1 /*
2 * Copyright (c) 2016, 2026, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2016, 2024 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 "asm/macroAssembler.inline.hpp"
27 #include "c1/c1_MacroAssembler.hpp"
28 #include "c1/c1_Runtime1.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/os.hpp"
38 #include "runtime/sharedRuntime.hpp"
39 #include "runtime/stubRoutines.hpp"
40 #include "utilities/macros.hpp"
41
42 void C1_MacroAssembler::explicit_null_check(Register base) {
43 ShouldNotCallThis(); // unused
44 }
45
46 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
47 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
48 generate_stack_overflow_check(bang_size_in_bytes);
49 save_return_pc();
50 push_frame(frame_size_in_bytes);
51
52 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
53 bs->nmethod_entry_barrier(this);
54 }
55
56 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
57 if (breakAtEntry) z_illtrap(0xC1);
58 }
59
60 void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {
61 const Register tmp = Z_R1_scratch;
62
63 assert_different_registers(Rmark, Roop, Rbox, tmp);
64
65 verify_oop(Roop, FILE_AND_LINE);
66
67 // Save object being locked into the BasicObjectLock...
68 z_stg(Roop, Address(Rbox, BasicObjectLock::obj_offset()));
69
70 fast_lock(Rbox, Roop, Rmark, tmp, slow_case);
71 }
72
73 void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {
74 assert_different_registers(Rmark, Roop, Rbox);
75
76 // Load object.
77 z_lg(Roop, Address(Rbox, BasicObjectLock::obj_offset()));
78 verify_oop(Roop, FILE_AND_LINE);
79
80 fast_unlock(Roop, Rmark, Z_R1_scratch, slow_case);
81 }
82
83 void C1_MacroAssembler::try_allocate(
84 Register obj, // result: Pointer to object after successful allocation.
85 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
86 int con_size_in_bytes, // Object size in bytes if known at compile time.
87 Register t1, // Temp register.
88 Label& slow_case // Continuation point if fast allocation fails.
89 ) {
90 if (UseTLAB) {
91 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
92 } else {
93 // Allocation in shared Eden not implemented, because sapjvm allocation trace does not allow it.
94 z_brul(slow_case);
95 }
96 }
97
98 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register Rzero, Register t1) {
99 assert_different_registers(obj, klass, len, t1, Rzero);
100 if (UseCompactObjectHeaders) {
101 z_lg(t1, Address(klass, in_bytes(Klass::prototype_header_offset())));
102 z_stg(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
103 } else {
104 load_const_optimized(t1, (intx)markWord::prototype().value());
105 z_stg(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
106 store_klass(klass, obj, t1);
107 }
108
109 if (len->is_valid()) {
110 // Length will be in the klass gap.
111 z_st(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
112 } else if (!UseCompactObjectHeaders) {
113 store_klass_gap(Rzero, obj); // Zero klass gap.
114 }
115 }
116
117 void C1_MacroAssembler::initialize_body(Register objectFields, Register len_in_bytes, Register Rzero) {
118 assert_different_registers(objectFields, len_in_bytes, Rzero);
119
120 // Initialize object fields.
121 // See documentation for MVCLE instruction!!!
122 assert(objectFields->encoding()%2==0, "objectFields must be an even register");
123 assert(len_in_bytes->encoding() == (objectFields->encoding()+1), "objectFields and len_in_bytes must be a register pair");
124 assert(Rzero->encoding()%2==1, "Rzero must be an odd register");
125
126 // Use Rzero as src length, then mvcle will copy nothing
127 // and fill the object with the padding value 0.
128 move_long_ext(objectFields, as_Register(Rzero->encoding()-1), 0);
129 }
130
131 void C1_MacroAssembler::allocate_object(
132 Register obj, // Result: pointer to object after successful allocation.
133 Register t1, // temp register
134 Register t2, // temp register: Must be a global register for try_allocate.
135 int hdr_size, // object header size in words
136 int obj_size, // object size in words
137 Register klass, // object klass
138 Label& slow_case // Continuation point if fast allocation fails.
139 ) {
140 assert_different_registers(obj, t1, t2, klass);
141
142 // Allocate space and initialize header.
143 try_allocate(obj, noreg, obj_size * wordSize, t1, slow_case);
144
145 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
146 }
147
148 void C1_MacroAssembler::initialize_object(
149 Register obj, // result: Pointer to object after successful allocation.
150 Register klass, // object klass
151 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
152 int con_size_in_bytes, // Object size in bytes if known at compile time.
153 Register t1, // temp register
154 Register t2 // temp register
155 ) {
156 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
157 "con_size_in_bytes is not multiple of alignment");
158 assert(var_size_in_bytes == noreg, "not implemented");
159 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
160
161 const Register Rzero = t2;
162
163 z_xgr(Rzero, Rzero);
164 initialize_header(obj, klass, noreg, Rzero, t1);
165
166 // Clear rest of allocated space.
