https://gcc.gnu.org/bugzilla/show_bug.cgi?id=73650
--- Comment #6 from Alan Modra <amodra at gmail dot com> --- It's a bit interesting that the problem insn (from ira dump): (insn 70 66 76 3 (parallel [ (set (reg:CC 198) (compare:CC (reg/v:SI 188 [ n ]) (const_int 0 [0]))) (set (reg:SI 197 [ n ]) (reg/v:SI 188 [ n ])) ]) 465 {*movsi_internal2} (expr_list:REG_DEAD (reg/v:SI 188 [ n ]) (expr_list:REG_UNUSED (reg:CC 198) (nil)))) could be replaced with (set (reg:SI 197) (reg/v:SI 188)).