https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70160
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Ilya Enkovich from comment #6) > Thanks a lot for your analysis! When chain is built we scan all register > definitions and their uses. Thus it includes all register definitions and > uses. Uninitialized uses are missed though. Simply skipping them in > convert_reg should be OK. I'm testing this patch: Ah, ok. > I'm not sure what's wrong with debug insns. If register is converted into a > vector one then why can't it be used in debug insns? It is still the same > DI reg with the same value, we just replace its uses with V2DI subreg uses > to force SSE hard reg allocation. I don't have a testcase. If the original pseudo still contains the right value after the STV pass, then sure, there is no need to adjust debug insns.
