Add support to normalize affine.for ops i.e., convert the lower bound to zero
and loop step to one. The Upper bound is set to the trip count of the loop.
The exact value of loopIV is calculated just inside the body of affine.for.
Currently loops with lower bounds having single result are supported. No such
restriction exists on upper bounds.
Differential Revision: https://reviews.llvm.org/D92233
This patch renames AffineParallelNormalize to AffineLoopNormalize to make it
more generic and be able to hold more loop normalization transformations in
the future for affine.for and affine.parallel ops. Eventually, it could also be
extended to support scf.for and scf.parallel. As a starting point for affine.for,
the patch also adds support for removing single iteration affine.for ops to the
the pass.
Differential Revision: https://reviews.llvm.org/D90267
