The simplifier runs with phase 2, then 1 then 0 (multiple times). Generally you want to make sure that something does not inline before its RULE can fire. There are quite a few examples in the base package, if you grep for RULE Simon | -----Original Message----- | From: Henning Thielemann [mailto:lemming@henning-thielemann.de] | Sent: 14 March 2014 17:27 | To: Simon Peyton Jones; GHC Users List | Subject: Re: GHC-7.8 warning on rules that may not fire | | Am 14.03.2014 18:05, schrieb Simon Peyton Jones: | | > You may think they are fragile, but not as fragile as saying nothing | > and hoping for the best, which is *super*-fragile. You can't rely on | > rules to take priority, because the rule only fires if it matches, and | > it may only match if some other inlining has taken place. (We tried | > that originally.) | | Ok, how shall I choose "n" in "INLINE[n]"? Is there a meaning of the | phase numbers? I guess it is important to adhere to some conventions in | order to work together with other libraries. | | If I understand correctly I can alter the number of phases with the - | fsimplifier-phases option - how can I choose phase numbers for INLINE | that are universally reasonable?