1 /*
2 * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2016 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/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/os.hpp"
39 #include "runtime/sharedRuntime.hpp"
40 #include "runtime/stubRoutines.hpp"
41 #include "utilities/macros.hpp"
42
43 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
44 Label ic_miss, ic_hit;
45 verify_oop(receiver, FILE_AND_LINE);
46 int klass_offset = oopDesc::klass_offset_in_bytes();
47
48 if (!ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(klass_offset)) {
49 if (VM_Version::has_CompareBranch()) {
50 z_cgij(receiver, 0, Assembler::bcondEqual, ic_miss);
51 } else {
52 z_ltgr(receiver, receiver);
53 z_bre(ic_miss);
54 }
55 }
56
57 compare_klass_ptr(iCache, klass_offset, receiver, false);
58 z_bre(ic_hit);
59
60 // If icache check fails, then jump to runtime routine.
61 // Note: RECEIVER must still contain the receiver!
62 load_const_optimized(Z_R1_scratch, AddressLiteral(SharedRuntime::get_ic_miss_stub()));
63 z_br(Z_R1_scratch);
64 align(CodeEntryAlignment);
65 bind(ic_hit);
66 }
67
68 void C1_MacroAssembler::explicit_null_check(Register base) {
69 ShouldNotCallThis(); // unused
70 }
71
72 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
73 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
74 generate_stack_overflow_check(bang_size_in_bytes);
75 save_return_pc();
76 push_frame(frame_size_in_bytes);
77
78 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
79 bs->nmethod_entry_barrier(this);
80 }
81
82 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
83 if (breakAtEntry) z_illtrap(0xC1);
84 }
85
86 void C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
87 const int hdr_offset = oopDesc::mark_offset_in_bytes();
88 assert_different_registers(hdr, obj, disp_hdr);
89
90 verify_oop(obj, FILE_AND_LINE);
91
92 // Load object header.
93 z_lg(hdr, Address(obj, hdr_offset));
94
95 // Save object being locked into the BasicObjectLock...
96 z_stg(obj, Address(disp_hdr, BasicObjectLock::obj_offset()));
97
98 if (DiagnoseSyncOnValueBasedClasses != 0) {
99 load_klass(Z_R1_scratch, obj);
100 testbit(Address(Z_R1_scratch, Klass::access_flags_offset()), exact_log2(JVM_ACC_IS_VALUE_BASED_CLASS));
101 z_btrue(slow_case);
102 }
103
104 assert(LockingMode != LM_MONITOR, "LM_MONITOR is already handled, by emit_lock()");
105
106 if (LockingMode == LM_LIGHTWEIGHT) {
107 Unimplemented();
108 } else if (LockingMode == LM_LEGACY) {
109 NearLabel done;
110 // and mark it as unlocked.
111 z_oill(hdr, markWord::unlocked_value);
112 // Save unlocked object header into the displaced header location on the stack.
113 z_stg(hdr, Address(disp_hdr, (intptr_t) 0));
114 // Test if object header is still the same (i.e. unlocked), and if so, store the
115 // displaced header address in the object header. If it is not the same, get the
116 // object header instead.
117 z_csg(hdr, disp_hdr, hdr_offset, obj);
118 // If the object header was the same, we're done.
119 branch_optimized(Assembler::bcondEqual, done);
120 // If the object header was not the same, it is now in the hdr register.
121 // => Test if it is a stack pointer into the same stack (recursive locking), i.e.:
122 //
123 // 1) (hdr & markWord::lock_mask_in_place) == 0
124 // 2) rsp <= hdr
125 // 3) hdr <= rsp + page_size
126 //
127 // These 3 tests can be done by evaluating the following expression:
128 //
129 // (hdr - Z_SP) & (~(page_size-1) | markWord::lock_mask_in_place)
130 //
131 // assuming both the stack pointer and page_size have their least
132 // significant 2 bits cleared and page_size is a power of 2
133 z_sgr(hdr, Z_SP);
134
135 load_const_optimized(Z_R0_scratch, (~(os::vm_page_size() - 1) | markWord::lock_mask_in_place));
136 z_ngr(hdr, Z_R0_scratch); // AND sets CC (result eq/ne 0).
137 // For recursive locking, the result is zero. => Save it in the displaced header
138 // location (null in the displaced hdr location indicates recursive locking).
139 z_stg(hdr, Address(disp_hdr, (intptr_t) 0));
140 // Otherwise we don't care about the result and handle locking via runtime call.
