[FFmpeg-devel] [RFC] use ff_avc_find_startcode in ff_find_start_code
Tue Feb 19 18:15:42 CET 2008
On Tue, Feb 19, 2008 at 05:13:44PM +0100, Reimar D?ffinger wrote:
> On Tue, Feb 19, 2008 at 04:41:35PM +0100, Michael Niedermayer wrote:
> > > 844 dezicycles in A2, 63644 runs, 1892 skips
> > ^^^^
> > please do something about the skips!
> That was because I ran it on the wrong file :-(
> > [...]
> > > And yes, I remembered to disable speedstep this time.
> > Thanks you
> > Also please dont run anything else (like mp3 players) while testing
> > and provide benchmark scores for 3 runs so we know how much randomnes
> > is in there.
> Ok, now something hopefully correct, all kinds of combinations tested.
> For the matrix test file things are within measurement errors for
> overall time.
> The higher limit to skip values seems to have pushed it to an advantage
> for my code, but I am quite suspicious about the values.
> A clear difference for the GXF file, though I admit it is an extremely
> stupidly encoded file, so the values there are not worht too much
Could you post the asm code gcc generates for you for this function?
movzbl -1(%ebx), %eax
cmpb $1, %al
addl $3, %ebx
cmpl %ebx, %ebp
and for the new code:
addl $4, %ecx
cmpl %ebx, %edi
movl -4(%ecx), %eax
leal -4(%ecx), %esi
movl %ecx, %ebx
leal -16843009(%eax), %edx
andl %eax, %edx
andl $-2139062144, %edx
Also what cpu and gcc version do you have?
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
It is dangerous to be right in matters on which the established authorities
are wrong. -- Voltaire
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