3 files changed, 7 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 7ab17fce04d..ca43804481b 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -1305,6 +1305,8 @@ bool MachineInstr::isDereferenceableInvariantLoad(AliasAnalysis *AA) const {
 
   for (MachineMemOperand *MMO : memoperands()) {
     if (MMO->isVolatile()) return false;
+    // TODO: Figure out whether isAtomic is really necessary (see D57601).
+    if (MMO->isAtomic()) return false;
     if (MMO->isStore()) return false;
     if (MMO->isInvariant() && MMO->isDereferenceable())
       continue;
diff --git a/llvm/lib/CodeGen/MachinePipeliner.cpp b/llvm/lib/CodeGen/MachinePipeliner.cpp
index fab44512914..1e729d4851a 100644
--- a/llvm/lib/CodeGen/MachinePipeliner.cpp
+++ b/llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -2766,7 +2766,9 @@ void SwingSchedulerDAG::updateMemOperands(MachineInstr &NewMI,
     return;
   SmallVector<MachineMemOperand *, 2> NewMMOs;
   for (MachineMemOperand *MMO : NewMI.memoperands()) {
-    if (MMO->isVolatile() || (MMO->isInvariant() && MMO->isDereferenceable()) ||
+    // TODO: Figure out whether isAtomic is really necessary (see D57601).
+    if (MMO->isVolatile() || MMO->isAtomic() ||
+        (MMO->isInvariant() && MMO->isDereferenceable()) ||
         (!MMO->getValue())) {
       NewMMOs.push_back(MMO);
       continue;
diff --git a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
index ab503206a51..3e68e09c44e 100644
--- a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -131,7 +131,8 @@ static bool getUnderlyingObjectsForInstr(const MachineInstr *MI,
                                          const DataLayout &DL) {
   auto allMMOsOkay = [&]() {
     for (const MachineMemOperand *MMO : MI->memoperands()) {
-      if (MMO->isVolatile())
+      // TODO: Figure out whether isAtomic is really necessary (see D57601).
+      if (MMO->isVolatile() || MMO->isAtomic())
         return false;
 
       if (const PseudoSourceValue *PSV = MMO->getPseudoValue()) {