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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/95126] [9/10/11/12 Regression] Missed opportunity to turn static variables into immediates Date: Mon, 13 Dec 2021 04:56:36 +0000 [thread overview] Message-ID: <bug-95126-4-9rV72XwIMX@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-95126-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95126 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |needs-bisection Severity|normal |enhancement Summary|Missed opportunity to turn |[9/10/11/12 Regression] |static variables into |Missed opportunity to turn |immediates |static variables into | |immediates Target Milestone|--- |9.5 Known to work| |5.1.0 Known to fail| |5.2.0 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Hmm, in GCC 5.1.0 (and before) we used to produce: mov rdi, QWORD PTR s.1839[rip] jmp func In GCC 5.2.0 and above GCC produces: movzx edi, WORD PTR s.1839[rip+2] movzx edx, WORD PTR s.1839[rip] sal rdi, 16 mov rax, rdi movzx edi, WORD PTR s.1839[rip+4] or rax, rdx sal rdi, 32 or rdi, rax jmp func In both cases, the expander sees: <bb 2>: func (s); [tail call] return; But the expander goes bad. So this has to be a patch which was backported to the GCC 5 branch which caused to produce even worse code.
next prev parent reply other threads:[~2021-12-13 4:56 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-14 10:16 [Bug c/95126] New: " pskocik at gmail dot com 2020-05-14 11:47 ` [Bug c/95126] " rguenth at gcc dot gnu.org 2021-12-13 4:56 ` pinskia at gcc dot gnu.org [this message] 2021-12-13 5:02 ` [Bug middle-end/95126] [9/10/11/12 Regression] " pinskia at gcc dot gnu.org 2022-01-21 13:34 ` rguenth at gcc dot gnu.org 2022-02-08 5:38 ` amodra at gmail dot com 2022-02-26 22:07 ` roger at nextmovesoftware dot com 2022-05-27 9:42 ` [Bug middle-end/95126] [10/11/12/13 " rguenth at gcc dot gnu.org 2022-06-04 11:23 ` cvs-commit at gcc dot gnu.org 2022-06-10 13:55 ` roger at nextmovesoftware dot com
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