Date: Thu, 17 Feb 2022 13:46:19 GMT From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 24ac1bd8ec3d - stable/13 - arm64: optimize set_syscall_retval() Message-ID: <202202171346.21HDkJb7048171@gitrepo.freebsd.org>
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The branch stable/13 has been updated by trasz: URL: https://cgit.FreeBSD.org/src/commit/?id=24ac1bd8ec3d20fdfa8e8b81d4a349554959ef35 commit 24ac1bd8ec3d20fdfa8e8b81d4a349554959ef35 Author: Edward Tomasz Napierala <trasz@FreeBSD.org> AuthorDate: 2021-02-08 10:46:29 +0000 Commit: Edward Tomasz Napierala <trasz@FreeBSD.org> CommitDate: 2022-02-13 23:17:34 +0000 arm64: optimize set_syscall_retval() Microoptimize set_syscall_retval() for arm64 by predicting the return value to be zero. This is similar to what has been done for other architectures Reviewed By: emaste, mhorne Differential Revision: https://reviews.freebsd.org/D26991 (cherry picked from commit fb8c2f743ab695f6004650b58bf96972e2535b20) --- sys/arm64/arm64/vm_machdep.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/sys/arm64/arm64/vm_machdep.c b/sys/arm64/arm64/vm_machdep.c index 9c97a2848200..a5451c631336 100644 --- a/sys/arm64/arm64/vm_machdep.c +++ b/sys/arm64/arm64/vm_machdep.c @@ -150,12 +150,14 @@ cpu_set_syscall_retval(struct thread *td, int error) frame = td->td_frame; - switch (error) { - case 0: + if (__predict_true(error == 0)) { frame->tf_x[0] = td->td_retval[0]; frame->tf_x[1] = td->td_retval[1]; frame->tf_spsr &= ~PSR_C; /* carry bit */ - break; + return; + } + + switch (error) { case ERESTART: frame->tf_elr -= 4; break;
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