1 /*
2 * Copyright (c) 1999, 2026, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2012, 2025 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/collectedHeap.hpp"
30 #include "gc/shared/tlab_globals.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "oops/arrayOop.hpp"
33 #include "oops/markWord.hpp"
34 #include "runtime/basicLock.hpp"
35 #include "runtime/os.hpp"
36 #include "runtime/sharedRuntime.hpp"
37 #include "runtime/stubRoutines.hpp"
38 #include "utilities/align.hpp"
39 #include "utilities/macros.hpp"
40 #include "utilities/powerOfTwo.hpp"
41
42
43 void C1_MacroAssembler::explicit_null_check(Register base) {
44 Unimplemented();
45 }
46
47
48 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes,
49 int sp_offset_for_orig_pc,
50 bool needs_stack_repair, bool has_scalarized_args,
51 Label* verified_inline_entry_label) {
52 const Register return_pc = R20;
53 mflr(return_pc);
54
55 // Make sure there is enough stack space for this method's activation.
56 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
57 generate_stack_overflow_check(bang_size_in_bytes);
58
59 std(return_pc, _abi0(lr), R1_SP); // SP->lr = return_pc
60 push_frame(frame_size_in_bytes, R0); // SP -= frame_size_in_bytes
61
62 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
63 bs->nmethod_entry_barrier(this, R20);
64 }
65
66
67 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
68 if (breakAtEntry) illtrap();
69 // build frame
70 }
71
72
73 void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Register Rscratch, Label& slow_case) {
74 assert_different_registers(Rmark, Roop, Rbox, Rscratch);
75
76 Label done, cas_failed, slow_int;
77
78 // The following move must be the first instruction of emitted since debug
79 // information may be generated for it.
80 // Load object header.
81 ld(Rmark, oopDesc::mark_offset_in_bytes(), Roop);
82
83 verify_oop(Roop, FILE_AND_LINE);
84
85 // Save object being locked into the BasicObjectLock...
86 std(Roop, in_bytes(BasicObjectLock::obj_offset()), Rbox);
87
88 fast_lock(Rbox, Roop, Rmark, Rscratch, slow_int);
89 b(done);
90
91 bind(slow_int);
92 b(slow_case); // far
93
94 bind(done);
95 }
96
97
98 void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {
99 assert_different_registers(Rmark, Roop, Rbox);
100
101 Label slow_int, done;
102
103 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
104 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
105
106 // Load object.
107 ld(Roop, in_bytes(BasicObjectLock::obj_offset()), Rbox);
108 verify_oop(Roop, FILE_AND_LINE);
109
110 fast_unlock(Roop, Rmark, slow_int);
111 b(done);
112 bind(slow_int);
113 b(slow_case); // far
114
115 // Done
116 bind(done);
117 }
118
119
120 void C1_MacroAssembler::try_allocate(
121 Register obj, // result: pointer to object after successful allocation
122 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
123 int con_size_in_bytes, // object size in bytes if known at compile time
124 Register t1, // temp register
125 Register t2, // temp register
126 Label& slow_case // continuation point if fast allocation fails
127 ) {
128 if (UseTLAB) {
129 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
130 } else {
131 b(slow_case);
132 }
133 }
134
135
136 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
137 assert_different_registers(obj, klass, len, t1, t2);
138
139 if (UseCompactObjectHeaders) {
140 ld(t1, in_bytes(Klass::prototype_header_offset()), klass);
141 std(t1, oopDesc::mark_offset_in_bytes(), obj);
142 } else {
143 load_const_optimized(t1, (intx)markWord::prototype().value());
144 std(t1, oopDesc::mark_offset_in_bytes(), obj);
145 store_klass(obj, klass);
146 }
147
148 if (len->is_valid()) {
149 stw(len, arrayOopDesc::length_offset_in_bytes(), obj);
150 } else if (!UseCompactObjectHeaders) {
151 // Otherwise length is in the class gap.
152 store_klass_gap(obj);
153 }
154 }
155
156
157 void C1_MacroAssembler::initialize_body(Register base, Register index) {
158 assert_different_registers(base, index);
159 srdi(index, index, LogBytesPerWord);
160 clear_memory_doubleword(base, index);
161 }
162
163 void C1_MacroAssembler::initialize_body(Register obj, Register tmp1, Register tmp2,
164 int obj_size_in_bytes, int hdr_size_in_bytes) {
165 const int index = (obj_size_in_bytes - hdr_size_in_bytes) / HeapWordSize;
166
167 // 2x unrolled loop is shorter with more than 9 HeapWords.
168 if (index <= 9) {
169 clear_memory_unrolled(obj, index, R0, hdr_size_in_bytes);
170 } else {
171 const Register base_ptr = tmp1,
172 cnt_dwords = tmp2;
173
174 addi(base_ptr, obj, hdr_size_in_bytes); // Compute address of first element.
175 clear_memory_doubleword(base_ptr, cnt_dwords, R0, index);
176 }
177 }
178
179 void C1_MacroAssembler::allocate_object(
180 Register obj, // result: pointer to object after successful allocation
181 Register t1, // temp register
182 Register t2, // temp register
183 Register t3, // temp register
184 int hdr_size, // object header size in words
185 int obj_size, // object size in words
186 Register klass, // object klass
187 Label& slow_case // continuation point if fast allocation fails
188 ) {
189 assert_different_registers(obj, t1, t2, t3, klass);
190
191 // allocate space & initialize header
192 if (!is_simm16(obj_size * wordSize)) {
193 // Would need to use extra register to load
194 // object size => go the slow case for now.
