1 /*
2 * Copyright (c) 1997, 2016, 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 // ----------------------------------------------------------------------------
35
36 #define __ _masm.
37 address CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf, address mark) {
38 // Stub is fixed up when the corresponding call is converted from
39 // calling compiled code to calling interpreted code.
40 // movq rbx, 0
41 // jmp -5 # to self
42
43 if (mark == NULL) {
44 mark = cbuf.insts_mark(); // Get mark within main instrs section.
45 }
46
47 // Note that the code buffer's insts_mark is always relative to insts.
48 // That's why we must use the macroassembler to generate a stub.
49 MacroAssembler _masm(&cbuf);
50
51 address base = __ start_a_stub(to_interp_stub_size());
52 if (base == NULL) {
53 return NULL; // CodeBuffer::expand failed.
54 }
55 // Static stub relocation stores the instruction address of the call.
56 __ relocate(static_stub_Relocation::spec(mark), Assembler::imm_operand);
57 // Static stub relocation also tags the Method* in the code-stream.
58 __ mov_metadata(rbx, (Metadata*) NULL); // Method is zapped till fixup time.
59 // This is recognized as unresolved by relocs/nativeinst/ic code.
60 __ jump(RuntimeAddress(__ pc()));
61
62 assert(__ pc() - base <= to_interp_stub_size(), "wrong stub size");
63
64 // Update current stubs pointer and restore insts_end.
65 __ end_a_stub();
66 return base;
67 }
68 #undef __
69
70 int CompiledStaticCall::to_interp_stub_size() {
71 return NOT_LP64(10) // movl; jmp
72 LP64_ONLY(15); // movq (1+1+8); jmp (1+4)
73 }
74
75 // Relocation entries for call stub, compiled java to interpreter.
76 int CompiledStaticCall::reloc_to_interp_stub() {
77 return 4; // 3 in emit_to_interp_stub + 1 in emit_call
78 }
79
80 void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {
81 address stub = find_stub();
82 guarantee(stub != NULL, "stub not found");
83
84 if (TraceICs) {
85 ResourceMark rm;
86 tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
87 p2i(instruction_address()),
88 callee->name_and_sig_as_C_string());
89 }
90
91 // Creation also verifies the object.
92 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
93 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
94
95 #ifdef ASSERT
96 // read the value once
97 intptr_t data = method_holder->data();
98 address destination = jump->jump_destination();
99 assert(data == 0 || data == (intptr_t)callee(),
100 "a) MT-unsafe modification of inline cache");
101 assert(destination == (address)-1 || destination == entry,
102 "b) MT-unsafe modification of inline cache");
103 #endif
104
105 // Update stub.
106 method_holder->set_data((intptr_t)callee());
107 jump->set_jump_destination(entry);
108
109 // Update jump to call.
110 set_destination_mt_safe(stub);
111 }
112
113 void CompiledStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
114 assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
115 // Reset stub.
116 address stub = static_stub->addr();
117 assert(stub != NULL, "stub not found");
118 // Creation also verifies the object.
119 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
120 method_holder->set_data(0);
121 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
122 jump->set_jump_destination((address)-1);
123 }
124
125
126 //-----------------------------------------------------------------------------
127 // Non-product mode code
128 #ifndef PRODUCT
129
130 void CompiledStaticCall::verify() {
131 // Verify call.
132 NativeCall::verify();
133 if (os::is_MP()) {
134 verify_alignment();
135 }
136
137 // Verify stub.
138 address stub = find_stub();
139 assert(stub != NULL, "no stub found for static call");
140 // Creation also verifies the object.
141 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
142 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
143
144 // Verify state.
145 assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
146 }
147 #endif // !PRODUCT