1 /*
2 * Copyright (c) 2016, 2021, 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, int max_monitors) {
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 NearLabel done;
90
91 verify_oop(obj, FILE_AND_LINE);
92
93 // Load object header.
94 z_lg(hdr, Address(obj, hdr_offset));
95
96 // Save object being locked into the BasicObjectLock...
97 z_stg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
98
99 if (DiagnoseSyncOnValueBasedClasses != 0) {
100 load_klass(Z_R1_scratch, obj);
101 testbit(Address(Z_R1_scratch, Klass::access_flags_offset()), exact_log2(JVM_ACC_IS_VALUE_BASED_CLASS));
102 z_btrue(slow_case);
103 }
104
105 // and mark it as unlocked.
106 z_oill(hdr, markWord::unlocked_value);
107 // Save unlocked object header into the displaced header location on the stack.
108 z_stg(hdr, Address(disp_hdr, (intptr_t)0));
109 // Test if object header is still the same (i.e. unlocked), and if so, store the
110 // displaced header address in the object header. If it is not the same, get the
111 // object header instead.
112 z_csg(hdr, disp_hdr, hdr_offset, obj);
113 // If the object header was the same, we're done.
114 branch_optimized(Assembler::bcondEqual, done);
115 // If the object header was not the same, it is now in the hdr register.
116 // => Test if it is a stack pointer into the same stack (recursive locking), i.e.:
117 //
118 // 1) (hdr & markWord::lock_mask_in_place) == 0
119 // 2) rsp <= hdr
120 // 3) hdr <= rsp + page_size
121 //
122 // These 3 tests can be done by evaluating the following expression:
123 //
124 // (hdr - Z_SP) & (~(page_size-1) | markWord::lock_mask_in_place)
125 //
126 // assuming both the stack pointer and page_size have their least
127 // significant 2 bits cleared and page_size is a power of 2
128 z_sgr(hdr, Z_SP);
129
130 load_const_optimized(Z_R0_scratch, (~(os::vm_page_size()-1) | markWord::lock_mask_in_place));
131 z_ngr(hdr, Z_R0_scratch); // AND sets CC (result eq/ne 0).
132 // For recursive locking, the result is zero. => Save it in the displaced header
133 // location (NULL in the displaced hdr location indicates recursive locking).
134 z_stg(hdr, Address(disp_hdr, (intptr_t)0));
135 // Otherwise we don't care about the result and handle locking via runtime call.
136 branch_optimized(Assembler::bcondNotZero, slow_case);
137 // done
138 bind(done);
139 }
140
141 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
142 const int aligned_mask = BytesPerWord -1;
143 const int hdr_offset = oopDesc::mark_offset_in_bytes();
144 assert_different_registers(hdr, obj, disp_hdr);
145 NearLabel done;
146
147 // Load displaced header.
148 z_ltg(hdr, Address(disp_hdr, (intptr_t)0));
149 // If the loaded hdr is NULL we had recursive locking, and we are done.
150 z_bre(done);
151 // Load object.
152 z_lg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
153 verify_oop(obj, FILE_AND_LINE);
154 // Test if object header is pointing to the displaced header, and if so, restore
155 // the displaced header in the object. If the object header is not pointing to
156 // the displaced header, get the object header instead.
157 z_csg(disp_hdr, hdr, hdr_offset, obj);
158 // If the object header was not pointing to the displaced header,
159 // we do unlocking via runtime call.
160 branch_optimized(Assembler::bcondNotEqual, slow_case);
161 // done
162 bind(done);
163 }
164
165 void C1_MacroAssembler::try_allocate(
166 Register obj, // result: Pointer to object after successful allocation.
167 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
168 int con_size_in_bytes, // Object size in bytes if known at compile time.
169 Register t1, // Temp register: Must be global register for incr_allocated_bytes.
170 Label& slow_case // Continuation point if fast allocation fails.
171 ) {
172 if (UseTLAB) {
173 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
174 } else {
175 // Allocation in shared Eden not implemented, because sapjvm allocation trace does not allow it.
176 z_brul(slow_case);
177 }
178 }
179
180 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register Rzero, Register t1) {
181 assert_different_registers(obj, klass, len, t1, Rzero);
182 // This assumes that all prototype bits fit in an int32_t.
183 load_const_optimized(t1, (intx)markWord::prototype().value());
184 z_stg(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
185
186 if (len->is_valid()) {
187 // Length will be in the klass gap, if one exists.
188 z_st(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
189 } else if (UseCompressedClassPointers) {
190 store_klass_gap(Rzero, obj); // Zero klass gap for compressed oops.
191 }
192 store_klass(klass, obj, t1);
193 }
194
195 void C1_MacroAssembler::initialize_body(Register objectFields, Register len_in_bytes, Register Rzero) {
196 Label done;
197 assert_different_registers(objectFields, len_in_bytes, Rzero);
198
199 // Initialize object fields.
200 // See documentation for MVCLE instruction!!!
201 assert(objectFields->encoding()%2==0, "objectFields must be an even register");
202 assert(len_in_bytes->encoding() == (objectFields->encoding()+1), "objectFields and len_in_bytes must be a register pair");
203 assert(Rzero->encoding()%2==1, "Rzero must be an odd register");
204
205 // Use Rzero as src length, then mvcle will copy nothing
206 // and fill the object with the padding value 0.
