1 /* 2 * Copyright (C) 2014 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 <stdint.h> 18 19 #include "context_arm64.h" 20 21 #include "base/bit_utils.h" 22 #include "quick/quick_method_frame_info.h" 23 #include "thread-inl.h" 24 25 namespace art { 26 namespace arm64 { 27 28 static constexpr uint64_t gZero = 0; 29 30 void Arm64Context::Reset() { 31 std::fill_n(gprs_, arraysize(gprs_), nullptr); 32 std::fill_n(fprs_, arraysize(fprs_), nullptr); 33 gprs_[SP] = &sp_; 34 gprs_[kPC] = &pc_; 35 gprs_[X0] = &arg0_; 36 // Initialize registers with easy to spot debug values. 37 sp_ = Arm64Context::kBadGprBase + SP; 38 pc_ = Arm64Context::kBadGprBase + kPC; 39 arg0_ = 0; 40 } 41 42 void Arm64Context::FillCalleeSaves(uint8_t* frame, const QuickMethodFrameInfo& frame_info) { 43 int spill_pos = 0; 44 45 // Core registers come first, from the highest down to the lowest. 46 for (uint32_t core_reg : HighToLowBits(frame_info.CoreSpillMask())) { 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 60 void Arm64Context::SetGPR(uint32_t reg, uintptr_t value) { 61 DCHECK_LT(reg, arraysize(gprs_)); 62 // Note: we use kPC == XZR, so do not ensure that reg != XZR. 63 DCHECK(IsAccessibleGPR(reg)); 64 DCHECK_NE(gprs_[reg], &gZero); // Can't overwrite this static value since they are never reset. 65 *gprs_[reg] = value; 66 } 67 68 void Arm64Context::SetFPR(uint32_t reg, uintptr_t value) { 69 DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfDRegisters)); 70 DCHECK(IsAccessibleFPR(reg)); 71 DCHECK_NE(fprs_[reg], &gZero); // Can't overwrite this static value since they are never reset. 72 *fprs_[reg] = value; 73 } 74 75 void Arm64Context::SmashCallerSaves() { 76 // This needs to be 0 because we want a null/zero return value. 77 gprs_[X0] = const_cast<uint64_t*>(&gZero); 78 gprs_[X1] = nullptr; 79 gprs_[X2] = nullptr; 80 gprs_[X3] = nullptr; 81 gprs_[X4] = nullptr; 82 gprs_[X5] = nullptr; 83 gprs_[X6] = nullptr; 84 gprs_[X7] = nullptr; 85 gprs_[X8] = nullptr; 86 gprs_[X9] = nullptr; 87 gprs_[X10] = nullptr; 88 gprs_[X11] = nullptr; 89 gprs_[X12] = nullptr; 90 gprs_[X13] = nullptr; 91 gprs_[X14] = nullptr; 92 gprs_[X15] = nullptr; 93 gprs_[X18] = nullptr; 94 95 // d0-d7, d16-d31 are caller-saved; d8-d15 are callee-saved. 96 97 fprs_[D0] = nullptr; 98 fprs_[D1] = nullptr; 99 fprs_[D2] = nullptr; 100 fprs_[D3] = nullptr; 101 fprs_[D4] = nullptr; 102 fprs_[D5] = nullptr; 103 fprs_[D6] = nullptr; 104 fprs_[D7] = nullptr; 105 106 fprs_[D16] = nullptr; 107 fprs_[D17] = nullptr; 108 fprs_[D18] = nullptr; 109 fprs_[D19] = nullptr; 110 fprs_[D20] = nullptr; 111 fprs_[D21] = nullptr; 112 fprs_[D22] = nullptr; 113 fprs_[D23] = nullptr; 114 fprs_[D24] = nullptr; 115 fprs_[D25] = nullptr; 116 fprs_[D26] = nullptr; 117 fprs_[D27] = nullptr; 118 fprs_[D28] = nullptr; 119 fprs_[D29] = nullptr; 120 fprs_[D30] = nullptr; 121 fprs_[D31] = nullptr; 122 } 123 124 extern "C" NO_RETURN void art_quick_do_long_jump(uint64_t*, uint64_t*); 125 126 void Arm64Context::DoLongJump() { 127 uint64_t gprs[arraysize(gprs_)]; 128 uint64_t fprs[kNumberOfDRegisters]; 129 130 // The long jump routine called below expects to find the value for SP at index 31. 131 DCHECK_EQ(SP, 31); 132 133 for (size_t i = 0; i < arraysize(gprs_); ++i) { 134 gprs[i] = gprs_[i] != nullptr ? *gprs_[i] : Arm64Context::kBadGprBase + i; 135 } 136 for (size_t i = 0; i < kNumberOfDRegisters; ++i) { 137 fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : Arm64Context::kBadFprBase + i; 138 } 139 DCHECK_EQ(reinterpret_cast<uintptr_t>(Thread::Current()), gprs[TR]); 140 art_quick_do_long_jump(gprs, fprs); 141 } 142 143 } // namespace arm64 144 } // namespace art 145
