1 /*
2 * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25 #include "c1/c1_MacroAssembler.hpp"
26 #include "c1/c1_Runtime1.hpp"
27 #include "code/compiledIC.hpp"
28 #include "compiler/compilerDefinitions.inline.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/globals.hpp"
38 #include "runtime/os.hpp"
39 #include "runtime/sharedRuntime.hpp"
40 #include "runtime/stubRoutines.hpp"
41 #include "utilities/checkedCast.hpp"
42 #include "utilities/globalDefinitions.hpp"
43
44 int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Register tmp, Label& slow_case) {
45 assert(hdr == rax, "hdr must be rax, for the cmpxchg instruction");
46 assert_different_registers(hdr, obj, disp_hdr, tmp);
47 int null_check_offset = -1;
48
49 verify_oop(obj);
50
51 // save object being locked into the BasicObjectLock
52 movptr(Address(disp_hdr, BasicObjectLock::obj_offset()), obj);
53
54 null_check_offset = offset();
55
56 lightweight_lock(disp_hdr, obj, hdr, tmp, slow_case);
57
58 return null_check_offset;
59 }
60
61 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
62 assert(disp_hdr == rax, "disp_hdr must be rax, for the cmpxchg instruction");
63 assert(hdr != obj && hdr != disp_hdr && obj != disp_hdr, "registers must be different");
64
65 // load object
66 movptr(obj, Address(disp_hdr, BasicObjectLock::obj_offset()));
67 verify_oop(obj);
68
69 lightweight_unlock(obj, disp_hdr, hdr, slow_case);
70 }
71
72
73 // Defines obj, preserves var_size_in_bytes
74 void C1_MacroAssembler::try_allocate(Register obj, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, Label& slow_case) {
75 if (UseTLAB) {
76 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
77 } else {
78 jmp(slow_case);
79 }
80 }
81
82
83 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
84 assert_different_registers(obj, klass, len, t1, t2);
85 if (UseCompactObjectHeaders) {
86 movptr(t1, Address(klass, Klass::prototype_header_offset()));
87 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), t1);
88 } else if (UseCompressedClassPointers) { // Take care not to kill klass
89 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value()));
90 movptr(t1, klass);
91 encode_klass_not_null(t1, rscratch1);
92 movl(Address(obj, oopDesc::klass_offset_in_bytes()), t1);
93 } else {
94 movptr(Address(obj, oopDesc::mark_offset_in_bytes()), checked_cast<int32_t>(markWord::prototype().value()));
95 movptr(Address(obj, oopDesc::klass_offset_in_bytes()), klass);
96 }
97
98 if (len->is_valid()) {
99 movl(Address(obj, arrayOopDesc::length_offset_in_bytes()), len);
100 int base_offset = arrayOopDesc::length_offset_in_bytes() + BytesPerInt;
101 if (!is_aligned(base_offset, BytesPerWord)) {
102 assert(is_aligned(base_offset, BytesPerInt), "must be 4-byte aligned");
103 // Clear gap/first 4 bytes following the length field.
104 xorl(t1, t1);
105 movl(Address(obj, base_offset), t1);
106 }
107 } else if (UseCompressedClassPointers && !UseCompactObjectHeaders) {
108 xorptr(t1, t1);
109 store_klass_gap(obj, t1);
110 }
111 }
112
113
114 // preserves obj, destroys len_in_bytes
115 void C1_MacroAssembler::initialize_body(Register obj, Register len_in_bytes, int hdr_size_in_bytes, Register t1) {
116 assert(hdr_size_in_bytes >= 0, "header size must be positive or 0");
117 Label done;
118
119 // len_in_bytes is positive and ptr sized
120 subptr(len_in_bytes, hdr_size_in_bytes);
121 zero_memory(obj, len_in_bytes, hdr_size_in_bytes, t1);
122 bind(done);
123 }
124
125
126 void C1_MacroAssembler::allocate_object(Register obj, Register t1, Register t2, int header_size, int object_size, Register klass, Label& slow_case) {
127 assert(obj == rax, "obj must be in rax, for cmpxchg");
128 assert_different_registers(obj, t1, t2); // XXX really?
