From 91de1f62fb95e07997b0c3f5e6671a77ce68f7eb Mon Sep 17 00:00:00 2001
From: peter klausler <pklausler@nvidia.com>
Date: Tue, 7 May 2019 17:05:14 -0700
Subject: [PATCH] [flang] dodge clang build problem with constexpr

Original-commit: flang-compiler/f18@83995a5a981dc25babd87ebbc816f026f3033b2e
Reviewed-on: https://github.com/flang-compiler/f18/pull/449
Tree-same-pre-rewrite: false
---
 flang/lib/evaluate/descender.h | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/flang/lib/evaluate/descender.h b/flang/lib/evaluate/descender.h
index 5db2472c0c57..cb7312519406 100644
--- a/flang/lib/evaluate/descender.h
+++ b/flang/lib/evaluate/descender.h
@@ -107,19 +107,23 @@ public:
   template<typename T> void Descend(const Expr<T> &expr) { Visit(expr.u); }
   template<typename T> void Descend(Expr<T> &expr) { Visit(expr.u); }
 
-  template<typename D, typename R, typename... O>
-  void Descend(const Operation<D, R, O...> &op) {
+  template<typename D, typename R, typename X>
+  void Descend(const Operation<D, R, X> &op) {
     Visit(op.left());
-    if constexpr (op.operands > 1) {
-      Visit(op.right());
-    }
   }
-  template<typename D, typename R, typename... O>
-  void Descend(Operation<D, R, O...> &op) {
+  template<typename D, typename R, typename X>
+  void Descend(Operation<D, R, X> &op) {
     Visit(op.left());
-    if constexpr (op.operands > 1) {
-      Visit(op.right());
-    }
+  }
+  template<typename D, typename R, typename X, typename Y>
+  void Descend(const Operation<D, R, X, Y> &op) {
+    Visit(op.left());
+    Visit(op.right());
+  }
+  template<typename D, typename R, typename X, typename Y>
+  void Descend(Operation<D, R, X, Y> &op) {
+    Visit(op.left());
+    Visit(op.right());
   }
 
   void Descend(const Relational<SomeType> &r) { Visit(r.u); }
-- 
2.34.1