From 3f7f7ab7e266cb0e951528d699fa5910af0908fe Mon Sep 17 00:00:00 2001
From: Martin Kroeker <martin@ruby.chemie.uni-freiburg.de>
Date: Tue, 10 Mar 2020 12:51:07 +0100
Subject: [PATCH] Restore INTERFACE64 for arm64

---
 Makefile.system | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Makefile.system b/Makefile.system
index 829c08f16..11cb5b3a0 100644
--- a/Makefile.system
+++ b/Makefile.system
@@ -635,6 +635,16 @@ endif
 ifeq ($(ARCH), arm64)
 NO_BINARY_MODE  = 1
 BINARY_DEFINED  = 1
+ifdef INTERFACE64
+ifneq ($(INTERFACE64), 0)
+ifeq ($(F_COMPILER), GFORTRAN)
+FCOMMON_OPT +=  -fdefault-integer-8
+endif
+ifeq ($(F_COMPILER), FLANG)
+FCOMMON_OPT += -i8
+endif
+endif
+endif
 endif