Only the main Presburger library under the Presburger directory has been switched to use arbitrary precision. Users have been changed to just cast returned values back to int64_t or to use newly added convenience functions that perform the same cast internally.
The performance impact of this has been tested by checking test runtimes after copy-pasting 100 copies of each function. Affine/simplify-structures.mlir goes from 0.76s to 0.80s after this patch. Its performance sees no regression compared to its original performance at commit 18a06d4f3a7474d062d1fe7d405813ed2e40b4fc before a series of patches that I landed to offset the performance overhead of switching to arbitrary precision.
Affine/canonicalize.mlir and SCF/canonicalize.mlir show no noticable difference, staying at 2.02s and about 2.35s respectively.
Also, for Affine and SCF tests as a whole (no copy-pasting), the runtime remains about 0.09s on average before and after.