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| 1 // Copyright 2016 the V8 project authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 #include "src/compiler/x64/unwinding-info-writer-x64.h" |
| 6 #include "src/compiler/instruction.h" |
| 7 |
| 8 namespace v8 { |
| 9 namespace internal { |
| 10 namespace compiler { |
| 11 |
| 12 void UnwindingInfoWriter::BeginInstructionBlock(int pc_offset, |
| 13 const InstructionBlock* block) { |
| 14 block_will_exit_ = false; |
| 15 |
| 16 auto lookup = block_initial_states_.find(block->rpo_number().ToInt()); |
| 17 if (lookup != block_initial_states_.end()) { |
| 18 if (!lookup->second.register_.is(eh_frame_writer_.base_register()) && |
| 19 lookup->second.offset_ != eh_frame_writer_.base_offset()) { |
| 20 eh_frame_writer_.AdvanceLocation(pc_offset); |
| 21 eh_frame_writer_.SetBaseAddressRegisterAndOffset(lookup->second.register_, |
| 22 lookup->second.offset_); |
| 23 } else if (!lookup->second.register_.is(eh_frame_writer_.base_register())) { |
| 24 eh_frame_writer_.AdvanceLocation(pc_offset); |
| 25 eh_frame_writer_.SetBaseAddressRegister(lookup->second.register_); |
| 26 } else if (lookup->second.offset_ != eh_frame_writer_.base_offset()) { |
| 27 eh_frame_writer_.AdvanceLocation(pc_offset); |
| 28 eh_frame_writer_.SetBaseAddressOffset(lookup->second.offset_); |
| 29 } |
| 30 |
| 31 tracking_fp_ = lookup->second.tracking_fp_; |
| 32 } else { |
| 33 // The entry block always lacks an explicit initial state. |
| 34 // The exit block may lack an explicit state, if it is only reached by |
| 35 // the block ending in a ret. |
| 36 // All the other blocks must have an explicit initial state. |
| 37 DCHECK(block->predecessors().empty() || block->successors().empty()); |
| 38 } |
| 39 } |
| 40 |
| 41 void UnwindingInfoWriter::EndInstructionBlock(const InstructionBlock* block) { |
| 42 if (block_will_exit_) return; |
| 43 |
| 44 for (const RpoNumber& successor : block->successors()) { |
| 45 BlockInitialState state = {eh_frame_writer_.base_register(), |
| 46 eh_frame_writer_.base_offset(), tracking_fp_}; |
| 47 auto inserted = block_initial_states_.insert({successor.ToInt(), state}); |
| 48 // If we already had an entry for this BB, check that the values are the |
| 49 // same we were trying to insert. |
| 50 if (!inserted.second) { |
| 51 DCHECK(inserted.first->second.register_.is(state.register_)); |
| 52 DCHECK_EQ(inserted.first->second.offset_, state.offset_); |
| 53 DCHECK_EQ(inserted.first->second.tracking_fp_, state.tracking_fp_); |
| 54 } |
| 55 } |
| 56 } |
| 57 |
| 58 void UnwindingInfoWriter::MarkFrameConstructed(int pc_base) { |
| 59 // push rbp |
| 60 eh_frame_writer_.AdvanceLocation(pc_base + 1); |
| 61 eh_frame_writer_.IncreaseBaseAddressOffset(kInt64Size); |
| 62 eh_frame_writer_.RecordRegisterSavedToStack(rbp); |
| 63 |
| 64 // mov rbp, rsp |
| 65 eh_frame_writer_.AdvanceLocation(pc_base + 4); |
| 66 eh_frame_writer_.SetBaseAddressRegister(rbp); |
| 67 |
| 68 tracking_fp_ = true; |
| 69 } |
| 70 |
| 71 void UnwindingInfoWriter::MarkFrameDeconstructed(int pc_base) { |
| 72 // mov rsp, rbp |
| 73 eh_frame_writer_.AdvanceLocation(pc_base + 3); |
| 74 eh_frame_writer_.SetBaseAddressRegister(rsp); |
| 75 |
| 76 // pop rbp |
| 77 eh_frame_writer_.AdvanceLocation(pc_base + 4); |
| 78 eh_frame_writer_.IncreaseBaseAddressOffset(-kInt64Size); |
| 79 |
| 80 tracking_fp_ = false; |
| 81 } |
| 82 |
| 83 } // namespace compiler |
| 84 } // namespace internal |
| 85 } // namespace v8 |
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