[GHC] #14521: Infinite loop at runtime when a given function is not marked INLINE

[GHC]

#14521: Infinite loop at runtime when a given function is not marked INLINE
-------------------------------------+-------------------------------------
           Reporter:  OlivierSohn    |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.2
           Keywords:                 |  Operating System:  MacOS X
       Architecture:                 |   Type of failure:  Incorrect result
  Unknown/Multiple                   |  at runtime
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Hello,

 in https://github.com/OlivierSohn/hamazed/issues/1 I describe the
 following issue:

 When compiling on OSX with optimizations (`stack clean && stack build`
 with resolver `lts-9.12` (ghc 8.0.2)), the program loops infinitely (400%
 CPU, and execution is blocked) when an animation is triggered, if the
 function `Animation.animate'` is not inlined.

 The bug is visible at this commit :
 https://github.com/OlivierSohn/hamazed/commit/9f25223ef0502f91cd9633654bdb172f714c3920
 (to reproduce, shoot at a number in the game)

 The fix is the commit that follows :
 https://github.com/OlivierSohn/hamazed/commit/597619bb14974d2bbacfb284a9e276a7cf2d2f52

 stack version: `1.3.2, Git revision
 3f675146590da4f3edf768b89355f798229da2a5 (4395 commits) x86_64
 hpack-0.15.0`

 Could this be a compiler bug?

 The code is available at https://github.com/OlivierSohn/hamazed

 I could try to create another program that reproduces the issue more
 easily (without having to play the game), just let me know if you need it.

 Thank you,
 Olivier

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14521>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler