1 /*
2 * Copyright (c) 1999, 2021, 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 "gc/shared/barrierSet.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/frame.inline.hpp"
37 #include "runtime/os.hpp"
38 #include "runtime/sharedRuntime.hpp"
39 #include "runtime/stubRoutines.hpp"
40
41 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
42 const Register rklass_decode_tmp = LP64_ONLY(rscratch1) NOT_LP64(noreg);
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, rklass_decode_tmp);
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 return null_check_offset;
104 }
105
106
107 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
108 const int aligned_mask = BytesPerWord -1;
109 const int hdr_offset = oopDesc::mark_offset_in_bytes();
110 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction");
111 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
112 Label done;
113
114 // load displaced header
115 movptr(hdr, Address(disp_hdr, 0));
116 // if the loaded hdr is NULL we had recursive locking
117 testptr(hdr, hdr);
118 // if we had recursive locking, we are done
119 jcc(Assembler::zero, done);
120 // load object
121 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
122
123 verify_oop(obj);
124 // test if object header is pointing to the displaced header, and if so, restore
125 // the displaced header in the object - if the object header is not pointing to
126 // the displaced header, get the object header instead
127 MacroAssembler::lock(); // must be immediately before cmpxchg!
128 cmpxchgptr(hdr, Address(obj, hdr_offset));
129 // if the object header was not pointing to the displaced header,
130 // we do unlocking via runtime call
131 jcc(Assembler::notEqual, slow_case);
132 // done
133 bind(done);
134 }
135
136
137 // Defines obj, preserves var_size_in_bytes
138 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
139 if (UseTLAB) {
140 tlab_allocate(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
141 } else {
142 eden_allocate(noreg, obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
143 }
144 }
145
146
147 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
148 assert_different_registers(obj, klass, len);
149 Register tmp_encode_klass = LP64_ONLY(rscratch1) NOT_LP64(noreg);
150 if (EnableValhalla) {
151 // Need to copy markWord::prototype header for klass
152 assert_different_registers(obj, klass, len, t1, t2);
153 movptr(t1, Address(klass, Klass::prototype_header_offset()));
154 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
155 } else {
156 // This assumes that all prototype bits fit in an int32_t
157 movptr(Address(obj, oopDesc::mark_offset_in_bytes ()), (int32_t)(intptr_t)markWord::prototype().value());
158 }
159 #ifdef _LP64
160 if (UseCompressedClassPointers) { // Take care not to kill klass
161 movptr(t1, klass);
162 encode_klass_not_null(t1, tmp_encode_klass);
163 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
164 } else
165 #endif
166 {
167 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
168 }
169
170 if (len->is_valid()) {
171 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
172 }
173 #ifdef _LP64
174 else if (UseCompressedClassPointers) {
175 xorptr(t1, t1);
176 store_klass_gap(obj, t1);
177 }
178 #endif
179 }
180
181
182 // preserves obj, destroys len_in_bytes
183 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
184 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0");
185 Label done;
186
187 // len_in_bytes is positive and ptr sized
188 subptr(len_in_bytes, hdr_size_in_bytes);
189 jcc(Assembler::zero, done);
190 zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1);
191 bind(done);
192 }
193
194
195 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
196 assert(obj == rax, "obj must be in rax, for cmpxchg");
197 assert_different_registers(obj, t1, t2); // XXX really?
