diff --git a/README.txt b/README.txt
index 8022e3c61..8bd53fbcc 100644
--- a/README.txt
+++ b/README.txt
@@ -99,7 +99,7 @@ want to put libraries in a lib64 directory instead of the usual lib
 directory. This is how Linux/AMD64 keeps 64bit libraries segregated
 from 32bit libraries. This is done by configuring like this:
 
-  ./configure libdir64='$(prefix)/lib64'
+  ./configure libdir64='$(prefix)/lib64' vpidir1=vpi64 vpidir2=.
 
 2.3 (Optional) Testing
 
diff --git a/cadpli/Makefile.in b/cadpli/Makefile.in
index a8c88ed74..f8c37bad4 100644
--- a/cadpli/Makefile.in
+++ b/cadpli/Makefile.in
@@ -16,7 +16,7 @@
 #    59 Temple Place - Suite 330
 #    Boston, MA 02111-1307, USA
 #
-#ident "$Id: Makefile.in,v 1.4 2003/02/27 22:13:22 steve Exp $"
+#ident "$Id: Makefile.in,v 1.5 2003/10/02 21:30:40 steve Exp $"
 #
 #
 SHELL = /bin/sh
@@ -33,6 +33,8 @@ bindir = @bindir@
 libdir = @libdir@
 includedir = $(prefix)/include
 
+vpidir = @libdir@/ivl/@vpidir1@
+
 strip_dynamic=@strip_dynamic@
 
 CC = @CC@
@@ -74,16 +76,16 @@ clean:
 distclean: clean
 	rm -f Makefile config.status config.log config.cache
 
-install: all installdirs $(libdir)/ivl/cadpli.vpl
+install: all installdirs $(vpidir)/cadpli.vpl
 
-$(libdir)/ivl/cadpli.vpl: ./cadpli.vpl
-	$(INSTALL_PROGRAM) ./cadpli.vpl $(libdir)/ivl/cadpli.vpl
+$(vpidir)/cadpli.vpl: ./cadpli.vpl
+	$(INSTALL_PROGRAM) ./cadpli.vpl $(vpidir)/cadpli.vpl
 
 installdirs: ../mkinstalldirs
-	$(srcdir)/../mkinstalldirs $(libdir)/ivl
+	$(srcdir)/../mkinstalldirs $(vpidir)
 
 uninstall:
-	rm -f $(libdir)/ivl/cadpli.vpl
+	rm -f $(vpidir)/cadpli.vpl
 
 
 -include $(patsubst %.o, dep/%.d, $O)
diff --git a/cadpli/configure.in b/cadpli/configure.in
index ca923ce6c..ff155b4bd 100644
--- a/cadpli/configure.in
+++ b/cadpli/configure.in
@@ -219,4 +219,14 @@ esac
 AC_SUBST(ident_support)
 AC_MSG_RESULT($ident_support)
 
+# where to put vpi subdirectories
+AC_MSG_CHECKING(for VPI subdirectories)
+if test x${vpidir1} = x
+then
+	vpidir1="."
+fi
+
+AC_SUBST(vpidir1)
+AC_MSG_RESULT(${vpidir1})
+
 AC_OUTPUT(Makefile)
diff --git a/configure.in b/configure.in
index c30404ecb..5d107828f 100644
--- a/configure.in
+++ b/configure.in
@@ -50,7 +50,7 @@ AC_SUBST(EXEEXT)
 
 AC_LANG_CPLUSPLUS
 
-AC_CHECK_HEADERS(getopt.h malloc.h stdint.h libiberty.h iosfwd sys/wait.h)
+AC_CHECK_HEADERS(getopt.h malloc.h inttypes.h libiberty.h iosfwd sys/wait.h)
 
 AC_CHECK_LIB(z, gzwrite)
 AC_CHECK_LIB(z, gzwrite, HAVE_LIBZ=yes, HAVE_LIBZ=no)
@@ -264,6 +264,16 @@ esac
 AC_SUBST(ident_support)
 AC_MSG_RESULT($ident_support)
 
