How does one compile 64-bit executables on HP-UX PA-RISC?

[Steve Ellcey]

> If I use gcc -m64, I get an error.
> 
> drkirkby@hpbox:~$ gcc -m64 test.c
> cc1: error: unrecognized command line option "-m64"
> 
> Can anyone tell me how to build 64-bit binaries with gcc on this machine?
> 
> Dave

GCC on HP-UX PA-RISC uses seperate compilers for 32 and 64 bit modes
because 32 bit mode is SOM based and 64 bit mode is ELF based.  You can
get pre-built GCC compilers from http://www.hp.com/go/gcc and if you do
then you would need to download and install 2 different compilers to
generate both 32 and 64 bit code.  The 32 bit compiler from this
location installs as /opt/hp-gcc/bin/gcc and the 64 bit compiler
installs as /opt/hp-gcc64/bin/gcc.  If you are building GCC yourself you
need to build GCC with a target like 'hppa64-hp-hpux11.23' to build a
compiler that can generate 64 bit objects (but it will not  be able to
generate 32 bit objects).  If you build with a target such as
'hppa2.0w-hp-hpux11.23' then you will get a compiler that can generate
32 bit objects but not 64 bit objects.

Steve Ellcey
sje@cup.hp.com