1 /*
2 * Copyright (c) 2003, 2010, 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 "incls/_precompiled.incl"
26 #include "incls/_vtableStubs_x86_64.cpp.incl"
27
28 // machine-dependent part of VtableStubs: create VtableStub of correct size and
29 // initialize its code
30
31 #define __ masm->
32
33 #ifndef PRODUCT
34 extern "C" void bad_compiled_vtable_index(JavaThread* thread,
35 oop receiver,
36 int index);
37 #endif
38
39 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
40 const int amd64_code_length = VtableStub::pd_code_size_limit(true);
41 VtableStub* s = new(amd64_code_length) VtableStub(true, vtable_index);
42 ResourceMark rm;
43 CodeBuffer cb(s->entry_point(), amd64_code_length);
44 MacroAssembler* masm = new MacroAssembler(&cb);
45
46 #ifndef PRODUCT
47 if (CountCompiledCalls) {
48 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
49 }
50 #endif
51
52 // get receiver (need to skip return address on top of stack)
53 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
54
55 // Free registers (non-args) are rax, rbx
56
57 // get receiver klass
58 address npe_addr = __ pc();
59 __ load_klass(rax, j_rarg0);
60
61 // compute entry offset (in words)
62 int entry_offset =
63 instanceKlass::vtable_start_offset() + vtable_index * vtableEntry::size();
64
65 #ifndef PRODUCT
66 if (DebugVtables) {
67 Label L;
68 // check offset vs vtable length
69 __ cmpl(Address(rax, instanceKlass::vtable_length_offset() * wordSize),
70 vtable_index * vtableEntry::size());
71 __ jcc(Assembler::greater, L);
72 __ movl(rbx, vtable_index);
73 __ call_VM(noreg,
74 CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, rbx);
75 __ bind(L);
76 }
77 #endif // PRODUCT
78
79 // load methodOop and target address
80 const Register method = rbx;
81
82 __ movptr(method, Address(rax,
83 entry_offset * wordSize +
84 vtableEntry::method_offset_in_bytes()));
85 if (DebugVtables) {
86 Label L;
87 __ cmpptr(method, (int32_t)NULL_WORD);
88 __ jcc(Assembler::equal, L);
89 __ cmpptr(Address(method, methodOopDesc::from_compiled_offset()), (int32_t)NULL_WORD);
90 __ jcc(Assembler::notZero, L);
91 __ stop("Vtable entry is NULL");
92 __ bind(L);
93 }
94 // rax: receiver klass
95 // rbx: methodOop
96 // rcx: receiver
97 address ame_addr = __ pc();
98 __ jmp( Address(rbx, methodOopDesc::from_compiled_offset()));
99
100 __ flush();
101
102 if (PrintMiscellaneous && (WizardMode || Verbose)) {
103 tty->print_cr("vtable #%d at "PTR_FORMAT"[%d] left over: %d",
104 vtable_index, s->entry_point(),
105 (int)(s->code_end() - s->entry_point()),
106 (int)(s->code_end() - __ pc()));
107 }
108 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
109 // shut the door on sizing bugs
110 int slop = 3; // 32-bit offset is this much larger than an 8-bit one
111 assert(vtable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
112
113 s->set_exception_points(npe_addr, ame_addr);
114 return s;
115 }
116
117
118 VtableStub* VtableStubs::create_itable_stub(int itable_index) {
119 // Note well: pd_code_size_limit is the absolute minimum we can get
120 // away with. If you add code here, bump the code stub size
121 // returned by pd_code_size_limit!
122 const int amd64_code_length = VtableStub::pd_code_size_limit(false);
123 VtableStub* s = new(amd64_code_length) VtableStub(false, itable_index);
124 ResourceMark rm;
125 CodeBuffer cb(s->entry_point(), amd64_code_length);
126 MacroAssembler* masm = new MacroAssembler(&cb);
127
128 #ifndef PRODUCT
129 if (CountCompiledCalls) {
130 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
131 }
132 #endif
133
134 // Entry arguments:
135 // rax: Interface
136 // j_rarg0: Receiver
137
138 // Free registers (non-args) are rax (interface), rbx
139
140 // get receiver (need to skip return address on top of stack)
141
142 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
143 // get receiver klass (also an implicit null-check)
144 address npe_addr = __ pc();
145
146 // Most registers are in use; we'll use rax, rbx, r10, r11
147 // (various calling sequences use r[cd]x, r[sd]i, r[89]; stay away from them)
148 __ load_klass(r10, j_rarg0);
149
150 // If we take a trap while this arg is on the stack we will not
151 // be able to walk the stack properly. This is not an issue except
152 // when there are mistakes in this assembly code that could generate
153 // a spurious fault. Ask me how I know...