+# where to put vpi subdirectories
+AC_MSG_CHECKING(for VPI subdirectories)
+if test x${vpidir1} = x
+then
+	vpidir1="."
+fi
+
+AC_SUBST(vpidir1)
+AC_SUBST(vpidir2)
+AC_MSG_RESULT(${vpidir1} ${vpidir2})
 
 AC_CONFIG_SUBDIRS(vvp tgt-vvp tgt-fpga libveriuser cadpli)
 
diff --git a/verilog.spec b/verilog.spec
index 35b45b429..8c0d96e31 100644
--- a/verilog.spec
+++ b/verilog.spec
@@ -26,7 +26,7 @@ to the IEEE-1364 standard.
 
 %build
 %ifarch x86_64
-./configure --prefix=/usr libdir64='$(prefix)/lib64'
+./configure --prefix=/usr libdir64='$(prefix)/lib64' vpidir1=vpi64 vpidir1=.
 %else
 ./configure --prefix=/usr
 %endif
@@ -49,16 +49,18 @@ make prefix=$RPM_BUILD_ROOT/usr install
 %attr(-,root,root) /usr/bin/vvp
 %attr(-,root,root) /usr/lib/ivl/ivl
 %attr(-,root,root) /usr/lib/ivl/ivlpp
-%attr(-,root,root) /usr/lib/ivl/system.vpi
-%attr(-,root,root) /usr/lib/ivl/cadpli.vpl
 %attr(-,root,root) /usr/lib/ivl/null.tgt
 %attr(-,root,root) /usr/lib/ivl/vvp.tgt
 %attr(-,root,root) /usr/lib/ivl/fpga.tgt
 %attr(-,root,root) /usr/lib/ivl/iverilog.conf
 %ifarch x86_64
+%attr(-,root,root) /usr/lib/ivl/vpi64/system.vpi
+%attr(-,root,root) /usr/lib/ivl/vpi64/cadpli.vpl
 %attr(-,root,root) /usr/lib64/libvpi.a
 %attr(-,root,root) /usr/lib64/libveriuser.a
 %else
+%attr(-,root,root) /usr/lib/ivl/system.vpi
+%attr(-,root,root) /usr/lib/ivl/cadpli.vpl
 %attr(-,root,root) /usr/lib/libvpi.a
 %attr(-,root,root) /usr/lib/libveriuser.a
 %endif
diff --git a/vpi/Makefile.in b/vpi/Makefile.in
index d74bd1a93..6d9c9ab8d 100644
--- a/vpi/Makefile.in
+++ b/vpi/Makefile.in
@@ -18,7 +18,7 @@
 #    59 Temple Place - Suite 330
 #    Boston, MA 02111-1307, USA
 #
-#ident "$Id: Makefile.in,v 1.44 2003/09/30 01:33:39 steve Exp $"
+#ident "$Id: Makefile.in,v 1.45 2003/10/02 21:30:40 steve Exp $"
 #
 #
 SHELL = /bin/sh
@@ -35,6 +35,8 @@ bindir = @bindir@
 libdir = @libdir@
 includedir = $(prefix)/include
 
+vpidir = $(libdir)/ivl/@vpidir1@
+
 strip_dynamic=@strip_dynamic@
 
 CC = @CC@
@@ -83,17 +85,17 @@ clean:
 distclean: clean
 	rm -f Makefile
 
-install: all installdirs $(libdir)/ivl/system.vpi
+install: all installdirs $(vpidir)/system.vpi
 
-$(libdir)/ivl/system.vpi: ./system.vpi
-	$(INSTALL_PROGRAM) ./system.vpi $(libdir)/ivl/system.vpi
-	$(STRIP) $(strip_dynamic) $(libdir)/ivl/system.vpi
+$(vpidir)/system.vpi: ./system.vpi
+	$(INSTALL_PROGRAM) ./system.vpi $(vpidir)/system.vpi
+	$(STRIP) $(strip_dynamic) $(vpidir)/system.vpi
 
 installdirs: ../mkinstalldirs
-	$(srcdir)/../mkinstalldirs $(libdir)/ivl
+	$(srcdir)/../mkinstalldirs $(vpidir)
 
