On Tuesday 04/15/08 @ 8:27 pm MDT, I received this from "Ed L." 
<pgsql at bluepolka.net>:
> On Tue Apr 15 13:19:37 PDT 2008, Andrew Sullivan wrote:
> >> $ /opt/ansic/bin/cc -V
> >> cc: HP aC++/ANSI C B3910B A.06.05 [Jul 25 2005]
> >
> >[. . .]
> >
> >> checking for gcc... /opt/ansic/bin/cc
> >
> >It usually gives me heartburn when gcc tests find some
> > non-gcc compiler and think it's gcc.  Is this because aC++
> > (if that's what it's called) has some gcc-like mode that
> > it's using?  If so, any way to turn that off?
>
> I have no idea, not sure how to find out.  There are flags to
> turn *on* gcc compatibility, but I'm not using them and that
> line comes from within configure.  Where else would I look?

Your question makes me wonder if the gcc check is necessary since 
my old Pg 8.1.2 configure.log shows that, using the same 
compiler+flags, there's no obvious check for gcc like the one 
above (and it builds correctly):

checking build system type... ia64-hp-hpux11.23
checking host system type... ia64-hp-hpux11.23
checking which template to use... hpux
checking whether to build with 64-bit integer date/time 
support... no
checking whether NLS is wanted... no
checking for default port number... 5432
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables... 
checking for suffix of object files... o
checking whether we are using the GNU C compiler... no
checking whether cc accepts -g... yes
checking for cc option to accept ANSI C... none needed
configure: using CFLAGS=+DD64
checking whether the C compiler still works... yes
checking how to run the C preprocessor... cc -Ae -E