[k4st]

At Trail of Bits, we've been working on this type of IR for C and C++ code [1]. We operate as a kind of Clang middle end, taking in a Clang AST, and spitting LLVM IR that is Clang-compatible out the other end. In this middle area, we progressively lower from a high-level MLIR dialect down to LLVM.

[1] https://github.com/trailofbits/vast

[JonChesterfield]

There's been a longstanding wish to do things like inject a std::vector::reserve ahead of a loop that appends to a vector. Difficult to do once you've lowered the standard library to pointer arithmetic on structs. Clang emitting a MLIR dialect that preserves a lot of C++ semantic information before translation to IR would be a big deal in the LLVM pipeline.