Created attachment 51208 [details]
Code that reproduces the issue
I am using g++ 11.1.1 on OpenSUSE Tumbleweed 20210713.
When compiled with `g++ -O3 example.cpp` the code snippet triggers a floating point exception and the program exits through the `signalHandler` function. I believe this behaviour to be incorrect.
When compiled with `g++ -O3 -fno-tree-slp-vectorize example.cpp` (or any lower level of optimisation) the exception is not triggered and the program exits normally.
When compiled with any older version of `g++` with `O3` the exception is not triggered and the program exits normally.
The program can also be modified to read it's input values from a file (see commented section). This is shown to prove that the optimisation is not dependent on the values being available at compile time. Indeed, this is a snippet of a larger program in which the values are read in from a file.
I believe the issue has been fixed already and is a duplicate of PR100778. There's an updated GCC 11 package pending in https://build.opensuse.org/project/show/openSUSE:Factory:Staging:A which you could verify against (or in devel:gcc which should even be published).
A locally built g++ from the GCC 11 branch doesn't reproduce the issue for me.
*** This bug has been marked as a duplicate of bug 100778 ***
Thank you for looking into it. I have verified that gcc-11.2-RC-20210721 fixes the issue.