TL;DR: How to preserve multilibs directory hierarchy for GCC 64 bit
configuration on AIX when 32 bit multilib exists in the top-level
directory, no explicit MULTILIB_DIRNAME.
Currently the powerpc-ibm-aix* port supports a 64-bit explicit
multilib and a 32 bit implicit, default multilib in the top-level
directory.
MULTILIB_OPTIONS = pthread maix64
MULTILIB_DIRNAMES = pthread ppc64
There is no explicit "maix32" multilib with "ppc32" directory.
My colleagues and I are trying to add a compatible, 64 bit
configuration where the compiler itself is a 64 bit application. If
GCC is a 64 bit application, the build process requires that it
generate 64 bit code by default. I thought that adding an explicit
"maix32" multilib option with "." directory
MULTILIB_OPTIONS = pthread maix64/maix32
MULTILIB_DIRNAMES = pthread ppc64 .
and
MULTILIB_DEFAULTS { "maix64" }
in 64 bit mode would maintain the existing directory hierarchy. In 32
bit mode with
MULTILIB_DEFAULTS { "maix32" }
the above configuration functions. In 64 bit mode, the build
machinery seems confused that "." is at the wrong level in the
hierarchy.
I see t-sol2 uses "." for MULTILIB_OSDIRNAMES but I do not see any
other target example that uses "." in MULTILIB_DIRNAMES.
Does anyone have a suggestion to achieve the same, compatible
hierarchy using the GCC build system for a 64 bit configuration on
AIX?
Thanks, David
