Should PHI result and arg types match?

[Jakub Jelinek]

On Fri, Oct 19, 2018 at 12:47:00PM -0400, Aldy Hernandez wrote:
> Howdy!
> 
> Are the types for PHI arguments and the corresponding result supposed to
> match?

Like with most other gimple stmts, they need to satisfy
useless_type_conversion_p (TREE_TYPE (phiresult), TREE_TYPE (phiarg))
for all args.  And, most pointer conversions are considered useless,
exceptions are if different address spaces are involved or conversions
from function/method pointers to other pointers or vice versa, or if the
pointers have different modes.

	Jakub