[Transforms] Use std::nullopt instead of None (NFC)

This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

1 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
index bc3a30a..da8d375 100644
--- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
@@ -703,7 +703,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
     if (CompletelyUnroll) {
       if (PreserveOnlyFirst) {
         if (i == 0)
-          return None;
+          return std::nullopt;
         return j == 0;
       }
       // Complete (but possibly inexact) unrolling
@@ -711,7 +711,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
         return true;
       if (Info.TripCount && j != Info.TripCount)
         return false;
-      return None;
+      return std::nullopt;
     }
 
     if (ULO.Runtime) {
@@ -719,7 +719,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
       // exits may be stale.
       if (IsLatch && j != 0)
         return false;
-      return None;
+      return std::nullopt;
     }
 
     if (j != Info.BreakoutTrip &&
@@ -728,7 +728,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
       // unconditional branch for some iterations.
       return false;
     }
-    return None;
+    return std::nullopt;
   };
 
   // Fold branches for iterations where we know that they will exit or not