3 files changed, 23 insertions, 20 deletions
diff --git a/llvm/lib/CodeGen/ExecutionDepsFix.cpp b/llvm/lib/CodeGen/ExecutionDepsFix.cpp
index 70945832942..12ea9e3844b 100644
--- a/llvm/lib/CodeGen/ExecutionDepsFix.cpp
+++ b/llvm/lib/CodeGen/ExecutionDepsFix.cpp
@@ -558,7 +558,9 @@ void ExeDepsFix::processUndefReads(MachineBasicBlock *MBB) {
 
   // Collect this block's live out register units.
   LiveRegSet.init(TRI);
-  LiveRegSet.addLiveOuts(MBB);
+  // We do not need to care about pristine registers as they are just preserved
+  // but not actually used in the function.
+  LiveRegSet.addLiveOutsNoPristines(MBB);
 
   MachineInstr *UndefMI = UndefReads.back().first;
   unsigned OpIdx = UndefReads.back().second;
diff --git a/llvm/lib/CodeGen/LivePhysRegs.cpp b/llvm/lib/CodeGen/LivePhysRegs.cpp
index 6cb3ee15a79..4945b3d216c 100644
--- a/llvm/lib/CodeGen/LivePhysRegs.cpp
+++ b/llvm/lib/CodeGen/LivePhysRegs.cpp
@@ -135,22 +135,25 @@ static void addLiveIns(LivePhysRegs &LiveRegs, const MachineBasicBlock &MBB) {
 /// Add pristine registers to the given \p LiveRegs. This function removes
 /// actually saved callee save registers when \p InPrologueEpilogue is false.
 static void addPristines(LivePhysRegs &LiveRegs, const MachineFunction &MF,
+                         const MachineFrameInfo &MFI,
                          const TargetRegisterInfo &TRI) {
-  const MachineFrameInfo &MFI = *MF.getFrameInfo();
-  if (!MFI.isCalleeSavedInfoValid())
-    return;
-
   for (const MCPhysReg *CSR = TRI.getCalleeSavedRegs(&MF); CSR && *CSR; ++CSR)
     LiveRegs.addReg(*CSR);
   for (const CalleeSavedInfo &Info : MFI.getCalleeSavedInfo())
     LiveRegs.removeReg(Info.getReg());
 }
 
-void LivePhysRegs::addLiveOuts(const MachineBasicBlock *MBB,
-                               bool AddPristinesAndCSRs) {
-  if (AddPristinesAndCSRs) {
-    const MachineFunction &MF = *MBB->getParent();
-    addPristines(*this, MF, *TRI);
+void LivePhysRegs::addLiveOutsNoPristines(const MachineBasicBlock *MBB) {
+  // To get the live-outs we simply merge the live-ins of all successors.
+  for (const MachineBasicBlock *Succ : MBB->successors())
+    ::addLiveIns(*this, *Succ);
+}
+
+void LivePhysRegs::addLiveOuts(const MachineBasicBlock *MBB) {
+  const MachineFunction &MF = *MBB->getParent();
+  const MachineFrameInfo &MFI = *MF.getFrameInfo();
+  if (MFI.isCalleeSavedInfoValid()) {
+    addPristines(*this, MF, MFI, *TRI);
     if (MBB->isReturnBlock()) {
       // The return block has no successors whose live-ins we could merge
       // below. So instead we add the callee saved registers manually.
@@ -159,16 +162,13 @@ void LivePhysRegs::addLiveOuts(const MachineBasicBlock *MBB,
     }
   }
 
-  // To get the live-outs we simply merge the live-ins of all successors.
-  for (const MachineBasicBlock *Succ : MBB->successors())
-    ::addLiveIns(*this, *Succ);
+  addLiveOutsNoPristines(MBB);
 }
 
-void LivePhysRegs::addLiveIns(const MachineBasicBlock *MBB,
-                              bool AddPristines) {
-  if (AddPristines) {
-    const MachineFunction &MF = *MBB->getParent();
-    addPristines(*this, MF, *TRI);
-  }
+void LivePhysRegs::addLiveIns(const MachineBasicBlock *MBB) {
+  const MachineFunction &MF = *MBB->getParent();
+  const MachineFrameInfo &MFI = *MF.getFrameInfo();
+  if (MFI.isCalleeSavedInfoValid())
+    addPristines(*this, MF, MFI, *TRI);
   ::addLiveIns(*this, *MBB);
 }
diff --git a/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp b/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp
index fd571de86de..0d09c2375dc 100644
--- a/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp
+++ b/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp
@@ -127,7 +127,8 @@ bool StackMapLiveness::calculateLiveness(MachineFunction &MF) {
   for (auto &MBB : MF) {
     DEBUG(dbgs() << "****** BB " << MBB.getName() << " ******\n");
     LiveRegs.init(TRI);
-    LiveRegs.addLiveOuts(&MBB);
+    // FIXME: This should probably be addLiveOuts().
+    LiveRegs.addLiveOutsNoPristines(&MBB);
     bool HasStackMap = false;
     // Reverse iterate over all instructions and add the current live register
     // set to an instruction if we encounter a patchpoint instruction.