1 /*
2 * Copyright (c) 1999, 2022, 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.
22 *
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
42 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
43 const int aligned_mask = BytesPerWord -1;
44 const int hdr_offset = oopDesc::mark_offset_in_bytes();
45 assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
46 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
47 Label done;
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_in_bytes()), 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 // and mark it as unlocked
67 orptr(hdr, markWord::unlocked_value);
68 if (EnableValhalla) {
69 // Mask inline_type bit such that we go to the slow path if object is an inline type
70 andptr(hdr, ~((int) markWord::inline_type_bit_in_place));
71 }
72 // save unlocked object header into the displaced header location on the stack
73 movptr(Address(disp_hdr, 0), hdr);
74 // test if object header is still the same (i.e. unlocked), and if so, store the
75 // displaced header address in the object header - if it is not the same, get the
76 // object header instead
77 MacroAssembler::lock(); // must be immediately before cmpxchg!
78 cmpxchgptr(disp_hdr, Address(obj, hdr_offset));
79 // if the object header was the same, we're done
80 jcc(Assembler::equal, done);
81 // if the object header was not the same, it is now in the hdr register
82 // => test if it is a stack pointer into the same stack (recursive locking), i.e.:
83 //
84 // 1) (hdr & aligned_mask) == 0
85 // 2) rsp <= hdr
86 // 3) hdr <= rsp + page_size
87 //
88 // these 3 tests can be done by evaluating the following expression:
89 //
90 // (hdr - rsp) & (aligned_mask - page_size)
91 //
92 // assuming both the stack pointer and page_size have their least
93 // significant 2 bits cleared and page_size is a power of 2
94 subptr(hdr, rsp);
95 andptr(hdr, aligned_mask - os::vm_page_size());
96 // for recursive locking, the result is zero => save it in the displaced header
97 // location (NULL in the displaced hdr location indicates recursive locking)
98 movptr(Address(disp_hdr, 0), hdr);
99 // otherwise we don't care about the result and handle locking via runtime call
100 jcc(Assembler::notZero, slow_case);
101 // done
102 bind(done);
103
104 inc_held_monitor_count();
105
106 return null_check_offset;
107 }
108
109 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
110 const int aligned_mask = BytesPerWord -1;
111 const int hdr_offset = oopDesc::mark_offset_in_bytes();
112 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction");
113 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
114 Label done;
115
116 // load displaced header
117 movptr(hdr, Address(disp_hdr, 0));
118 // if the loaded hdr is NULL we had recursive locking
119 testptr(hdr, hdr);
120 // if we had recursive locking, we are done
121 jcc(Assembler::zero, done);
122 // load object
123 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
124
125 verify_oop(obj);
126 // test if object header is pointing to the displaced header, and if so, restore
127 // the displaced header in the object - if the object header is not pointing to
128 // the displaced header, get the object header instead
129 MacroAssembler::lock(); // must be immediately before cmpxchg!
130 cmpxchgptr(hdr, Address(obj, hdr_offset));
131 // if the object header was not pointing to the displaced header,
132 // we do unlocking via runtime call
133 jcc(Assembler::notEqual, slow_case);
134 // done
135 bind(done);
136
137 dec_held_monitor_count();
138 }
139
140
141 // Defines obj, preserves var_size_in_bytes
142 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
143 if (UseTLAB) {
144 tlab_allocate(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
145 } else {
146 jmp(slow_case);
147 }
148 }
149
150
151 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
152 assert_different_registers(obj, klass, len);
153 if (EnableValhalla) {
154 // Need to copy markWord::prototype header for klass
155 assert_different_registers(obj, klass, len, t1, t2);
156 movptr(t1, Address(klass, Klass::prototype_header_offset()));
157 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
158 } else {
159 // This assumes that all prototype bits fit in an int32_t
160 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value()));
161 }
162 #ifdef _LP64
163 if (UseCompressedClassPointers) { // Take care not to kill klass
164 movptr(t1, klass);
165 encode_klass_not_null(t1, rscratch1);
166 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
167 } else
168 #endif
169 {
170 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
171 }
172
173 if (len->is_valid()) {
174 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
175 }
176 #ifdef _LP64
177 else if (UseCompressedClassPointers) {
178 xorptr(t1, t1);
179 store_klass_gap(obj, t1);
180 }
181 #endif
182 }
183
184
185 // preserves obj, destroys len_in_bytes
186 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
187 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0");
188 Label done;
189
190 // len_in_bytes is positive and ptr sized
191 subptr(len_in_bytes, hdr_size_in_bytes);
192 zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1);
193 bind(done);
194 }
195
196
197 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
198 assert(obj == rax, "obj must be in rax, for cmpxchg");
199 assert_different_registers(obj, t1, t2); // XXX really?
