don't hardcode gcc
remove -O flags
honor CFLAGS
disable root check for install target
set DIR (for install) to PREFIX

Index: BSDmakefile
--- BSDmakefile.orig
+++ BSDmakefile
@@ -26,14 +26,12 @@
 # along with this program. If not, see http://www.gnu.org/licenses/.
 
 OS    != uname
-CC     = gcc
+CC     ?= cc
 FLAGS  = -fsigned-char -fwrapv -Wall -std=gnu99 -Iinclude
 LIBS   = -lm -lcrypt
 
 .ifmake debug
-    EXTRA = -O0 -g3
 .else
-    EXTRA = -O3
     FLAGS += -DNDEBUG
 .endif
 
@@ -49,6 +47,8 @@ LIBS   = -lm -lcrypt
 
 .if ($(OS) == OpenBSD)
     LIBS = -lm
+    FLAGS += $(CFLAGS)
+    DIR=${PREFIX}/bin
 .endif
 
 DIRS = compile database init runtime seqio symbol util xcall
@@ -115,11 +115,6 @@ debug: ${OBJS}
 	${CC} ${EXTRA} ${FLAGS} -o ${PROG} ${OBJS} ${LIBS}
 
 install: ${PROG}
-	@if [ "$${USER}" != "root" ]; then \
-	    echo "You must install ${PROG} as root"; \
-	    exit 1; \
-	fi
-
 	@if [ ! -d ${DIR} ]; then \
 	    mkdir -p ${DIR}; \
 	fi