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 "precompiled.hpp"
26 #include "asm/assembler.hpp"
27 #include "assembler_x86.inline.hpp"
28 #include "code/vtableStubs.hpp"
29 #include "interp_masm_x86_64.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "oops/klassVtable.hpp"
33 #include "runtime/sharedRuntime.hpp"
34 #include "vmreg_x86.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,
46 oop receiver,
47 int index);
48 #endif
49
50 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
51 const int amd64_code_length = VtableStub::pd_code_size_limit(true);
52 VtableStub* s = new(amd64_code_length) VtableStub(true, vtable_index);
53 ResourceMark rm;
54 CodeBuffer cb(s->entry_point(), amd64_code_length);
55 MacroAssembler* masm = new MacroAssembler(&cb);
56
57 #ifndef PRODUCT
58 if (CountCompiledCalls) {
59 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
60 }
61 #endif
62
63 // get receiver (need to skip return address on top of stack)
64 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
65
66 // Free registers (non-args) are rax, rbx
67
68 // get receiver klass
69 address npe_addr = __ pc();
70 __ load_klass(rax, j_rarg0);
71
72 // compute entry offset (in words)
73 int entry_offset =
74 instanceKlass::vtable_start_offset() + vtable_index * vtableEntry::size();
75
76 #ifndef PRODUCT
77 if (DebugVtables) {
78 Label L;
79 // check offset vs vtable length
80 __ cmpl(Address(rax, instanceKlass::vtable_length_offset() * wordSize),
81 vtable_index * vtableEntry::size());
82 __ jcc(Assembler::greater, L);
83 __ movl(rbx, vtable_index);
84 __ call_VM(noreg,
85 CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, rbx);
86 __ bind(L);
87 }
88 #endif // PRODUCT
89
90 // load methodOop and target address
91 const Register method = rbx;
92
93 __ movptr(method, Address(rax,
94 entry_offset * wordSize +
95 vtableEntry::method_offset_in_bytes()));
96 if (DebugVtables) {
97 Label L;
98 __ cmpptr(method, (int32_t)NULL_WORD);
99 __ jcc(Assembler::equal, L);
100 __ cmpptr(Address(method, methodOopDesc::from_compiled_offset()), (int32_t)NULL_WORD);
101 __ jcc(Assembler::notZero, L);
102 __ stop("Vtable entry is NULL");
103 __ bind(L);
104 }
105 // rax: receiver klass
106 // rbx: methodOop
107 // rcx: receiver
108 address ame_addr = __ pc();
109 __ jmp( Address(rbx, methodOopDesc::from_compiled_offset()));
110
111 __ flush();
112
113 if (PrintMiscellaneous && (WizardMode || Verbose)) {
114 tty->print_cr("vtable #%d at "PTR_FORMAT"[%d] left over: %d",
115 vtable_index, s->entry_point(),
116 (int)(s->code_end() - s->entry_point()),
117 (int)(s->code_end() - __ pc()));
118 }
119 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
120 // shut the door on sizing bugs
121 int slop = 3; // 32-bit offset is this much larger than an 8-bit one
122 assert(vtable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
123
124 s->set_exception_points(npe_addr, ame_addr);
125 return s;
126 }
127
128
129 VtableStub* VtableStubs::create_itable_stub(int itable_index) {
130 // Note well: pd_code_size_limit is the absolute minimum we can get
131 // away with. If you add code here, bump the code stub size
132 // returned by pd_code_size_limit!
133 const int amd64_code_length = VtableStub::pd_code_size_limit(false);
134 VtableStub* s = new(amd64_code_length) VtableStub(false, itable_index);
135 ResourceMark rm;
136 CodeBuffer cb(s->entry_point(), amd64_code_length);
137 MacroAssembler* masm = new MacroAssembler(&cb);
138
139 #ifndef PRODUCT
140 if (CountCompiledCalls) {
141 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
142 }
143 #endif
144
145 // Entry arguments:
146 // rax: Interface
147 // j_rarg0: Receiver
148
149 // Free registers (non-args) are rax (interface), rbx
150
151 // get receiver (need to skip return address on top of stack)
152
153 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
154 // get receiver klass (also an implicit null-check)
155 address npe_addr = __ pc();
156
157 // Most registers are in use; we'll use rax, rbx, r10, r11
158 // (various calling sequences use r[cd]x, r[sd]i, r[89]; stay away from them)
159 __ load_klass(r10, j_rarg0);
160
161 // If we take a trap while this arg is on the stack we will not
162 // be able to walk the stack properly. This is not an issue except
163 // when there are mistakes in this assembly code that could generate
164 // a spurious fault. Ask me how I know...
