Although a previous patch allowed mixed vector sizes within a vector
region, we generally still required equal vector sizes within a vector
stmt. Specifically, vect_get_vector_types_for_stmt computes two vector
types: the vector type corresponding to STMT_VINFO_VECTYPE and the
vector type that determines the minimum vectorisation factor for the
stmt ("nunits_vectype"). It then required these two types to be
the same size.
There doesn't seem to be any need for that restriction though. AFAICT,
all vectorizable_* functions either do their own compatibility checks
or don't need to do them (because gimple guarantees that the scalar
types are compatible).
It should always be the case that nunits_vectype has at least as many
elements as the other vectype, but that's something we can assert for.
I couldn't resist a couple of other tweaks while there:
- there's no need to compute nunits_vectype if its element type is
the same as STMT_VINFO_VECTYPE's.
- it's useful to distinguish the nunits_vectype from the main vectype
in dump messages
- when reusing the existing STMT_VINFO_VECTYPE, it's useful to say so
in the dump, and say what the type is
2019-11-14 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* tree-vect-stmts.c (vect_get_vector_types_for_stmt): Don't
require vectype and nunits_vectype to have the same size;
instead assert that nunits_vectype has at least as many
elements as vectype. Don't compute a separate nunits_vectype
if the scalar type is obviously the same as vectype's.
Tweak dump messages.
From-SVN: r278244