141 branch_optimized(Assembler::bcondNotZero, slow_case);
142 // done
143 bind(done);
144 }
145 }
146
147 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
148 const int aligned_mask = BytesPerWord -1;
149 const int hdr_offset = oopDesc::mark_offset_in_bytes();
150 assert_different_registers(hdr, obj, disp_hdr);
151 NearLabel done;
152
153 if (LockingMode != LM_LIGHTWEIGHT) {
154 // Load displaced header.
155 z_ltg(hdr, Address(disp_hdr, (intptr_t) 0));
156 // If the loaded hdr is null we had recursive locking, and we are done.
157 z_bre(done);
158 }
159
160 // Load object.
161 z_lg(obj, Address(disp_hdr, BasicObjectLock::obj_offset()));
162 verify_oop(obj, FILE_AND_LINE);
163
164 if (LockingMode == LM_LIGHTWEIGHT) {
165 Unimplemented();
166 } else {
167 // Test if object header is pointing to the displaced header, and if so, restore
168 // the displaced header in the object. If the object header is not pointing to
169 // the displaced header, get the object header instead.
170 z_csg(disp_hdr, hdr, hdr_offset, obj);
171 // If the object header was not pointing to the displaced header,
172 // we do unlocking via runtime call.
173 branch_optimized(Assembler::bcondNotEqual, slow_case);
174 // done
175 }
176 bind(done);
177 }
178
179 void C1_MacroAssembler::try_allocate(
180 Register obj, // result: Pointer to object after successful allocation.
181 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
182 int con_size_in_bytes, // Object size in bytes if known at compile time.
183 Register t1, // Temp register: Must be global register for incr_allocated_bytes.
184 Label& slow_case // Continuation point if fast allocation fails.
185 ) {
186 if (UseTLAB) {
187 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
188 } else {
189 // Allocation in shared Eden not implemented, because sapjvm allocation trace does not allow it.
190 z_brul(slow_case);
191 }
192 }
193
194 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register Rzero, Register t1) {
195 assert_different_registers(obj, klass, len, t1, Rzero);
196 // This assumes that all prototype bits fit in an int32_t.
197 load_const_optimized(t1, (intx)markWord::prototype().value());
198 z_stg(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
199
200 if (len->is_valid()) {
201 // Length will be in the klass gap, if one exists.
202 z_st(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
203 } else if (UseCompressedClassPointers) {
204 store_klass_gap(Rzero, obj); // Zero klass gap for compressed oops.
205 }
206 store_klass(klass, obj, t1);
207 }
208
209 void C1_MacroAssembler::initialize_body(Register objectFields, Register len_in_bytes, Register Rzero) {
210 Label done;
211 assert_different_registers(objectFields, len_in_bytes, Rzero);
212
213 // Initialize object fields.
214 // See documentation for MVCLE instruction!!!
215 assert(objectFields->encoding()%2==0, "objectFields must be an even register");
216 assert(len_in_bytes->encoding() == (objectFields->encoding()+1), "objectFields and len_in_bytes must be a register pair");
217 assert(Rzero->encoding()%2==1, "Rzero must be an odd register");
218
219 // Use Rzero as src length, then mvcle will copy nothing
220 // and fill the object with the padding value 0.
221 move_long_ext(objectFields, as_Register(Rzero->encoding()-1), 0);
222 bind(done);
223 }
224
225 void C1_MacroAssembler::allocate_object(
226 Register obj, // Result: pointer to object after successful allocation.
227 Register t1, // temp register
228 Register t2, // temp register: Must be a global register for try_allocate.
229 int hdr_size, // object header size in words
230 int obj_size, // object size in words
231 Register klass, // object klass
232 Label& slow_case // Continuation point if fast allocation fails.
233 ) {
234 assert_different_registers(obj, t1, t2, klass);
235
236 // Allocate space and initialize header.
237 try_allocate(obj, noreg, obj_size * wordSize, t1, slow_case);
238
239 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
240 }
241
242 void C1_MacroAssembler::initialize_object(
243 Register obj, // result: Pointer to object after successful allocation.
244 Register klass, // object klass
245 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
246 int con_size_in_bytes, // Object size in bytes if known at compile time.
247 Register t1, // temp register
248 Register t2 // temp register
249 ) {
250 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
251 "con_size_in_bytes is not multiple of alignment");
252 assert(var_size_in_bytes == noreg, "not implemented");
253 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
254
255 const Register Rzero = t2;
256
257 z_xgr(Rzero, Rzero);
258 initialize_header(obj, klass, noreg, Rzero, t1);
259
260 // Clear rest of allocated space.
