errors building mod_perl 64 bit on Solaris 10 sparc with solarisstudio compiler

-c modperl_perl.c && mv modperl_perl.o modperl_perl.lo
"modperl_perl.c", line 272: undefined symbol: PL_rehash_seed
"modperl_perl.c", line 273: undefined symbol: PL_rehash_seed_set
cc: acomp failed for modperl_perl.c
*** Error code 2
make: Fatal error: Command failed for target `modperl_perl.lo'
Current working directory /var/tmp/mod_perl-2.0.7/src/modules/perl
*** Error code 1
make: Fatal error: Command failed for target `modperl_lib'
bash-3.2#


bash-3.2# file /usr/bin/perl
/usr/bin/perl:  ELF 64-bit MSB executable SPARCV9 Version 1, dynamically
linked, not stripped
bash-3.2# which perl
/usr/bin/perl
bash-3.2#


bash-3.2# file /apps/apache2/prefork/bin/httpd
/apps/apache2/prefork/bin/httpd:        ELF 64-bit MSB executable SPARCV9
Version 1, dynamically linked, not stripped
bash-3.2#


So, both apache(httpd) and perl are 64 bit.

bash-3.2# env
LDFLAGS=-m64
MANPATH=/usr/share/man:/opt/VRTS/man
TERM=vt100
SHELL=/sbin/sh
SSH_CLIENT=10.146.3.35 53379 22
CFLAHS=-m64
OLDPWD=/var/tmp
SSH_TTY=/dev/pts/9
USER=root
LD_LIBRARY_PATH=/opt/solarisstudio12.3/lib:/usr/
perl5/5.18.0/lib/5.18.0:/usr/perl5/5.18.0/lib/site_perl:/
opt/csw/lib:/usr/local/lib:/usr/lib:/lib:/usr/sfw/lib
PATH=/opt/solarisstudio12.3/bin:/opt/csw/bin:/usr/ccs/bin:
/usr/sbin:/usr/bin:/usr/sfw/bin
MAIL=/var/mail//root
PWD=/var/tmp/mod_perl-2.0.7
LANG=en_US.UTF-8
TZ=US/Pacific
SHLVL=1
HOME=/root
CFLAGS=-m64 -xO3
LOGNAME=root
CC=cc
_=/usr/bin/env
bash-3.2#