https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99927
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Before combine it looks fine:
(insn 23 22 105 6 (parallel [
(set (reg:SI 108)
(udiv:SI (reg:SI 104)
(reg/v:SI 102 [ var_6 ])))
(set (reg:SI 107)
(umod:SI (reg:SI 104)
(reg/v:SI 102 [ var_6 ])))
(clobber (reg:CC 17 flags))
]) "pr99927.c":13:24 449 {*udivmodsi4}
(expr_list:REG_DEAD (reg:SI 104)
(expr_list:REG_UNUSED (reg:SI 108)
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil)))))
(insn 105 23 106 6 (set (reg:QI 135)
(const_int 1 [0x1])) "pr99927.c":13:24 77 {*movqi_internal}
(nil))
(insn 106 105 107 6 (parallel [
(set (reg:QI 134)
(and:QI (subreg:QI (reg:SI 107) 0)
(const_int 1 [0x1])))
(clobber (reg:CC 17 flags))
]) "pr99927.c":13:24 491 {*andqi_1}
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil)))
(insn 107 106 108 6 (set (reg:CCZ 17 flags)
(compare:CCZ (reg:SI 107)
(const_int 0 [0]))) "pr99927.c":13:24 7 {*cmpsi_ccno_1}
(expr_list:REG_DEAD (reg:SI 107)
(nil)))
(insn 108 107 111 6 (set (reg:QI 96 [ var_lsm_flag.12 ])
(if_then_else:QI (eq (reg:CCZ 17 flags)
(const_int 0 [0]))
(reg:QI 134)
(reg:QI 135))) "pr99927.c":13:24 1104 {*movqicc_noc}
(expr_list:REG_DEAD (reg:QI 134)
(nil)))
but in combine dump there is:
(insn 23 22 105 6 (parallel [
(set (reg:SI 108)
(udiv:SI (reg:SI 104)
(reg/v:SI 102 [ var_6 ])))
(set (reg:SI 107)
(umod:SI (reg:SI 104)
(reg/v:SI 102 [ var_6 ])))
(clobber (reg:CC 17 flags))
]) "pr99927.c":13:24 449 {*udivmodsi4}
(expr_list:REG_DEAD (reg:SI 104)
(expr_list:REG_UNUSED (reg:SI 108)
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil)))))
(note 105 23 106 6 NOTE_INSN_DELETED)
(note 106 105 107 6 NOTE_INSN_DELETED)
(insn 107 106 108 6 (set (reg:QI 135)
(const_int 1 [0x1])) "pr99927.c":13:24 77 {*movqi_internal}
(nil))
(note 108 107 111 6 NOTE_INSN_DELETED)
(insn 111 108 85 6 (set (reg:QI 96 [ var_lsm_flag.12 ])
(if_then_else:QI (eq (reg:CCZ 17 flags)
(const_int 0 [0]))
(subreg:QI (reg:SI 107) 0)
(reg:QI 135))) "pr99927.c":13:24 1104 {*movqicc_noc}
(expr_list:REG_DEAD (reg:SI 107)
(expr_list:REG_DEAD (reg:QI 135)
(nil))))
