Hi all,

I noticed we have a hand-crafted "bit_count" function in the aarch64 backend that implements the popcount operation.
We already have a midend popcount_hwi function operating on HOST_WIDE_INTs which seems to be exactly what we need.

This patch removes the aarch64-specific version and updates the one callsite where it's used, the '%P' output operand,
which itself is only used by the *andim_ashift<mode>_bfiz pattern in aarch64.md.

Bootstrapped and tested on aarch64.

Ok for trunk?

Thanks,
Kyrill

2015-08-19  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

     * config/aarch64/aarch64.c (bit_count): Delete prototype
     and definition.
     (aarch64_print_operand): Use popcount_hwi instead of the above.