1 /*
2 * Copyright (c) 2008, 2016, 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.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/assembler.hpp"
27 #include "assembler_arm.inline.hpp"
28 #include "code/vtableStubs.hpp"
29 #include "interp_masm_arm.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "oops/klassVtable.hpp"
33 #include "runtime/sharedRuntime.hpp"
34 #include "vmreg_arm.inline.hpp"
35 #ifdef COMPILER2
36 #include "opto/runtime.hpp"
37 #endif
38
39 // machine-dependent part of VtableStubs: create VtableStub of correct size and
40 // initialize its code
41
42 #define __ masm->
43
44 #ifndef PRODUCT
45 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index);
46 #endif
47
48 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
49 const int code_length = VtableStub::pd_code_size_limit(true);
50 VtableStub* s = new(code_length) VtableStub(true, vtable_index);
51 // Can be NULL if there is no free space in the code cache.
52 if (s == NULL) {
53 return NULL;
54 }
55
56 ResourceMark rm;
57 CodeBuffer cb(s->entry_point(), code_length);
58 MacroAssembler* masm = new MacroAssembler(&cb);
59
60 assert(VtableStub::receiver_location() == R0->as_VMReg(), "receiver expected in R0");
61
62 const Register tmp = Rtemp; // Rtemp OK, should be free at call sites
63
64 address npe_addr = __ pc();
65 __ load_klass(tmp, R0);
66
67 {
68 int entry_offset = in_bytes(Klass::vtable_start_offset()) + vtable_index * vtableEntry::size_in_bytes();
69 int method_offset = vtableEntry::method_offset_in_bytes() + entry_offset;
70
71 assert ((method_offset & (wordSize - 1)) == 0, "offset should be aligned");
72 int offset_mask = AARCH64_ONLY(0xfff << LogBytesPerWord) NOT_AARCH64(0xfff);
73 if (method_offset & ~offset_mask) {
74 __ add(tmp, tmp, method_offset & ~offset_mask);
75 }
76 __ ldr(Rmethod, Address(tmp, method_offset & offset_mask));
77 }
78
79 address ame_addr = __ pc();
80 #ifdef AARCH64
81 __ ldr(tmp, Address(Rmethod, Method::from_compiled_offset()));
82 __ br(tmp);
83 #else
84 __ ldr(PC, Address(Rmethod, Method::from_compiled_offset()));
85 #endif // AARCH64
86
87 masm->flush();
88
89 if (PrintMiscellaneous && (WizardMode || Verbose)) {
90 tty->print_cr("vtable #%d at " PTR_FORMAT "[%d] left over: %d",
91 vtable_index, p2i(s->entry_point()),
92 (int)(s->code_end() - s->entry_point()),
93 (int)(s->code_end() - __ pc()));
94 }
95 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
96 // FIXME ARM: need correct 'slop' - below is x86 code
97 // shut the door on sizing bugs
98 //int slop = 8; // 32-bit offset is this much larger than a 13-bit one
99 //assert(vtable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
100
101 s->set_exception_points(npe_addr, ame_addr);
102 return s;
103 }
104
105 VtableStub* VtableStubs::create_itable_stub(int itable_index) {
106 const int code_length = VtableStub::pd_code_size_limit(false);
107 VtableStub* s = new(code_length) VtableStub(false, itable_index);
108 // Can be NULL if there is no free space in the code cache.