207 move_long_ext(objectFields, as_Register(Rzero->encoding()-1), 0);
208 bind(done);
209 }
210
211 void C1_MacroAssembler::allocate_object(
212 Register obj, // Result: pointer to object after successful allocation.
213 Register t1, // temp register
214 Register t2, // temp register: Must be a global register for try_allocate.
215 int hdr_size, // object header size in words
216 int obj_size, // object size in words
217 Register klass, // object klass
218 Label& slow_case // Continuation point if fast allocation fails.
219 ) {
220 assert_different_registers(obj, t1, t2, klass);
221
222 // Allocate space and initialize header.
223 try_allocate(obj, noreg, obj_size * wordSize, t1, slow_case);
224
225 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
226 }
227
228 void C1_MacroAssembler::initialize_object(
229 Register obj, // result: Pointer to object after successful allocation.
230 Register klass, // object klass
231 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
232 int con_size_in_bytes, // Object size in bytes if known at compile time.
233 Register t1, // temp register
234 Register t2 // temp register
235 ) {
236 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
237 "con_size_in_bytes is not multiple of alignment");
238 assert(var_size_in_bytes == noreg, "not implemented");
239 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
240
241 const Register Rzero = t2;
242
243 z_xgr(Rzero, Rzero);
244 initialize_header(obj, klass, noreg, Rzero, t1);
245
246 // Clear rest of allocated space.
247 const int threshold = 4 * BytesPerWord;
248 if (con_size_in_bytes <= threshold) {
249 // Use explicit null stores.
250 // code size = 6*n bytes (n = number of fields to clear)
251 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
252 z_stg(Rzero, Address(obj, i));
253 } else {
254 // Code size generated by initialize_body() is 16.
255 Register object_fields = Z_R0_scratch;
256 Register len_in_bytes = Z_R1_scratch;
257 z_la(object_fields, hdr_size_in_bytes, obj);
258 load_const_optimized(len_in_bytes, con_size_in_bytes - hdr_size_in_bytes);
259 initialize_body(object_fields, len_in_bytes, Rzero);
260 }
261
262 // Dtrace support is unimplemented.
263 // if (CURRENT_ENV->dtrace_alloc_probes()) {
264 // assert(obj == rax, "must be");
265 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id)));
266 // }
267
268 verify_oop(obj, FILE_AND_LINE);
269 }
270
271 void C1_MacroAssembler::allocate_array(
272 Register obj, // result: Pointer to array after successful allocation.
273 Register len, // array length
274 Register t1, // temp register
275 Register t2, // temp register
276 int hdr_size, // object header size in words
277 int elt_size, // element size in bytes
278 Register klass, // object klass
279 Label& slow_case // Continuation point if fast allocation fails.
280 ) {
281 assert_different_registers(obj, len, t1, t2, klass);
282
283 // Determine alignment mask.
284 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
285
286 // Check for negative or excessive length.
287 compareU64_and_branch(len, (int32_t)max_array_allocation_length, bcondHigh, slow_case);
288
289 // Compute array size.
290 // Note: If 0 <= len <= max_length, len*elt_size + header + alignment is
291 // smaller or equal to the largest integer. Also, since top is always
292 // aligned, we can do the alignment here instead of at the end address
293 // computation.
294 const Register arr_size = t2;
295 switch (elt_size) {
296 case 1: lgr_if_needed(arr_size, len); break;
297 case 2: z_sllg(arr_size, len, 1); break;
298 case 4: z_sllg(arr_size, len, 2); break;
299 case 8: z_sllg(arr_size, len, 3); break;
300 default: ShouldNotReachHere();
301 }
302 add2reg(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask); // Add space for header & alignment.
303 z_nill(arr_size, (~MinObjAlignmentInBytesMask) & 0xffff); // Align array size.
304
305 try_allocate(obj, arr_size, 0, t1, slow_case);
306
307 initialize_header(obj, klass, len, noreg, t1);
308
309 // Clear rest of allocated space.
310 Label done;
311 Register object_fields = t1;
312 Register Rzero = Z_R1_scratch;
313 z_aghi(arr_size, -(hdr_size * BytesPerWord));
314 z_bre(done); // Jump if size of fields is zero.
315 z_la(object_fields, hdr_size * BytesPerWord, obj);
316 z_xgr(Rzero, Rzero);
317 initialize_body(object_fields, arr_size, Rzero);
318 bind(done);
319
320 // Dtrace support is unimplemented.
321 // if (CURRENT_ENV->dtrace_alloc_probes()) {
322 // assert(obj == rax, "must be");
323 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id)));
324 // }
325
326 verify_oop(obj, FILE_AND_LINE);
327 }
328
329
330 #ifndef PRODUCT
331
332 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
333 if (!VerifyOops) return;
334 verify_oop_addr(Address(Z_SP, stack_offset), FILE_AND_LINE);
335 }
336
337 void C1_MacroAssembler::verify_not_null_oop(Register r) {
338 if (!VerifyOops) return;
339 NearLabel not_null;
340 compareU64_and_branch(r, (intptr_t)0, bcondNotEqual, not_null);
341 stop("non-null oop required");
342 bind(not_null);
343 verify_oop(r, FILE_AND_LINE);
344 }
345
346 void C1_MacroAssembler::invalidate_registers(Register preserve1,
347 Register preserve2,
348 Register preserve3) {
349 Register dead_value = noreg;
350 for (int i = 0; i < FrameMap::nof_cpu_regs; i++) {
351 Register r = as_Register(i);
352 if (r != preserve1 && r != preserve2 && r != preserve3 && r != Z_SP && r != Z_thread) {
353 if (dead_value == noreg) {
354 load_const_optimized(r, 0xc1dead);
355 dead_value = r;
356 } else {
357 z_lgr(r, dead_value);
358 }
359 }
360 }
361 }
362
363 #endif // !PRODUCT