Disabling case-of-bottom leads to simplifier loop
While working on #17760 (closed) I noticed that disabling the simplifier's case-of-bottom transform results in the simplifier running out of ticks while compiling GHC.Tc.Deriv.Generics
:
Simplifier ticks exhausted
When trying UnfoldingDone nlHsVarApps1
To increase the limit, use -fsimpl-tick-factor=N (default 100).
If you need to increase the limit substantially, please file a
bug report and indicate the factor you needed.
If GHC was unable to complete compilation even with a very large factor
(a thousand or more), please consult the "Known bugs or infelicities"
section in the Users Guide before filing a report. There are a
few situations unlikely to occur in practical programs for which
simplifier non-termination has been judged acceptable.
To see detailed counts use -ddump-simpl-stats
Total ticks: 276647
This is the case even if the tick factor is increased. This can be reproduced by building the wip/T18745
branch.