[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, 7 insertions, 7 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 20aa801..72779ab 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -6620,17 +6620,17 @@ canFoldTermCondOfLoop(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
                       const LoopInfo &LI) {
   if (!L->isInnermost()) {
     LLVM_DEBUG(dbgs() << "Cannot fold on non-innermost loop\n");
-    return None;
+    return std::nullopt;
   }
   // Only inspect on simple loop structure
   if (!L->isLoopSimplifyForm()) {
     LLVM_DEBUG(dbgs() << "Cannot fold on non-simple loop\n");
-    return None;
+    return std::nullopt;
   }
 
   if (!SE.hasLoopInvariantBackedgeTakenCount(L)) {
     LLVM_DEBUG(dbgs() << "Cannot fold on backedge that is loop variant\n");
-    return None;
+    return std::nullopt;
   }
 
   BasicBlock *LoopPreheader = L->getLoopPreheader();
@@ -6640,18 +6640,18 @@ canFoldTermCondOfLoop(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
   // Terminating condition is foldable when it is an eq/ne icmp
   BranchInst *BI = cast<BranchInst>(LoopLatch->getTerminator());
   if (BI->isUnconditional())
-    return None;
+    return std::nullopt;
   Value *TermCond = BI->getCondition();
   if (!isa<ICmpInst>(TermCond) || !cast<ICmpInst>(TermCond)->isEquality()) {
     LLVM_DEBUG(dbgs() << "Cannot fold on branching condition that is not an "
                          "ICmpInst::eq / ICmpInst::ne\n");
-    return None;
+    return std::nullopt;
   }
   if (!TermCond->hasOneUse()) {
     LLVM_DEBUG(
         dbgs()
         << "Cannot replace terminating condition with more than one use\n");
-    return None;
+    return std::nullopt;
   }
 
   // For `IsToFold`, a primary IV can be replaced by other affine AddRec when it
@@ -6769,7 +6769,7 @@ canFoldTermCondOfLoop(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
              << "  ToHelpFold: " << *ToHelpFold << "\n");
 
   if (!ToFold || !ToHelpFold)
-    return None;
+    return std::nullopt;
   return {{ToFold, {ToHelpFold, TermValueS}}};
 }