5/21/2025 at 11:12:29 AM
The most insidious version of this I experienced was when a library changed the FPU settings.Fortunately, it was sufficient to reset the FPU settings after initializing the library. But it sure took a long time to figure out what happened!
by c-linkage
5/24/2025 at 8:19:30 PM
There's a great Random ASCII blog post about an obscure FPU issue like this [1]. - The crash was in a FPU that Chrome barely uses
- The instruction that crashed Chrome was thousands of instructions away from the one that triggered the exception
- The instruction that triggered the exception was not at fault
- The crash only happened because of third-party code running inside of Chrome
- The crash was ultimately found to be caused by a code-gen bug in Visual Studio 2015
I've run into this kind of thing once myself (sharing a process with other companies is fun!). It was real confusing to get a stack trace showing our code suddenly crashing on a line of code that was doing the exact same thing with the exact same values as it had always done before.[1]: https://randomascii.wordpress.com/2016/09/16/everything-old-...
by DavidVoid
5/24/2025 at 10:20:35 PM
This also happened in python ecosystem where gevent were messing with numpy because gevent was compiled with -ffast-math, which disables subnormal numbersBlog post: https://moyix.blogspot.com/2022/09/someones-been-messing-wit... HN discussion: https://news.ycombinator.com/item?id=41212072
by minetest2048