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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/99927] [11 Regression] Maybe wrong code since r11-39-gf9e1ea10e657af9f
Date: Tue, 06 Apr 2021 15:03:44 +0000	[thread overview]
Message-ID: <bug-99927-4-AfmF0eMnRE@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-99927-4@http.gcc.gnu.org/bugzilla/>

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?

  parent reply	other threads:[~2021-04-06 15:03 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-06  8:22 [Bug tree-optimization/99927] New: " marxin at gcc dot gnu.org
2021-04-06  8:54 ` [Bug tree-optimization/99927] " rguenth at gcc dot gnu.org
2021-04-06 13:57 ` jakub at gcc dot gnu.org
2021-04-06 14:02 ` jakub at gcc dot gnu.org
2021-04-06 14:17 ` rguenth at gcc dot gnu.org
2021-04-06 14:44 ` jakub at gcc dot gnu.org
2021-04-06 15:03 ` jakub at gcc dot gnu.org [this message]
2021-04-06 15:37 ` jakub at gcc dot gnu.org
2021-04-06 15:42 ` jakub at gcc dot gnu.org
2021-04-06 19:59 ` segher at gcc dot gnu.org
2021-04-06 20:05 ` jakub at gcc dot gnu.org
2021-04-07 17:38 ` [Bug tree-optimization/99927] [11 Regression] Wrong " segher at gcc dot gnu.org
2021-04-07 17:46 ` jakub at gcc dot gnu.org
2021-04-07 18:09 ` segher at gcc dot gnu.org
2021-04-08  2:39 ` segher at gcc dot gnu.org
2021-04-12 14:21 ` rguenth at gcc dot gnu.org
2021-04-12 18:00 ` segher at gcc dot gnu.org
2021-04-18 15:01 ` cvs-commit at gcc dot gnu.org
2021-04-18 15:08 ` [Bug rtl-optimization/99927] " segher at gcc dot gnu.org
2021-04-27 11:40 ` jakub at gcc dot gnu.org
2021-04-29 10:44 ` rguenth at gcc dot gnu.org
2021-07-19 16:07 ` [Bug rtl-optimization/99927] [9/10 only] " pinskia at gcc dot gnu.org
2021-07-19 16:07 ` pinskia at gcc dot gnu.org
2021-07-19 17:13 ` cvs-commit at gcc dot gnu.org
2021-07-19 17:15 ` cvs-commit at gcc dot gnu.org
2021-07-19 17:16 ` segher at gcc dot gnu.org

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