1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2014, Red Hat Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "code/compiledIC.hpp"
29 #include "code/icBuffer.hpp"
30 #include "code/nmethod.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "runtime/mutexLocker.hpp"
33 #include "runtime/safepoint.hpp"
34
35 // ----------------------------------------------------------------------------
36
37 #define __ _masm.
38 address CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf, address mark) {
39 // Stub is fixed up when the corresponding call is converted from
40 // calling compiled code to calling interpreted code.
41 // mov rmethod, 0
42 // jmp -4 # to self
43
44 if (mark == NULL) {
45 mark = cbuf.insts_mark(); // Get mark within main instrs section.
46 }
47
48 // Note that the code buffer's insts_mark is always relative to insts.
49 // That's why we must use the macroassembler to generate a stub.
50 MacroAssembler _masm(&cbuf);
51
52 address base = __ start_a_stub(to_interp_stub_size());
53 int offset = __ offset();
54 if (base == NULL) {
55 return NULL; // CodeBuffer::expand failed
56 }
57 // static stub relocation stores the instruction address of the call
58 __ relocate(static_stub_Relocation::spec(mark));
59 // static stub relocation also tags the Method* in the code-stream.
60 __ mov_metadata(rmethod, (Metadata*)NULL);
61 __ movptr(rscratch1, 0);
62 __ br(rscratch1);
63
64 assert((__ offset() - offset) <= (int)to_interp_stub_size(), "stub too big");
65 __ end_a_stub();
66 return base;
67 }
68 #undef __
69
70 int CompiledStaticCall::to_interp_stub_size() {
71 return 7 * NativeInstruction::instruction_size;
72 }
73
74 int CompiledStaticCall::to_trampoline_stub_size() {
75 // Somewhat pessimistically, we count 3 instructions here (although
76 // there are only two) because we sometimes emit an alignment nop.
77 // Trampoline stubs are always word aligned.
78 return 3 * NativeInstruction::instruction_size + wordSize;
79 }
80
81 // Relocation entries for call stub, compiled java to interpreter.
82 int CompiledStaticCall::reloc_to_interp_stub() {
83 return 4; // 3 in emit_to_interp_stub + 1 in emit_call
84 }
85
86 void CompiledDirectStaticCall::set_to_interpreted(const methodHandle& callee, address entry) {
87 address stub = find_stub(false /* is_aot */);
88 guarantee(stub != NULL, "stub not found");
89
90 if (TraceICs) {
91 ResourceMark rm;
92 tty->print_cr("CompiledDirectStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
93 p2i(instruction_address()),
94 callee->name_and_sig_as_C_string());
95 }
96
97 // Creation also verifies the object.
98 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
99 #ifndef PRODUCT
100 NativeGeneralJump* jump = nativeGeneralJump_at(method_holder->next_instruction_address());
101
102 // read the value once
103 volatile intptr_t data = method_holder->data();
104 assert(data == 0 || data == (intptr_t)callee(),
105 "a) MT-unsafe modification of inline cache");
106 assert(data == 0 || jump->jump_destination() == entry,
107 "b) MT-unsafe modification of inline cache");
108 #endif
109 // Update stub.
110 method_holder->set_data((intptr_t)callee());
111 NativeGeneralJump::insert_unconditional(method_holder->next_instruction_address(), entry);
112 ICache::invalidate_range(stub, to_interp_stub_size());
113 // Update jump to call.
114 set_destination_mt_safe(stub);
115 }
116
117 void CompiledDirectStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
118 assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
119 // Reset stub.
120 address stub = static_stub->addr();
121 assert(stub != NULL, "stub not found");
122 // Creation also verifies the object.
123 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
124 method_holder->set_data(0);
125 }
126
127 //-----------------------------------------------------------------------------
128 // Non-product mode code
129 #ifndef PRODUCT
130
131 void CompiledDirectStaticCall::verify() {
132 // Verify call.
133 _call->verify();
134 if (os::is_MP()) {
135 _call->verify_alignment();
136 }
137
138 // Verify stub.
139 address stub = find_stub(false /* is_aot */);
140 assert(stub != NULL, "no stub found for static call");
141 // Creation also verifies the object.
142 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
143 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
144
145 // Verify state.
146 assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
147 }
148
149 #endif // !PRODUCT