[Bug tree-optimization/120080] [16 regression] ICE when building llvm-20.1.3 (find_bit_tests, at tree-switch-conversion.cc:1799) since r16-347-g1381a5114788a2

[sjames at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120080

--- Comment #11 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Filip Kastl from comment #10)
> This should work as a trivial fix: Replace the crashing line with
> 
> if (l == 0)
>   return clusters.copy();
> 
> I'll bootstrap and regtest this fix and then I'll push it.

Thanks, that's what I had in mind, but I had the same question below so wasn't
sure...

> 
> I thought that switch lowering shouldn't run into empty switches (can't
> recall what made me think that though).  I'll look into why that happens.