Re: [discuss] semantics, "replay debugging" vs. "reverse debugging"

teawater
2008-10-22T17:19:01Z

So I just say "some insn". Not all.

On Thu, Oct 23, 2008 at 01:09, Dave Korn <dave.korn@artimi.com> wrote:
> teawater wrote on 22 October 2008 17:43:
>
>> Sorry I am wrong.
>> In ARM, Just adds set cpsr reg. So:
>> add r0,r0,#10
>> Can reverse without record too.
>
> Your examples are too limited to be of practical use; almost every
> instruction executed destroys information.
>
> It's easy to reverse "add r0,r0,#10" by subtracting 10 from r0. But how do
> you reverse "add r0,r1,#10", or anything else where the source and dest
> register are different? The original value of r0 is gone without trace, and
> r1 was not changed by the instruction!
>
>
> cheers,
> DaveK
> --
> Can't think of a witty .sigline today....
>
>