167 const int threshold = 4 * BytesPerWord;
168 if (con_size_in_bytes <= threshold) {
169 // Use explicit null stores.
170 // code size = 6*n bytes (n = number of fields to clear)
171 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
172 z_stg(Rzero, Address(obj, i));
173 } else {
174 // Code size generated by initialize_body() is 16.
175 Register object_fields = Z_R0_scratch;
176 Register len_in_bytes = Z_R1_scratch;
177 z_la(object_fields, hdr_size_in_bytes, obj);
178 load_const_optimized(len_in_bytes, con_size_in_bytes - hdr_size_in_bytes);
179 initialize_body(object_fields, len_in_bytes, Rzero);
180 }
181
182 // Dtrace support is unimplemented.
183 // if (CURRENT_ENV->dtrace_alloc_probes()) {
184 // assert(obj == rax, "must be");
185 // call(RuntimeAddress(Runtime1::entry_for (StubId::c1_dtrace_object_alloc_id)));
186 // }
187
188 verify_oop(obj, FILE_AND_LINE);
189 }
190
191 void C1_MacroAssembler::allocate_array(
192 Register obj, // result: Pointer to array after successful allocation.
193 Register len, // array length
194 Register t1, // temp register
195 Register t2, // temp register
196 int base_offset_in_bytes, // elements offset in bytes
197 int elt_size, // element size in bytes
198 Register klass, // object klass
199 Label& slow_case, // Continuation point if fast allocation fails.
200 bool zero_array // zero the allocated array or not
201 ) {
202 assert_different_registers(obj, len, t1, t2, klass);
203
204 // Determine alignment mask.
205 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
206
207 // Check for negative or excessive length.
208 compareU64_and_branch(len, (int32_t)max_array_allocation_length, bcondHigh, slow_case);
209
210 // Compute array size.
211 // Note: If 0 <= len <= max_length, len*elt_size + header + alignment is
212 // smaller or equal to the largest integer. Also, since top is always
213 // aligned, we can do the alignment here instead of at the end address
214 // computation.
215 const Register arr_size = t2;
216 switch (elt_size) {
217 case 1: lgr_if_needed(arr_size, len); break;
218 case 2: z_sllg(arr_size, len, 1); break;
219 case 4: z_sllg(arr_size, len, 2); break;
220 case 8: z_sllg(arr_size, len, 3); break;
221 default: ShouldNotReachHere();
222 }
223 add2reg(arr_size, base_offset_in_bytes + MinObjAlignmentInBytesMask); // Add space for header & alignment.
224 z_nill(arr_size, (~MinObjAlignmentInBytesMask) & 0xffff); // Align array size.
225
226 try_allocate(obj, arr_size, 0, t1, slow_case);
227
228 initialize_header(obj, klass, len, noreg, t1);
229
230 // Clear rest of allocated space.
231 if (zero_array) {
232 Label done;
233 Register object_fields = t1;
234 Register Rzero = Z_R1_scratch;
235 z_aghi(arr_size, -base_offset_in_bytes);
236 z_bre(done); // Jump if size of fields is zero.
237 z_la(object_fields, base_offset_in_bytes, obj);
238 z_xgr(Rzero, Rzero);
239 initialize_body(object_fields, arr_size, Rzero);
240 bind(done);
241 }
242
243 // Dtrace support is unimplemented.
244 // if (CURRENT_ENV->dtrace_alloc_probes()) {
245 // assert(obj == rax, "must be");
246 // call(RuntimeAddress(Runtime1::entry_for (StubId::c1_dtrace_object_alloc_id)));
247 // }
248
249 verify_oop(obj, FILE_AND_LINE);
250 }
251
252
253 #ifndef PRODUCT
254
255 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
256 if (!VerifyOops) return;
257 verify_oop_addr(Address(Z_SP, stack_offset), FILE_AND_LINE);
258 }
259
260 void C1_MacroAssembler::verify_not_null_oop(Register r) {
261 if (!VerifyOops) return;
262 NearLabel not_null;
263 compareU64_and_branch(r, (intptr_t)0, bcondNotEqual, not_null);
264 stop("non-null oop required");
265 bind(not_null);
266 verify_oop(r, FILE_AND_LINE);
267 }
268
269 void C1_MacroAssembler::invalidate_registers(Register preserve1,
270 Register preserve2,
271 Register preserve3) {
272 Register dead_value = noreg;
273 for (int i = 0; i < FrameMap::nof_cpu_regs; i++) {
274 Register r = as_Register(i);
275 if (r != preserve1 && r != preserve2 && r != preserve3 && r != Z_SP && r != Z_thread) {
276 if (dead_value == noreg) {
277 load_const_optimized(r, 0xc1dead);
278 dead_value = r;
279 } else {
280 z_lgr(r, dead_value);
281 }
282 }
283 }
284 }
285
286 #endif // !PRODUCT