https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61225
--- Comment #30 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Trying to combine the load+add+store, combine is trying insns like
Failed to match this instruction:
(parallel [
(set (mem:SI (reg/v/f:SI 90 [ x ]) [1 *x_5(D)+0 S4 A32])
(plus:SI (mem:SI (reg/v/f:SI 90 [ x ]) [1 *x_5(D)+0 S4 A32])
(const_int -1 [0xffffffffffffffff])))
(set (reg:SI 88 [ _2 ])
(plus:SI (mem:SI (reg/v/f:SI 90 [ x ]) [1 *x_5(D)+0 S4 A32])
(const_int -1 [0xffffffffffffffff])))
])
and it does not know how to split that into two (make the second SET
just a load). If it could do that -- and costs work out for the target --
all would work fine as far as I see. Alternatively, the target could
use a define_split for this pattern.
