[RDF] Add phis for entry block live-ins (in addition to function live-ins)

llvm-svn: 293491

3 files changed, 22 insertions, 14 deletions

diff --git a/llvm/lib/Target/Hexagon/RDFGraph.cpp b/llvm/lib/Target/Hexagon/RDFGraph.cpp
index ee8db96d40f..e5cfc7a96b4 100644
--- a/llvm/lib/Target/Hexagon/RDFGraph.cpp
+++ b/llvm/lib/Target/Hexagon/RDFGraph.cpp
@@ -764,7 +764,7 @@ void RegisterAggr::print(raw_ostream &OS) const {
 DataFlowGraph::DataFlowGraph(MachineFunction &mf, const TargetInstrInfo &tii,
       const TargetRegisterInfo &tri, const MachineDominatorTree &mdt,
       const MachineDominanceFrontier &mdf, const TargetOperandInfo &toi)
-    : MF(mf), TII(tii), TRI(tri), MDT(mdt), MDF(mdf), TOI(toi) {
+    : MF(mf), TII(tii), TRI(tri), MDT(mdt), MDF(mdf), TOI(toi), LiveIns(TRI) {
 }
 
 // The implementation of the definition stack.
@@ -1010,12 +1010,20 @@ void DataFlowGraph::build(unsigned Options) {
   BlockRefsMap RefM;
   buildBlockRefs(EA, RefM);
 
-  // Add function-entry phi nodes.
+  // Collect function live-ins and entry block live-ins.
   MachineRegisterInfo &MRI = MF.getRegInfo();
-  for (auto I = MRI.livein_begin(), E = MRI.livein_end(); I != E; ++I) {
+  MachineBasicBlock &EntryB = *EA.Addr->getCode();
+  assert(EntryB.pred_empty() && "Function entry block has predecessors");
+  for (auto I = MRI.livein_begin(), E = MRI.livein_end(); I != E; ++I)
+    LiveIns.insert(RegisterRef(I->first));
+  for (auto I : EntryB.liveins())
+    LiveIns.insert(RegisterRef(I.PhysReg, I.LaneMask));
+
+  // Add function-entry phi nodes for the live-in registers.
+  for (std::pair<RegisterId,LaneBitmask> P : LiveIns) {
     NodeAddr<PhiNode*> PA = newPhi(EA);
-    RegisterRef RR = RegisterRef(I->first);
     uint16_t PhiFlags = NodeAttrs::PhiRef | NodeAttrs::Preserving;
+    RegisterRef RR(P.first, P.second);
     NodeAddr<DefNode*> DA = newDef(PA, RR, PhiFlags);
     PA.Addr->addMember(DA, *this);
   }
diff --git a/llvm/lib/Target/Hexagon/RDFGraph.h b/llvm/lib/Target/Hexagon/RDFGraph.h
index 49d78a8b22b..b3132f69bf2 100644
--- a/llvm/lib/Target/Hexagon/RDFGraph.h
+++ b/llvm/lib/Target/Hexagon/RDFGraph.h
@@ -763,6 +763,7 @@ namespace rdf {
     const TargetRegisterInfo &getTRI() const { return TRI; }
     const MachineDominatorTree &getDT() const { return MDT; }
     const MachineDominanceFrontier &getDF() const { return MDF; }
+    const RegisterAggr &getLiveIns() const { return LiveIns; }
 
     struct DefStack {
       DefStack() = default;
@@ -957,19 +958,20 @@ namespace rdf {
       return BlockNodes[BB];
     }
 
-    NodeAddr<FuncNode*> Func;
-    NodeAllocator Memory;
-    // Local map:  MachineBasicBlock -> NodeAddr<BlockNode*>
-    std::map<MachineBasicBlock*,NodeAddr<BlockNode*>> BlockNodes;
-    // Lane mask map.
-    LaneMaskIndex LMI;
-
     MachineFunction &MF;
     const TargetInstrInfo &TII;
     const TargetRegisterInfo &TRI;
     const MachineDominatorTree &MDT;
     const MachineDominanceFrontier &MDF;
     const TargetOperandInfo &TOI;
+
+    RegisterAggr LiveIns;
+    NodeAddr<FuncNode*> Func;
+    NodeAllocator Memory;
+    // Local map:  MachineBasicBlock -> NodeAddr<BlockNode*>
+    std::map<MachineBasicBlock*,NodeAddr<BlockNode*>> BlockNodes;
+    // Lane mask map.
+    LaneMaskIndex LMI;
   };  // struct DataFlowGraph
 
   template <typename Predicate>
diff --git a/llvm/lib/Target/Hexagon/RDFLiveness.cpp b/llvm/lib/Target/Hexagon/RDFLiveness.cpp
index f0f93285254..4b9dea08173 100644
--- a/llvm/lib/Target/Hexagon/RDFLiveness.cpp
+++ b/llvm/lib/Target/Hexagon/RDFLiveness.cpp
@@ -684,9 +684,7 @@ void Liveness::computeLiveIns() {
   traverse(&MF.front(), LiveIn);
 
   // Add function live-ins to the live-in set of the function entry block.
-  auto &EntryIn = LiveMap[&MF.front()];
-  for (auto I = MRI.livein_begin(), E = MRI.livein_end(); I != E; ++I)
-    EntryIn.insert(RegisterRef(I->first));
+  LiveMap[&MF.front()].insert(DFG.getLiveIns());
 
   if (Trace) {
     // Dump the liveness map