Repository : http://darcs.haskell.org/ghc.git/
On branch : master https://github.com/ghc/ghc/commit/1ed0409010afeaa318676e351b833aea659bf93a >--------------------------------------------------------------- commit 1ed0409010afeaa318676e351b833aea659bf93a Author: Simon Peyton Jones <simo...@microsoft.com> Date: Thu May 30 12:08:39 2013 +0100 Make 'SPECIALISE instance' work again This is a long-standing regression (Trac #7797), which meant that in particular the Eq [Char] instance does not get specialised. (The *methods* do, but the dictionary itself doesn't.) So when you call a function f :: Eq a => blah on a string type (ie a=[Char]), 7.6 passes a dictionary of un-specialised methods. This only matters when calling an overloaded function from a specialised context, but that does matter in some programs. I remember (though I cannot find the details) that Nick Frisby discovered this to be the source of some pretty solid performanc regresisons. Anyway it works now. The key change is that a DFunUnfolding now takes a form that is both simpler than before (the DFunArg type is eliminated) and more general: data Unfolding = ... | DFunUnfolding { -- The Unfolding of a DFunId -- See Note [DFun unfoldings] -- df = /\a1..am. \d1..dn. MkD t1 .. tk -- (op1 a1..am d1..dn) -- (op2 a1..am d1..dn) df_bndrs :: [Var], -- The bound variables [a1..m],[d1..dn] df_con :: DataCon, -- The dictionary data constructor (never a newtype datacon) df_args :: [CoreExpr] -- Args of the data con: types, superclasses and methods, } -- in positional order That in turn allowed me to re-enable the DFunUnfolding specialisation in DsBinds. Lots of details here in TcInstDcls: Note [SPECIALISE instance pragmas] I also did some refactoring, in particular to pass the InScopeSet to exprIsConApp_maybe (which in turn means it has to go to a RuleFun). NB: Interface file format has changed! compiler/basicTypes/MkId.lhs | 8 +- compiler/coreSyn/CoreFVs.lhs | 33 +++-- compiler/coreSyn/CoreSubst.lhs | 65 +++++---- compiler/coreSyn/CoreSyn.lhs | 39 ++---- compiler/coreSyn/CoreTidy.lhs | 7 +- compiler/coreSyn/CoreUnfold.lhs | 11 +- compiler/coreSyn/PprCore.lhs | 10 +- compiler/deSugar/DsBinds.lhs | 39 +++--- compiler/iface/BinIface.hs | 15 +-- compiler/iface/IfaceSyn.lhs | 9 +- compiler/iface/MkIface.lhs | 4 +- compiler/iface/TcIface.lhs | 10 +- compiler/main/TidyPgm.lhs | 3 +- compiler/prelude/PrelRules.lhs | 180 +++++++------------------ compiler/simplCore/OccurAnal.lhs | 2 +- compiler/simplCore/SimplUtils.lhs | 12 +- compiler/simplCore/Simplify.lhs | 12 +- compiler/specialise/Rules.lhs | 76 +++++------ compiler/specialise/Specialise.lhs | 20 ++- compiler/typecheck/TcInstDcls.lhs | 120 ++++++++++------- compiler/vectorise/Vectorise/Generic/PADict.hs | 24 ++-- 21 files changed, 316 insertions(+), 383 deletions(-) Diff suppressed because of size. To see it, use: git show 1ed0409010afeaa318676e351b833aea659bf93a _______________________________________________ ghc-commits mailing list ghc-commits@haskell.org http://www.haskell.org/mailman/listinfo/ghc-commits
