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 "context_arm.h"
18
19#include "base/bit_utils.h"
20#include "quick/quick_method_frame_info.h"
21#include "thread-inl.h"
22
23namespace art {
24namespace arm {
25
26static constexpr uint32_t gZero = 0;
27
28void ArmContext::Reset() {
29  std::fill_n(gprs_, arraysize(gprs_), nullptr);
30  std::fill_n(fprs_, arraysize(fprs_), nullptr);
31  gprs_[SP] = &sp_;
32  gprs_[PC] = &pc_;
33  gprs_[R0] = &arg0_;
34  // Initialize registers with easy to spot debug values.
35  sp_ = ArmContext::kBadGprBase + SP;
36  pc_ = ArmContext::kBadGprBase + PC;
37  arg0_ = 0;
38}
39
40void ArmContext::FillCalleeSaves(uint8_t* frame, const QuickMethodFrameInfo& frame_info) {
41  int spill_pos = 0;
42
43  // Core registers come first, from the highest down to the lowest.
44  uint32_t core_regs = frame_info.CoreSpillMask();
45  DCHECK_EQ(0u, core_regs & (static_cast<uint32_t>(-1) << kNumberOfCoreRegisters));
46  for (uint32_t core_reg : HighToLowBits(core_regs)) {
47    gprs_[core_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
48    ++spill_pos;
49  }
50  DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()));
51
52  // FP registers come second, from the highest down to the lowest.
53  for (uint32_t fp_reg : HighToLowBits(frame_info.FpSpillMask())) {
54    fprs_[fp_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
55    ++spill_pos;
56  }
57  DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()) + POPCOUNT(frame_info.FpSpillMask()));
58}
59
60void ArmContext::SetGPR(uint32_t reg, uintptr_t value) {
61  DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfCoreRegisters));
62  DCHECK(IsAccessibleGPR(reg));
63  DCHECK_NE(gprs_[reg], &gZero);  // Can't overwrite this static value since they are never reset.
64  *gprs_[reg] = value;
65}
66
67void ArmContext::SetFPR(uint32_t reg, uintptr_t value) {
68  DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfSRegisters));
69  DCHECK(IsAccessibleFPR(reg));
70  DCHECK_NE(fprs_[reg], &gZero);  // Can't overwrite this static value since they are never reset.
71  *fprs_[reg] = value;
72}
73
74void ArmContext::SmashCallerSaves() {
75  // This needs to be 0 because we want a null/zero return value.
76  gprs_[R0] = const_cast<uint32_t*>(&gZero);
77  gprs_[R1] = const_cast<uint32_t*>(&gZero);
78  gprs_[R2] = nullptr;
79  gprs_[R3] = nullptr;
80
81  fprs_[S0] = nullptr;
82  fprs_[S1] = nullptr;
83  fprs_[S2] = nullptr;
84  fprs_[S3] = nullptr;
85  fprs_[S4] = nullptr;
86  fprs_[S5] = nullptr;
87  fprs_[S6] = nullptr;
88  fprs_[S7] = nullptr;
89  fprs_[S8] = nullptr;
90  fprs_[S9] = nullptr;
91  fprs_[S10] = nullptr;
92  fprs_[S11] = nullptr;
93  fprs_[S12] = nullptr;
94  fprs_[S13] = nullptr;
95  fprs_[S14] = nullptr;
96  fprs_[S15] = nullptr;
97}
98
99extern "C" NO_RETURN void art_quick_do_long_jump(uint32_t*, uint32_t*);
100
101void ArmContext::DoLongJump() {
102  uintptr_t gprs[kNumberOfCoreRegisters];
103  uint32_t fprs[kNumberOfSRegisters];
104  for (size_t i = 0; i < kNumberOfCoreRegisters; ++i) {
105    gprs[i] = gprs_[i] != nullptr ? *gprs_[i] : ArmContext::kBadGprBase + i;
106  }
107  for (size_t i = 0; i < kNumberOfSRegisters; ++i) {
108    fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : ArmContext::kBadFprBase + i;
109  }
110  DCHECK_EQ(reinterpret_cast<uintptr_t>(Thread::Current()), gprs[TR]);
111  art_quick_do_long_jump(gprs, fprs);
112}
113
114}  // namespace arm
115}  // namespace art
116