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 #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 // High-level access to an inline cache. Guaranteed to be MT-safe.
55
56 CompiledIC::CompiledIC(nmethod* nm, NativeCall* call)
57 : _ic_call(call)
58 {
59 address ic_call = call->instruction_address();
60
61 assert(ic_call != NULL, "ic_call address must be set");
62 assert(nm != NULL, "must pass nmethod");
63 assert(nm->contains(ic_call), "must be in nmethod");
64
65 // Search for the ic_call at the given address.
66 RelocIterator iter(nm, ic_call, ic_call+1);
67 bool ret = iter.next();
68 assert(ret == true, "relocInfo must exist at this address");
69 assert(iter.addr() == ic_call, "must find ic_call");
70 if (iter.type() == relocInfo::virtual_call_type) {
71 virtual_call_Relocation* r = iter.virtual_call_reloc();
72 _is_optimized = false;
73 _value = nativeMovConstReg_at(r->cached_value());
74 } else {
75 assert(iter.type() == relocInfo::opt_virtual_call_type, "must be a virtual call");
76 _is_optimized = true;
77 _value = NULL;
78 }
79 }
80
81 // ----------------------------------------------------------------------------
82
83 // A PPC CompiledStaticCall looks like this:
84 //
85 // >>>> consts
86 //
87 // [call target1]
88 // [IC cache]
89 // [call target2]
90 //
91 // <<<< consts
92 // >>>> insts
93 //
94 // bl offset16 -+ -+ ??? // How many bits available?
95 // | |
96 // <<<< insts | |
97 // >>>> stubs | |
98 // | |- trampoline_stub_Reloc
99 // trampoline stub: | <-+
100 // r2 = toc |
101 // r2 = [r2 + offset] | // Load call target1 from const section
102 // mtctr r2 |
103 // bctr |- static_stub_Reloc
104 // comp_to_interp_stub: <---+
105 // r1 = toc
106 // ICreg = [r1 + IC_offset] // Load IC from const section
107 // r1 = [r1 + offset] // Load call target2 from const section
108 // mtctr r1
109 // bctr
110 //
111 // <<<< stubs
112 //
113 // The call instruction in the code either
114 // - branches directly to a compiled method if offset encodable in instruction
115 // - branches to the trampoline stub if offset to compiled method not encodable
116 // - branches to the compiled_to_interp stub if target interpreted
117 //
118 // Further there are three relocations from the loads to the constants in
119 // the constant section.
120 //
121 // Usage of r1 and r2 in the stubs allows to distinguish them.
122
123 const int IC_pos_in_java_to_interp_stub = 8;
124 #define __ _masm.
125 void CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf) {
126 #ifdef COMPILER2
127 // Get the mark within main instrs section which is set to the address of the call.
128 address call_addr = cbuf.insts_mark();
129
130 // Note that the code buffer's insts_mark is always relative to insts.
131 // That's why we must use the macroassembler to generate a stub.
132 MacroAssembler _masm(&cbuf);
133
134 // Start the stub.
135 address stub = __ start_a_stub(CompiledStaticCall::to_interp_stub_size());
136 if (stub == NULL) {
137 Compile::current()->env()->record_out_of_memory_failure();
138 return;
139 }
140
141 // For java_to_interp stubs we use R11_scratch1 as scratch register
142 // and in call trampoline stubs we use R12_scratch2. This way we
143 // can distinguish them (see is_NativeCallTrampolineStub_at()).
144 Register reg_scratch = R11_scratch1;
145
146 // Create a static stub relocation which relates this stub
147 // with the call instruction at insts_call_instruction_offset in the
148 // instructions code-section.
149 __ relocate(static_stub_Relocation::spec(call_addr));
150 const int stub_start_offset = __ offset();
151
152 // Now, create the stub's code:
153 // - load the TOC
154 // - load the inline cache oop from the constant pool
155 // - load the call target from the constant pool
156 // - call
157 __ calculate_address_from_global_toc(reg_scratch, __ method_toc());
158 AddressLiteral ic = __ allocate_metadata_address((Metadata *)NULL);
159 __ load_const_from_method_toc(as_Register(Matcher::inline_cache_reg_encode()), ic, reg_scratch);
160
161 if (ReoptimizeCallSequences) {
162 __ b64_patchable((address)-1, relocInfo::none);
163 } else {
164 AddressLiteral a((address)-1);
165 __ load_const_from_method_toc(reg_scratch, a, reg_scratch);
166 __ mtctr(reg_scratch);
167 __ bctr();
168 }
169
170 // FIXME: Assert that the stub can be identified and patched.
171
172 // Java_to_interp_stub_size should be good.
173 assert((__ offset() - stub_start_offset) <= CompiledStaticCall::to_interp_stub_size(),
174 "should be good size");
175 assert(!is_NativeCallTrampolineStub_at(__ addr_at(stub_start_offset)),
176 "must not confuse java_to_interp with trampoline stubs");
177
178 // End the stub.
179 __ end_a_stub();
180 #else
181 ShouldNotReachHere();
182 #endif
183 }
184 #undef __
185
186 // Size of java_to_interp stub, this doesn't need to be accurate but it must
187 // be larger or equal to the real size of the stub.
188 // Used for optimization in Compile::Shorten_branches.
189 int CompiledStaticCall::to_interp_stub_size() {
190 return 12 * BytesPerInstWord;
191 }
192
193 // Relocation entries for call stub, compiled java to interpreter.
194 // Used for optimization in Compile::Shorten_branches.
195 int CompiledStaticCall::reloc_to_interp_stub() {
196 return 5;
197 }
198
199 void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {
200 address stub = find_stub();
201 guarantee(stub != NULL, "stub not found");
202
203 if (TraceICs) {
204 ResourceMark rm;
205 tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
206 instruction_address(),
207 callee->name_and_sig_as_C_string());
208 }
209
210 // Creation also verifies the object.
211 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
212 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
213
214 assert(method_holder->data() == 0 || method_holder->data() == (intptr_t)callee(),
215 "a) MT-unsafe modification of inline cache");
216 assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry,
217 "b) MT-unsafe modification of inline cache");
218
219 // Update stub.
220 method_holder->set_data((intptr_t)callee());
221 jump->set_jump_destination(entry);
222
223 // Update jump to call.
224 set_destination_mt_safe(stub);
225 }
226
227 void CompiledStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
228 assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
229 // Reset stub.
230 address stub = static_stub->addr();
231 assert(stub != NULL, "stub not found");
232 // Creation also verifies the object.
233 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
234 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
235 method_holder->set_data(0);
236 jump->set_jump_destination((address)-1);
237 }
238
239 //-----------------------------------------------------------------------------
240 // Non-product mode code
241 #ifndef PRODUCT
242
243 void CompiledStaticCall::verify() {
244 // Verify call.
245 NativeCall::verify();
246 if (os::is_MP()) {
247 verify_alignment();
248 }
249
250 // Verify stub.
251 address stub = find_stub();
252 assert(stub != NULL, "no stub found for static call");
253 // Creation also verifies the object.
254 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
255 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
256
257 // Verify state.
258 assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
259 }
260
261 #endif // !PRODUCT