-O bug?

[Serge D. Mechveliani]

Dear GHC developers, 

The point (1) below looks like a bug  (in all GHC versions!).

(1) -O for demo-test.

Take (the public)  docon-2.10  build it under -O,  install,
and build also under  -O  its test program by
    cd demotest
    ghc $doconCpOpt -O --make Main

Either the latter compilation will loop forever or it will take an 
unnaturally large resource.

Yes, the functions  T_.test, T_tt  are defined in rather a particular 
way (see them). I always build this test under -Onot, because 
compiling with optimization has not much sense for this part.
But slill.


(2) -O2

In my DoCon  programs, -O2 was always worse than -O:  
the code is about 1.3 times larger and 1.2 times slower.
There are some particular points in my programs. 
For example, almost everywhere I set Integer rather than Int, 
I do not recall others, now.

In never complained on (1) and (2) because did not recall of them
and because they do not bite me in practice, so far.

-----------------
Serge Mechveliani
mechvel at botik.ru