1 /*
2 * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2012, 2018 SAP SE. 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 "asm/macroAssembler.inline.hpp"
28 #include "c1/c1_MacroAssembler.hpp"
29 #include "c1/c1_Runtime1.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/os.hpp"
37 #include "runtime/sharedRuntime.hpp"
38 #include "runtime/stubRoutines.hpp"
39 #include "utilities/align.hpp"
40 #include "utilities/macros.hpp"
41 #include "utilities/powerOfTwo.hpp"
42
43 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
44 const Register temp_reg = R12_scratch2;
45 Label Lmiss;
46
47 verify_oop(receiver, FILE_AND_LINE);
48 load_klass_check_null(temp_reg, receiver, &Lmiss);
49
50 if (TrapBasedICMissChecks && TrapBasedNullChecks) {
51 trap_ic_miss_check(temp_reg, iCache);
52 } else {
53 Label Lok;
54 cmpd(CCR0, temp_reg, iCache);
55 beq(CCR0, Lok);
56 bind(Lmiss);
57 //load_const_optimized(temp_reg, SharedRuntime::get_ic_miss_stub(), R0);
58 calculate_address_from_global_toc(temp_reg, SharedRuntime::get_ic_miss_stub(), true, true, false);
59 mtctr(temp_reg);
60 bctr();
61 align(32, 12);
62 bind(Lok);
63 }
64 }
65
66
67 void C1_MacroAssembler::explicit_null_check(Register base) {
68 Unimplemented();
69 }
70
71
72 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
73 // Avoid stack bang as first instruction. It may get overwritten by patch_verified_entry.
74 const Register return_pc = R20;
75 mflr(return_pc);
76
77 // Make sure there is enough stack space for this method's activation.
78 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
79 generate_stack_overflow_check(bang_size_in_bytes);
80
81 std(return_pc, _abi0(lr), R1_SP); // SP->lr = return_pc
82 push_frame(frame_size_in_bytes, R0); // SP -= frame_size_in_bytes
83
84 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
85 bs->nmethod_entry_barrier(this, R20);
86 }
87
88
89 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
90 if (breakAtEntry) illtrap();
91 // build frame
92 }
93
94
95 void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Register Rscratch, Label& slow_case) {
96 assert_different_registers(Rmark, Roop, Rbox, Rscratch);
97
98 Label done, cas_failed, slow_int;
99
100 // The following move must be the first instruction of emitted since debug
101 // information may be generated for it.
102 // Load object header.
103 ld(Rmark, oopDesc::mark_offset_in_bytes(), Roop);
104
105 verify_oop(Roop, FILE_AND_LINE);
106
107 // Save object being locked into the BasicObjectLock...
108 std(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);
109
110 if (DiagnoseSyncOnValueBasedClasses != 0) {
111 load_klass(Rscratch, Roop);
112 lwz(Rscratch, in_bytes(Klass::access_flags_offset()), Rscratch);
113 testbitdi(CCR0, R0, Rscratch, exact_log2(JVM_ACC_IS_VALUE_BASED_CLASS));
114 bne(CCR0, slow_int);
115 }
116
117 // ... and mark it unlocked.
118 ori(Rmark, Rmark, markWord::unlocked_value);
119
120 // Save unlocked object header into the displaced header location on the stack.
121 std(Rmark, BasicLock::displaced_header_offset_in_bytes(), Rbox);
122
123 // Compare object markWord with Rmark and if equal exchange Rscratch with object markWord.
124 assert(oopDesc::mark_offset_in_bytes() == 0, "cas must take a zero displacement");
125 cmpxchgd(/*flag=*/CCR0,
126 /*current_value=*/Rscratch,
127 /*compare_value=*/Rmark,
128 /*exchange_value=*/Rbox,
129 /*where=*/Roop/*+0==mark_offset_in_bytes*/,
130 MacroAssembler::MemBarRel | MacroAssembler::MemBarAcq,
131 MacroAssembler::cmpxchgx_hint_acquire_lock(),
132 noreg,
133 &cas_failed,
134 /*check without membar and ldarx first*/true);
135 // If compare/exchange succeeded we found an unlocked object and we now have locked it
136 // hence we are done.
137 b(done);
138
139 bind(slow_int);
140 b(slow_case); // far
141
142 bind(cas_failed);
143 // We did not find an unlocked object so see if this is a recursive case.
144 sub(Rscratch, Rscratch, R1_SP);
145 load_const_optimized(R0, (~(os::vm_page_size()-1) | markWord::lock_mask_in_place));
146 and_(R0/*==0?*/, Rscratch, R0);
147 std(R0/*==0, perhaps*/, BasicLock::displaced_header_offset_in_bytes(), Rbox);
148 bne(CCR0, slow_int);
149
150 bind(done);
151
152 inc_held_monitor_count(Rmark /*tmp*/);
153 }
154
155
156 void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {
157 assert_different_registers(Rmark, Roop, Rbox);
158
159 Label slow_int, done;
160
161 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
162 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
163
164 // Test first if it is a fast recursive unlock.