154
155 const Register method = rbx;
156 Label throw_icce;
157
158 // Get methodOop and entrypoint for compiler
159 __ lookup_interface_method(// inputs: rec. class, interface, itable index
160 r10, rax, itable_index,
161 // outputs: method, scan temp. reg
162 method, r11,
163 throw_icce);
164
165 // method (rbx): methodOop
166 // j_rarg0: receiver
167
168 #ifdef ASSERT
169 if (DebugVtables) {
170 Label L2;
171 __ cmpptr(method, (int32_t)NULL_WORD);
172 __ jcc(Assembler::equal, L2);
173 __ cmpptr(Address(method, methodOopDesc::from_compiled_offset()), (int32_t)NULL_WORD);
174 __ jcc(Assembler::notZero, L2);
175 __ stop("compiler entrypoint is null");
176 __ bind(L2);
177 }
178 #endif // ASSERT
179
180 // rbx: methodOop
181 // j_rarg0: receiver
182 address ame_addr = __ pc();
183 __ jmp(Address(method, methodOopDesc::from_compiled_offset()));
184
185 __ bind(throw_icce);
186 __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
187
188 __ flush();
189
190 if (PrintMiscellaneous && (WizardMode || Verbose)) {
191 tty->print_cr("itable #%d at "PTR_FORMAT"[%d] left over: %d",
192 itable_index, s->entry_point(),
193 (int)(s->code_end() - s->entry_point()),
194 (int)(s->code_end() - __ pc()));
195 }
196 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
197 // shut the door on sizing bugs
198 int slop = 3; // 32-bit offset is this much larger than an 8-bit one
199 assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
200
201 s->set_exception_points(npe_addr, ame_addr);
202 return s;
203 }
204
205 int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
206 if (is_vtable_stub) {
207 // Vtable stub size
208 return (DebugVtables ? 512 : 24) + (CountCompiledCalls ? 13 : 0) +
209 (UseCompressedOops ? 16 : 0); // 1 leaq can be 3 bytes + 1 long
210 } else {
211 // Itable stub size
212 return (DebugVtables ? 512 : 74) + (CountCompiledCalls ? 13 : 0) +
213 (UseCompressedOops ? 32 : 0); // 2 leaqs
214 }
215 // In order to tune these parameters, run the JVM with VM options
216 // +PrintMiscellaneous and +WizardMode to see information about
217 // actual itable stubs. Look for lines like this:
218 // itable #1 at 0x5551212[71] left over: 3
219 // Reduce the constants so that the "left over" number is >=3
220 // for the common cases.
221 // Do not aim at a left-over number of zero, because a
222 // large vtable or itable index (>= 32) will require a 32-bit
223 // immediate displacement instead of an 8-bit one.
224 //
225 // The JVM98 app. _202_jess has a megamorphic interface call.
226 // The itable code looks like this:
227 // Decoding VtableStub itbl[1]@12
228 // mov 0x8(%rsi),%r10
229 // mov 0x198(%r10),%r11d
230 // lea 0x218(%r10,%r11,8),%r11
231 // lea 0x8(%r10),%r10
232 // mov (%r11),%rbx
233 // cmp %rbx,%rax
234 // je success
235 // loop:
236 // test %rbx,%rbx
237 // je throw_icce
238 // add $0x10,%r11
239 // mov (%r11),%rbx
240 // cmp %rbx,%rax
241 // jne loop
242 // success:
243 // mov 0x8(%r11),%r11d
244 // mov (%r10,%r11,1),%rbx
245 // jmpq *0x60(%rbx)
246 // throw_icce:
247 // jmpq throw_ICCE_entry
248 }
249
250 int VtableStub::pd_code_alignment() {
251 return wordSize;
252 }