1 /*
2 * Copyright (c) 1997, 2014, 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 #ifdef COMPILER2
34 #include "opto/matcher.hpp"
35 #endif
36
37 // Release the CompiledICHolder* associated with this call site is there is one.
38 void CompiledIC::cleanup_call_site(virtual_call_Relocation* call_site) {
39 // This call site might have become stale so inspect it carefully.
40 NativeCall* call = nativeCall_at(call_site->addr());
41 if (is_icholder_entry(call->destination())) {
42 NativeMovConstReg* value = nativeMovConstReg_at(call_site->cached_value());
43 InlineCacheBuffer::queue_for_release((CompiledICHolder*)value->data());
44 }
45 }
46
47 bool CompiledIC::is_icholder_call_site(virtual_call_Relocation* call_site) {
48 // This call site might have become stale so inspect it carefully.
49 NativeCall* call = nativeCall_at(call_site->addr());
50 return is_icholder_entry(call->destination());
51 }
52
53 // ----------------------------------------------------------------------------
54
55 // A PPC CompiledStaticCall looks like this:
56 //
57 // >>>> consts
58 //
59 // [call target1]
60 // [IC cache]
61 // [call target2]
62 //
63 // <<<< consts
64 // >>>> insts
65 //
66 // bl offset16 -+ -+ ??? // How many bits available?
67 // | |
68 // <<<< insts | |
69 // >>>> stubs | |
70 // | |- trampoline_stub_Reloc
71 // trampoline stub: | <-+
72 // r2 = toc |
73 // r2 = [r2 + offset] | // Load call target1 from const section
74 // mtctr r2 |
75 // bctr |- static_stub_Reloc
76 // comp_to_interp_stub: <---+
77 // r1 = toc
78 // ICreg = [r1 + IC_offset] // Load IC from const section
79 // r1 = [r1 + offset] // Load call target2 from const section
80 // mtctr r1
81 // bctr
82 //
83 // <<<< stubs
84 //
85 // The call instruction in the code either
86 // - branches directly to a compiled method if offset encodable in instruction
87 // - branches to the trampoline stub if offset to compiled method not encodable
88 // - branches to the compiled_to_interp stub if target interpreted
89 //
90 // Further there are three relocations from the loads to the constants in
91 // the constant section.
92 //
93 // Usage of r1 and r2 in the stubs allows to distinguish them.
94
95 const int IC_pos_in_java_to_interp_stub = 8;
96 #define __ _masm.
97 address CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf, address mark/* = NULL*/) {
98 #ifdef COMPILER2
99 if (mark == NULL) {
100 // Get the mark within main instrs section which is set to the address of the call.
101 mark = cbuf.insts_mark();
102 }
103
104 // Note that the code buffer's insts_mark is always relative to insts.
105 // That's why we must use the macroassembler to generate a stub.
106 MacroAssembler _masm(&cbuf);
107
108 // Start the stub.
109 address stub = __ start_a_stub(CompiledStaticCall::to_interp_stub_size());
110 if (stub == NULL) {
111 return NULL; // CodeCache is full
112 }
113
114 // For java_to_interp stubs we use R11_scratch1 as scratch register
115 // and in call trampoline stubs we use R12_scratch2. This way we
116 // can distinguish them (see is_NativeCallTrampolineStub_at()).
117 Register reg_scratch = R11_scratch1;
118
119 // Create a static stub relocation which relates this stub
120 // with the call instruction at insts_call_instruction_offset in the
121 // instructions code-section.
122 __ relocate(static_stub_Relocation::spec(mark));
123 const int stub_start_offset = __ offset();
124
125 // Now, create the stub's code:
126 // - load the TOC
127 // - load the inline cache oop from the constant pool
128 // - load the call target from the constant pool
129 // - call
130 __ calculate_address_from_global_toc(reg_scratch, __ method_toc());
131 AddressLiteral ic = __ allocate_metadata_address((Metadata *)NULL);
132 __ load_const_from_method_toc(as_Register(Matcher::inline_cache_reg_encode()), ic, reg_scratch);
133
134 if (ReoptimizeCallSequences) {
135 __ b64_patchable((address)-1, relocInfo::none);
136 } else {
137 AddressLiteral a((address)-1);
138 __ load_const_from_method_toc(reg_scratch, a, reg_scratch);
139 __ mtctr(reg_scratch);
140 __ bctr();
141 }
142
143 // FIXME: Assert that the stub can be identified and patched.
144
145 // Java_to_interp_stub_size should be good.
146 assert((__ offset() - stub_start_offset) <= CompiledStaticCall::to_interp_stub_size(),
147 "should be good size");
148 assert(!is_NativeCallTrampolineStub_at(__ addr_at(stub_start_offset)),
149 "must not confuse java_to_interp with trampoline stubs");
150
151 // End the stub.
152 __ end_a_stub();
153 return stub;
154 #else
155 ShouldNotReachHere();
156 #endif
157 }
158 #undef __
159
160 // Size of java_to_interp stub, this doesn't need to be accurate but it must
161 // be larger or equal to the real size of the stub.
162 // Used for optimization in Compile::Shorten_branches.
163 int CompiledStaticCall::to_interp_stub_size() {
164 return 12 * BytesPerInstWord;
165 }
166
167 // Relocation entries for call stub, compiled java to interpreter.
168 // Used for optimization in Compile::Shorten_branches.
169 int CompiledStaticCall::reloc_to_interp_stub() {
170 return 5;
171 }
172
173 void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {
174 address stub = find_stub();
175 guarantee(stub != NULL, "stub not found");
176
177 if (TraceICs) {
178 ResourceMark rm;
179 tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
180 p2i(instruction_address()),
181 callee->name_and_sig_as_C_string());
182 }
183
184 // Creation also verifies the object.
185 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
186 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
187
188 assert(method_holder->data() == 0 || method_holder->data() == (intptr_t)callee(),
189 "a) MT-unsafe modification of inline cache");
190 assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry,
191 "b) MT-unsafe modification of inline cache");
192
193 // Update stub.
194 method_holder->set_data((intptr_t)callee());
195 jump->set_jump_destination(entry);
196
197 // Update jump to call.
198 set_destination_mt_safe(stub);
199 }
200
201 void CompiledStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
202 assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
203 // Reset stub.
204 address stub = static_stub->addr();
205 assert(stub != NULL, "stub not found");
206 // Creation also verifies the object.
207 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
208 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
209 method_holder->set_data(0);
210 jump->set_jump_destination((address)-1);
211 }
212
213 //-----------------------------------------------------------------------------
214 // Non-product mode code
215 #ifndef PRODUCT
216
217 void CompiledStaticCall::verify() {
218 // Verify call.
219 NativeCall::verify();
220 if (os::is_MP()) {
221 verify_alignment();
222 }
223
224 // Verify stub.
225 address stub = find_stub();
226 assert(stub != NULL, "no stub found for static call");
227 // Creation also verifies the object.
228 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
229 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
230
231 // Verify state.
232 assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
233 }
234
235 #endif // !PRODUCT