This reverts commit 329aeb5db4,
and relands commit 61f006ac65.
This is a continuation of D89456.
As it was suggested there, now that SCEV models `PtrToInt`,
we can try to improve SCEV's pointer handling.
In particular, i believe, i will need this in the future
to further fix `SCEVAddExpr`operation type handling.
This removes special handling of `ConstantPointerNull`
from `ScalarEvolution::createSCEV()`, and add constant folding
into `ScalarEvolution::getPtrToIntExpr()`.
This way, `null` constants stay as such in SCEV's,
but gracefully become zero integers when asked.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D98147
This is a continuation of D89456.
As it was suggested there, now that SCEV models `PtrToInt`,
we can try to improve SCEV's pointer handling.
In particular, i believe, i will need this in the future
to further fix `SCEVAddExpr`operation type handling.
This removes special handling of `ConstantPointerNull`
from `ScalarEvolution::createSCEV()`, and add constant folding
into `ScalarEvolution::getPtrToIntExpr()`.
This way, `null` constants stay as such in SCEV's,
but gracefully become zero integers when asked.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D98147
Summary:
This is exposed by functional testing on PowerPC.
In some pipelined loops, Phi refer to phi did not get value defined by
the Phi, hence getting wrong value later.
As the comment mentioned, we should "use the value defined by the Phi,
unless we're generating the firstepilog and the Phi refers to a Phi
in a different stage.", so Phi refering to same stage Phi should use
the value defined by the Phi here.
Reviewers: bcahoon, hfinkel
Reviewed By: hfinkel
Subscribers: MaskRay, wuzish, nemanjai, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64035
llvm-svn: 365428
Roman Lebedev