This Code Smells of Desperation (www.os2museum.com)
from tedu@azorius.net to programming@azorius.net on 06 Aug 2023 18:06
https://azorius.net/p/NL4VGr6YvYSR63l512-This-Code-Smells-of-Desperation

A few weeks ago I had the questionable pleasure of diving into the math exception handler of WIN87EM.DLL, the Windows 3.1 math emulator and FPU support library. Actually WIN87EM.DLL appears to have been first shipped with Windows 3.0, and the version in Windows 3.1 is more or less identical. The version shipped with Windows 3.11 is byte for byte identical to the one in Windows 3.1.

Now, x87 math error handing is a very tricky subject where numerous details changed over FPU and CPU generations, and Intel had a fair share of bugs in this area. But the code in WIN87EM.DLL looks very much like the result of changes made in desperation until it worked somehow, even though the changes made little or no sense.

#programming