[Ffmpeg-devel] [PATCH] Upate of Zaurus IWMMXT patch
Tue Apr 10 14:51:02 CEST 2007
On 4/10/07, Vadim Lebedev <vadim at mbdsys.com> wrote:
> I'm affraid my ARM asm skills are a little rusty but
> shouldn't the order of these 2 lines be inverted, becase ADD
> instruction clears Z flag?
> + "subs r1, r1, #1 \n\t"
> + "add %0, %0, #32 \n\t"
That code is ok. On ARM every instuction can either update flags or
not, it is up to the programmer to decide what behaviour is desired.
So 'add' instruction does not update flags, but 'adds' does ('s'
suffix is important).
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