https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94291
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This is on try_combine on:
(gdb) p debug_rtx (i3)
(insn 20 12 22 2 (set (mem/c:SI (plus:SI (reg/f:SI 102 sfp)
(const_int -4 [0xfffffffffffffffc])) [1 x+0 S4 A32])
(reg:SI 125)) "pr94291.c":7:8 241 {*arm_movsi_insn}
(expr_list:REG_DEAD (reg:SI 125)
(nil)))
(gdb) p debug_rtx (i2)
(insn 12 7 20 2 (parallel [
(set (reg:CC 100 cc)
(compare:CC (reg:SI 121 [ <retval> ])
(const_int 0 [0])))
(set (reg:SI 125)
(reg:SI 121 [ <retval> ]))
]) "pr94291.c":7:8 248 {*movsi_compare0}
(expr_list:REG_UNUSED (reg:CC 100 cc)
(nil)))
where it is merged into cc = r121 cmp 0; [sfp-4] = r121 and as that isn't
recognized, it is being split_i2i3 into: [sfp-4] = r121 followed by cc = r121
cmp 0 where SET_DEST of newi2pat is a MEM rather than REG.
So, either we should somewhere punt instead of set split_i2i3 because the dest
is a MEM, not REG, or we should handle it somehow.
