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.
38address 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
70int CompiledStaticCall::to_interp_stub_size() {
71  return 7 * NativeInstruction::instruction_size;
72}
73
74// Relocation entries for call stub, compiled java to interpreter.
75int CompiledStaticCall::reloc_to_interp_stub() {
76  return 4; // 3 in emit_to_interp_stub + 1 in emit_call
77}
78
79void CompiledDirectStaticCall::set_to_interpreted(const methodHandle& callee, address entry) {
80  address stub = find_stub(false /* is_aot */);
81  guarantee(stub != NULL, "stub not found");
82
83  if (TraceICs) {
84    ResourceMark rm;
85    tty->print_cr("CompiledDirectStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
86                  p2i(instruction_address()),
87                  callee->name_and_sig_as_C_string());
88  }
89
90  // Creation also verifies the object.
91  NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
92#ifndef PRODUCT
93  NativeGeneralJump* jump = nativeGeneralJump_at(method_holder->next_instruction_address());
94
95  // read the value once
96  volatile intptr_t data = method_holder->data();
97  assert(data == 0 || data == (intptr_t)callee(),
98         "a) MT-unsafe modification of inline cache");
99  assert(data == 0 || jump->jump_destination() == entry,
100         "b) MT-unsafe modification of inline cache");
101#endif
102  // Update stub.
103  method_holder->set_data((intptr_t)callee());
104  NativeGeneralJump::insert_unconditional(method_holder->next_instruction_address(), entry);
105  ICache::invalidate_range(stub, to_interp_stub_size());
106  // Update jump to call.
107  set_destination_mt_safe(stub);
108}
109
110void CompiledDirectStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
111  assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
112  // Reset stub.
113  address stub = static_stub->addr();
114  assert(stub != NULL, "stub not found");
115  // Creation also verifies the object.
116  NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
117  method_holder->set_data(0);
118}
119
120//-----------------------------------------------------------------------------
121// Non-product mode code
122#ifndef PRODUCT
123
124void CompiledDirectStaticCall::verify() {
125  // Verify call.
126  _call->verify();
127  if (os::is_MP()) {
128    _call->verify_alignment();
129  }
130
131  // Verify stub.
132  address stub = find_stub(false /* is_aot */);
133  assert(stub != NULL, "no stub found for static call");
134  // Creation also verifies the object.
135  NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
136  NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
137
138  // Verify state.
139  assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
140}
141
142#endif // !PRODUCT
143