Line data Source code
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 11397343 : void UnwindingInfoWriter::BeginInstructionBlock(int pc_offset,
13 : const InstructionBlock* block) {
14 22794686 : if (!enabled()) return;
15 :
16 287 : block_will_exit_ = false;
17 :
18 : DCHECK_LT(block->rpo_number().ToInt(),
19 : static_cast<int>(block_initial_states_.size()));
20 : const BlockInitialState* initial_state =
21 574 : block_initial_states_[block->rpo_number().ToInt()];
22 287 : if (initial_state) {
23 502 : if (!initial_state->register_.is(eh_frame_writer_.base_register()) &&
24 9 : initial_state->offset_ != eh_frame_writer_.base_offset()) {
25 9 : eh_frame_writer_.AdvanceLocation(pc_offset);
26 : eh_frame_writer_.SetBaseAddressRegisterAndOffset(initial_state->register_,
27 9 : initial_state->offset_);
28 242 : } else if (!initial_state->register_.is(eh_frame_writer_.base_register())) {
29 0 : eh_frame_writer_.AdvanceLocation(pc_offset);
30 0 : eh_frame_writer_.SetBaseAddressRegister(initial_state->register_);
31 484 : } else if (initial_state->offset_ != eh_frame_writer_.base_offset()) {
32 0 : eh_frame_writer_.AdvanceLocation(pc_offset);
33 0 : eh_frame_writer_.SetBaseAddressOffset(initial_state->offset_);
34 : }
35 :
36 251 : tracking_fp_ = initial_state->tracking_fp_;
37 : } else {
38 : // The entry block always lacks an explicit initial state.
39 : // The exit block may lack an explicit state, if it is only reached by
40 : // the block ending in a ret.
41 : // All the other blocks must have an explicit initial state.
42 : DCHECK(block->predecessors().empty() || block->successors().empty());
43 : }
44 : }
45 :
46 11397344 : void UnwindingInfoWriter::EndInstructionBlock(const InstructionBlock* block) {
47 22794688 : if (!enabled() || block_will_exit_) return;
48 :
49 826 : for (const RpoNumber& successor : block->successors()) {
50 : int successor_index = successor.ToInt();
51 : DCHECK_LT(successor_index, static_cast<int>(block_initial_states_.size()));
52 : const BlockInitialState* existing_state =
53 911 : block_initial_states_[successor_index];
54 : // If we already had an entry for this BB, check that the values are the
55 : // same we are trying to insert.
56 330 : if (existing_state) {
57 : DCHECK(existing_state->register_.is(eh_frame_writer_.base_register()));
58 : DCHECK_EQ(existing_state->offset_, eh_frame_writer_.base_offset());
59 : DCHECK_EQ(existing_state->tracking_fp_, tracking_fp_);
60 : } else {
61 : block_initial_states_[successor_index] = new (zone_)
62 251 : BlockInitialState(eh_frame_writer_.base_register(),
63 753 : eh_frame_writer_.base_offset(), tracking_fp_);
64 : }
65 : }
66 : }
67 :
68 874198 : void UnwindingInfoWriter::MarkFrameConstructed(int pc_base) {
69 1748396 : if (!enabled()) return;
70 :
71 : // push rbp
72 46 : eh_frame_writer_.AdvanceLocation(pc_base + 1);
73 : eh_frame_writer_.IncreaseBaseAddressOffset(kInt64Size);
74 : // <base address> points at the bottom of the current frame on x64 and
75 : // <base register> is rsp, which points to the top of the frame by definition.
76 : // Thus, the distance between <base address> and the top is -<base offset>.
77 23 : int top_of_stack = -eh_frame_writer_.base_offset();
78 : eh_frame_writer_.RecordRegisterSavedToStack(rbp, top_of_stack);
79 :
80 : // mov rbp, rsp
81 23 : eh_frame_writer_.AdvanceLocation(pc_base + 4);
82 23 : eh_frame_writer_.SetBaseAddressRegister(rbp);
83 :
84 23 : tracking_fp_ = true;
85 : }
86 :
87 869523 : void UnwindingInfoWriter::MarkFrameDeconstructed(int pc_base) {
88 1739046 : if (!enabled()) return;
89 :
90 : // mov rsp, rbp
91 23 : eh_frame_writer_.AdvanceLocation(pc_base + 3);
92 23 : eh_frame_writer_.SetBaseAddressRegister(rsp);
93 :
94 : // pop rbp
95 23 : eh_frame_writer_.AdvanceLocation(pc_base + 4);
96 : eh_frame_writer_.IncreaseBaseAddressOffset(-kInt64Size);
97 :
98 23 : tracking_fp_ = false;
99 : }
100 :
101 : } // namespace compiler
102 : } // namespace internal
103 : } // namespace v8
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