesc::mark_offset_in_bytes();
46 assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
47 assert_different_registers(hdr, obj, disp_hdr, tmp);
48 int null_check_offset = -1;
49
50 verify_oop(obj);
51
52 // save object being locked into the BasicObjectLock
53 movptr(Address(disp_hdr, BasicObjectLock::obj_offset()), obj);
54
55 null_check_offset = offset();
56
57 if (DiagnoseSyncOnValueBasedClasses != 0) {
58 load_klass(hdr, obj, rscratch1);
59 movl(hdr, Address(hdr, Klass::access_flags_offset()));
60 testl(hdr, JVM_ACC_IS_VALUE_BASED_CLASS);
61 jcc(Assembler::notZero, slow_case);
62 }
63
64 // Load object header
65 movptr(hdr, Address(obj, hdr_offset));
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 fast_lock_impl(obj, hdr, thread, tmp, slow_case);
75 } else if (LockingMode == LM_LEGACY) {
76 Label done;
77 // and mark it as unlocked
78 orptr(hdr, markWord::unlocked_value);
79 if (EnableValhalla) {
80 // Mask inline_type bit such that we go to the slow path if object is an inline type
81 andptr(hdr, ~((int) markWord::inline_type_bit_in_place));
82 }
83 // save unlocked object header into the displaced header location on the stack
84 movptr(Address(disp_hdr, 0), hdr);
85 // test if object header is still the same (i.e. unlocked), and if so, store the
86 // displaced header address in the object header - if it is not the same, get the
87 // object header instead
88 MacroAssembler::lock(); // must be immediately before cmpxchg!
89 cmpxchgptr(disp_hdr, Address(obj, hdr_offset));
90 // if the object header was the same, we're done
91 jcc(Assembler::equal, done);
92 // if the object header was not the same, it is now in the hdr register
93 // => test if it is a stack pointer into the same stack (recursive locking), i.e.:
94 //
95 // 1) (hdr & aligned_mask) == 0
96 // 2) rsp <= hdr
97 // 3) hdr <= rsp + page_size
98 //
99 // these 3 tests can be done by evaluating the following expression:
100 //
101 // (hdr - rsp) & (aligned_mask - page_size)
102 //
103 // assuming both the stack pointer and page_size have their least
104 // significant 2 bits cleared and page_size is a power of 2
105 subptr(hdr, rsp);
106 andptr(hdr, aligned_mask - (int)os::vm_page_size());
107 // for recursive locking, the result is zero => save it in the displaced header
108 // location (null in the displaced hdr location indicates recursive locking)
109 movptr(Address(disp_hdr, 0), hdr);
110 // otherwise we don't care about the result and handle locking via runtime call
111 jcc(Assembler::notZero, slow_case);
112 // done
113 bind(done);
114 }
115
116 inc_held_monitor_count();
117
118 return null_check_offset;
119 }
120
121 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
122 const int aligned_mask = BytesPerWord -1;
123 const int hdr_offset = oopDesc::mark_offset_in_bytes();
124 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction");
125 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
126 Label done;
127
128 if (LockingMode != LM_LIGHTWEIGHT) {
129 // load displaced header
130 movptr(hdr, Address(disp_hdr, 0));
131 // if the loaded hdr is null we had recursive locking
132 testptr(hdr, hdr);
133 // if we had recursive locking, we are done
134 jcc(Assembler::zero, done);
135 }
136
137 // load object
138 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset()));
139 verify_oop(obj);
140
141 if (LockingMode == LM_LIGHTWEIGHT) {
142 movptr(disp_hdr, Address(obj, hdr_offset));
143 andptr(disp_hdr, ~(int32_t)markWord::lock_mask_in_place);
144 fast_unlock_impl(obj, disp_hdr, hdr, slow_case);
145 } else if (LockingMode == LM_LEGACY) {
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 MacroAssembler::lock(); // must be immediately before cmpxchg!
150 cmpxchgptr(hdr, Address(obj, hdr_offset));
151 // if the object header was not pointing to the displaced header,
152 // we do unlocking via runtime call
153 jcc(Assembler::notEqual, slow_case);
154 // done
155 }
156 bind(done);
157 dec_held_monitor_count();
158 }
159
160
161 // Defines obj, preserves var_size_in_bytes
162 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
163 if (UseTLAB) {
164 tlab_allocate(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
165 } else {
166 jmp(slow_case);
167 }
168 }
169
170
171 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
172 assert_different_registers(obj, klass, len);
173 if (EnableValhalla) {
174 // Need to copy markWord::prototype header for klass
175 assert_different_registers(obj, klass, len, t1, t2);
176 movptr(t1, Address(klass, Klass::prototype_header_offset()));
177 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
178 } else {
179 // This assumes that all prototype bits fit in an int32_t
180 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value()));
181 }
182 #ifdef _LP64
183 if (UseCompressedClassPointers) { // Take care not to kill klass
184 movptr(t1, klass);
185 encode_klass_not_null(t1, rscratch1);
186 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
187 } else
188 #endif
189 {
190 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
191 }
192
193 if (len->is_valid()) {
194 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
195 }
196 #ifdef _LP64
197 else if (UseCompressedClassPointers) {
198 xorptr(t1, t1);
199 store_klass_gap(obj, t1);
200 }
201 #endif
202 }
203
204
205 // preserves obj, destroys len_in_bytes
206 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
207 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0");
208 Label done;
209
210 // len_in_bytes is positive and ptr sized
211 subptr(len_in_bytes, hdr_size_in_bytes);
212 zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1);
213 bind(done);
214 }
215
216
217 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
218 assert(obj == rax, "obj must be in rax, for cmpxchg");
219 assert_different_registers(obj, t1, t2); // XXX really?
