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_mips.h"
18 
19 #include "base/bit_utils.h"
20 #include "quick/quick_method_frame_info.h"
21 
22 namespace art {
23 namespace mips {
24 
25 static constexpr uint32_t gZero = 0;
26 
Reset()27 void MipsContext::Reset() {
28   std::fill_n(gprs_, arraysize(gprs_), nullptr);
29   std::fill_n(fprs_, arraysize(fprs_), nullptr);
30   gprs_[SP] = &sp_;
31   gprs_[T9] = &t9_;
32   gprs_[A0] = &arg0_;
33   // Initialize registers with easy to spot debug values.
34   sp_ = MipsContext::kBadGprBase + SP;
35   t9_ = MipsContext::kBadGprBase + T9;
36   arg0_ = 0;
37 }
38 
FillCalleeSaves(uint8_t * frame,const QuickMethodFrameInfo & frame_info)39 void MipsContext::FillCalleeSaves(uint8_t* frame, const QuickMethodFrameInfo& frame_info) {
40   int spill_pos = 0;
41 
42   // Core registers come first, from the highest down to the lowest.
43   for (uint32_t core_reg : HighToLowBits(frame_info.CoreSpillMask())) {
44     gprs_[core_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
45     ++spill_pos;
46   }
47   DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()));
48 
49   // FP registers come second, from the highest down to the lowest.
50   for (uint32_t fp_reg : HighToLowBits(frame_info.FpSpillMask())) {
51     fprs_[fp_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
52     ++spill_pos;
53   }
54   DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()) + POPCOUNT(frame_info.FpSpillMask()));
55 }
56 
SetGPR(uint32_t reg,uintptr_t value)57 void MipsContext::SetGPR(uint32_t reg, uintptr_t value) {
58   CHECK_LT(reg, static_cast<uint32_t>(kNumberOfCoreRegisters));
59   DCHECK(IsAccessibleGPR(reg));
60   CHECK_NE(gprs_[reg], &gZero);  // Can't overwrite this static value since they are never reset.
61   *gprs_[reg] = value;
62 }
63 
SetFPR(uint32_t reg,uintptr_t value)64 void MipsContext::SetFPR(uint32_t reg, uintptr_t value) {
65   CHECK_LT(reg, static_cast<uint32_t>(kNumberOfFRegisters));
66   DCHECK(IsAccessibleFPR(reg));
67   CHECK_NE(fprs_[reg], &gZero);  // Can't overwrite this static value since they are never reset.
68   *fprs_[reg] = value;
69 }
70 
SmashCallerSaves()71 void MipsContext::SmashCallerSaves() {
72   // This needs to be 0 because we want a null/zero return value.
73   gprs_[V0] = const_cast<uint32_t*>(&gZero);
74   gprs_[V1] = const_cast<uint32_t*>(&gZero);
75   gprs_[A1] = nullptr;
76   gprs_[A2] = nullptr;
77   gprs_[A3] = nullptr;
78   gprs_[T0] = nullptr;
79   gprs_[T1] = nullptr;
80 
81   fprs_[F8] = nullptr;
82   fprs_[F9] = nullptr;
83   fprs_[F10] = nullptr;
84   fprs_[F11] = nullptr;
85   fprs_[F12] = nullptr;
86   fprs_[F13] = nullptr;
87   fprs_[F14] = nullptr;
88   fprs_[F15] = nullptr;
89   fprs_[F16] = nullptr;
90   fprs_[F17] = nullptr;
91   fprs_[F18] = nullptr;
92   fprs_[F19] = nullptr;
93 }
94 
95 extern "C" NO_RETURN void art_quick_do_long_jump(uint32_t*, uint32_t*);
96 
DoLongJump()97 void MipsContext::DoLongJump() {
98   uintptr_t gprs[kNumberOfCoreRegisters];
99   uint32_t fprs[kNumberOfFRegisters];
100   for (size_t i = 0; i < kNumberOfCoreRegisters; ++i) {
101     gprs[i] = gprs_[i] != nullptr ? *gprs_[i] : MipsContext::kBadGprBase + i;
102   }
103   for (size_t i = 0; i < kNumberOfFRegisters; ++i) {
104     fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : MipsContext::kBadFprBase + i;
105   }
106   art_quick_do_long_jump(gprs, fprs);
107 }
108 
109 }  // namespace mips
110 }  // namespace art
111