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


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....


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