165 ld(Rmark, BasicLock::displaced_header_offset_in_bytes(), Rbox);
166 cmpdi(CCR0, Rmark, 0);
167 beq(CCR0, done);
168
169 // Load object.
170 ld(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);
171 verify_oop(Roop, FILE_AND_LINE);
172
173 // Check if it is still a light weight lock, this is is true if we see
174 // the stack address of the basicLock in the markWord of the object.
175 cmpxchgd(/*flag=*/CCR0,
176 /*current_value=*/R0,
177 /*compare_value=*/Rbox,
178 /*exchange_value=*/Rmark,
179 /*where=*/Roop,
180 MacroAssembler::MemBarRel,
181 MacroAssembler::cmpxchgx_hint_release_lock(),
182 noreg,
183 &slow_int);
184 b(done);
185 bind(slow_int);
186 b(slow_case); // far
187
188 // Done
189 bind(done);
190
191 dec_held_monitor_count(Rmark /*tmp*/);
192 }
193
194
195 void C1_MacroAssembler::try_allocate(
196 Register obj, // result: pointer to object after successful allocation
197 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
198 int con_size_in_bytes, // object size in bytes if known at compile time
199 Register t1, // temp register, must be global register for incr_allocated_bytes
200 Register t2, // temp register
201 Label& slow_case // continuation point if fast allocation fails
202 ) {
203 if (UseTLAB) {
204 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
205 } else {
206 b(slow_case);
207 }
208 }
209
210
211 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
212 assert_different_registers(obj, klass, len, t1, t2);
213 load_const_optimized(t1, (intx)markWord::prototype().value());
214 std(t1, oopDesc::mark_offset_in_bytes(), obj);
215 store_klass(obj, klass);
216 if (len->is_valid()) {
217 stw(len, arrayOopDesc::length_offset_in_bytes(), obj);
218 } else if (UseCompressedClassPointers) {
219 // Otherwise length is in the class gap.
220 store_klass_gap(obj);
221 }
222 }
223
224
225 void C1_MacroAssembler::initialize_body(Register base, Register index) {
226 assert_different_registers(base, index);
227 srdi(index, index, LogBytesPerWord);
228 clear_memory_doubleword(base, index);
229 }
230
231 void C1_MacroAssembler::initialize_body(Register obj, Register tmp1, Register tmp2,
232 int obj_size_in_bytes, int hdr_size_in_bytes) {
233 const int index = (obj_size_in_bytes - hdr_size_in_bytes) / HeapWordSize;
234
235 // 2x unrolled loop is shorter with more than 9 HeapWords.
236 if (index <= 9) {
237 clear_memory_unrolled(obj, index, R0, hdr_size_in_bytes);
238 } else {
239 const Register base_ptr = tmp1,
240 cnt_dwords = tmp2;
241
242 addi(base_ptr, obj, hdr_size_in_bytes); // Compute address of first element.
243 clear_memory_doubleword(base_ptr, cnt_dwords, R0, index);
244 }
245 }
246
247 void C1_MacroAssembler::allocate_object(
248 Register obj, // result: pointer to object after successful allocation
249 Register t1, // temp register
250 Register t2, // temp register
251 Register t3, // temp register
252 int hdr_size, // object header size in words
253 int obj_size, // object size in words
254 Register klass, // object klass
255 Label& slow_case // continuation point if fast allocation fails
256 ) {
257 assert_different_registers(obj, t1, t2, t3, klass);
258
259 // allocate space & initialize header
260 if (!is_simm16(obj_size * wordSize)) {
261 // Would need to use extra register to load
262 // object size => go the slow case for now.
263 b(slow_case);
264 return;
265 }
266 try_allocate(obj, noreg, obj_size * wordSize, t2, t3, slow_case);
267
268 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
269 }
270
271 void C1_MacroAssembler::initialize_object(
272 Register obj, // result: pointer to object after successful allocation
273 Register klass, // object klass
274 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
275 int con_size_in_bytes, // object size in bytes if known at compile time
276 Register t1, // temp register
277 Register t2 // temp register
278 ) {
279 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
280
281 initialize_header(obj, klass, noreg, t1, t2);
282
283 #ifdef ASSERT
284 {
285 lwz(t1, in_bytes(Klass::layout_helper_offset()), klass);
286 if (var_size_in_bytes != noreg) {
287 cmpw(CCR0, t1, var_size_in_bytes);
288 } else {
289 cmpwi(CCR0, t1, con_size_in_bytes);
290 }
291 asm_assert_eq("bad size in initialize_object");
292 }
293 #endif
294
295 // Initialize body.
296 if (var_size_in_bytes != noreg) {
297 // Use a loop.
298 addi(t1, obj, hdr_size_in_bytes); // Compute address of first element.
