Re: [Valgrind-users] Dirty helper called more times than expected

[Sonny T. <son...@gm...>]

2013/10/6 Josef Weidendorfer

> Am 04.10.2013 21:47, schrieb Sonny Tavernier:
> > Hi,
> >
> > I have an unexpected behavior with a basic tool.
> > For each Put statement of a basic block, I register a dirty helper using
> > unsafeIRDirty_0_N.
> > The problem is that the dirty helper is called more times than expected,
> > e.g. there are 5 Put statements in a basic block but the dirty helper is
> > called 13 times.
>
> You seem to confuse instrumentation vs. execution time.
>
> As you set the counters to zero only at instrumentation time, of course
> they will diverge when a BB is executed a second time (as every BB is
> instrumented only once).
>
> Further, Valgrind works on super blocks (SBs), not just BBs.
> A SB may have multiple side exits. Thus, counters may be
> different whenever the execution flow exits an SB early.
>
> Josef
>

Thank you for your useful answer Josef.