[GHC] #14092: hs-boot unfolding visibility not consistent between --make and -c

[GHC]

#14092: hs-boot unfolding visibility not consistent between --make and -c
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        Reporter:  ezyang            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  low               |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:  hs-boot
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by ezyang):

 * priority:  normal => low


Comment:

 > However, the current --make behaviour produces code that is at least as
 good(modulo the bug exhibited above), and in your first (A.hs-boot, B.hs,
 A.hs, C.hs) example, it is better! I wonder if it is possible to exploit
 laziness to always have unfoldings available even when importing an .hs-
 boot.

 Yes. But the price you pay is that the compilation of A and B can no
 longer be done in parallel. I tend to think of an hs-boot files as one way
 you could speed up compilation, a bit like header files, at the cost of
 the quality of optimized code.

 >  It's the simplifier that is doing more inlining than it should, isn't
 it? (Not the typechecker.)

 Yes!

 > And how much does all this matter anyway?

 Not much, probably!

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14092#comment:3>
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