From 35810f5ccf735d8df0a783bc6ed5fbe455e64876 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Mon, 19 Jun 2017 10:59:40 +0200 Subject: s390: optimize syscall function Since kernel 2.6.0 all Linux version accept the system call number in register 1 for svc 0. There is no need to have special handling that uses EX for system calls < 256. This will simplify and speed up that code. A microbenchmark doing "syscall(__NR_getpid);" in a loops gets faster by ~12%. * sysdeps/unix/sysv/linux/s390/s390-32/syscall.S: Simplify code by always using SVC 0 instead of EX. * sysdeps/unix/sysv/linux/s390/s390-64/syscall.S: Likewise. --- ChangeLog | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'ChangeLog') diff --git a/ChangeLog b/ChangeLog index f4ac921321..bf6c25aceb 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2017-06-19 Christian Borntraeger + + * sysdeps/unix/sysv/linux/s390/s390-32/syscall.S (syscall): + Simplify code by always using SVC 0 instead of EX. + * sysdeps/unix/sysv/linux/s390/s390-64/syscall.S: Likewise. + 2017-06-16 H.J. Lu * elf/Versions (ld): Remove _dl_out_of_memory. -- cgit 1.4.1