220 assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
221
222 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
223
224 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB);
225 }
226
227 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) {
228 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
229 "con_size_in_bytes is not multiple of alignment");
230 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
231
232 initialize_header(obj, klass, noreg, t1, t2);
233
234 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
235 // clear rest of allocated space
236 const Register t1_zero = t1;
237 const Register index = t2;
238 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below)
239 if (var_size_in_bytes != noreg) {
240 mov(index, var_size_in_bytes);
241 initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
242 } else if (con_size_in_bytes <= threshold) {
243 // use explicit null stores
244 // code size = 2 + 3*n bytes (n = number of fields to clear)
245 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
246 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
247 movptr(Address(obj, i), t1_zero);
248 } else if (con_size_in_bytes > hdr_size_in_bytes) {
249 // use loop to null out the fields
250 // code size = 16 bytes for even n (n = number of fields to clear)
251 // initialize last object field first if odd number of fields
252 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
253 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3);
254 // initialize last object field if constant size is odd
255 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
256 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
257 // initialize remaining object fields: rdx is a multiple of 2
258 { Label loop;
259 bind(loop);
260 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)),
261 t1_zero);
262 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)),
263 t1_zero);)
264 decrement(index);
265 jcc(Assembler::notZero, loop);
266 }
267 }
268 }
269
270 if (CURRENT_ENV->dtrace_alloc_probes()) {
271 assert(obj == rax, "must be");
272 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
273 }
274
275 verify_oop(obj);
276 }
277
278 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, Address::ScaleFactor f, Register klass, Label& slow_case) {
279 assert(obj == rax, "obj must be in rax, for cmpxchg");
280 assert_different_registers(obj, len, t1, t2, klass);
281
282 // determine alignment mask
283 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
284
285 // check for negative or excessive length
286 cmpptr(len, checked_cast<int32_t>(max_array_allocation_length));
287 jcc(Assembler::above, slow_case);
288
289 const Register arr_size = t2; // okay to be the same
290 // align object end
291 movptr(arr_size, header_size * BytesPerWord + MinObjAlignmentInBytesMask);
292 lea(arr_size, Address(arr_size, len, f));
293 andptr(arr_size, ~MinObjAlignmentInBytesMask);
294
295 try_allocate(obj, arr_size, 0, t1, t2, slow_case);
296
297 initialize_header(obj, klass, len, t1, t2);
298
299 // clear rest of allocated space
300 const Register len_zero = len;
301 initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero);
302
303 if (CURRENT_ENV->dtrace_alloc_probes()) {
304 assert(obj == rax, "must be");
305 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
306 }
307
308 verify_oop(obj);
309 }
310
311
312
313 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
314 verify_oop(receiver);
315 // explicit null check not needed since load from [klass_offset] causes a trap
316 // check against inline cache
317 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check");
318 int start_offset = offset();
319
320 if (UseCompressedClassPointers) {
321 load_klass(rscratch1, receiver, rscratch2);
322 cmpptr(rscratch1, iCache);
323 } else {
324 cmpptr(iCache, Address(receiver, oopDesc::klass_offset_in_bytes()));
325 }
326 // if icache check fails, then jump to runtime routine
327 // Note: RECEIVER must still contain the receiver!
328 jump_cc(Assembler::notEqual,
329 RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
330 const int ic_cmp_size = LP64_ONLY(10) NOT_LP64(9);
331 assert(UseCompressedClassPointers || offset() - start_offset == ic_cmp_size, "check alignment in emit_method_entry");
332 }
333
334 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) {
335 push(rbp);
336 if (PreserveFramePointer) {
337 mov(rbp, rsp);
338 }
339 #if !defined(_LP64) && defined(COMPILER2)
340 if (UseSSE < 2 && !CompilerConfig::is_c1_only_no_jvmci()) {
341 // c2 leaves fpu stack dirty. Clean it on entry
342 empty_FPU_stack();
343 }
344 #endif // !_LP64 && COMPILER2
345 decrement(rsp, frame_size_in_bytes);
346
347 if (needs_stack_repair) {
348 // Save stack increment (also account for fixed framesize and rbp)
349 assert((sp_inc & (StackAlignmentInBytes-1)) == 0, "stack increment not aligned");
350 int real_frame_size = sp_inc + frame_size_in_bytes + wordSize;
351 movptr(Address(rsp, frame_size_in_bytes - wordSize), real_frame_size);
352 }
353 if (reset_orig_pc) {
354 // Zero orig_pc to detect deoptimization during buffering in the entry points
355 movptr(Address(rsp, sp_offset_for_orig_pc), 0);
356 }
357 }
358
359 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) {
360 // Make sure there is enough stack space for this method's activation.
