1 files changed, 23 insertions, 30 deletions

diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
index ec98394dca79..30745c7a5583 100644
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -131,7 +131,7 @@ namespace {
     // will be split.
     SetVector<std::pair<MachineBasicBlock *, MachineBasicBlock *>> ToSplit;
 
-    SparseBitVector<> RegsToClearKillFlags;
+    DenseSet<Register> RegsToClearKillFlags;
 
     using AllSuccsCache =
         std::map<MachineBasicBlock *, SmallVector<MachineBasicBlock *, 4>>;
@@ -476,14 +476,13 @@ bool MachineSinking::runOnMachineFunction(MachineFunction &MF) {
       // of a def-use chain, if there is any.
       // TODO: Sort the candidates using a cost-model.
       unsigned i = 0;
-      for (auto It = Candidates.rbegin(); It != Candidates.rend(); ++It) {
+      for (MachineInstr *I : llvm::reverse(Candidates)) {
         if (i++ == SinkIntoLoopLimit) {
           LLVM_DEBUG(dbgs() << "LoopSink:   Limit reached of instructions to "
                                "be analysed.");
           break;
         }
 
-        MachineInstr *I = *It;
         if (!SinkIntoLoop(L, *I))
           break;
         EverMadeChange = true;
@@ -683,13 +682,9 @@ bool MachineSinking::PostponeSplitCriticalEdge(MachineInstr &MI,
   // There is no need to do this check if all the uses are PHI nodes. PHI
   // sources are only defined on the specific predecessor edges.
   if (!BreakPHIEdge) {
-    for (MachineBasicBlock::pred_iterator PI = ToBB->pred_begin(),
-           E = ToBB->pred_end(); PI != E; ++PI) {
-      if (*PI == FromBB)
-        continue;
-      if (!DT->dominates(ToBB, *PI))
+    for (MachineBasicBlock *Pred : ToBB->predecessors())
+      if (Pred != FromBB && !DT->dominates(ToBB, Pred))
         return false;
-    }
   }
 
   ToSplit.insert(std::make_pair(FromBB, ToBB));
@@ -1329,7 +1324,8 @@ bool MachineSinking::SinkInstruction(MachineInstr &MI, bool &SawStore,
   // "zombie" define of that preg. E.g., EFLAGS. (<rdar://problem/8030636>)
   for (unsigned I = 0, E = MI.getNumOperands(); I != E; ++I) {
     const MachineOperand &MO = MI.getOperand(I);
-    if (!MO.isReg()) continue;
+    if (!MO.isReg() || MO.isUse())
+      continue;
     Register Reg = MO.getReg();
     if (Reg == 0 || !Register::isPhysicalRegister(Reg))
       continue;
@@ -1439,7 +1435,7 @@ bool MachineSinking::SinkInstruction(MachineInstr &MI, bool &SawStore,
   // used registers.
   for (MachineOperand &MO : MI.operands()) {
     if (MO.isReg() && MO.isUse())
-      RegsToClearKillFlags.set(MO.getReg()); // Remember to clear kill flags.
+      RegsToClearKillFlags.insert(MO.getReg()); // Remember to clear kill flags.
   }
 
   return true;
@@ -1718,10 +1714,7 @@ bool PostRAMachineSinking::tryToSinkCopy(MachineBasicBlock &CurBB,
   UsedRegUnits.clear();
   SeenDbgInstrs.clear();
 
-  for (auto I = CurBB.rbegin(), E = CurBB.rend(); I != E;) {
-    MachineInstr *MI = &*I;
-    ++I;
-
+  for (MachineInstr &MI : llvm::make_early_inc_range(llvm::reverse(CurBB))) {
     // Track the operand index for use in Copy.
     SmallVector<unsigned, 2> UsedOpsInCopy;
     // Track the register number defed in Copy.
@@ -1729,14 +1722,14 @@ bool PostRAMachineSinking::tryToSinkCopy(MachineBasicBlock &CurBB,
 
