#12472: "lazy" is not optimized away
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Reporter: ezyang | Owner: ezyang
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 8.1
Keywords: | Operating System: Unknown/Multiple
Architecture: | Type of failure: None/Unknown
Unknown/Multiple |
Test Case: | Blocked By:
Blocking: | Related Tickets:
Differential Rev(s): | Wiki Page:
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Consider:
{{{
import GHC.Magic
{-# INLINE f #-}
f x = True
g = lazy f False
}}}
Two things should happen: (1) f should not be inlined, but (2) lazy should
not be present in final STG (having been eliminated in core prep). I
thought this was briefly working on HEAD, but apparently it never worked
at all:
{{{
ezyang@sabre:~$ ghc-8.0 -c test.hs -ddump-stg -fforce-recomp -O2
==================== STG syntax: ====================
Test.f [InlPrag=INLINE (sat-args=1)]
:: forall t_axB. t_axB -> GHC.Types.Bool
[GblId,
Arity=1,
Caf=NoCafRefs,
Str=DmdType