From fb8c2f743ab695f6004650b58bf96972e2535b20 Mon Sep 17 00:00:00 2001 From: Edward Tomasz Napierala Date: Mon, 8 Feb 2021 10:46:29 +0000 Subject: 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 --- sys/arm64/arm64/vm_machdep.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'sys') diff --git a/sys/arm64/arm64/vm_machdep.c b/sys/arm64/arm64/vm_machdep.c index 9e9b588c7db1..d4dd32caef06 100644 --- a/sys/arm64/arm64/vm_machdep.c +++ b/sys/arm64/arm64/vm_machdep.c @@ -143,12 +143,14 @@ 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; -- cgit v1.2.3