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 23 namespace art { 24 namespace arm { 25 26 static constexpr uint32_t gZero = 0; 27 28 void 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 40 void 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 60 void 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 67 void 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 74 void 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 99 extern "C" NO_RETURN void art_quick_do_long_jump(uint32_t*, uint32_t*); 100 101 void 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