195 b(slow_case);
196 return;
197 }
198 try_allocate(obj, noreg, obj_size * wordSize, t2, t3, slow_case);
199
200 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
201 }
202
203 void C1_MacroAssembler::initialize_object(
204 Register obj, // result: pointer to object after successful allocation
205 Register klass, // object klass
206 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
207 int con_size_in_bytes, // object size in bytes if known at compile time
208 Register t1, // temp register
209 Register t2 // temp register
210 ) {
211 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
212
213 initialize_header(obj, klass, noreg, t1, t2);
214
215 #ifdef ASSERT
216 {
217 lwz(t1, in_bytes(Klass::layout_helper_offset()), klass);
218 if (var_size_in_bytes != noreg) {
219 cmpw(CR0, t1, var_size_in_bytes);
220 } else {
221 cmpwi(CR0, t1, con_size_in_bytes);
222 }
223 asm_assert_eq("bad size in initialize_object");
224 }
225 #endif
226
227 // Initialize body.
228 if (var_size_in_bytes != noreg) {
229 // Use a loop.
230 addi(t1, obj, hdr_size_in_bytes); // Compute address of first element.
231 addi(t2, var_size_in_bytes, -hdr_size_in_bytes); // Compute size of body.
232 initialize_body(t1, t2);
233 } else if (con_size_in_bytes > hdr_size_in_bytes) {
234 // Use a loop.
235 initialize_body(obj, t1, t2, con_size_in_bytes, hdr_size_in_bytes);
236 }
237
238 verify_oop(obj, FILE_AND_LINE);
239 }
240
241
242 void C1_MacroAssembler::allocate_array(
243 Register obj, // result: pointer to array after successful allocation
244 Register len, // array length
245 Register t1, // temp register
246 Register t2, // temp register
247 Register t3, // temp register
248 int base_offset_in_bytes, // elements offset in bytes
249 int elt_size, // element size in bytes
250 Register klass, // object klass
251 Label& slow_case, // continuation point if fast allocation fails
252 bool zero_array // zero the allocated array or not
253 ) {
254 assert_different_registers(obj, len, t1, t2, t3, klass);
255
256 // Determine alignment mask.
257 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
258 int log2_elt_size = exact_log2(elt_size);
259
260 // Check for negative or excessive length.
261 size_t max_length = max_array_allocation_length >> log2_elt_size;
262 if (UseTLAB) {
263 size_t max_tlab = align_up(ThreadLocalAllocBuffer::max_size() >> log2_elt_size, 64*K);
264 if (max_tlab < max_length) { max_length = max_tlab; }
265 }
266 load_const_optimized(t1, max_length);
267 cmpld(CR0, len, t1);
268 bc_far_optimized(Assembler::bcondCRbiIs1, bi0(CR0, Assembler::greater), slow_case);
269
270 // compute array size
271 // note: If 0 <= len <= max_length, len*elt_size + header + alignment is
272 // smaller or equal to the largest integer; also, since top is always
273 // aligned, we can do the alignment here instead of at the end address
274 // computation.
275 const Register arr_size = t1;
276 Register arr_len_in_bytes = len;
277 if (elt_size != 1) {
278 sldi(t1, len, log2_elt_size);
279 arr_len_in_bytes = t1;
280 }
281 addi(arr_size, arr_len_in_bytes, base_offset_in_bytes + MinObjAlignmentInBytesMask); // Add space for header & alignment.
282 clrrdi(arr_size, arr_size, LogMinObjAlignmentInBytes); // Align array size.
283
284 // Allocate space & initialize header.
285 try_allocate(obj, arr_size, 0, t2, t3, slow_case);
286 initialize_header(obj, klass, len, t2, t3);
287
288 if (zero_array) {
289 // Initialize body.
290 const Register base = t2;
291 const Register index = t3;
292 addi(base, obj, base_offset_in_bytes); // compute address of first element
293 addi(index, arr_size, -(base_offset_in_bytes)); // compute index = number of bytes to clear
294
295 // Zero first 4 bytes, if start offset is not word aligned.
296 if (!is_aligned(base_offset_in_bytes, BytesPerWord)) {
297 assert(is_aligned(base_offset_in_bytes, BytesPerInt), "must be 4-byte aligned");
298 li(t1, 0);
299 stw(t1, 0, base);
300 addi(base, base, BytesPerInt);
301 // Note: initialize_body will align index down, no need to correct it here.
302 }
303
304 initialize_body(base, index);
305 }
306
307 verify_oop(obj, FILE_AND_LINE);
308 }
309
310
311 #ifndef PRODUCT
312
313 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
314 verify_oop_addr((RegisterOrConstant)stack_offset, R1_SP, "broken oop in stack slot");
315 }
316
317 void C1_MacroAssembler::verify_not_null_oop(Register r) {
318 Label not_null;
319 cmpdi(CR0, r, 0);
320 bne(CR0, not_null);
321 stop("non-null oop required");
322 bind(not_null);
323 verify_oop(r, FILE_AND_LINE);
324 }
325
326 #endif // PRODUCT
327
328 void C1_MacroAssembler::null_check(Register r, Label* Lnull) {
329 if (TrapBasedNullChecks) { // SIGTRAP based
330 trap_null_check(r);
331 } else { // explicit
332 //const address exception_entry = Runtime1::entry_for(StubId::c1_throw_null_pointer_exception_id);
333 assert(Lnull != nullptr, "must have Label for explicit check");
334 cmpdi(CR0, r, 0);
335 bc_far_optimized(Assembler::bcondCRbiIs1, bi0(CR0, Assembler::equal), *Lnull);
336 }
337 }
338
339 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) {
340 Unimplemented();
341 }
342