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From: "roger at nextmovesoftware dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/110598] [14 Regression] wrong code on llvm-14.0.6 due to memcmp being miscompiled Date: Sun, 09 Jul 2023 22:34:50 +0000 [thread overview] Message-ID: <bug-110598-4-YWTBq3GHql@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-110598-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110598 Roger Sayle <roger at nextmovesoftware dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Assignee|unassigned at gcc dot gnu.org |roger at nextmovesoftware dot com Status|NEW |ASSIGNED --- Comment #4 from Roger Sayle <roger at nextmovesoftware dot com> --- Mine. The new peephole2 is misbehaving with the (odd) RTL sequence: (insn 62 61 63 2 (set (reg:DI 1 dx [111]) (const_int 0 [0])) "pr110598.c":10:10 90 {*movdi_internal} (insn 63 62 64 2 (parallel [ (set (reg:DI 1 dx [110]) (xor:DI (reg:DI 1 dx [111]) (reg:DI 1 dx))) (clobber (reg:CC 17 flags)) ]) "pr110598.c":10:10 626 {*xordi_1} (expr_list:REG_UNUSED (reg:CC 17 flags) (nil))) Doh! I need to confirm/check that rega != regb. Interesting that DF doesn't consider insn 62 as REG_UNUSED (i.e. dead), a classic false dependency.
next prev parent reply other threads:[~2023-07-09 22:34 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-07-08 17:00 [Bug c++/110598] New: [14 Regression] wrong code on llvm-14.0.6 slyfox at gcc dot gnu.org 2023-07-08 17:32 ` [Bug target/110598] [14 Regression] wrong code on llvm-14.0.6 due to memcmp being miscompiled pinskia at gcc dot gnu.org 2023-07-08 17:41 ` pinskia at gcc dot gnu.org 2023-07-08 20:31 ` slyfox at gcc dot gnu.org 2023-07-09 22:34 ` roger at nextmovesoftware dot com [this message] 2023-07-12 13:13 ` cvs-commit at gcc dot gnu.org 2023-07-12 16:15 ` slyfox at gcc dot gnu.org 2023-07-12 19:42 ` roger at nextmovesoftware dot com
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