200 assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
201
202 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
203
204 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB);
205 }
206
207 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) {
208 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
209 "con_size_in_bytes is not multiple of alignment");
210 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
211
212 initialize_header(obj, klass, noreg, t1, t2);
213
214 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
215 // clear rest of allocated space
216 const Register t1_zero = t1;
217 const Register index = t2;
218 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below)
219 if (var_size_in_bytes != noreg) {
220 mov(index, var_size_in_bytes);
221 initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
222 } else if (con_size_in_bytes <= threshold) {
223 // use explicit null stores
224 // code size = 2 + 3*n bytes (n = number of fields to clear)
225 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
226 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
227 movptr(Address(obj, i), t1_zero);
228 } else if (con_size_in_bytes > hdr_size_in_bytes) {
229 // use loop to null out the fields
230 // code size = 16 bytes for even n (n = number of fields to clear)
231 // initialize last object field first if odd number of fields
232 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
233 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3);
234 // initialize last object field if constant size is odd
235 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
236 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
237 // initialize remaining object fields: rdx is a multiple of 2
238 { Label loop;
239 bind(loop);
240 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)),
241 t1_zero);
242 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)),
243 t1_zero);)
244 decrement(index);
245 jcc(Assembler::notZero, loop);
246 }
247 }
248 }
249
250 if (CURRENT_ENV->dtrace_alloc_probes()) {
251 assert(obj == rax, "must be");
252 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
253 }
254
255 verify_oop(obj);
256 }
257
258 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, Address::ScaleFactor f, Register klass, Label& slow_case) {
259 assert(obj == rax, "obj must be in rax, for cmpxchg");
260 assert_different_registers(obj, len, t1, t2, klass);
261
262 // determine alignment mask
263 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
264
265 // check for negative or excessive length
266 cmpptr(len, checked_cast<int32_t>(max_array_allocation_length));
267 jcc(Assembler::above, slow_case);
268
269 const Register arr_size = t2; // okay to be the same
270 // align object end
271 movptr(arr_size, header_size * BytesPerWord + MinObjAlignmentInBytesMask);
272 lea(arr_size, Address(arr_size, len, f));
273 andptr(arr_size, ~MinObjAlignmentInBytesMask);
274
275 try_allocate(obj, arr_size, 0, t1, t2, slow_case);
276
277 initialize_header(obj, klass, len, t1, t2);
278
279 // clear rest of allocated space
280 const Register len_zero = len;
281 initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero);
282
283 if (CURRENT_ENV->dtrace_alloc_probes()) {
284 assert(obj == rax, "must be");
285 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
286 }
287
288 verify_oop(obj);
289 }
290
291
292
293 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
294 verify_oop(receiver);
295 // explicit NULL check not needed since load from [klass_offset] causes a trap
296 // check against inline cache
297 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check");
298 int start_offset = offset();
299
300 if (UseCompressedClassPointers) {
301 load_klass(rscratch1, receiver, rscratch2);
302 cmpptr(rscratch1, iCache);
303 } else {
304 cmpptr(iCache, Address(receiver, oopDesc::klass_offset_in_bytes()));
305 }
306 // if icache check fails, then jump to runtime routine
307 // Note: RECEIVER must still contain the receiver!
308 jump_cc(Assembler::notEqual,
309 RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
310 const int ic_cmp_size = LP64_ONLY(10) NOT_LP64(9);
311 assert(UseCompressedClassPointers || offset() - start_offset == ic_cmp_size, "check alignment in emit_method_entry");
312 }
313
314 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) {
315 push(rbp);
316 if (PreserveFramePointer) {
317 mov(rbp, rsp);
318 }
319 #if !defined(_LP64) && defined(COMPILER2)
320 if (UseSSE < 2 && !CompilerConfig::is_c1_only_no_jvmci()) {
321 // c2 leaves fpu stack dirty. Clean it on entry
322 empty_FPU_stack();
323 }
324 #endif // !_LP64 && COMPILER2
325 decrement(rsp, frame_size_in_bytes);
326
327 if (needs_stack_repair) {
328 // Save stack increment (also account for fixed framesize and rbp)
329 assert((sp_inc & (StackAlignmentInBytes-1)) == 0, "stack increment not aligned");
330 int real_frame_size = sp_inc + frame_size_in_bytes + wordSize;
331 movptr(Address(rsp, frame_size_in_bytes - wordSize), real_frame_size);
332 }
333 if (reset_orig_pc) {
334 // Zero orig_pc to detect deoptimization during buffering in the entry points
335 movptr(Address(rsp, sp_offset_for_orig_pc), 0);
336 }
337 }
338
339 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) {
340 // Make sure there is enough stack space for this method's activation.
