1 /*
2 * Copyright (c) 2003, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2014, Red Hat Inc. 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/assembler.inline.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "code/compiledIC.hpp"
29 #include "code/vtableStubs.hpp"
30 #include "interp_masm_aarch64.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/instanceKlass.hpp"
33 #include "oops/klassVtable.hpp"
34 #include "runtime/sharedRuntime.hpp"
35 #include "vmreg_aarch64.inline.hpp"
36 #ifdef COMPILER2
37 #include "opto/runtime.hpp"
38 #endif
39
40 // machine-dependent part of VtableStubs: create VtableStub of correct size and
41 // initialize its code
42
43 #define __ masm->
44
45 #ifndef PRODUCT
46 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index);
47 #endif
48
49 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
50 // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
51 const int stub_code_length = code_size_limit(true);
52 VtableStub* s = new(stub_code_length) VtableStub(true, vtable_index);
53 // Can be null if there is no free space in the code cache.
54 if (s == nullptr) {
55 return nullptr;
56 }
57
58 // Count unused bytes in instruction sequences of variable size.
59 // We add them to the computed buffer size in order to avoid
60 // overflow in subsequently generated stubs.
61 address start_pc;
62 int slop_bytes = 0;
63 int slop_delta = 0;
64
65 ResourceMark rm;
66 CodeBuffer cb(s->entry_point(), stub_code_length);
67 MacroAssembler* masm = new MacroAssembler(&cb);
68
69 #if (!defined(PRODUCT) && defined(COMPILER2))
70 if (CountCompiledCalls) {
71 __ lea(r16, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
72 __ increment(Address(r16));
73 }
74 #endif
75
76 // get receiver (need to skip return address on top of stack)
77 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
78
79 // get receiver klass
80 address npe_addr = __ pc();
81 __ load_klass(r16, j_rarg0);
82
83 #ifndef PRODUCT
84 if (DebugVtables) {
85 Label L;
86 // TODO: find upper bound for this debug code.
87 start_pc = __ pc();
88
89 // check offset vs vtable length
90 __ ldrw(rscratch1, Address(r16, Klass::vtable_length_offset()));
91 __ cmpw(rscratch1, vtable_index * vtableEntry::size());
92 __ br(Assembler::GT, L);
93 __ enter();
94 __ mov(r2, vtable_index);
95
96 __ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, r2);
97 const ptrdiff_t estimate = 256;
98 const ptrdiff_t codesize = __ pc() - start_pc;
99 slop_delta = estimate - codesize; // call_VM varies in length, depending on data
100 slop_bytes += slop_delta;
101 assert(slop_delta >= 0, "vtable #%d: Code size estimate (%d) for DebugVtables too small, required: %d", vtable_index, (int)estimate, (int)codesize);
102
103 __ leave();
104 __ bind(L);
105 }
106 #endif // PRODUCT
107
108 start_pc = __ pc();
109 __ lookup_virtual_method(r16, vtable_index, rmethod);
110 slop_delta = 8 - (int)(__ pc() - start_pc);
111 slop_bytes += slop_delta;
112 assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
113
114 #ifndef PRODUCT
115 if (DebugVtables) {
116 Label L;
117 __ cbz(rmethod, L);
118 __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
119 __ cbnz(rscratch1, L);
120 __ stop("Vtable entry is null");
121 __ bind(L);
122 }
123 #endif // PRODUCT
124
125 // r0: receiver klass
126 // rmethod: Method*
127 // r2: receiver
128 address ame_addr = __ pc();
129 __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
130 __ br(rscratch1);
131
132 masm->flush();
133 bookkeeping(masm, tty, s, npe_addr, ame_addr, true, vtable_index, slop_bytes, 0);
134
135 return s;
136 }
137
138
139 VtableStub* VtableStubs::create_itable_stub(int itable_index) {
140 // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
141 const int stub_code_length = code_size_limit(false);
142 VtableStub* s = new(stub_code_length) VtableStub(false, itable_index);
143 // Can be null if there is no free space in the code cache.
