[Bug rtl-optimization/66248] subreg truncation not hoisted from loop

[sje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66248

Steve Ellcey <sje at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |sje at gcc dot gnu.org
         Resolution|---                         |INVALID

--- Comment #1 from Steve Ellcey <sje at gcc dot gnu.org> ---
The truncate can not be moved out of the loop because that would affect the
overflow behaviour of ret.  I.e. we need to truncate ret on each iteration of
the loop because doing the truncation may affect the value of ret used in the
addition during the next iteration of the loop.  This is not the same as
doing one truncation at the end in cases where ret overflows the maximum value
of a short type.