https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72778
--- Comment #7 from Vladimir Makarov <vmakarov at gcc dot gnu.org> --- (In reply to Uroš Bizjak from comment #6) Hi, Uros. Thanks for reporting this. It was my mistake that I did not check bootstrap with GO. I am going to fix it soon. > Before the patch, register allocator used to leave self-assignments (e.g. > insn 20) in the insn stream. Post-reload vzeroupper insertion mode-swithing > pass depends on these instructions. Self-assignments are later removed by > subsequent passes. > > > Can we have these self-assignments back? Unfortunately, LRA can produce wrong moves (it was even before I implemented invariant inheritance which also can do it). It is important to remove them at this stage, otherwise GCC crashes on later passes.
