Use MBB.liveouts()

Author: MacDue

llvm/include/llvm/CodeGen/LiveRegUnits.h

@@ -136,11 +136,8 @@ class LiveRegUnits {
   /// Adds registers living out of block \p MBB.
   /// Live out registers are the union of the live-in registers of the successor
   /// blocks and pristine registers. Live out registers of the end block are the
-  /// callee saved registers. If the target lowering information \p TLI is
-  /// provided, runtime-defined live ins of successors will be excluded from the
-  /// live outs.
-  LLVM_ABI void addLiveOuts(const MachineBasicBlock &MBB,
-                            const TargetLowering *TLI = nullptr);
+  /// callee saved registers.
+  LLVM_ABI void addLiveOuts(const MachineBasicBlock &MBB);
 
   /// Adds registers living into block \p MBB.
   LLVM_ABI void addLiveIns(const MachineBasicBlock &MBB);

llvm/include/llvm/CodeGen/MachineBasicBlock.h

@@ -553,8 +553,8 @@ class MachineBasicBlock
         LiveRegI = (*BlockI)->livein_begin();
         if (!advanceToValidPosition())
           return;
-        if (LiveRegI->PhysReg == ExceptionPointer ||
-            LiveRegI->PhysReg == ExceptionSelector)
+        if ((*BlockI)->isEHPad() && (LiveRegI->PhysReg == ExceptionPointer ||
+                                     LiveRegI->PhysReg == ExceptionSelector))
           ++(*this);
       }
     }

llvm/lib/CodeGen/LiveRegUnits.cpp

@@ -87,15 +87,16 @@ void LiveRegUnits::accumulate(const MachineInstr &MI) {
 
 /// Add live-in registers of basic block \p MBB to \p LiveUnits.
 static void addBlockLiveIns(LiveRegUnits &LiveUnits,
-                            const MachineBasicBlock &MBB,
-                            MCPhysReg ExceptionPointer = {},
-                            MCPhysReg ExceptionSelector = {}) {
-  for (const auto &LI : MBB.liveins()) {
-    if (MBB.isEHPad() &&
-        (LI.PhysReg == ExceptionPointer || LI.PhysReg == ExceptionSelector))
-      continue;
+                            const MachineBasicBlock &MBB) {
+  for (const auto &LI : MBB.liveins())
+    LiveUnits.addRegMasked(LI.PhysReg, LI.LaneMask);
+}
+
+/// Add live-out registers of basic block \p MBB to \p LiveUnits.
+static void addBlockLiveOuts(LiveRegUnits &LiveUnits,
+                             const MachineBasicBlock &MBB) {
+  for (const auto &LI : MBB.liveouts())
     LiveUnits.addRegMasked(LI.PhysReg, LI.LaneMask);
-  }
 }
 
 /// Adds all callee saved registers to \p LiveUnits.
@@ -142,25 +143,10 @@ void LiveRegUnits::addPristines(const MachineFunction &MF) {
   addUnits(Pristine.getBitVector());
 }
 
-void LiveRegUnits::addLiveOuts(const MachineBasicBlock &MBB,
-                               const TargetLowering *TLI) {
+void LiveRegUnits::addLiveOuts(const MachineBasicBlock &MBB) {
   const MachineFunction &MF = *MBB.getParent();
-
   addPristines(MF);
-
-  MCPhysReg ExceptionPointer;
-  MCPhysReg ExceptionSelector;
-
-  // Remove live-ins from successors that are defined by the runtime.
-  if (TLI && MF.getFunction().hasPersonalityFn()) {
-    auto PersonalityFn = MF.getFunction().getPersonalityFn();
-    ExceptionPointer = TLI->getExceptionPointerRegister(PersonalityFn);
-    ExceptionSelector = TLI->getExceptionSelectorRegister(PersonalityFn);
-  }
-
-  // To get the live-outs we simply merge the live-ins of all successors.
-  for (const MachineBasicBlock *Succ : MBB.successors())
-    addBlockLiveIns(*this, *Succ, ExceptionPointer, ExceptionSelector);
+  addBlockLiveOuts(*this, MBB);
 
   // For the return block: Add all callee saved registers.
   if (MBB.isReturnBlock()) {

llvm/lib/CodeGen/MachineBasicBlock.cpp

@@ -1781,9 +1781,6 @@ MachineBasicBlock::livein_iterator MachineBasicBlock::livein_begin() const {
 
 MachineBasicBlock::liveout_iterator MachineBasicBlock::liveout_begin() const {
   const MachineFunction &MF = *getParent();
-  assert(MF.getProperties().hasTracksLiveness() &&
-         "Liveness information is accurate");
-
   const TargetLowering &TLI = *MF.getSubtarget().getTargetLowering();
   MCRegister ExceptionPointer, ExceptionSelector;
   if (MF.getFunction().hasPersonalityFn()) {

llvm/lib/Target/AArch64/MachineSMEABIPass.cpp

@@ -277,7 +277,7 @@ void MachineSMEABI::collectNeededZAStates(SMEAttrs SMEFnAttrs) {
     }
 
     LiveRegUnits LiveUnits(*TRI);
-    LiveUnits.addLiveOuts(MBB, Subtarget->getTargetLowering());
+    LiveUnits.addLiveOuts(MBB);
 
     auto GetPhysLiveRegs = [&] {
       LiveRegs PhysLiveRegs = LiveRegs::None;