It would be nice to factor out the common tails, e.g. by branching to
#14372: CMM contains a bunch of tail-merging opportunities -------------------------------------+------------------------------------- Reporter: heisenbug | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 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 nomeata): the first tail already emitted. Branches can be expensive, so this might not be a clear win. Have you measured the effect? (You can do that without modifying GHC: Just get your hands on the assembly file, make the changes you want to see, and compare.) The other idea, detecting blocks that are equal up-to a constant, sounds fun. But again, the question is: Is it worth it? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14372#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler