https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99927
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |segher at gcc dot gnu.org
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So, we have at the start of first try_combine called on bb 6:
...
(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)))
(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]))
(reg:QI 96 [ var_lsm_flag.12 ])
(reg:QI 135))) "pr99927.c":13:24 1104 {*movqicc_noc}
(expr_list:REG_DEAD (reg:QI 135)
(nil)))
(jump_insn 85 111 35 6 (set (pc)
(if_then_else (ne (reg:CCZ 17 flags)
(const_int 0 [0]))
(label_ref 45)
(pc))) 806 {*jcc}
(expr_list:REG_DEAD (reg:CCZ 17 flags)
(int_list:REG_BR_PROB 536870916 (nil)))
-> 45)
where LOG_LINKS of 108 are i105/r135, i106/r134 and i107/r17,
of 111 are i108/r96 and 85 has NULL LOG_LINKS.
But, r17 is used in all of i108, i111 and i85, so isn't single use, so isn't it
incorrect that it has the i107/r17 link?
