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Re: interesting case of DCE with dataflow.
On Wed, Feb 06, 2008 at 10:59:12AM -0500, Kenneth Zadeck wrote:
> > The final code generated appears something like the following.
> >
> > foo:
> > cmpslt $c6,$zero,$c1
> > brz $c6,$link
> > i2cs $c6,@MID_11(4660)
> > i2c $c6,@BOT_11(4660)
> > incsi $c1,-1
> > .L5:
> > stw ($c3[0]),$c6
> > addzi $c2,$c2,4 -----> This is a redundant add instruction.
> > addzi $c3,$c3,4
> > brinzdec $c1,.L5
> > brz $zero,$link
> >
> >
> I am completely missing your question. i do not see any redundancy of
> the insn that you say is redundant. that insn is indexing thru in and
> the next insn is indexing thru res.
>
> Obviously i am missing something.
Except the load from in has been removed (it's redundant); so only the
indexing is left.
--
Daniel Jacobowitz
CodeSourcery