361 // Note that we do this before doing an enter(). This matches the
362 // ordering of C2's stack overflow check / rsp decrement and allows
363 // the SharedRuntime stack overflow handling to be consistent
364 // between the two compilers.
365 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
366 generate_stack_overflow_check(bang_size_in_bytes);
367
368 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, has_scalarized_args, needs_stack_repair);
369
370 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
371 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub
372 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */);
373
374 if (verified_inline_entry_label != nullptr) {
375 // Jump here from the scalarized entry points that already created the frame.
376 bind(*verified_inline_entry_label);
377 }
378 }
379
380 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
381 if (breakAtEntry || VerifyFPU) {
382 // Verified Entry first instruction should be 5 bytes long for correct
383 // patching by patch_verified_entry().
384 //
385 // Breakpoint and VerifyFPU have one byte first instruction.
386 // Also first instruction will be one byte "push(rbp)" if stack banging
387 // code is not generated (see build_frame() above).
388 // For all these cases generate long instruction first.
389 fat_nop();
390 }
391 if (breakAtEntry) int3();
392 // build frame
393 IA32_ONLY( verify_FPU(0, "method_entry"); )
394 }
395
396 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) {
397 assert(InlineTypePassFieldsAsArgs, "sanity");
398 // Make sure there is enough stack space for this method's activation.
399 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
400 generate_stack_overflow_check(bang_size_in_bytes);
401
402 GrowableArray<SigEntry>* sig = ces->sig();
403 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? ces->sig_cc_ro() : ces->sig_cc();
404 VMRegPair* regs = ces->regs();
405 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc();
406 int args_on_stack = ces->args_on_stack();
407 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc();
408
409 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!");
410 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length());
411 int args_passed = sig->length();
412 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt);
413
414 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC.
415 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, true, ces->c1_needs_stack_repair());
416
417 // The runtime call might safepoint, make sure nmethod entry barrier is executed
418 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
419 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub
420 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */);
421
422 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args.
423 movptr(rbx, (intptr_t)(ces->method()));
424 if (is_inline_ro_entry) {
425 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_no_receiver_id)));
426 } else {
427 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_id)));
428 }
429 int rt_call_offset = offset();
430
431 // Remove the temp frame
432 addptr(rsp, frame_size_in_bytes);
433 pop(rbp);
434
435 // Check if we need to extend the stack for packing
436 int sp_inc = 0;
437 if (args_on_stack > args_on_stack_cc) {
438 sp_inc = extend_stack_for_inline_args(args_on_stack);
439 }
440
441 shuffle_inline_args(true, is_inline_ro_entry, sig_cc,
442 args_passed_cc, args_on_stack_cc, regs_cc, // from
443 args_passed, args_on_stack, regs, // to
444 sp_inc, rax);
445
446 // Create the real frame. Below jump will then skip over the stack banging and frame
447 // setup code in the verified_inline_entry (which has a different real_frame_size).
448 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, sp_inc, false, ces->c1_needs_stack_repair());
449
450 jmp(verified_inline_entry_label);
451 return rt_call_offset;
452 }
453
454 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) {
455 // rbp, + 0: link
456 // + 1: return address
457 // + 2: argument with offset 0
458 // + 3: argument with offset 1
459 // + 4: ...
460
461 movptr(reg, Address(rbp, (offset_in_words + 2) * BytesPerWord));
462 }
463
464 #ifndef PRODUCT
465
466 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
467 if (!VerifyOops) return;
468 verify_oop_addr(Address(rsp, stack_offset));
469 }
470
471 void C1_MacroAssembler::verify_not_null_oop(Register r) {
472 if (!VerifyOops) return;
473 Label not_null;
474 testptr(r, r);
475 jcc(Assembler::notZero, not_null);
476 stop("non-null oop required");
477 bind(not_null);
478 verify_oop(r);
479 }
480
481 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) {
482 #ifdef ASSERT
483 if (inv_rax) movptr(rax, 0xDEAD);
484 if (inv_rbx) movptr(rbx, 0xDEAD);
485 if (inv_rcx) movptr(rcx, 0xDEAD);
486 if (inv_rdx) movptr(rdx, 0xDEAD);
487 if (inv_rsi) movptr(rsi, 0xDEAD);
488 if (inv_rdi) movptr(rdi, 0xDEAD);
489 #endif
490 }
491
492 #endif // ifndef PRODUCT