1 files changed, 16 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index f1be359862c..9cb7ed0c64f 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -39768,6 +39768,19 @@ bool X86TargetLowering::IsDesirableToPromoteOp(SDValue Op, EVT &PVT) const {
     return Ld->getBasePtr() == St->getBasePtr();
   };
 
+  auto IsFoldableAtomicRMW = [](SDValue Load, SDValue Op) {
+    if (!Load.hasOneUse() || Load.getOpcode() != ISD::ATOMIC_LOAD)
+      return false;
+    if (!Op.hasOneUse())
+      return false;
+    SDNode *User = *Op->use_begin();
+    if (User->getOpcode() != ISD::ATOMIC_STORE)
+      return false;
+    auto *Ld = cast<AtomicSDNode>(Load);
+    auto *St = cast<AtomicSDNode>(User);
+    return Ld->getBasePtr() == St->getBasePtr();
+  };
+
   bool Commute = false;
   switch (Op.getOpcode()) {
   default: return false;
@@ -39802,6 +39815,9 @@ bool X86TargetLowering::IsDesirableToPromoteOp(SDValue Op, EVT &PVT) const {
         ((Commute && !isa<ConstantSDNode>(N1)) ||
          (Op.getOpcode() != ISD::MUL && IsFoldableRMW(N0, Op))))
       return false;
+    if (IsFoldableAtomicRMW(N0, Op) ||
+        (Commute && IsFoldableAtomicRMW(N1, Op)))
+      return false;
   }
   }