fix logic for SCEVNArayExpr

Author: kasuga-fj

llvm/lib/Analysis/DependenceAnalysis.cpp

@@ -3497,19 +3497,17 @@ SCEVSignedMonotonicityChecker::visitNAryHelper(const SCEVNAryExpr *Expr) {
  case MonotonicityType::Invariant:
  break;
  case MonotonicityType::MultiMonotonic: {
+ if (!Expr->hasNoSignedWrap())
+ return unknownMonotonicity(Expr);
  switch (Result) {
  case MonotonicityType::Unknown:
  llvm_unreachable("should have been handled above");
  case MonotonicityType::NoSignedWrap:
  break;
  case MonotonicityType::Invariant:
- if (!Expr->hasNoSignedWrap())
- return unknownMonotonicity(Expr);
  Result = MonotonicityType::MultiMonotonic;
  break;
  case MonotonicityType::MultiMonotonic:
- if (!Expr->hasNoSignedWrap())
- return unknownMonotonicity(Expr);
  if (!isa<SCEVAddExpr>(Expr))
  return unknownMonotonicity(Expr);
  // Monotonic + Monotonic might be a loop invariant, e.g., the following