[flang][cuda] Assign a scalar character function result on the host (#217076)
A managed function result makes an assignment a cuf.data_transfer:
function f() result(r)
character(len=:), allocatable :: r ! managed under -gpu=mem:managed
end function
character(len=256) :: c
c = f()
The rank-0 result r is lowered to a !fir.boxchar<1>, an {address,
length}
value rather than a reference, so the non-descriptor transfer path has
no
address to take:
'fir.convert' op invalid type conversion '!fir.boxchar<1>' /
'!fir.llvm_ptr<i8>'
A fixed-length result does have an address, but the copy is sized by the
character kind instead of the length: one character copied, c left
unpadded.
Managed and unified results are host accessible, so assign a scalar
character
result on the host and get the padding rules. Array results pass by
descriptor and are unaffected.
llvm-project
923f7b05 - [flang][cuda] Assign a scalar character function result on the host (#217076)