341 // Note that we do this before doing an enter(). This matches the
342 // ordering of C2's stack overflow check / rsp decrement and allows
343 // the SharedRuntime stack overflow handling to be consistent
344 // between the two compilers.
345 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
346 generate_stack_overflow_check(bang_size_in_bytes);
347
348 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, has_scalarized_args, needs_stack_repair);
349
350 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
351 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub
352 bs->nmethod_entry_barrier(this, NULL /* slow_path */, NULL /* continuation */);
353
354 if (verified_inline_entry_label != NULL) {
355 // Jump here from the scalarized entry points that already created the frame.
356 bind(*verified_inline_entry_label);
357 }
358 }
359
360 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
361 if (breakAtEntry || VerifyFPU) {
362 // Verified Entry first instruction should be 5 bytes long for correct
363 // patching by patch_verified_entry().
364 //
365 // Breakpoint and VerifyFPU have one byte first instruction.
366 // Also first instruction will be one byte "push(rbp)" if stack banging
367 // code is not generated (see build_frame() above).
368 // For all these cases generate long instruction first.
369 fat_nop();
370 }
371 if (breakAtEntry) int3();
372 // build frame
373 IA32_ONLY( verify_FPU(0, "method_entry"); )
374 }
375
376 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) {
377 assert(InlineTypePassFieldsAsArgs, "sanity");
378 // Make sure there is enough stack space for this method's activation.
379 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
380 generate_stack_overflow_check(bang_size_in_bytes);
381
382 GrowableArray<SigEntry>* sig = &ces->sig();
383 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? &ces->sig_cc_ro() : &ces->sig_cc();
384 VMRegPair* regs = ces->regs();
385 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc();
386 int args_on_stack = ces->args_on_stack();
387 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc();
388
389 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!");
390 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length());
391 int args_passed = sig->length();
392 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt);
393
394 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC.
395 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, 0, true, ces->c1_needs_stack_repair());
396
397 // The runtime call might safepoint, make sure nmethod entry barrier is executed
398 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
399 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub
400 bs->nmethod_entry_barrier(this, NULL /* slow_path */, NULL /* continuation */);
401
402 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args.
403 movptr(rbx, (intptr_t)(ces->method()));
404 if (is_inline_ro_entry) {
405 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_no_receiver_id)));
406 } else {
407 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_id)));
408 }
409 int rt_call_offset = offset();
410
411 // Remove the temp frame
412 addptr(rsp, frame_size_in_bytes);
413 pop(rbp);
414
415 // Check if we need to extend the stack for packing
416 int sp_inc = 0;
417 if (args_on_stack > args_on_stack_cc) {
418 sp_inc = extend_stack_for_inline_args(args_on_stack);
419 }
420
421 shuffle_inline_args(true, is_inline_ro_entry, sig_cc,
422 args_passed_cc, args_on_stack_cc, regs_cc, // from
423 args_passed, args_on_stack, regs, // to
424 sp_inc, rax);
425
426 // Create the real frame. Below jump will then skip over the stack banging and frame
427 // setup code in the verified_inline_entry (which has a different real_frame_size).
428 build_frame_helper(frame_size_in_bytes, sp_offset_for_orig_pc, sp_inc, false, ces->c1_needs_stack_repair());
429
430 jmp(verified_inline_entry_label);
431 return rt_call_offset;
432 }
433
434 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) {
435 // rbp, + 0: link
436 // + 1: return address
437 // + 2: argument with offset 0
438 // + 3: argument with offset 1
439 // + 4: ...
440
441 movptr(reg, Address(rbp, (offset_in_words + 2) * BytesPerWord));
442 }
443
444 #ifndef PRODUCT
445
446 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
447 if (!VerifyOops) return;
448 verify_oop_addr(Address(rsp, stack_offset));
449 }
450
451 void C1_MacroAssembler::verify_not_null_oop(Register r) {
452 if (!VerifyOops) return;
453 Label not_null;
454 testptr(r, r);
455 jcc(Assembler::notZero, not_null);
456 stop("non-null oop required");
457 bind(not_null);
458 verify_oop(r);
459 }
460
461 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) {
462 #ifdef ASSERT
463 if (inv_rax) movptr(rax, 0xDEAD);
464 if (inv_rbx) movptr(rbx, 0xDEAD);
465 if (inv_rcx) movptr(rcx, 0xDEAD);
466 if (inv_rdx) movptr(rdx, 0xDEAD);
467 if (inv_rsi) movptr(rsi, 0xDEAD);
468 if (inv_rdi) movptr(rdi, 0xDEAD);
469 #endif
470 }
471
472 #endif // ifndef PRODUCT