261 const int threshold = 4 * BytesPerWord;
262 if (con_size_in_bytes <= threshold) {
263 // Use explicit null stores.
264 // code size = 6*n bytes (n = number of fields to clear)
265 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
266 z_stg(Rzero, Address(obj, i));
267 } else {
268 // Code size generated by initialize_body() is 16.
269 Register object_fields = Z_R0_scratch;
270 Register len_in_bytes = Z_R1_scratch;
271 z_la(object_fields, hdr_size_in_bytes, obj);
272 load_const_optimized(len_in_bytes, con_size_in_bytes - hdr_size_in_bytes);
273 initialize_body(object_fields, len_in_bytes, Rzero);
274 }
275
276 // Dtrace support is unimplemented.
277 // if (CURRENT_ENV->dtrace_alloc_probes()) {
278 // assert(obj == rax, "must be");
279 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id)));
280 // }
281
282 verify_oop(obj, FILE_AND_LINE);
283 }
284
285 void C1_MacroAssembler::allocate_array(
286 Register obj, // result: Pointer to array after successful allocation.
287 Register len, // array length
288 Register t1, // temp register
289 Register t2, // temp register
290 int hdr_size, // object header size in words
291 int elt_size, // element size in bytes
292 Register klass, // object klass
293 Label& slow_case // Continuation point if fast allocation fails.
294 ) {
295 assert_different_registers(obj, len, t1, t2, klass);
296
297 // Determine alignment mask.
298 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
299
300 // Check for negative or excessive length.
301 compareU64_and_branch(len, (int32_t)max_array_allocation_length, bcondHigh, slow_case);
302
303 // Compute array size.
304 // Note: If 0 <= len <= max_length, len*elt_size + header + alignment is
305 // smaller or equal to the largest integer. Also, since top is always
306 // aligned, we can do the alignment here instead of at the end address
307 // computation.
308 const Register arr_size = t2;
309 switch (elt_size) {
310 case 1: lgr_if_needed(arr_size, len); break;
311 case 2: z_sllg(arr_size, len, 1); break;
312 case 4: z_sllg(arr_size, len, 2); break;
313 case 8: z_sllg(arr_size, len, 3); break;
314 default: ShouldNotReachHere();
315 }
316 add2reg(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask); // Add space for header & alignment.
317 z_nill(arr_size, (~MinObjAlignmentInBytesMask) & 0xffff); // Align array size.
318
319 try_allocate(obj, arr_size, 0, t1, slow_case);
320
321 initialize_header(obj, klass, len, noreg, t1);
322
323 // Clear rest of allocated space.
324 Label done;
325 Register object_fields = t1;
326 Register Rzero = Z_R1_scratch;
327 z_aghi(arr_size, -(hdr_size * BytesPerWord));
328 z_bre(done); // Jump if size of fields is zero.
329 z_la(object_fields, hdr_size * BytesPerWord, obj);
330 z_xgr(Rzero, Rzero);
331 initialize_body(object_fields, arr_size, Rzero);
332 bind(done);
333
334 // Dtrace support is unimplemented.
335 // if (CURRENT_ENV->dtrace_alloc_probes()) {
336 // assert(obj == rax, "must be");
337 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id)));
338 // }
339
340 verify_oop(obj, FILE_AND_LINE);
341 }
342
343
344 #ifndef PRODUCT
345
346 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
347 if (!VerifyOops) return;
348 verify_oop_addr(Address(Z_SP, stack_offset), FILE_AND_LINE);
349 }
350
351 void C1_MacroAssembler::verify_not_null_oop(Register r) {
352 if (!VerifyOops) return;
353 NearLabel not_null;
354 compareU64_and_branch(r, (intptr_t)0, bcondNotEqual, not_null);
355 stop("non-null oop required");
356 bind(not_null);
357 verify_oop(r, FILE_AND_LINE);
358 }
359
360 void C1_MacroAssembler::invalidate_registers(Register preserve1,
361 Register preserve2,
362 Register preserve3) {
363 Register dead_value = noreg;
364 for (int i = 0; i < FrameMap::nof_cpu_regs; i++) {
365 Register r = as_Register(i);
366 if (r != preserve1 && r != preserve2 && r != preserve3 && r != Z_SP && r != Z_thread) {
367 if (dead_value == noreg) {
368 load_const_optimized(r, 0xc1dead);
369 dead_value = r;
370 } else {
371 z_lgr(r, dead_value);
372 }
373 }
374 }
375 }
376
377 #endif // !PRODUCT