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 "mirror/art_method-inl.h"
20 #include "mirror/object-inl.h"
21 #include "quick/quick_method_frame_info.h"
22 #include "stack.h"
23 #include "thread.h"
24
25 namespace art {
26 namespace arm {
27
28 static constexpr uint32_t gZero = 0;
29
Reset()30 void ArmContext::Reset() {
31 for (size_t i = 0; i < kNumberOfCoreRegisters; i++) {
32 gprs_[i] = nullptr;
33 }
34 for (size_t i = 0; i < kNumberOfSRegisters; i++) {
35 fprs_[i] = nullptr;
36 }
37 gprs_[SP] = &sp_;
38 gprs_[PC] = &pc_;
39 // Initialize registers with easy to spot debug values.
40 sp_ = ArmContext::kBadGprBase + SP;
41 pc_ = ArmContext::kBadGprBase + PC;
42 }
43
FillCalleeSaves(const StackVisitor & fr)44 void ArmContext::FillCalleeSaves(const StackVisitor& fr) {
45 mirror::ArtMethod* method = fr.GetMethod();
46 const QuickMethodFrameInfo frame_info = method->GetQuickFrameInfo();
47 size_t spill_count = POPCOUNT(frame_info.CoreSpillMask());
48 size_t fp_spill_count = POPCOUNT(frame_info.FpSpillMask());
49 if (spill_count > 0) {
50 // Lowest number spill is farthest away, walk registers and fill into context
51 int j = 1;
52 for (size_t i = 0; i < kNumberOfCoreRegisters; i++) {
53 if (((frame_info.CoreSpillMask() >> i) & 1) != 0) {
54 gprs_[i] = fr.CalleeSaveAddress(spill_count - j, frame_info.FrameSizeInBytes());
55 j++;
56 }
57 }
58 }
59 if (fp_spill_count > 0) {
60 // Lowest number spill is farthest away, walk registers and fill into context
61 int j = 1;
62 for (size_t i = 0; i < kNumberOfSRegisters; i++) {
63 if (((frame_info.FpSpillMask() >> i) & 1) != 0) {
64 fprs_[i] = fr.CalleeSaveAddress(spill_count + fp_spill_count - j,
65 frame_info.FrameSizeInBytes());
66 j++;
67 }
68 }
69 }
70 }
71
SetGPR(uint32_t reg,uintptr_t value)72 bool ArmContext::SetGPR(uint32_t reg, uintptr_t value) {
73 DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfCoreRegisters));
74 DCHECK_NE(gprs_[reg], &gZero); // Can't overwrite this static value since they are never reset.
75 if (gprs_[reg] != nullptr) {
76 *gprs_[reg] = value;
77 return true;
78 } else {
79 return false;
80 }
81 }
82
SetFPR(uint32_t reg,uintptr_t value)83 bool ArmContext::SetFPR(uint32_t reg, uintptr_t value) {
84 DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfSRegisters));
85 DCHECK_NE(fprs_[reg], &gZero); // Can't overwrite this static value since they are never reset.
86 if (fprs_[reg] != nullptr) {
87 *fprs_[reg] = value;
88 return true;
89 } else {
90 return false;
91 }
92 }
93
SmashCallerSaves()94 void ArmContext::SmashCallerSaves() {
95 // This needs to be 0 because we want a null/zero return value.
96 gprs_[R0] = const_cast<uint32_t*>(&gZero);
97 gprs_[R1] = const_cast<uint32_t*>(&gZero);
98 gprs_[R2] = nullptr;
99 gprs_[R3] = nullptr;
100 }
101
102 extern "C" void art_quick_do_long_jump(uint32_t*, uint32_t*);
103
DoLongJump()104 void ArmContext::DoLongJump() {
105 uintptr_t gprs[kNumberOfCoreRegisters];
106 uint32_t fprs[kNumberOfSRegisters];
107 for (size_t i = 0; i < kNumberOfCoreRegisters; ++i) {
108 gprs[i] = gprs_[i] != nullptr ? *gprs_[i] : ArmContext::kBadGprBase + i;
109 }
110 for (size_t i = 0; i < kNumberOfSRegisters; ++i) {
111 fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : ArmContext::kBadFprBase + i;
112 }
113 DCHECK_EQ(reinterpret_cast<uintptr_t>(Thread::Current()), gprs[TR]);
114 art_quick_do_long_jump(gprs, fprs);
115 }
116
117 } // namespace arm
118 } // namespace art
119