[mlir][IntegerRangeAnalysis] Teach the analysis to infer overflow flags

[krzysz00]

When analyzing operations that might exhibit overflow, we can often determine whether or not such an overflow could occur, which is data that can be expressed using the nuw and nsw overflow flags. This is information that can be annotated onto operations and might be usable to make some bits of the analysis more precise.

So the ConstantIntRanges struct could grow a std::optionalarith::OverflowFlags field to mark whether the associated operation could've overflowed while computing that result.

[llvmbot]

@llvm/issue-subscribers-mlir

Author: Krzysztof Drewniak (krzysz00)

When analyzing operations that might exhibit overflow, we can often determine whether or not such an overflow could occur, which is data that can be expressed using the nuw and nsw overflow flags. This is information that can be annotated onto operations and might be usable to make some bits of the analysis more precise.

So the ConstantIntRanges struct could grow a std::optional<arith::OverflowFlags> field to mark whether the associated operation could've overflowed while computing that result.

[badumbatish]

is this an issue for beginner?

[krzysz00]

@badumbatish It might take some time to get familiar with IntRangeOptimizations.cpp and all the infrastructure that's going on in there. So this isn't a trivial issue, but it would make a good way to get familiar with the code.

(Sorry, didn't see your comment until now)