129 assert(header_size >= 0 && object_size >= header_size, "illegal sizes");
130
131 try_allocate(obj, noreg, object_size * BytesPerWord, t1, t2, slow_case);
132
133 initialize_object(obj, klass, noreg, object_size * HeapWordSize, t1, t2, UseTLAB);
134 }
135
136 void C1_MacroAssembler::initialize_object(Register obj, Register klass, Register var_size_in_bytes, int con_size_in_bytes, Register t1, Register t2, bool is_tlab_allocated) {
137 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
138 "con_size_in_bytes is not multiple of alignment");
139 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
140 if (UseCompactObjectHeaders) {
141 assert(hdr_size_in_bytes == 8, "check object headers size");
142 }
143 initialize_header(obj, klass, noreg, t1, t2);
144
145 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
146 // clear rest of allocated space
147 const Register t1_zero = t1;
148 const Register index = t2;
149 const int threshold = 6 * BytesPerWord; // approximate break even point for code size (see comments below)
150 if (var_size_in_bytes != noreg) {
151 mov(index, var_size_in_bytes);
152 initialize_body(obj, index, hdr_size_in_bytes, t1_zero);
153 } else if (con_size_in_bytes <= threshold) {
154 // use explicit null stores
155 // code size = 2 + 3*n bytes (n = number of fields to clear)
156 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
157 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
158 movptr(Address(obj, i), t1_zero);
159 } else if (con_size_in_bytes > hdr_size_in_bytes) {
160 // use loop to null out the fields
161 // code size = 16 bytes for even n (n = number of fields to clear)
162 // initialize last object field first if odd number of fields
163 xorptr(t1_zero, t1_zero); // use t1_zero reg to clear memory (shorter code)
164 movptr(index, (con_size_in_bytes - hdr_size_in_bytes) >> 3);
165 // initialize last object field if constant size is odd
166 if (((con_size_in_bytes - hdr_size_in_bytes) & 4) != 0)
167 movptr(Address(obj, con_size_in_bytes - (1*BytesPerWord)), t1_zero);
168 // initialize remaining object fields: rdx is a multiple of 2
169 { Label loop;
170 bind(loop);
171 movptr(Address(obj, index, Address::times_8, hdr_size_in_bytes - (1*BytesPerWord)),
172 t1_zero);
173 decrement(index);
174 jcc(Assembler::notZero, loop);
175 }
176 }
177 }
178
179 if (CURRENT_ENV->dtrace_alloc_probes()) {
180 assert(obj == rax, "must be");
181 call(RuntimeAddress(Runtime1::entry_for(StubId::c1_dtrace_object_alloc_id)));
182 }
183
184 verify_oop(obj);
185 }
186
187 void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int base_offset_in_bytes, Address::ScaleFactor f, Register klass, Label& slow_case, bool zero_array) {
188 assert(obj == rax, "obj must be in rax, for cmpxchg");
189 assert_different_registers(obj, len, t1, t2, klass);
190
191 // determine alignment mask
192 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
193
194 // check for negative or excessive length
195 cmpptr(len, checked_cast<int32_t>(max_array_allocation_length));
196 jcc(Assembler::above, slow_case);
197
198 const Register arr_size = t2; // okay to be the same
199 // align object end
200 movptr(arr_size, base_offset_in_bytes + MinObjAlignmentInBytesMask);
201 lea(arr_size, Address(arr_size, len, f));
202 andptr(arr_size, ~MinObjAlignmentInBytesMask);
203
204 try_allocate(obj, arr_size, 0, t1, t2, slow_case);
205
206 initialize_header(obj, klass, len, t1, t2);
207
208 // clear rest of allocated space
209 if (zero_array) {
210 const Register len_zero = len;
211 // Align-up to word boundary, because we clear the 4 bytes potentially
212 // following the length field in initialize_header().
213 int base_offset = align_up(base_offset_in_bytes, BytesPerWord);
214 initialize_body(obj, arr_size, base_offset, len_zero);
215 }
216
217 if (CURRENT_ENV->dtrace_alloc_probes()) {
218 assert(obj == rax, "must be");
219 call(RuntimeAddress(Runtime1::entry_for(StubId::c1_dtrace_object_alloc_id)));
220 }
221
222 verify_oop(obj);
223 }
224
225 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
226 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
227 // Make sure there is enough stack space for this method's activation.
228 // Note that we do this before doing an enter(). This matches the
229 // ordering of C2's stack overflow check / rsp decrement and allows
230 // the SharedRuntime stack overflow handling to be consistent
231 // between the two compilers.
232 generate_stack_overflow_check(bang_size_in_bytes);
233
234 push(rbp);
235 if (PreserveFramePointer) {
236 mov(rbp, rsp);
237 }
238 decrement(rsp, frame_size_in_bytes); // does not emit code for frame_size == 0
239
240 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
241 // C1 code is not hot enough to micro optimize the nmethod entry barrier with an out-of-line stub
242 bs->nmethod_entry_barrier(this, nullptr /* slow_path */, nullptr /* continuation */);
243 }
244
245
246 void C1_MacroAssembler::remove_frame(int frame_size_in_bytes) {
247 increment(rsp, frame_size_in_bytes); // Does not emit code for frame_size == 0
248 pop(rbp);
249 }
250
251
252 void C1_MacroAssembler::verified_entry(bool breakAtEntry) {
253 if (breakAtEntry) int3();
254 // build frame
255 }
256
257 void C1_MacroAssembler::load_parameter(int offset_in_words, Register reg) {
258 // rbp, + 0: link
259 // + 1: return address
260 // + 2: argument with offset 0
261 // + 3: argument with offset 1
262 // + 4: ...
263
264 movptr(reg, Address(rbp, (offset_in_words + 2) * BytesPerWord));
265 }
266
267 #ifndef PRODUCT
268
269 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
270 if (!VerifyOops) return;
271 verify_oop_addr(Address(rsp, stack_offset));
272 }
273
274 void C1_MacroAssembler::verify_not_null_oop(Register r) {
275 if (!VerifyOops) return;
276 Label not_null;
277 testptr(r, r);
278 jcc(Assembler::notZero, not_null);
279 stop("non-null oop required");
280 bind(not_null);
281 verify_oop(r);
282 }
283
284 void C1_MacroAssembler::invalidate_registers(bool inv_rax, bool inv_rbx, bool inv_rcx, bool inv_rdx, bool inv_rsi, bool inv_rdi) {
285 #ifdef ASSERT
286 if (inv_rax) movptr(rax, 0xDEAD);
287 if (inv_rbx) movptr(rbx, 0xDEAD);
288 if (inv_rcx) movptr(rcx, 0xDEAD);
289 if (inv_rdx) movptr(rdx, 0xDEAD);
290 if (inv_rsi) movptr(rsi, 0xDEAD);
291 if (inv_rdi) movptr(rdi, 0xDEAD);
292 #endif
293 }
294
295 #endif // ifndef PRODUCT