Author: trasz Date: Thu Oct 29 15:36:20 2020 New Revision: 367138 URL: https://svnweb.freebsd.org/changeset/base/367138
Log: Optimize set_syscall_retval for riscv by predicting the return value to be zero. Reviewed by: mhorne, kp MFC after: 2 weeks Sponsored by: EPSRC Differential Revision: https://reviews.freebsd.org/D26990 Modified: head/sys/riscv/riscv/vm_machdep.c Modified: head/sys/riscv/riscv/vm_machdep.c ============================================================================== --- head/sys/riscv/riscv/vm_machdep.c Thu Oct 29 15:28:15 2020 (r367137) +++ head/sys/riscv/riscv/vm_machdep.c Thu Oct 29 15:36:20 2020 (r367138) @@ -132,12 +132,14 @@ cpu_set_syscall_retval(struct thread *td, int error) frame = td->td_frame; - switch (error) { - case 0: + if (__predict_true(error == 0)) { frame->tf_a[0] = td->td_retval[0]; frame->tf_a[1] = td->td_retval[1]; frame->tf_t[0] = 0; /* syscall succeeded */ - break; + return; + } + + switch (error) { case ERESTART: frame->tf_sepc -= 4; /* prev instruction */ break; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