144 if (s == nullptr) {
145 return nullptr;
146 }
147
148 // Count unused bytes in instruction sequences of variable size.
149 // We add them to the computed buffer size in order to avoid
150 // overflow in subsequently generated stubs.
151 address start_pc;
152 int slop_bytes = 0;
153 int slop_delta = 0;
154
155 ResourceMark rm;
156 CodeBuffer cb(s->entry_point(), stub_code_length);
157 MacroAssembler* masm = new MacroAssembler(&cb);
158
159 #if (!defined(PRODUCT) && defined(COMPILER2))
160 if (CountCompiledCalls) {
161 __ lea(r10, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
162 __ increment(Address(r10));
163 }
164 #endif
165
166 // get receiver (need to skip return address on top of stack)
167 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
168
169 // Entry arguments:
170 // rscratch2: CompiledICData
171 // j_rarg0: Receiver
172
173 // This stub is called from compiled code which has no callee-saved registers,
174 // so all registers except arguments are free at this point.
175 const Register recv_klass_reg = r10;
176 const Register holder_klass_reg = r16; // declaring interface klass (DEFC)
177 const Register resolved_klass_reg = r17; // resolved interface klass (REFC)
178 const Register temp_reg = r11;
179 const Register temp_reg2 = r15;
180 const Register icdata_reg = rscratch2;
181
182 Label L_no_such_interface;
183
184 __ ldr(resolved_klass_reg, Address(icdata_reg, CompiledICData::itable_refc_klass_offset()));
185 __ ldr(holder_klass_reg, Address(icdata_reg, CompiledICData::itable_defc_klass_offset()));
186
187 start_pc = __ pc();
188
189 // get receiver klass (also an implicit null-check)
190 address npe_addr = __ pc();
191 __ load_klass(recv_klass_reg, j_rarg0);
192
193 // Receiver subtype check against REFC.
194 // Get selected method from declaring class and itable index
195 __ lookup_interface_method_stub(recv_klass_reg, holder_klass_reg, resolved_klass_reg, rmethod,
196 temp_reg, temp_reg2, itable_index, L_no_such_interface);
197
198 // Reduce "estimate" such that "padding" does not drop below 8.
199 const ptrdiff_t estimate = 144;
200 const ptrdiff_t codesize = __ pc() - start_pc;
201 slop_delta = (int)(estimate - codesize);
202 slop_bytes += slop_delta;
203 assert(slop_delta >= 0, "itable #%d: Code size estimate (%d) for lookup_interface_method too small, required: %d", itable_index, (int)estimate, (int)codesize);
204
205 #ifdef ASSERT
206 if (DebugVtables) {
207 Label L2;
208 __ cbz(rmethod, L2);
209 __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
210 __ cbnz(rscratch1, L2);
211 __ stop("compiler entrypoint is null");
212 __ bind(L2);
213 }
214 #endif // ASSERT
215
216 // rmethod: Method*
217 // j_rarg0: receiver
218 address ame_addr = __ pc();
219 __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
220 __ br(rscratch1);
221
222 __ bind(L_no_such_interface);
223 // Handle IncompatibleClassChangeError in itable stubs.
224 // More detailed error message.
225 // We force resolving of the call site by jumping to the "handle
226 // wrong method" stub, and so let the interpreter runtime do all the
227 // dirty work.
228 assert(SharedRuntime::get_handle_wrong_method_stub() != nullptr, "check initialization order");
229 __ far_jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub()));
230
231 masm->flush();
232 bookkeeping(masm, tty, s, npe_addr, ame_addr, false, itable_index, slop_bytes, 0);
233
234 return s;
235 }
236
237 int VtableStub::pd_code_alignment() {
238 // aarch64 cache line size is not an architected constant. We just align on 4 bytes (instruction size).
239 const unsigned int icache_line_size = 4;
240 return icache_line_size;
241 }