[Bug rtl-optimization/87361] [9 regression] gcc.target/sparc/20161111-1.c FAILs

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87361

--- Comment #7 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> I think nonzero_bits should use SUBREG_PROMOTED_VAR_P and
> SUBREG_PROMOTED_UNSIGNED_P for REGs, not LOAD_EXTEND_OP, which is
> only for MEMs.

I don't see how SUBREG_PROMOTED_VAR_P/SUBREG_PROMOTED_UNSIGNED_P will fit in
the picture here, it's limited to RTL expansion.  Ideally the REE pass should
deal with that instead, but it doesn't know anything about implicit extensions.