299 addi(t2, var_size_in_bytes, -hdr_size_in_bytes); // Compute size of body.
300 initialize_body(t1, t2);
301 } else if (con_size_in_bytes > hdr_size_in_bytes) {
302 // Use a loop.
303 initialize_body(obj, t1, t2, con_size_in_bytes, hdr_size_in_bytes);
304 }
305
306 if (CURRENT_ENV->dtrace_alloc_probes()) {
307 Unimplemented();
308 // assert(obj == O0, "must be");
309 // call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
310 // relocInfo::runtime_call_type);
311 }
312
313 verify_oop(obj, FILE_AND_LINE);
314 }
315
316
317 void C1_MacroAssembler::allocate_array(
318 Register obj, // result: pointer to array after successful allocation
319 Register len, // array length
320 Register t1, // temp register
321 Register t2, // temp register
322 Register t3, // temp register
323 int hdr_size, // object header size in words
324 int elt_size, // element size in bytes
325 Register klass, // object klass
326 Label& slow_case // continuation point if fast allocation fails
327 ) {
328 assert_different_registers(obj, len, t1, t2, t3, klass);
329
330 // Determine alignment mask.
331 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
332 int log2_elt_size = exact_log2(elt_size);
333
334 // Check for negative or excessive length.
335 size_t max_length = max_array_allocation_length >> log2_elt_size;
336 if (UseTLAB) {
337 size_t max_tlab = align_up(ThreadLocalAllocBuffer::max_size() >> log2_elt_size, 64*K);
338 if (max_tlab < max_length) { max_length = max_tlab; }
339 }
340 load_const_optimized(t1, max_length);
341 cmpld(CCR0, len, t1);
342 bc_far_optimized(Assembler::bcondCRbiIs1, bi0(CCR0, Assembler::greater), slow_case);
343
344 // compute array size
345 // note: If 0 <= len <= max_length, len*elt_size + header + alignment is
346 // smaller or equal to the largest integer; also, since top is always
347 // aligned, we can do the alignment here instead of at the end address
348 // computation.
349 const Register arr_size = t1;
350 Register arr_len_in_bytes = len;
351 if (elt_size != 1) {
352 sldi(t1, len, log2_elt_size);
353 arr_len_in_bytes = t1;
354 }
355 addi(arr_size, arr_len_in_bytes, hdr_size * wordSize + MinObjAlignmentInBytesMask); // Add space for header & alignment.
356 clrrdi(arr_size, arr_size, LogMinObjAlignmentInBytes); // Align array size.
357
358 // Allocate space & initialize header.
359 try_allocate(obj, arr_size, 0, t2, t3, slow_case);
360 initialize_header(obj, klass, len, t2, t3);
361
362 // Initialize body.
363 const Register base = t2;
364 const Register index = t3;
365 addi(base, obj, hdr_size * wordSize); // compute address of first element
366 addi(index, arr_size, -(hdr_size * wordSize)); // compute index = number of bytes to clear
367 initialize_body(base, index);
368
369 if (CURRENT_ENV->dtrace_alloc_probes()) {
370 Unimplemented();
371 //assert(obj == O0, "must be");
372 //call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
373 // relocInfo::runtime_call_type);
374 }
375
376 verify_oop(obj, FILE_AND_LINE);
377 }
378
379
380 #ifndef PRODUCT
381
382 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
383 verify_oop_addr((RegisterOrConstant)stack_offset, R1_SP, "broken oop in stack slot");
384 }
385
386 void C1_MacroAssembler::verify_not_null_oop(Register r) {
387 Label not_null;
388 cmpdi(CCR0, r, 0);
389 bne(CCR0, not_null);
390 stop("non-null oop required");
391 bind(not_null);
392 verify_oop(r, FILE_AND_LINE);
393 }
394
395 #endif // PRODUCT
396
397 void C1_MacroAssembler::null_check(Register r, Label* Lnull) {
398 if (TrapBasedNullChecks) { // SIGTRAP based
399 trap_null_check(r);
400 } else { // explicit
401 //const address exception_entry = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);
402 assert(Lnull != NULL, "must have Label for explicit check");
403 cmpdi(CCR0, r, 0);
404 bc_far_optimized(Assembler::bcondCRbiIs1, bi0(CCR0, Assembler::equal), *Lnull);
405 }
406 }
407
408 address C1_MacroAssembler::call_c_with_frame_resize(address dest, int frame_resize) {
409 if (frame_resize) { resize_frame(-frame_resize, R0); }
410 #if defined(ABI_ELFv2)
411 address return_pc = call_c(dest, relocInfo::runtime_call_type);
412 #else
413 address return_pc = call_c(CAST_FROM_FN_PTR(FunctionDescriptor*, dest), relocInfo::runtime_call_type);
414 #endif
415 if (frame_resize) { resize_frame(frame_resize, R0); }
416 return return_pc;
417 }