1 #ifdef USE_PRAGMA_IDENT_SRC
2 #pragma ident "@(#)vtableStubs_x86_64.cpp 1.24 07/10/08 13:01:14 JVM"
3 #endif
4 /*
5 * Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 #include "incls/_precompiled.incl"
29 #include "incls/_vtableStubs_x86_64.cpp.incl"
30
31 // machine-dependent part of VtableStubs: create VtableStub of correct size and
32 // initialize its code
33
34 #define __ masm->
35
36 #ifndef PRODUCT
37 extern "C" void bad_compiled_vtable_index(JavaThread* thread,
38 oop receiver,
39 int index);
40 #endif
41
42 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
43 const int amd64_code_length = VtableStub::pd_code_size_limit(true);
44 VtableStub* s = new(amd64_code_length) VtableStub(true, vtable_index);
45 ResourceMark rm;
46 CodeBuffer cb(s->entry_point(), amd64_code_length);
47 MacroAssembler* masm = new MacroAssembler(&cb);
48
49 #ifndef PRODUCT
50 if (CountCompiledCalls) {
51 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
52 }
53 #endif
54
55 // get receiver (need to skip return address on top of stack)
56 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
57
58 // Free registers (non-args) are rax, rbx
59
60 // get receiver klass
61 address npe_addr = __ pc();
62 __ movq(rax, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));
63
64 // compute entry offset (in words)
65 int entry_offset =
66 instanceKlass::vtable_start_offset() + vtable_index * vtableEntry::size();
67
68 #ifndef PRODUCT
69 if (DebugVtables) {
70 Label L;
71 // check offset vs vtable length
72 __ cmpl(Address(rax, instanceKlass::vtable_length_offset() * wordSize),
73 vtable_index * vtableEntry::size());
74 __ jcc(Assembler::greater, L);
75 __ movl(rbx, vtable_index);
76 __ call_VM(noreg,
77 CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, rbx);
78 __ bind(L);
79 }
80 #endif // PRODUCT
81
82 // load methodOop and target address
83 const Register method = rbx;
84
85 __ movq(method, Address(rax,
86 entry_offset * wordSize +
87 vtableEntry::method_offset_in_bytes()));
88 if (DebugVtables) {
89 Label L;
90 __ cmpq(method, (int)NULL);
91 __ jcc(Assembler::equal, L);
92 __ cmpq(Address(method, methodOopDesc::from_compiled_offset()), (int)NULL_WORD);
93 __ jcc(Assembler::notZero, L);
94 __ stop("Vtable entry is NULL");
95 __ bind(L);
96 }
97 // rax: receiver klass
98 // rbx: methodOop
99 // rcx: receiver
100 address ame_addr = __ pc();
101 __ jmp( Address(rbx, methodOopDesc::from_compiled_offset()));
102
103 __ flush();
104 s->set_exception_points(npe_addr, ame_addr);
105 return s;
106 }
107
108
109 VtableStub* VtableStubs::create_itable_stub(int vtable_index) {
110 // Note well: pd_code_size_limit is the absolute minimum we can get
111 // away with. If you add code here, bump the code stub size
112 // returned by pd_code_size_limit!
113 const int amd64_code_length = VtableStub::pd_code_size_limit(false);
114 VtableStub* s = new(amd64_code_length) VtableStub(false, vtable_index);
115 ResourceMark rm;
116 CodeBuffer cb(s->entry_point(), amd64_code_length);
117 MacroAssembler* masm = new MacroAssembler(&cb);
118
119 #ifndef PRODUCT
120 if (CountCompiledCalls) {
121 __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
122 }
123 #endif
124
125 // Entry arguments:
126 // rax: Interface
127 // j_rarg0: Receiver
128
129 // Free registers (non-args) are rax (interface), rbx
130
131 // get receiver (need to skip return address on top of stack)
132
133 assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
134 // get receiver klass (also an implicit null-check)
135 address npe_addr = __ pc();
136
137 __ movq(rbx, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));
138
139 // If we take a trap while this arg is on the stack we will not
140 // be able to walk the stack properly. This is not an issue except
141 // when there are mistakes in this assembly code that could generate
142 // a spurious fault. Ask me how I know...
143
144 __ pushq(j_rarg1); // Most registers are in use, so save one
145
146 // compute itable entry offset (in words)
147 const int base = instanceKlass::vtable_start_offset() * wordSize;
148 assert(vtableEntry::size() * wordSize == 8,
149 "adjust the scaling in the code below");
150 // Get length of vtable
151 __ movl(j_rarg1,
152 Address(rbx, instanceKlass::vtable_length_offset() * wordSize));
153 __ leaq(rbx, Address(rbx, j_rarg1, Address::times_8, base));
154
155 if (HeapWordsPerLong > 1) {
156 // Round up to align_object_offset boundary
157 __ round_to_q(rbx, BytesPerLong);
158 }
159 Label hit, next, entry, throw_icce;
160
161 __ jmpb(entry);
162
163 __ bind(next);
164 __ addq(rbx, itableOffsetEntry::size() * wordSize);
165
166 __ bind(entry);
167
168 // If the entry is NULL then we've reached the end of the table
169 // without finding the expected interface, so throw an exception
170 __ movq(j_rarg1, Address(rbx, itableOffsetEntry::interface_offset_in_bytes()));
171 __ testq(j_rarg1, j_rarg1);
172 __ jcc(Assembler::zero, throw_icce);
173 __ cmpq(rax, j_rarg1);
174 __ jccb(Assembler::notEqual, next);
175
176 // We found a hit, move offset into j_rarg1
177 __ movl(j_rarg1, Address(rbx, itableOffsetEntry::offset_offset_in_bytes()));
178
179 // Compute itableMethodEntry
180 const int method_offset =
181 (itableMethodEntry::size() * wordSize * vtable_index) +
182 itableMethodEntry::method_offset_in_bytes();
183
184 // Get methodOop and entrypoint for compiler
185
186 // Get klass pointer again
187 __ movq(rax, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));
188
189 const Register method = rbx;
190 __ movq(method, Address(rax, j_rarg1, Address::times_1, method_offset));
191
192 // Restore saved register, before possible trap.
193 __ popq(j_rarg1);
194
195 // method (rbx): methodOop
196 // j_rarg0: receiver
197
198
199 #ifdef ASSERT
200 if (DebugVtables) {
201 Label L2;
202 __ cmpq(method, (int)NULL);
203 __ jcc(Assembler::equal, L2);
204 __ cmpq(Address(method, methodOopDesc::from_compiled_offset()), (int)NULL_WORD);
205 __ jcc(Assembler::notZero, L2);
206 __ stop("compiler entrypoint is null");
207 __ bind(L2);
208 }
209 #endif // ASSERT
210
211 // rbx: methodOop
212 // j_rarg0: receiver
213 address ame_addr = __ pc();
214 __ jmp(Address(method, methodOopDesc::from_compiled_offset()));
215
216 __ bind(throw_icce);
217 // Restore saved register
218 __ popq(j_rarg1);
219 __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
220
221 __ flush();
222
223 guarantee(__ pc() <= s->code_end(), "overflowed buffer");
224
225 s->set_exception_points(npe_addr, ame_addr);
226 return s;
227 }
228
229 int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
230 if (is_vtable_stub) {
231 // Vtable stub size
232 return (DebugVtables ? 512 : 24) + (CountCompiledCalls ? 13 : 0);
233 } else {
234 // Itable stub size
235 return (DebugVtables ? 636 : 72) + (CountCompiledCalls ? 13 : 0);
236 }
237 }
238
239 int VtableStub::pd_code_alignment() {
240 return wordSize;
241 }