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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/63906] [5 Regression] lra_remat miscompiles glibc on aarch64
Date: Mon, 17 Nov 2014 05:01:00 -0000	[thread overview]
Message-ID: <bug-63906-4-RzLPgDw0Wz@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-63906-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63906

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vmakarov at gcc dot gnu.org
            Summary|[5 Regression] dse after    |[5 Regression] lra_remat
                   |reload miscompiles glibc    |miscompiles glibc on
                   |with lra_remat turned on    |aarch64
                   |aarch64                     |

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
No the problem is LRA_REMAT thinks:
(insn 2653 217 219 13 (set (reg/v/f:DI 3 x3 [orig:97 needed ] [97])
        (mem/c:DI (plus:DI (reg/f:DI 29 x29)
                (const_int 152 [0x98])) [34 %sfp+-136 S8 A64])) dl-deps.c:224
42 {*movdi_aarch64}
     (nil))

Is really sp but it is not as sp has changed just a few instructions above:
(insn 210 2652 214 13 (set (reg/f:DI 31 sp)
        (minus:DI (reg/f:DI 3 x3 [1110])
            (reg:DI 1 x1 [485]))) dl-deps.c:224 218 {subdi3}
     (nil))

Meaning LRA_remat cannot think sp is a constant if alloca is ever used.


  parent reply	other threads:[~2014-11-17  5:01 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-17  3:22 [Bug rtl-optimization/63906] New: [5 Regression] lra_remat mis-compiles " pinskia at gcc dot gnu.org
2014-11-17  3:22 ` [Bug rtl-optimization/63906] " pinskia at gcc dot gnu.org
2014-11-17  3:53 ` pinskia at gcc dot gnu.org
2014-11-17  3:54 ` pinskia at gcc dot gnu.org
2014-11-17  4:46 ` [Bug rtl-optimization/63906] [5 Regression] dse after reload miscompiles glibc with lra_remat turned " pinskia at gcc dot gnu.org
2014-11-17  4:47 ` pinskia at gcc dot gnu.org
2014-11-17  5:01 ` pinskia at gcc dot gnu.org [this message]
2014-11-17  9:19 ` [Bug rtl-optimization/63906] [5 Regression] lra_remat miscompiles glibc " rguenth at gcc dot gnu.org
2014-11-17 20:30 ` vmakarov at gcc dot gnu.org
2014-11-18  0:15 ` vmakarov at gcc dot gnu.org
2014-11-18  3:23 ` pinskia at gcc dot gnu.org

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