VPVectorPointer for part 0 is just the pointer operand. Simplify it
after unrolling. This removes a large number of redundant GEPs with
index 0.
PR: https://github.com/llvm/llvm-project/pull/149735
Materialize constant vector trip counts before ::execute, if the trip
count can be computed as Original (TC / (VF * UF)) * (VF * UF). For now
this excludes when the tail is folded or scalar epilogues are required.
This enables removing a number of redundant branches from the middle
block.
For now this is also only done when not vectorizing the epilogue, as the
simplification complicates stitching the 2 plans together.
PR: https://github.com/llvm/llvm-project/pull/142309
After unrolling, there may be additional simplifications that can be
applied. One example is removing SCALAR-STEPS for the first part where
only the first lane is demanded.
This removes redundant adds of 0 from a large number of tests (~200),
many which I am still working on updating.
In preparation for removing redundant WideIV steps added in
https://github.com/llvm/llvm-project/pull/119284.
PR: https://github.com/llvm/llvm-project/pull/123655
`forgetLcssaPhiWithNewPredecessor` performs additional invalidation if
there is an existing SCEV for the phi, but earlier
`forgetBlockAndLoopDispositions` or `forgetLoop` may already invalidate
the SCEV for the phi.
Change the order to first call `forgetLcssaPhiWithNewPredecessor` to
ensure it runs before its SCEV gets invalidated too eagerly.
Fixes https://github.com/llvm/llvm-project/issues/119665.
PR: https://github.com/llvm/llvm-project/pull/119897
