assembler.cc revision ed8dd492e43cbaaa435c4892447072c84dbaf2dc 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "assembler.h"
18
19#include <algorithm>
20#include <vector>
21
22#include "arm/assembler_arm.h"
23#include "arm64/assembler_arm64.h"
24#include "mips/assembler_mips.h"
25#include "x86/assembler_x86.h"
26#include "globals.h"
27#include "memory_region.h"
28
29namespace art {
30
31static byte* NewContents(size_t capacity) {
32  return new byte[capacity];
33}
34
35
36AssemblerBuffer::AssemblerBuffer() {
37  static const size_t kInitialBufferCapacity = 4 * KB;
38  contents_ = NewContents(kInitialBufferCapacity);
39  cursor_ = contents_;
40  limit_ = ComputeLimit(contents_, kInitialBufferCapacity);
41  fixup_ = NULL;
42  slow_path_ = NULL;
43#ifndef NDEBUG
44  has_ensured_capacity_ = false;
45  fixups_processed_ = false;
46#endif
47
48  // Verify internal state.
49  CHECK_EQ(Capacity(), kInitialBufferCapacity);
50  CHECK_EQ(Size(), 0U);
51}
52
53
54AssemblerBuffer::~AssemblerBuffer() {
55  delete[] contents_;
56}
57
58
59void AssemblerBuffer::ProcessFixups(const MemoryRegion& region) {
60  AssemblerFixup* fixup = fixup_;
61  while (fixup != NULL) {
62    fixup->Process(region, fixup->position());
63    fixup = fixup->previous();
64  }
65}
66
67
68void AssemblerBuffer::FinalizeInstructions(const MemoryRegion& instructions) {
69  // Copy the instructions from the buffer.
70  MemoryRegion from(reinterpret_cast<void*>(contents()), Size());
71  instructions.CopyFrom(0, from);
72  // Process fixups in the instructions.
73  ProcessFixups(instructions);
74#ifndef NDEBUG
75  fixups_processed_ = true;
76#endif
77}
78
79
80void AssemblerBuffer::ExtendCapacity() {
81  size_t old_size = Size();
82  size_t old_capacity = Capacity();
83  size_t new_capacity = std::min(old_capacity * 2, old_capacity + 1 * MB);
84
85  // Allocate the new data area and copy contents of the old one to it.
86  byte* new_contents = NewContents(new_capacity);
87  memmove(reinterpret_cast<void*>(new_contents),
88          reinterpret_cast<void*>(contents_),
89          old_size);
90
91  // Compute the relocation delta and switch to the new contents area.
92  ptrdiff_t delta = new_contents - contents_;
93  contents_ = new_contents;
94
95  // Update the cursor and recompute the limit.
96  cursor_ += delta;
97  limit_ = ComputeLimit(new_contents, new_capacity);
98
99  // Verify internal state.
100  CHECK_EQ(Capacity(), new_capacity);
101  CHECK_EQ(Size(), old_size);
102}
103
104
105Assembler* Assembler::Create(InstructionSet instruction_set) {
106  switch (instruction_set) {
107    case kArm:
108    case kThumb2:
109      return new arm::ArmAssembler();
110    case kArm64:
111      return new arm64::Arm64Assembler();
112    case kMips:
113      return new mips::MipsAssembler();
114    case kX86:
115      return new x86::X86Assembler();
116    default:
117      LOG(FATAL) << "Unknown InstructionSet: " << instruction_set;
118      return NULL;
119  }
120}
121
122}  // namespace art
123