https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68269
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 37330
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37330&action=edit
gcc6-pr68269.patch
I think it is just wrong to assume the computation can be performed in any
integral mode. Various targets include very wide modes not intended for
computations, but just as containers holding typically vector data.
So IMHO we should either punt if the mode is unsupported (it is not going to
match any instructions anyway), or not look through SUBREGs where it is a
supported lowpart mode subreg of unsupported mode property.