 uninstall:
-	rm -f $(libdir)/ivl/system.vpi
+	rm -f $(vpidir)/system.vpi
 
 
 -include $(patsubst %.o, dep/%.d, $O)
diff --git a/vvp/Makefile.in b/vvp/Makefile.in
index 4fb67876a..0f65f5db0 100644
--- a/vvp/Makefile.in
+++ b/vvp/Makefile.in
@@ -16,7 +16,7 @@
 #    59 Temple Place - Suite 330
 #    Boston, MA 02111-1307, USA
 #
-#ident "$Id: Makefile.in,v 1.54 2003/10/02 19:33:44 steve Exp $"
+#ident "$Id: Makefile.in,v 1.55 2003/10/02 21:30:40 steve Exp $"
 #
 #
 SHELL = /bin/sh
@@ -46,7 +46,7 @@ RANLIB = @RANLIB@
 LEX = @LEX@
 YACC = @YACC@
 
-CPPFLAGS = -I. -I.. -I $(srcdir) -I$(srcdir)/.. @CPPFLAGS@ @DEFS@ -DMODULE_DIR=\"$(libdir)/ivl\"
+CPPFLAGS = -I. -I.. -I $(srcdir) -I$(srcdir)/.. @CPPFLAGS@ @DEFS@
 CXXFLAGS = @CXXFLAGS@
 LDFLAGS = @LDFLAGS@
 LIBS = @LIBS@ @EXTRALIBS@
@@ -54,6 +54,11 @@ LIBS = @LIBS@ @EXTRALIBS@
 dllib=@DLLIB@
 rdynamic=@rdynamic@
 
+CPPFLAGS += -DMODULE_DIR=\"$(libdir)/ivl/@vpidir1@\"
+ifneq (x@vpidir2@,x)
+CPPFLAGS += -DMODULE_DIR2=\"$(libdir)/ivl/@vpidir2@\"
+endif
+
 all: dep vvp@EXEEXT@ libvpi.a
 
 clean:
diff --git a/vvp/configure.in b/vvp/configure.in
index 68e8cb935..cd5223069 100644
--- a/vvp/configure.in
+++ b/vvp/configure.in
@@ -208,4 +208,15 @@ fi
 AC_SUBST(libdir64)
 AC_MSG_RESULT(${libdir64})
 
+# where to put vpi subdirectories
+AC_MSG_CHECKING(for VPI subdirectories)
+if test x${vpidir1} = x
+then
+	vpidir1="vpi"
+fi
+
+AC_SUBST(vpidir1)
+AC_SUBST(vpidir2)
+AC_MSG_RESULT(${vpidir1} ${vpidir2})
+
 AC_OUTPUT(Makefile)
diff --git a/vvp/vpi_modules.cc b/vvp/vpi_modules.cc
index 95ce1b3ba..a0940ea43 100644
--- a/vvp/vpi_modules.cc
+++ b/vvp/vpi_modules.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_modules.cc,v 1.15 2003/02/16 02:21:20 steve Exp $"
+#ident "$Id: vpi_modules.cc,v 1.16 2003/10/02 21:30:40 steve Exp $"
 #endif
 
 # include  "config.h"
@@ -33,11 +33,17 @@ typedef void (*vlog_startup_routines_t)(void);
 
 const char* vpip_module_path[64] = {
       MODULE_DIR,
+#ifdef MODULE_DIR2
+      MODULE_DIR2,
+#endif
       0
 };
 
+#ifdef MODULE_DIR2
+unsigned vpip_module_path_cnt = 2;
+#else
 unsigned vpip_module_path_cnt = 1;
-
+#endif
 
 void vpip_load_module(const char*name)
 {
@@ -138,6 +144,9 @@ void vpip_load_module(const char*name)
 
 /*
  * $Log: vpi_modules.cc,v $
+ * Revision 1.16  2003/10/02 21:30:40  steve
+ *  Configure control for the vpi subdirectory.
+ *
  * Revision 1.15  2003/02/16 02:21:20  steve
  *  Support .vpl files as loadable LIBRARIES.
  *