     // We must sink this DBG_VALUE if its operand is sunk. To avoid searching
     // for DBG_VALUEs later, record them when they're encountered.
-    if (MI->isDebugValue()) {
+    if (MI.isDebugValue()) {
       SmallDenseMap<MCRegister, SmallVector<unsigned, 2>, 4> MIUnits;
       bool IsValid = true;
-      for (MachineOperand &MO : MI->debug_operands()) {
+      for (MachineOperand &MO : MI.debug_operands()) {
         if (MO.isReg() && Register::isPhysicalRegister(MO.getReg())) {
           // Bail if we can already tell the sink would be rejected, rather
           // than needlessly accumulating lots of DBG_VALUEs.
-          if (hasRegisterDependency(MI, UsedOpsInCopy, DefedRegsInCopy,
+          if (hasRegisterDependency(&MI, UsedOpsInCopy, DefedRegsInCopy,
                                     ModifiedRegUnits, UsedRegUnits)) {
             IsValid = false;
             break;
@@ -1750,28 +1743,28 @@ bool PostRAMachineSinking::tryToSinkCopy(MachineBasicBlock &CurBB,
       }
       if (IsValid) {
         for (auto RegOps : MIUnits)
-          SeenDbgInstrs[RegOps.first].push_back({MI, RegOps.second});
+          SeenDbgInstrs[RegOps.first].push_back({&MI, RegOps.second});
       }
       continue;
     }
 
-    if (MI->isDebugOrPseudoInstr())
+    if (MI.isDebugOrPseudoInstr())
       continue;
 
     // Do not move any instruction across function call.
-    if (MI->isCall())
+    if (MI.isCall())
       return false;
 
-    if (!MI->isCopy() || !MI->getOperand(0).isRenamable()) {
-      LiveRegUnits::accumulateUsedDefed(*MI, ModifiedRegUnits, UsedRegUnits,
+    if (!MI.isCopy() || !MI.getOperand(0).isRenamable()) {
+      LiveRegUnits::accumulateUsedDefed(MI, ModifiedRegUnits, UsedRegUnits,
                                         TRI);
       continue;
     }
 
     // Don't sink the COPY if it would violate a register dependency.
-    if (hasRegisterDependency(MI, UsedOpsInCopy, DefedRegsInCopy,
+    if (hasRegisterDependency(&MI, UsedOpsInCopy, DefedRegsInCopy,
                               ModifiedRegUnits, UsedRegUnits)) {
-      LiveRegUnits::accumulateUsedDefed(*MI, ModifiedRegUnits, UsedRegUnits,
+      LiveRegUnits::accumulateUsedDefed(MI, ModifiedRegUnits, UsedRegUnits,
                                         TRI);
       continue;
     }
@@ -1782,7 +1775,7 @@ bool PostRAMachineSinking::tryToSinkCopy(MachineBasicBlock &CurBB,
     // Don't sink if we cannot find a single sinkable successor in which Reg
     // is live-in.
     if (!SuccBB) {
-      LiveRegUnits::accumulateUsedDefed(*MI, ModifiedRegUnits, UsedRegUnits,
+      LiveRegUnits::accumulateUsedDefed(MI, ModifiedRegUnits, UsedRegUnits,
                                         TRI);
       continue;
     }
@@ -1793,7 +1786,7 @@ bool PostRAMachineSinking::tryToSinkCopy(MachineBasicBlock &CurBB,
     // recorded which reg units that DBG_VALUEs read, if this instruction
     // writes any of those units then the corresponding DBG_VALUEs must sink.
     MapVector<MachineInstr *, MIRegs::second_type> DbgValsToSinkMap;
-    for (auto &MO : MI->operands()) {
+    for (auto &MO : MI.operands()) {
       if (!MO.isReg() || !MO.isDef())
         continue;
 
@@ -1811,10 +1804,10 @@ bool PostRAMachineSinking::tryToSinkCopy(MachineBasicBlock &CurBB,
 
     // Clear the kill flag if SrcReg is killed between MI and the end of the
     // block.
-    clearKillFlags(MI, CurBB, UsedOpsInCopy, UsedRegUnits, TRI);
+    clearKillFlags(&MI, CurBB, UsedOpsInCopy, UsedRegUnits, TRI);
     MachineBasicBlock::iterator InsertPos = SuccBB->getFirstNonPHI();
-    performSink(*MI, *SuccBB, InsertPos, DbgValsToSink);
-    updateLiveIn(MI, SuccBB, UsedOpsInCopy, DefedRegsInCopy);
+    performSink(MI, *SuccBB, InsertPos, DbgValsToSink);
+    updateLiveIn(&MI, SuccBB, UsedOpsInCopy, DefedRegsInCopy);
 
     Changed = true;
     ++NumPostRACopySink;