> So like this instead (if it passes another bootstrap/regtest)?
>
> 2020-12-10 Jakub Jelinek
>
> PR middle-end/98190
> * expr.c (expand_assignment): If to_rtx is a promoted SUBREG,
> ensure sign or zero extension either through use of store_expr
> or by extending
On Thu, Dec 10, 2020 at 11:15:30AM +0100, Eric Botcazou wrote:
> Are you sure that the optimization is worth the hassle (and maybe the risk,
> i.e. can't store_field clobber the entire field)?
I'm not sure, after all, only the testcases I've mentioned were affected
in the whole
> 2020-12-10 Jakub Jelinek
>
> PR middle-end/98190
> * expr.c (expand_assignment): If to_rtx is a promoted SUBREG,
> ensure sign or zero extension when the most significant bit has
> been overwritten, either through use of store_expr or by extending
> manually.
>
Hi!
Some target decide to promote certain scalar variables to wider mode,
so their DECL_RTL is a SUBREG with SUBREG_PROMOTED_VAR_P.
When storing to such vars, store_expr takes care of sign or zero extending,
but if we store e.g. through MEM_REF into them, no sign or zero extension
happens and
