Displaying 2 results from an estimated 2 matches for "opaque_value".
2016 Aug 24
2
Request suggestions about how to remove redundencies caused by SCEV expansion fundementally
On Wed, Aug 24, 2016 at 3:07 PM, Daniel Berlin <dberlin at dberlin.org> wrote:
>
>
> On Fri, Aug 19, 2016 at 3:57 PM, Wei Mi via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
>>
>> SCEV expansion sometimes generates redundent expr even if there is an
>> available expr which can be reused. The redundent exprs can be a lot
>> different from existing
2016 Aug 29
4
Request suggestions about how to remove redundencies caused by SCEV expansion fundementally
...expansion.
>
> So how are you thinking about moving forward here?
Shorterm I feel easy to try is to enhance the expansion of
SCEVNAryExpr: As suggested by Andy, for a new SCEV C = A1 + A2 + B
which is generated by getAddExpr(A, B), adding an opaque value node
somewhere to record C equals to opaque_value = Value_A + Value_B. It
is possible that B doesn't have Value_B recorded in ExprValueMap. Need
to find some representation saying opaque_value = Value_A + expand(B).
This will relieve the problem in PR29065. I may extend ExprValueMap
from recording a single value to some form more flexible to r...