109 if (s == NULL) {
110 return NULL;
111 }
112
113 ResourceMark rm;
114 CodeBuffer cb(s->entry_point(), code_length);
115 MacroAssembler* masm = new MacroAssembler(&cb);
116
117 assert(VtableStub::receiver_location() == R0->as_VMReg(), "receiver expected in R0");
118
119 // R0-R3 / R0-R7 registers hold the arguments and cannot be spoiled
120 const Register Rclass = AARCH64_ONLY(R9) NOT_AARCH64(R4);
121 const Register Rlength = AARCH64_ONLY(R10) NOT_AARCH64(R5);
122 const Register Rscan = AARCH64_ONLY(R11) NOT_AARCH64(R6);
123 const Register tmp = Rtemp;
124
125 assert_different_registers(Ricklass, Rclass, Rlength, Rscan, tmp);
126
127 // Calculate the start of itable (itable goes after vtable)
128 const int scale = exact_log2(vtableEntry::size_in_bytes());
129 address npe_addr = __ pc();
130 __ load_klass(Rclass, R0);
131 __ ldr_s32(Rlength, Address(Rclass, Klass::vtable_length_offset()));
132
133 __ add(Rscan, Rclass, in_bytes(Klass::vtable_start_offset()));
134 __ add(Rscan, Rscan, AsmOperand(Rlength, lsl, scale));
135
136 // Search through the itable for an interface equal to incoming Ricklass
137 // itable looks like [intface][offset][intface][offset][intface][offset]
138 const int entry_size = itableOffsetEntry::size() * HeapWordSize;
139 assert(itableOffsetEntry::interface_offset_in_bytes() == 0, "not added for convenience");
140
141 Label loop;
142 __ bind(loop);
143 __ ldr(tmp, Address(Rscan, entry_size, post_indexed));
144 #ifdef AARCH64
145 Label found;
146 __ cmp(tmp, Ricklass);
147 __ b(found, eq);
148 __ cbnz(tmp, loop);
149 #else
150 __ cmp(tmp, Ricklass); // set ZF and CF if interface is found
151 __ cmn(tmp, 0, ne); // check if tmp == 0 and clear CF if it is
152 __ b(loop, ne);
153 #endif // AARCH64
154
155 assert(StubRoutines::throw_IncompatibleClassChangeError_entry() != NULL, "Check initialization order");
156 #ifdef AARCH64
157 __ jump(StubRoutines::throw_IncompatibleClassChangeError_entry(), relocInfo::runtime_call_type, tmp);
158 __ bind(found);
159 #else
160 // CF == 0 means we reached the end of itable without finding icklass
161 __ jump(StubRoutines::throw_IncompatibleClassChangeError_entry(), relocInfo::runtime_call_type, noreg, cc);
162 #endif // !AARCH64
163
164 // Interface found at previous position of Rscan, now load the method oop
165 __ ldr_s32(tmp, Address(Rscan, itableOffsetEntry::offset_offset_in_bytes() - entry_size));
166 {
167 const int method_offset = itableMethodEntry::size() * HeapWordSize * itable_index +
168 itableMethodEntry::method_offset_in_bytes();
169 __ add_slow(Rmethod, Rclass, method_offset);
170 }
171 __ ldr(Rmethod, Address(Rmethod, tmp));
172
173 address ame_addr = __ pc();
174
175 #ifdef AARCH64
176 __ ldr(tmp, Address(Rmethod, Method::from_compiled_offset()));
177 __ br(tmp);
178 #else
179 __ ldr(PC, Address(Rmethod, Method::from_compiled_offset()));
180 #endif // AARCH64
181
182 masm->flush();
183
184 if (PrintMiscellaneous && (WizardMode || Verbose)) {
185 tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d",
186 itable_index, p2i(s->entry_point()),
187 (int)(s->code_end() - s->entry_point()),
188 (int)(s->code_end() - __ pc()));
189 }
190 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
191 // FIXME ARM: need correct 'slop' - below is x86 code
192 // shut the door on sizing bugs
193 //int slop = 8; // 32-bit offset is this much larger than a 13-bit one
194 //assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
195
196 s->set_exception_points(npe_addr, ame_addr);
197 return s;
198 }
199
200 int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
201 int instr_count;
202
203 if (is_vtable_stub) {
204 // vtable stub size
205 instr_count = NOT_AARCH64(4) AARCH64_ONLY(5);
206 } else {
207 // itable stub size
208 instr_count = NOT_AARCH64(20) AARCH64_ONLY(20);
209 }
210
211 #ifdef AARCH64
212 if (UseCompressedClassPointers) {
213 instr_count += MacroAssembler::instr_count_for_decode_klass_not_null();
214 }
215 #endif // AARCH64
216
217 return instr_count * Assembler::InstructionSize;
218 }
219
220 int VtableStub::pd_code_alignment() {
221 return 8;
222 }