Author: eadler
Date: Sun Apr 5 05:07:24 2015
New Revision: 281100
URL: https://svnweb.freebsd.org/changeset/base/281100
Log:
head/sys/amd64/amd64/support.S: unroll loop
unroll the loop in ENTRY(pagezero)
acc' to the submitter this results in a reproducible 1% perf
improvement under buildworld like workload
I validated correctness and run-testing, but not performance impact
Submitted by: [email protected]
Reviewed by: adrian
PR: 199151
MFC After: 1 month
Modified:
head/sys/amd64/amd64/support.S
Modified: head/sys/amd64/amd64/support.S
==============================================================================
--- head/sys/amd64/amd64/support.S Sun Apr 5 05:00:25 2015
(r281099)
+++ head/sys/amd64/amd64/support.S Sun Apr 5 05:07:24 2015
(r281100)
@@ -73,7 +73,11 @@ ENTRY(pagezero)
movnti %rax,8(%rdi,%rdx)
movnti %rax,16(%rdi,%rdx)
movnti %rax,24(%rdi,%rdx)
- addq $32,%rdx
+ movnti %rax,32(%rdi,%rdx)
+ movnti %rax,40(%rdi,%rdx)
+ movnti %rax,48(%rdi,%rdx)
+ movnti %rax,56(%rdi,%rdx)
+ addq $64,%rdx
jne 1b
sfence
POP_FRAME_POINTER
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "[email protected]"
