Herbert Xu [EMAIL PROTECTED] writes:
But your code differs significantly from Stephen's version.
However, if it is correct it does look like a good improvement.
So please write a simple test program. It can't that bad since
there are only 65536 values to test :)
I think the code is simple
On Sun, 2007-10-28 at 21:18 +0100, Urs Thuermann wrote:
I have written a short test program to show this and tested it on i686
(gcc-4.2.2) and powerpc (gcc-3.4.5) without optimization and with -O6.
Thanks for that.
BTW, shouldn't unsigned long be replaced by unsigned int to avoid
64-bit
On Sun, 2007-10-28 at 14:01 -0700, Joe Perches wrote:
probably unsigned long should be u16.
Or not.
x86 u16 performs much worse than u32 (~ 50% worse)
-
To unsubscribe from this list: send the line unsubscribe netdev in
the body of a message to [EMAIL PROTECTED]
More majordomo info at
It's a bit after 2.6.1 now...
Removes unnecessary if, uses 16 bit rotate left.
Performance improves ~30%
Signed-off-by: Joe Perches [EMAIL PROTECTED]
diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 7c0b515..1c50f4c 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@
From: Joe Perches [EMAIL PROTECTED]
Date: Mon, 22 Oct 2007 18:36:28 -0700
On Mon, 2007-10-22 at 17:35 -0700, David Miller wrote:
Your code is rotating bit 15 down by one bit and bits 0-14 up by one
bit.
Yes, a 16 bit rotate left.
There was a discussion a few years ago:
On Mon, 2007-10-22 at 18:43 -0700, David Miller wrote:
Ok, but again did you test it?
Nope. Stephen Hemminger did in 2003.
-
To unsubscribe from this list: send the line unsubscribe netdev in
the body of a message to [EMAIL PROTECTED]
More majordomo info at
On Mon, 2007-10-22 at 17:35 -0700, David Miller wrote:
Your code is rotating bit 15 down by one bit and bits 0-14 up by one
bit.
Yes, a 16 bit rotate left.
There was a discussion a few years ago:
http://oss.sgi.com/archives/netdev/2003-10/msg00734.html
From the spec:
Implementers of DDP
On Mon, 22 Oct 2007 12:36:19 -0700
Joe Perches [EMAIL PROTECTED] wrote:
It's a bit after 2.6.1 now...
Removes unnecessary if, uses 16 bit rotate left.
Performance improves ~30%
Signed-off-by: Joe Perches [EMAIL PROTECTED]
diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index
Joe Perches [EMAIL PROTECTED] wrote:
On Mon, 2007-10-22 at 18:43 -0700, David Miller wrote:
Ok, but again did you test it?
Nope. Stephen Hemminger did in 2003.
But your code differs significantly from Stephen's version.
However, if it is correct it does look like a good improvement.
So
On Mon, 2007-10-22 at 20:30 -0700, Stephen Hemminger wrote:
Corrected fast code is:
while (len--) {
sum += *data++;
sum = 1;
sum = (((sum 0x1) 16) + sum) 0x;
}
At least it is correct on the standalone
10 matches
Mail list logo
