On 6/24/21 9:25 AM, Andrew MacLeod wrote:
On 6/24/21 8:29 AM, Richard Biener wrote:
THe original function in EVRP currently looks like:
=========== BB 2 ============
<bb 2> :
if (a_5(D) == b_6(D))
goto <bb 8>; [INV]
else
goto <bb 7>; [INV]
=========== BB 8 ============
Equivalence set : [a_5(D), b_6(D)] edge 2->8 provides
a_5 and b_6 as equivalences
<bb 8> :
goto <bb 6>; [100.00%]
=========== BB 6 ============
<bb 6> :
# i_1 = PHI <0(8), i_10(5)>
if (i_1 < a_5(D))
goto <bb 3>; [INV]
else
goto <bb 7>; [INV]
=========== BB 3 ============
Relational : (i_1 < a_5(D)) edge 6->3 provides
this relation
<bb 3> :
if (i_1 == b_6(D))
goto <bb 4>; [INV]
else
goto <bb 5>; [INV]
So It knows that a_5 and b_6 are equivalence, and it knows that i_1 <
a_5 in BB3 as well..
so we should be able to indicate that i_1 == b_6 as [0,0].. we
currently aren't. I think I had turned on equivalence mapping during
relational processing, so should be able to tag that without
transitive relations... I'll have a look at why.
And once we get a bit further along, you will be able to access this
without ranger.. if one wants to simply register the relations directly.
Anyway, I'll get back to you why its currently being missed.
Andrew
As promised. There was a typo in the equivalency comparisons... so it
was getting missed. With the fix, the oracle identifies the relation
and evrp will now fold that expression away and the IL becomes:
<bb 2> :
if (a_5(D) == b_6(D))
goto <bb 4>; [INV]
else
goto <bb 5>; [INV]
<bb 3> :
i_10 = i_1 + 1;
<bb 4> :
# i_1 = PHI <0(2), i_10(3)>
if (i_1 < a_5(D))
goto <bb 3>; [INV]
else
goto <bb 5>; [INV]
<bb 5> :
return;
for the other cases you quote, there are no predictions such that if a
!= 0 then this equivalency exists...
+ if (a != 0)
+ {
+ c = b;
+ }
but the oracle would register that in the TRUE block, c and b are
equivalent... so some other pass that was interested in tracking
conditions that make a block relevant would be able to compare relations...
Andrew