165
166 const Register method = rbx;
167 Label throw_icce;
168
169 // Get methodOop and entrypoint for compiler
170 __ lookup_interface_method(// inputs: rec. class, interface, itable index
171 r10, rax, itable_index,
172 // outputs: method, scan temp. reg
173 method, r11,
174 throw_icce);
175
176 // method (rbx): methodOop
177 // j_rarg0: receiver
178
179 #ifdef ASSERT
180 if (DebugVtables) {
181 Label L2;
182 __ cmpptr(method, (int32_t)NULL_WORD);
183 __ jcc(Assembler::equal, L2);
184 __ cmpptr(Address(method, methodOopDesc::from_compiled_offset()), (int32_t)NULL_WORD);
185 __ jcc(Assembler::notZero, L2);
186 __ stop("compiler entrypoint is null");
187 __ bind(L2);
188 }
189 #endif // ASSERT
190
191 // rbx: methodOop
192 // j_rarg0: receiver
193 address ame_addr = __ pc();
194 __ jmp(Address(method, methodOopDesc::from_compiled_offset()));
195
196 __ bind(throw_icce);
197 __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
198
199 __ flush();
200
201 if (PrintMiscellaneous && (WizardMode || Verbose)) {
202 tty->print_cr("itable #%d at "PTR_FORMAT"[%d] left over: %d",
203 itable_index, s->entry_point(),
204 (int)(s->code_end() - s->entry_point()),
205 (int)(s->code_end() - __ pc()));
206 }
207 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
208 // shut the door on sizing bugs
209 int slop = 3; // 32-bit offset is this much larger than an 8-bit one
210 assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
211
212 s->set_exception_points(npe_addr, ame_addr);
213 return s;
214 }
215
216 int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
217 if (is_vtable_stub) {
218 // Vtable stub size
219 return (DebugVtables ? 512 : 24) + (CountCompiledCalls ? 13 : 0) +
220 (UseCompressedOops ? 16 : 0); // 1 leaq can be 3 bytes + 1 long
221 } else {
222 // Itable stub size
223 return (DebugVtables ? 512 : 74) + (CountCompiledCalls ? 13 : 0) +
224 (UseCompressedOops ? 32 : 0); // 2 leaqs
225 }
226 // In order to tune these parameters, run the JVM with VM options
227 // +PrintMiscellaneous and +WizardMode to see information about
228 // actual itable stubs. Look for lines like this:
229 // itable #1 at 0x5551212[71] left over: 3
230 // Reduce the constants so that the "left over" number is >=3
231 // for the common cases.
232 // Do not aim at a left-over number of zero, because a
233 // large vtable or itable index (>= 32) will require a 32-bit
234 // immediate displacement instead of an 8-bit one.
235 //
236 // The JVM98 app. _202_jess has a megamorphic interface call.
237 // The itable code looks like this:
238 // Decoding VtableStub itbl[1]@12
239 // mov 0x8(%rsi),%r10
240 // mov 0x198(%r10),%r11d
241 // lea 0x218(%r10,%r11,8),%r11
242 // lea 0x8(%r10),%r10
243 // mov (%r11),%rbx
244 // cmp %rbx,%rax
245 // je success
246 // loop:
247 // test %rbx,%rbx
248 // je throw_icce
249 // add $0x10,%r11
250 // mov (%r11),%rbx
251 // cmp %rbx,%rax
252 // jne loop
253 // success:
254 // mov 0x8(%r11),%r11d
255 // mov (%r10,%r11,1),%rbx
256 // jmpq *0x60(%rbx)
257 // throw_icce:
258 // jmpq throw_ICCE_entry
259 }
260
261 int VtableStub::pd_code_alignment() {
262 return wordSize;
263 }