1 files changed, 7 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
index 2540e545ae4d..0327efbf9614 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAtomicRMW.cpp
@@ -61,7 +61,13 @@ bool isIdempotentRMW(AtomicRMWInst& RMWI) {
 /// equivalent to its value operand.
 bool isSaturating(AtomicRMWInst& RMWI) {
   if (auto CF = dyn_cast<ConstantFP>(RMWI.getValOperand()))
-    switch(RMWI.getOperation()) {
+    switch (RMWI.getOperation()) {
+    case AtomicRMWInst::FMax:
+      // maxnum(x, +inf) -> +inf
+      return !CF->isNegative() && CF->isInfinity();
+    case AtomicRMWInst::FMin:
+      // minnum(x, -inf) -> +inf
+      return CF->isNegative() && CF->isInfinity();
     case AtomicRMWInst::FAdd:
     case AtomicRMWInst::FSub:
       return CF->isNaN();