[mlir][AffineMap] NFC - Refactor getProjectedMap and split into projectDims and projectSymbols

[nicolasvasilache]

Summary

The default behavior of getProjectedMap may be surprising as it implicitly compresses the dims and
the unused symbols.

Make these explicit in the API and refactor to more idiomatic implementations with better reuse.

[nicolasvasilache]

Update

[bondhugula]

mlir/include/mlir/IR/AffineMap.h

575–576

Please avoid Flag suffixes; it's redundant and inconsistent with the style here.

[qcolombet]

mlir/include/mlir/IR/AffineMap.h

417–419

Was there a typo in the original comment: not listed -> listed?

[ftynse]

mlir/lib/IR/AffineMap.cpp

574–580

Add documentation plz.

721–722

Nit: llvm::is_one_of<> makes this slightly more concise.

724

Nit: camelCase.

731–738

Optional: this is now possible without lambdas, along the lines of

for (...) {
  ...
  if constexpr (isDim) {
    replacements.push_back(getAffineDimExpr(...));
  } else {
    replacements.push_back(getAffineSymbolExpr(...));
  }
}}

which may or may not be more readable.

802

Nit: expand auto (presumably to AffineMap that we don't use by refernece)

[nicolasvasilache]

mlir/include/mlir/IR/AffineMap.h

575–576

The issue is that the natural name collides with the compressDims / compressSymbols functions in the .cpp
Do you have a preferred way to spell these names ?

575–576

Please feel free to just commit an NFC on top of this with your preferred spelling.

mlir/lib/IR/AffineMap.cpp

731–738

nice, didn't know about this yet.
not more readable here IMO so not applying but good to know for the future.

802

thanks missed that copypastaing

[nicolasvasilache]

Address comments.

[ftynse]

mlir/lib/IR/AffineMap.cpp

731–738

Yeah, that's what I expected. It is more useful to replace things like enable_if<foo> / enable_if<!foo> pairs.