1f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch// Copyright 2016 the V8 project authors. All rights reserved. 2f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch// Use of this source code is governed by a BSD-style license that can be 3f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch// found in the LICENSE file. 4f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 5f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch#include "src/compiler/arm/unwinding-info-writer-arm.h" 6f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch#include "src/compiler/instruction.h" 7f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 8f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochnamespace v8 { 9f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochnamespace internal { 10f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochnamespace compiler { 11f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 12f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochvoid UnwindingInfoWriter::BeginInstructionBlock(int pc_offset, 13f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch const InstructionBlock* block) { 14f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (!enabled()) return; 15f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 16f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch block_will_exit_ = false; 17f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 18c8c1d9e03f4babd16833b0f8ccf6aab5fa6e8c7aBen Murdoch DCHECK_LT(block->rpo_number().ToInt(), 19c8c1d9e03f4babd16833b0f8ccf6aab5fa6e8c7aBen Murdoch static_cast<int>(block_initial_states_.size())); 20f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch const BlockInitialState* initial_state = 21f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch block_initial_states_[block->rpo_number().ToInt()]; 22f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (initial_state) { 23f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (initial_state->saved_lr_ != saved_lr_) { 24f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.AdvanceLocation(pc_offset); 25f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (initial_state->saved_lr_) { 26f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.RecordRegisterSavedToStack(lr, kPointerSize); 27f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch } else { 28f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.RecordRegisterFollowsInitialRule(lr); 29f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch } 30f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch saved_lr_ = initial_state->saved_lr_; 31f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch } 32f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch } else { 33f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // The entry block always lacks an explicit initial state. 34f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // The exit block may lack an explicit state, if it is only reached by 35f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // the block ending in a bx lr. 36f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // All the other blocks must have an explicit initial state. 37f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch DCHECK(block->predecessors().empty() || block->successors().empty()); 38f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch } 39f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} 40f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 41f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochvoid UnwindingInfoWriter::EndInstructionBlock(const InstructionBlock* block) { 42f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (!enabled() || block_will_exit_) return; 43f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 44f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch for (const RpoNumber& successor : block->successors()) { 45f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch int successor_index = successor.ToInt(); 46c8c1d9e03f4babd16833b0f8ccf6aab5fa6e8c7aBen Murdoch DCHECK_LT(successor_index, static_cast<int>(block_initial_states_.size())); 47f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch const BlockInitialState* existing_state = 48f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch block_initial_states_[successor_index]; 49f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 50f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // If we already had an entry for this BB, check that the values are the 51f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // same we are trying to insert. 52f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (existing_state) { 53f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch DCHECK_EQ(existing_state->saved_lr_, saved_lr_); 54f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch } else { 55f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch block_initial_states_[successor_index] = 56f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch new (zone_) BlockInitialState(saved_lr_); 57f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch } 58f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch } 59f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} 60f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 61f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochvoid UnwindingInfoWriter::MarkFrameConstructed(int at_pc) { 62f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (!enabled()) return; 63f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 64f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // Regardless of the type of frame constructed, the relevant part of the 65f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // layout is always the one in the diagram: 66f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // 67f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // | .... | higher addresses 68f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // +----------+ ^ 69f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // | LR | | | 70f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // +----------+ | | 71f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // | saved FP | | | 72f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // +----------+ <-- FP v 73f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // | .... | stack growth 74f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // 75f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // The LR is pushed on the stack, and we can record this fact at the end of 76f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // the construction, since the LR itself is not modified in the process. 77f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.AdvanceLocation(at_pc); 78f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.RecordRegisterSavedToStack(lr, kPointerSize); 79f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch saved_lr_ = true; 80f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} 81f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 82f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochvoid UnwindingInfoWriter::MarkFrameDeconstructed(int at_pc) { 83f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (!enabled()) return; 84f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 85f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch // The lr is restored by the last operation in LeaveFrame(). 86f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.AdvanceLocation(at_pc); 87f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.RecordRegisterFollowsInitialRule(lr); 88f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch saved_lr_ = false; 89f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} 90f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 91f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochvoid UnwindingInfoWriter::MarkLinkRegisterOnTopOfStack(int pc_offset) { 92f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (!enabled()) return; 93f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 94f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.AdvanceLocation(pc_offset); 95f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.SetBaseAddressRegisterAndOffset(sp, 0); 96f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.RecordRegisterSavedToStack(lr, 0); 97f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} 98f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 99f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdochvoid UnwindingInfoWriter::MarkPopLinkRegisterFromTopOfStack(int pc_offset) { 100f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch if (!enabled()) return; 101f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 102f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.AdvanceLocation(pc_offset); 103f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.SetBaseAddressRegisterAndOffset(fp, 0); 104f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch eh_frame_writer_.RecordRegisterFollowsInitialRule(lr); 105f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} 106f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch 107f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} // namespace compiler 108f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} // namespace internal 109f91f0611dbaf29ca0f1d4aecb357ce243a19d2faBen Murdoch} // namespace v8 110