#15570: Core transformations generate bad indexCharOffAddr# call
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Reporter: alpmestan | Owner: alpmestan
Type: bug | Status: new
Priority: normal | Milestone: 8.6.1
Component: Compiler | Version: 8.5
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: |
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Comment (by simonpj):
This is all very mysterious. What I get from HEAD (for `f`) is this:
{{{
Rec {
-- RHS size: {terms: 33, types: 19, coercions: 0, joins: 0/0}
Bug.$wgo [InlPrag=NOUSERINLINE[2], Occ=LoopBreaker]
:: Int# -> [Char] -> (# Char, [Char] #)
[GblId, Arity=2, Caf=NoCafRefs, Str=, Unf=OtherCon []]
Bug.$wgo
= \ (ww_s2QZ :: Int#) (w_s2QW :: [Char]) ->
case quotRemInt# ww_s2QZ 62# of { (# ipv_a2OJ, ipv1_a2OK #) ->
case indexCharOffAddr# chars62_r2NR ipv1_a2OK of wild_X4
{ __DEFAULT ->
case <# ww_s2QZ 62# of {
__DEFAULT ->
Bug.$wgo
ipv_a2OJ (GHC.Types.: @ Char (GHC.Types.C# wild_X4) w_s2QW);
1# ->
case indexCharOffAddr# chars62_r2NR ww_s2QZ of wild1_XM
{ __DEFAULT ->
(# GHC.Types.C# wild1_XM, w_s2QW #)
}
}
}
}
end Rec }
-- RHS size: {terms: 13, types: 15, coercions: 0, joins: 0/0}
Bug.f_go [InlPrag=NOUSERINLINE[2]] :: Int -> [Char] -> [Char]
[GblId,
Arity=2,
Caf=NoCafRefs,
Str=m2,
Unf=Unf{Src=InlineStable, TopLvl=True, Value=True, ConLike=True,
WorkFree=True, Expandable=True,
Guidance=ALWAYS_IF(arity=2,unsat_ok=True,boring_ok=False)
Tmpl= \ (w_s2QV [Occ=Once!] :: Int)
(w1_s2QW [Occ=Once] :: [Char]) ->
case w_s2QV of { I# ww1_s2QZ [Occ=Once] ->
case Bug.$wgo ww1_s2QZ w1_s2QW of
{ (# ww3_s2R5 [Occ=Once], ww4_s2R6 [Occ=Once] #) ->
GHC.Types.: @ Char ww3_s2R5 ww4_s2R6
}
}}]
Bug.f_go
= \ (w_s2QV :: Int) (w1_s2QW :: [Char]) ->
case w_s2QV of { I# ww1_s2QZ ->
case Bug.$wgo ww1_s2QZ w1_s2QW of { (# ww3_s2R5, ww4_s2R6 #) ->
GHC.Types.: @ Char ww3_s2R5 ww4_s2R6
}
}
-- RHS size: {terms: 12, types: 14, coercions: 0, joins: 0/0}
f :: Int -> String
[GblId,
Arity=1,
Caf=NoCafRefs,
Str=m2,
Unf=Unf{Src=InlineStable, TopLvl=True, Value=True, ConLike=True,
WorkFree=True, Expandable=True,
Guidance=ALWAYS_IF(arity=1,unsat_ok=True,boring_ok=False)
Tmpl= \ (n__aXh [Occ=Once] :: Int) ->
Bug.f_go n__aXh (GHC.Types.[] @ Char)}]
f = \ (n__aXh :: Int) ->
case n__aXh of { I# ww1_s2QZ ->
case Bug.$wgo ww1_s2QZ (GHC.Types.[] @ Char) of
{ (# ww3_s2R5, ww4_s2R6 #) ->
GHC.Types.: @ Char ww3_s2R5 ww4_s2R6
}
}
}}}
which looks very plausible.
You are getting something quite different with your Hadrian build. Can
you give precise repro instructions? (Including `build.mk` etc.)
I'm very puzzled about this mysterious case of `GHC.Real.even3`. Where on
earth does that come from? And if it is equal to `-1` why doesn't the
case get eliminated?
--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15570#comment:2
GHC http://www.haskell.org/ghc/
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