#15832: returnIO/bindIO destroys runtime explicit stack information in some cases -------------------------------------+------------------------------------- Reporter: infinity0 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): If you look at the STG you will see that in the good case we get STG of the form, {{{#!hs main = (>>) (return undefined) (print (X (error ...))) }}} The second argument then becomes a CAF during codegen. This CAF then as a cost-center added to it due to `-fprof-cafs`. The bad case, on the other hand, is of the form: {{{#!hs main = (>>=) (return undefined) (\_ -> print (X (error ...))) }}} Here the second argument is not a CAF and therefore will not get a cost- center. This is the reason for this difference. Out of curiosity, what is your application? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15832#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler