diff options
Diffstat (limited to 'compiler/dex/global_value_numbering.cc')
| -rw-r--r-- | compiler/dex/global_value_numbering.cc | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/compiler/dex/global_value_numbering.cc b/compiler/dex/global_value_numbering.cc index a8fd8122ff..ab3c946897 100644 --- a/compiler/dex/global_value_numbering.cc +++ b/compiler/dex/global_value_numbering.cc @@ -28,7 +28,7 @@ GlobalValueNumbering::GlobalValueNumbering(CompilationUnit* cu, ScopedArenaAlloc allocator_(allocator), bbs_processed_(0u), max_bbs_to_process_(kMaxBbsToProcessMultiplyFactor * mir_graph_->GetNumReachableBlocks()), - last_value_(0u), + last_value_(kNullValue), modifications_allowed_(true), mode_(mode), global_value_map_(std::less<uint64_t>(), allocator->Adapter()), @@ -128,7 +128,11 @@ bool GlobalValueNumbering::FinishBasicBlock(BasicBlock* bb) { merge_lvns_.clear(); bool change = (lvns_[bb->id] == nullptr) || !lvns_[bb->id]->Equals(*work_lvn_); - if (change) { + if (mode_ == kModeGvn) { + // In GVN mode, keep the latest LVN even if Equals() indicates no change. This is + // to keep the correct values of fields that do not contribute to Equals() as long + // as they depend only on predecessor LVNs' fields that do contribute to Equals(). + // Currently, that's LVN::merge_map_ used by LVN::GetStartingVregValueNumberImpl(). std::unique_ptr<const LocalValueNumbering> old_lvn(lvns_[bb->id]); lvns_[bb->id] = work_lvn_.release(); } else { @@ -178,7 +182,7 @@ bool GlobalValueNumbering::NullCheckedInAllPredecessors( } // IF_EQZ/IF_NEZ checks some sreg, see if that sreg contains the value_name. int s_reg = pred_bb->last_mir_insn->ssa_rep->uses[0]; - if (!pred_lvn->IsSregValue(s_reg, value_name)) { + if (pred_lvn->GetSregValue(s_reg) != value_name) { return false; } } |