1 /*
2 * Copyright (c) 1997, 2013, 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/macroAssembler.inline.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/icBuffer.hpp"
29 #include "code/nmethod.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "runtime/mutexLocker.hpp"
32 #include "runtime/safepoint.hpp"
33
34 // Release the CompiledICHolder* associated with this call site is there is one.
35 void CompiledIC::cleanup_call_site(virtual_call_Relocation* call_site) {
36 // This call site might have become stale so inspect it carefully.
37 NativeCall* call = nativeCall_at(call_site->addr());
38 if (is_icholder_entry(call->destination())) {
39 NativeMovConstReg* value = nativeMovConstReg_at(call_site->cached_value());
40 InlineCacheBuffer::queue_for_release((CompiledICHolder*)value->data());
41 }
42 }
43
44 bool CompiledIC::is_icholder_call_site(virtual_call_Relocation* call_site) {
45 // This call site might have become stale so inspect it carefully.
46 NativeCall* call = nativeCall_at(call_site->addr());
47 return is_icholder_entry(call->destination());
48 }
49
50 //-----------------------------------------------------------------------------
51 // High-level access to an inline cache. Guaranteed to be MT-safe.
52
53 CompiledIC::CompiledIC(nmethod* nm, NativeCall* call)
54 : _ic_call(call)
55 {
56 address ic_call = call->instruction_address();
57
58 assert(ic_call != NULL, "ic_call address must be set");
59 assert(nm != NULL, "must pass nmethod");
60 assert(nm->contains(ic_call), "must be in nmethod");
61
62 // Search for the ic_call at the given address.
63 RelocIterator iter(nm, ic_call, ic_call+1);
64 bool ret = iter.next();
65 assert(ret == true, "relocInfo must exist at this address");
66 assert(iter.addr() == ic_call, "must find ic_call");
67 if (iter.type() == relocInfo::virtual_call_type) {
68 virtual_call_Relocation* r = iter.virtual_call_reloc();
69 _is_optimized = false;
70 _value = nativeMovConstReg_at(r->cached_value());
71 } else {
72 assert(iter.type() == relocInfo::opt_virtual_call_type, "must be a virtual call");
73 _is_optimized = true;
74 _value = NULL;
75 }
76 }
77
78 // ----------------------------------------------------------------------------
79
80 #define __ _masm.
81 void CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf) {
82 // Stub is fixed up when the corresponding call is converted from
83 // calling compiled code to calling interpreted code.
84 // movq rbx, 0
85 // jmp -5 # to self
86
87 address mark = cbuf.insts_mark(); // Get mark within main instrs section.
88
89 // Note that the code buffer's insts_mark is always relative to insts.
90 // That's why we must use the macroassembler to generate a stub.
91 MacroAssembler _masm(&cbuf);
92
93 address base =
94 __ start_a_stub(to_interp_stub_size()*2);
95 if (base == NULL) return; // CodeBuffer::expand failed.
96 // Static stub relocation stores the instruction address of the call.
97 __ relocate(static_stub_Relocation::spec(mark), Assembler::imm_operand);
98 // Static stub relocation also tags the Method* in the code-stream.
99 __ mov_metadata(rbx, (Metadata*) NULL); // Method is zapped till fixup time.
100 // This is recognized as unresolved by relocs/nativeinst/ic code.
101 __ jump(RuntimeAddress(__ pc()));
102
103 // Update current stubs pointer and restore insts_end.
104 __ end_a_stub();
105 }
106 #undef __
107
108 int CompiledStaticCall::to_interp_stub_size() {
109 return NOT_LP64(10) // movl; jmp
110 LP64_ONLY(15); // movq (1+1+8); jmp (1+4)
111 }
112
113 // Relocation entries for call stub, compiled java to interpreter.
114 int CompiledStaticCall::reloc_to_interp_stub() {
115 return 4; // 3 in emit_to_interp_stub + 1 in emit_call
116 }
117
118 void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {
119 address stub = find_stub();
120 guarantee(stub != NULL, "stub not found");
121
122 if (TraceICs) {
123 ResourceMark rm;
124 tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
125 p2i(instruction_address()),
126 callee->name_and_sig_as_C_string());
127 }
128
129 // Creation also verifies the object.
130 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
131 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
132
133 assert(method_holder->data() == 0 || method_holder->data() == (intptr_t)callee(),
134 "a) MT-unsafe modification of inline cache");
135 assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry,
136 "b) MT-unsafe modification of inline cache");
137
138 // Update stub.
139 method_holder->set_data((intptr_t)callee());
140 jump->set_jump_destination(entry);
141
142 // Update jump to call.
143 set_destination_mt_safe(stub);
144 }
145
146 void CompiledStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
147 assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
148 // Reset stub.
149 address stub = static_stub->addr();
150 assert(stub != NULL, "stub not found");
151 // Creation also verifies the object.
152 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
153 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
154 method_holder->set_data(0);
155 jump->set_jump_destination((address)-1);
156 }
157
158 //-----------------------------------------------------------------------------
159 // Non-product mode code
160 #ifndef PRODUCT
161
162 void CompiledStaticCall::verify() {
163 // Verify call.
164 NativeCall::verify();
165 if (os::is_MP()) {
166 verify_alignment();
167 }
168
169 // Verify stub.
170 address stub = find_stub();
171 assert(stub != NULL, "no stub found for static call");
172 // Creation also verifies the object.
173 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
174 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
175
176 // Verify state.
177 assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
178 }
179
180 #endif // !PRODUCT