198 assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
199
200 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
201
202 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB);
203 }
204
205 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) {
206 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
207 "con_size_in_bytes is not multiple of alignment");
208 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
209
210 initialize_header(obj, klass, noreg, t1, t2);
211
212 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
213 // clear rest of allocated space
214 const Register t1_zero = t1;
215 const Register index = t2;
216 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below)
217 if (var_size_in_bytes != noreg) {
218 mov(index, var_size_in_bytes);
219 initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
220 } else if (con_size_in_bytes <= threshold) {
221 // use explicit null stores
222 // code size = 2 + 3*n bytes (n = number of fields to clear)
223 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
224 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
225 movptr(Address(obj, i), t1_zero);
226 } else if (con_size_in_bytes > hdr_size_in_bytes) {
227 // use loop to null out the fields
228 // code size = 16 bytes for even n (n = number of fields to clear)
229 // initialize last object field first if odd number of fields
230 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
231 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3);
232 // initialize last object field if constant size is odd
233 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
234 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
235 // initialize remaining object fields: rdx is a multiple of 2
236 { Label loop;
237 bind(loop);
238 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)),
239 t1_zero);
240 NOT_LP64(movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (2*BytesPerWord)),
241 t1_zero);)
242 decrement(index);
243 jcc(Assembler::notZero, loop);
244 }
245 }
246 }
247
248 if (CURRENT_ENV->dtrace_alloc_probes()) {
249 assert(obj == rax, "must be");
250 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
251 }
252
253 verify_oop(obj);
254 }
255
256 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, Address::ScaleFactor f, Register klass, Label& slow_case) {
257 assert(obj == rax, "obj must be in rax, for cmpxchg");
258 assert_different_registers(obj, len, t1, t2, klass);
259
260 // determine alignment mask
261 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
262
263 // check for negative or excessive length
264 cmpptr(len, (int32_t)max_array_allocation_length);
265 jcc(Assembler::above, slow_case);
266
267 const Register arr_size = t2; // okay to be the same
268 // align object end
269 movptr(arr_size, (int32_t)header_size * BytesPerWord + MinObjAlignmentInBytesMask);
270 lea(arr_size, Address(arr_size, len, f));
271 andptr(arr_size, ~MinObjAlignmentInBytesMask);
272
273 try_allocate(obj, arr_size, 0, t1, t2, slow_case);
274
275 initialize_header(obj, klass, len, t1, t2);
276
277 // clear rest of allocated space
278 const Register len_zero = len;
279 initialize_body(obj, arr_size, header_size * BytesPerWord, len_zero);
280
281 if (CURRENT_ENV->dtrace_alloc_probes()) {
282 assert(obj == rax, "must be");
283 call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
284 }
285
286 verify_oop(obj);
287 }
288
289
290
291 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
292 verify_oop(receiver);
293 // explicit NULL check not needed since load from [klass_offset] causes a trap
294 // check against inline cache
295 assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check");
296 int start_offset = offset();
297 Register tmp_load_klass = LP64_ONLY(rscratch2) NOT_LP64(noreg);
298
299 if (UseCompressedClassPointers) {
300 load_klass(rscratch1, receiver, tmp_load_klass);
301 cmpptr(rscratch1, iCache);
302 } else {
303 cmpptr(iCache, Address(receiver, oopDesc::klass_offset_in_bytes()));
304 }
305 // if icache check fails, then jump to runtime routine
306 // Note: RECEIVER must still contain the receiver!
307 jump_cc(Assembler::notEqual,
308 RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
309 const int ic_cmp_size = LP64_ONLY(10) NOT_LP64(9);
310 assert(UseCompressedClassPointers || offset() - start_offset == ic_cmp_size, "check alignment in emit_method_entry");
311 }
312
313 void C1_MacroAssembler::build_frame_helper(int frame_size_in_bytes, int sp_inc, bool needs_stack_repair) {
314 push(rbp);
315 if (PreserveFramePointer) {
316 mov(rbp, rsp);
317 }
318 #if !defined(_LP64) && defined(COMPILER2)
319 if (UseSSE < 2 && !CompilerConfig::is_c1_only_no_jvmci()) {
320 // c2 leaves fpu stack dirty. Clean it on entry
321 empty_FPU_stack();
322 }
323 #endif // !_LP64 && COMPILER2
324 decrement(rsp, frame_size_in_bytes);
325
326 if (needs_stack_repair) {
327 // Save stack increment (also account for fixed framesize and rbp)
328 assert((sp_inc & (StackAlignmentInBytes-1)) == 0, "stack increment not aligned");
329 int real_frame_size = sp_inc + frame_size_in_bytes + wordSize;
330 movptr(Address(rsp, frame_size_in_bytes - wordSize), real_frame_size);
331 }
332 }
333
334 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) {
335 if (has_scalarized_args) {
336 // Initialize orig_pc to detect deoptimization during buffering in the entry points
337 movptr(Address(rsp, sp_offset_for_orig_pc - frame_size_in_bytes - wordSize), 0);
338 }
339 if (!needs_stack_repair && verified_inline_entry_label != NULL) {
340 bind(*verified_inline_entry_label);
341 }
342 // Make sure there is enough stack space for this method's activation.
343 // Note that we do this before doing an enter(). This matches the
344 // ordering of C2's stack overflow check / rsp decrement and allows
345 // the SharedRuntime stack overflow handling to be consistent
346 // between the two compilers.
347 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
348 generate_stack_overflow_check(bang_size_in_bytes);
349
350 build_frame_helper(frame_size_in_bytes, 0, needs_stack_repair);
351
352 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
353 bs->nmethod_entry_barrier(this);
354
355 if (needs_stack_repair && verified_inline_entry_label != NULL) {
356 // Jump here from the scalarized entry points that require additional stack space
357 // for packing scalarized arguments and therefore already created the frame.
358 bind(*verified_inline_entry_label);
359 }
360 }
361
362 void C1_MacroAssembler::verified_entry() {
363 if (C1Breakpoint || VerifyFPU) {
364 // Verified Entry first instruction should be 5 bytes long for correct
365 // patching by patch_verified_entry().
