Index: Makefile
===================================================================
--- Makefile	(revision 469174)
+++ Makefile	(working copy)
@@ -10,7 +10,7 @@
 DIST_SUBDIR=	arpack
 EXTRACT_ONLY=	${PORTNAME}${PORTVERSION}.tar.gz
 
-MAINTAINER=	ports@FreeBSD.org
+MAINTAINER=	robert.ayrapetyan@gmail.com
 COMMENT=	Argand Library: large eigenvalue subroutines (serial version)
 
 BUILD_DEPENDS=	tradcpp:devel/tradcpp
@@ -17,10 +17,18 @@
 
 CONFLICTS=	arpack-ng-[0-9]*
 CPP=		tradcpp
-FFLAGS+=	-ffixed-line-length-none
 LDFLAGS+=	-L${LOCALBASE}/lib
 MAKE_JOBS_UNSAFE=	yes
 USES=		fortran
+.if !defined(ARCH)
+    ARCH!=          uname -p
+.endif
+.if ${ARCH} == amd64
+    fortran_ARGS=   flang
+    FFLAGS+=        -Mextend
+.else
+    FFLAGS+=        -ffixed-line-length-none
+.endif
 USE_LDCONFIG=	yes
 WRKSRC=		${WRKDIR}/ARPACK