Displaying 2 results from an estimated 2 matches for "constantscev".
2019 Aug 25
2
SCEV related question
...calarEvolution is not able to give correct
back edge taken count for an expression.
So in my case flow reaches to howFarToZero() and in that function, I have
following expressions as SCEV
Start = (15 + (-1 * %i) (which is set to Distance SCEV)
Step = 1
now, first of all, should I expect Start as ConstantSCEV (15) instead of
the whole expression
the problem here is getUnsignedRangeMax(Distance) returns very large number
because of -1 in the SCEV.
How we can make this work? Here we can clearly say that after 15 steps this
expression will be 0
and thus we have a value for backedge taken count.
Any help...
2019 Aug 26
2
SCEV related question
...expression.
> >
> > So in my case flow reaches to howFarToZero() and in that function, I
> have following expressions as SCEV
> >
> > Start = (15 + (-1 * %i) (which is set to Distance SCEV)
> > Step = 1
> >
> > now, first of all, should I expect Start as ConstantSCEV (15) instead of
> the whole expression
> > the problem here is getUnsignedRangeMax(Distance) returns very large
> number because of -1 in the SCEV.
>
> Given you have have above, in howFarToZero SCEV is reasoning about the
> loop as if it were:
>
> unsigned i = ...;
>...