366 //
367 // C1Breakpoint and VerifyFPU have one byte first instruction.
368 // Also first instruction will be one byte "push(rbp)" if stack banging
369 // code is not generated (see build_frame() above).
370 // For all these cases generate long instruction first.
371 fat_nop();
372 }
373 if (C1Breakpoint)int3();
374 // build frame
375 IA32_ONLY( verify_FPU(0, "method_entry"); )
376 }
377
378 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) {
379 assert(InlineTypePassFieldsAsArgs, "sanity");
380 // Make sure there is enough stack space for this method's activation.
381 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
382 generate_stack_overflow_check(bang_size_in_bytes);
383
384 GrowableArray<SigEntry>* sig = &ces->sig();
385 GrowableArray<SigEntry>* sig_cc = is_inline_ro_entry ? &ces->sig_cc_ro() : &ces->sig_cc();
386 VMRegPair* regs = ces->regs();
387 VMRegPair* regs_cc = is_inline_ro_entry ? ces->regs_cc_ro() : ces->regs_cc();
388 int args_on_stack = ces->args_on_stack();
389 int args_on_stack_cc = is_inline_ro_entry ? ces->args_on_stack_cc_ro() : ces->args_on_stack_cc();
390
391 assert(sig->length() <= sig_cc->length(), "Zero-sized inline class not allowed!");
392 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sig_cc->length());
393 int args_passed = sig->length();
394 int args_passed_cc = SigEntry::fill_sig_bt(sig_cc, sig_bt);
395
396 // Check if we need to extend the stack for packing
397 int sp_inc = 0;
398 if (args_on_stack > args_on_stack_cc) {
399 sp_inc = extend_stack_for_inline_args(args_on_stack);
400 }
401
402 // Create a temp frame so we can call into the runtime. It must be properly set up to accommodate GC.
403 build_frame_helper(frame_size_in_bytes, sp_inc, ces->c1_needs_stack_repair());
404
405 // Initialize orig_pc to detect deoptimization during buffering in below runtime call
406 movptr(Address(rsp, sp_offset_for_orig_pc), 0);
407
408 // The runtime call might safepoint, make sure nmethod entry barrier is executed
409 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
410 bs->nmethod_entry_barrier(this);
411
412 // FIXME -- call runtime only if we cannot in-line allocate all the incoming inline type args.
413 movptr(rbx, (intptr_t)(ces->method()));
414 if (is_inline_ro_entry) {
415 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_no_receiver_id)));
416 } else {
417 call(RuntimeAddress(Runtime1::entry_for(Runtime1::buffer_inline_args_id)));
418 }
419 int rt_call_offset = offset();
420
421 // Remove the temp frame
422 addptr(rsp, frame_size_in_bytes);
423 pop(rbp);
424
425 shuffle_inline_args(true, is_inline_ro_entry, sig_cc,
426 args_passed_cc, args_on_stack_cc, regs_cc, // from
427 args_passed, args_on_stack, regs, // to
428 sp_inc, rax);
429
430 if (ces->c1_needs_stack_repair()) {
431 // Create the real frame. Below jump will then skip over the stack banging and frame
432 // setup code in the verified_inline_entry (which has a different real_frame_size).
433 build_frame_helper(frame_size_in_bytes, sp_inc, true);
434 }
435
436 jmp(verified_inline_entry_label);
437 return rt_call_offset;
438 }
439
440 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) {
441 // rbp, + 0: link
442 // + 1: return address
443 // + 2: argument with offset 0
444 // + 3: argument with offset 1
445 // + 4: ...
446
447 movptr(reg, Address(rbp, (offset_in_words + 2) * BytesPerWord));
448 }
449
450 #ifndef PRODUCT
451
452 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
453 if (!VerifyOops) return;
454 verify_oop_addr(Address(rsp, stack_offset));
455 }
456
457 void C1_MacroAssembler::verify_not_null_oop(Register r) {
458 if (!VerifyOops) return;
459 Label not_null;
460 testptr(r, r);
461 jcc(Assembler::notZero, not_null);
462 stop("non-null oop required");
463 bind(not_null);
464 verify_oop(r);
465 }
466
467 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) {
468 #ifdef ASSERT
469 if (inv_rax) movptr(rax, 0xDEAD);
470 if (inv_rbx) movptr(rbx, 0xDEAD);
471 if (inv_rcx) movptr(rcx, 0xDEAD);
472 if (inv_rdx) movptr(rdx, 0xDEAD);
473 if (inv_rsi) movptr(rsi, 0xDEAD);
474 if (inv_rdi) movptr(rdi, 0xDEAD);
475 #endif
476 }
477
478 #endif // ifndef PRODUCT