In [351798f](https://github.com/hifi-finance/prb-math/commit/351798ff42ec1e3a9e3691b1e6442edaa13105c7), I added a new function `mulDivSigned`, which is a variant of `mulDiv` for signed numbers. It's not used anywhere in `PRBMathSD59x18` or `PRBMathUD60x18`, but it's technically part of the code that gets shipped. We should write tests for it.
This issue appears to be discussing a feature request or bug report related to the repository. Based on the content, it seems to be still under discussion. The issue was opened by PaulRBerg and has received 0 comments.