[MLIR] Fix permuteLoops utility

[bondhugula]

Summary

Rewrite mlir::permuteLoops for affine loop permutation to fix incorrect
approach. Avoiding using sinkLoops entirely - use single move approach.
Add test pass.

This fixes https://bugs.llvm.org/show_bug.cgi?id=45328

Depends on D77003.

Signed-off-by: Uday Bondhugula <[e-mail]>

[bondhugula]

Update child revision

[andydavis1]

Thanks for fixing this bug Uday!

mlir/lib/Transforms/Utils/LoopUtils.cpp

762

Can you add some comments describing what is going on here? having 'input' indexed at a hard coded value of 0 needs explanation. Are you splicing ops from one loop before into the first loops parent block?

[bondhugula]

Address review comment - add comment.

[dcaballe]

Thanks for addressing this, Uday!

mlir/test/Dialect/Affine/loop-permute.mlir

36

Nice! That's an interesting way to check that the loop order is the expected :)

[nicolasvasilache]

mlir/test/Dialect/Affine/loop-permute.mlir

27

plz use captures instead of SSA names.

[bondhugula]

mlir/test/Dialect/Affine/loop-permute.mlir

27

This is a different/special scenario - see below the 3! permutations. We don't need to capture the loop IVs anywhere.