Re: BUG #18839: ARMv7 builds fail due to missing __crc32cw and similar

Mathew Heard <mat999@gmail.com> writes:
> If I am correct, postgresql is identifying the CPU of the build system as
> ARMv8 in that test, and using this rather than the target architecture.

The configure script isn't "identifying" anything.  It's just seeing
whether references to __crc32cb() etc will compile with different
-march flags.  It's not apparent why a successful test of that sort
would not lead to a successful compilation with the same flags later
on.  We might do a *run time* probe of the actual CPU type, but that
has nothing to do with compilation.

You still haven't told us which -march setting configure is selecting,
nor provided the config.log trace showing why it chose that one.
You also haven't described the compilation environment in any detail
--- eg, I still am not sure if this is a hard-float or soft-float
environment.

            regards, tom lane