1 //===--- RDFDeadCode.cpp --------------------------------------------------===//
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // RDF-based generic dead code elimination.
35     T V = Queue.front();  in pop_front()  local
37     Set.erase(V);  in pop_front()
38     return V;  in pop_front()
40   void push_back(T V) {  in push_back()
41     if (Set.count(V))  in push_back()
43     Queue.push(V);  in push_back()
44     Set.insert(V);  in push_back()
53 // Check if the given instruction has observable side-effects, i.e. if
59   const MachineInstr *MI = S.Addr->getCode();  in isLiveInstr()  local
60   if (MI->mayStore() || MI->isBranch() || MI->isCall() || MI->isReturn())  in isLiveInstr()
62   if (MI->hasOrderedMemoryRef() || MI->hasUnmodeledSideEffects() ||  in isLiveInstr()
63       MI->isPosition())  in isLiveInstr()
65   if (MI->isPHI())  in isLiveInstr()
67   for (auto &Op : MI->operands()) {  in isLiveInstr()
89   for (NodeAddr<RefNode*> RA : IA.Addr->members(DFG)) {  in scanInstr()
97   NodeAddr<InstrNode*> IA = DA.Addr->getOwner(DFG);  in processDef()
98   for (NodeAddr<UseNode*> UA : IA.Addr->members_if(DFG.IsUse, DFG)) {  in processDef()
115 // dead instructions. Return "true" if any of these sets is non-empty,
122   // considered live, i.e. instructions with observable side-effects, such  in collect()
129   for (NodeAddr<BlockNode*> BA : DFG.getFunc().Addr->members(DFG))  in collect()
130     for (NodeAddr<InstrNode*> IA : BA.Addr->members(DFG))  in collect()
151   auto IsDead = [this] (NodeAddr<InstrNode*> IA) -> bool {  in collect()
152     for (NodeAddr<DefNode*> DA : IA.Addr->members_if(DFG.IsDef, DFG))  in collect()
158   for (NodeAddr<BlockNode*> BA : DFG.getFunc().Addr->members(DFG)) {  in collect()
159     for (NodeAddr<InstrNode*> IA : BA.Addr->members(DFG)) {  in collect()
160       for (NodeAddr<RefNode*> RA : IA.Addr->members(DFG))  in collect()
190     uint16_t Type = BA.Addr->getType();  in erase()
197     uint16_t Kind = BA.Addr->getKind();  in erase()
199       append_range(DRNs, NodeAddr<CodeNode*>(BA).Addr->members(DFG));  in erase()
209   auto UsesFirst = [] (NodeAddr<RefNode*> A, NodeAddr<RefNode*> B) -> bool {  in erase()
210     uint16_t KindA = A.Addr->getKind(), KindB = B.Addr->getKind();  in erase()
232     NodeAddr<BlockNode*> BA = IA.Addr->getOwner(DFG);  in erase()
233     BA.Addr->removeMember(IA, DFG);  in erase()
237     MachineInstr *MI = NodeAddr<StmtNode*>(IA).Addr->getCode();  in erase()  local
239       dbgs() << "erasing: " << *MI;  in erase()
240     MI->eraseFromParent();  in erase()