// Copyright 2016 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "src/compiler/backend/s390/unwinding-info-writer-s390.h" #include "src/compiler/backend/instruction.h" namespace v8 { namespace internal { namespace compiler { void UnwindingInfoWriter::BeginInstructionBlock(int pc_offset, const InstructionBlock* block) { if (!enabled()) return; block_will_exit_ = false; DCHECK_LT(block->rpo_number().ToInt(), static_cast<int>(block_initial_states_.size())); const BlockInitialState* initial_state = block_initial_states_[block->rpo_number().ToInt()]; if (!initial_state) return; if (initial_state->saved_lr_ != saved_lr_) { eh_frame_writer_.AdvanceLocation(pc_offset); if (initial_state->saved_lr_) { eh_frame_writer_.RecordRegisterSavedToStack(r14, kSystemPointerSize); eh_frame_writer_.RecordRegisterSavedToStack(fp, 0); } else { eh_frame_writer_.RecordRegisterFollowsInitialRule(r14); } saved_lr_ = initial_state->saved_lr_; } } void UnwindingInfoWriter::EndInstructionBlock(const InstructionBlock* block) { if (!enabled() || block_will_exit_) return; for (const RpoNumber& successor : block->successors()) { int successor_index = successor.ToInt(); DCHECK_LT(successor_index, static_cast<int>(block_initial_states_.size())); const BlockInitialState* existing_state = block_initial_states_[successor_index]; // If we already had an entry for this BB, check that the values are the // same we are trying to insert. if (existing_state) { DCHECK_EQ(existing_state->saved_lr_, saved_lr_); } else { block_initial_states_[successor_index] = zone_->New<BlockInitialState>(saved_lr_); } } } void UnwindingInfoWriter::MarkFrameConstructed(int at_pc) { if (!enabled()) return; // Regardless of the type of frame constructed, the relevant part of the // layout is always the one in the diagram: // // | .... | higher addresses // +----------+ ^ // | LR | | | // +----------+ | | // | saved FP | | | // +----------+ <-- FP v // | .... | stack growth // // The LR is pushed on the stack, and we can record this fact at the end of // the construction, since the LR itself is not modified in the process. eh_frame_writer_.AdvanceLocation(at_pc); eh_frame_writer_.RecordRegisterSavedToStack(r14, kSystemPointerSize); eh_frame_writer_.RecordRegisterSavedToStack(fp, 0); saved_lr_ = true; } void UnwindingInfoWriter::MarkFrameDeconstructed(int at_pc) { if (!enabled()) return; // The lr is restored by the last operation in LeaveFrame(). eh_frame_writer_.AdvanceLocation(at_pc); eh_frame_writer_.RecordRegisterFollowsInitialRule(r14); saved_lr_ = false; } void UnwindingInfoWriter::MarkLinkRegisterOnTopOfStack(int pc_offset) { if (!enabled()) return; eh_frame_writer_.AdvanceLocation(pc_offset); eh_frame_writer_.SetBaseAddressRegisterAndOffset(sp, 0); eh_frame_writer_.RecordRegisterSavedToStack(r14, 0); } void UnwindingInfoWriter::MarkPopLinkRegisterFromTopOfStack(int pc_offset) { if (!enabled()) return; eh_frame_writer_.AdvanceLocation(pc_offset); eh_frame_writer_.SetBaseAddressRegisterAndOffset(fp, 0); eh_frame_writer_.RecordRegisterFollowsInitialRule(r14); } } // namespace compiler } // namespace internal } // namespace v8