const hash_value arg

Author: j2kun

mlir/include/mlir/Dialect/Polynomial/IR/Polynomial.h

@@ -101,15 +101,15 @@ class Polynomial {
 
   unsigned getDegree() const;
 
-  friend ::llvm::hash_code hash_value(Polynomial arg);
+  friend ::llvm::hash_code hash_value(const Polynomial &arg);
 
 private:
   // The monomial terms for this polynomial.
   SmallVector<Monomial> terms;
 };
 
 // Make Polynomial hashable.
-inline ::llvm::hash_code hash_value(Polynomial arg) {
+inline ::llvm::hash_code hash_value(const Polynomial &arg) {
   return ::llvm::hash_combine_range(arg.terms.begin(), arg.terms.end());
 }