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From: "hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/103069] cmpxchg isn't optimized Date: Mon, 24 Jan 2022 23:52:04 +0000 [thread overview] Message-ID: <bug-103069-4-UQOQV2ZRg4@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-103069-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103069 --- Comment #7 from H.J. Lu <hjl.tools at gmail dot com> --- nptl/pthread_mutex_unlock.c in glibc has: do { newval = oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK; } while (!atomic_compare_exchange_weak_release (&mutex->__data.__lock, &oldval, newval)); GCC 12 generates: 90a81: 41 89 c0 mov %eax,%r8d 90a84: 41 81 e0 00 00 f8 ff and $0xfff80000,%r8d 90a8b: f0 44 0f b1 07 lock cmpxchg %r8d,(%rdi) 90a90: 75 ef jne 90a81 <__pthread_mutex_unlock_ful l+0x81>
next prev parent reply other threads:[~2022-01-24 23:52 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-11-03 19:08 [Bug target/103069] New: " hjl.tools at gmail dot com 2021-11-03 20:53 ` [Bug target/103069] " thiago at kde dot org 2021-11-04 21:25 ` thiago at kde dot org 2021-11-15 11:10 ` cvs-commit at gcc dot gnu.org 2021-11-15 14:26 ` hjl.tools at gmail dot com 2021-11-18 8:31 ` cvs-commit at gcc dot gnu.org 2022-01-24 23:49 ` hjl.tools at gmail dot com 2022-01-24 23:52 ` hjl.tools at gmail dot com [this message] 2022-01-24 23:53 ` hjl.tools at gmail dot com 2022-01-24 23:55 ` hjl.tools at gmail dot com 2022-01-25 0:04 ` thiago at kde dot org 2022-02-15 8:59 ` wwwhhhyyy333 at gmail dot com 2022-02-22 3:36 ` cvs-commit at gcc dot gnu.org 2022-02-22 3:38 ` wwwhhhyyy333 at gmail dot com 2022-02-22 4:16 ` thiago at kde dot org 2022-02-22 8:21 ` wwwhhhyyy333 at gmail dot com 2022-02-22 18:05 ` thiago at kde dot org 2022-02-22 18:41 ` jakub at gcc dot gnu.org 2022-02-22 20:25 ` thiago at kde dot org 2022-02-23 3:35 ` wwwhhhyyy333 at gmail dot com 2022-02-23 4:06 ` thiago at kde dot org 2022-04-13 8:18 ` cvs-commit at gcc dot gnu.org 2022-05-06 8:31 ` jakub at gcc dot gnu.org 2023-05-08 12:23 ` rguenth at gcc dot gnu.org
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