lower levels it is preserved with @let@/@letrec@s).
\begin{code}
-module DsBinds ( dsHsBinds, dsHsNestedBinds, AutoScc(..) ) where
+module DsBinds ( dsTopLHsBinds, dsLHsBinds, decomposeRuleLhs, AutoScc(..) ) where
#include "HsVersions.h"
-import {-# SOURCE #-} DsExpr( dsLExpr )
+import {-# SOURCE #-} DsExpr( dsLExpr, dsExpr )
import {-# SOURCE #-} Match( matchWrapper )
import DsMonad
import StaticFlags ( opt_AutoSccsOnAllToplevs,
opt_AutoSccsOnExportedToplevs )
+import OccurAnal ( occurAnalyseExpr )
import CostCentre ( mkAutoCC, IsCafCC(..) )
-import Id ( idType, idName, isExportedId, isSpecPragmaId, Id )
-import NameSet
-import VarSet
+import Id ( Id, idType, idName, isExportedId, mkLocalId, setInlinePragma )
+import Rules ( addIdSpecialisations, mkLocalRule )
+import Var ( Var, isGlobalId )
+import VarEnv
import Type ( mkTyVarTy, substTyWith )
import TysWiredIn ( voidTy )
import Outputable
import SrcLoc ( Located(..) )
-import Maybe ( isJust )
+import Maybes ( isJust, catMaybes, orElse )
import Bag ( bagToList )
+import BasicTypes ( Activation(..), isAlwaysActive )
import Monad ( foldM )
+import FastString ( mkFastString )
+import List ( (\\) )
+import Util ( mapSnd )
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-dsHsNestedBinds :: LHsBinds Id -> DsM [(Id,CoreExpr)]
-dsHsNestedBinds binds = dsHsBinds NoSccs binds []
+dsTopLHsBinds :: AutoScc -> LHsBinds Id -> DsM [(Id,CoreExpr)]
+dsTopLHsBinds auto_scc binds = ds_lhs_binds auto_scc binds
-dsHsBinds :: AutoScc -- scc annotation policy (see below)
- -> LHsBinds Id
- -> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
- -> DsM [(Id,CoreExpr)] -- Result
+dsLHsBinds :: LHsBinds Id -> DsM [(Id,CoreExpr)]
+dsLHsBinds binds = ds_lhs_binds NoSccs binds
-dsHsBinds auto_scc binds rest
- = foldM (dsLHsBind auto_scc) rest (bagToList binds)
+
+------------------------
+ds_lhs_binds :: AutoScc -> LHsBinds Id -> DsM [(Id,CoreExpr)]
+ -- scc annotation policy (see below)
+ds_lhs_binds auto_scc binds = foldM (dsLHsBind auto_scc) [] (bagToList binds)
dsLHsBind :: AutoScc
-> [(Id,CoreExpr)] -- Put this on the end (avoid quadratic append)
-- Dictionary bindings are always VarMonoBinds, so
-- we only need do this here
addDictScc var core_expr `thenDs` \ core_expr' ->
+ returnDs ((var, core_expr') : rest)
- let
- -- Gross hack to prevent inlining into SpecPragmaId rhss
- -- Consider fromIntegral = fromInteger . toInteger
- -- spec1 = fromIntegral Int Float
- -- Even though fromIntegral is small we don't want to inline
- -- it inside spec1, so that we collect the specialised call
- -- Solution: make spec1 an INLINE thing.
- core_expr'' = mkInline (isSpecPragmaId var) core_expr'
- in
-
- returnDs ((var, core_expr'') : rest)
-
-dsHsBind auto_scc rest (FunBind (L _ fun) _ matches)
+dsHsBind auto_scc rest (FunBind (L _ fun) _ matches _)
= matchWrapper (FunRhs (idName fun)) matches `thenDs` \ (args, body) ->
addAutoScc auto_scc (fun, mkLams args body) `thenDs` \ pair ->
returnDs (pair : rest)
-dsHsBind auto_scc rest (PatBind pat grhss ty)
+dsHsBind auto_scc rest (PatBind pat grhss ty _)
= dsGuarded grhss ty `thenDs` \ body_expr ->
mkSelectorBinds pat body_expr `thenDs` \ sel_binds ->
mappM (addAutoScc auto_scc) sel_binds `thenDs` \ sel_binds ->
-- For the (rare) case when there are some mixed-up
-- dictionary bindings (for which a Rec is convenient)
-- we reply on the enclosing dsBind to wrap a Rec around.
-dsHsBind auto_scc rest (AbsBinds [] [] exports inlines binds)
- = dsHsBinds (addSccs auto_scc exports) binds []`thenDs` \ core_prs ->
+dsHsBind auto_scc rest (AbsBinds [] [] exports binds)
+ = ds_lhs_binds (addSccs auto_scc exports) binds `thenDs` \ core_prs ->
let
- core_prs' = addLocalInlines exports inlines core_prs
- exports' = [(global, Var local) | (_, global, local) <- exports]
+ core_prs' = addLocalInlines exports core_prs
+ exports' = [(global, Var local) | (_, global, local, _) <- exports]
in
returnDs (core_prs' ++ exports' ++ rest)
-- Another common case: one exported variable
-- Non-recursive bindings come through this way
dsHsBind auto_scc rest
- (AbsBinds all_tyvars dicts exps@[(tyvars, global, local)] inlines binds)
+ (AbsBinds all_tyvars dicts exports@[(tyvars, global, local, prags)] binds)
= ASSERT( all (`elem` tyvars) all_tyvars )
- dsHsBinds (addSccs auto_scc exps) binds [] `thenDs` \ core_prs ->
+ ds_lhs_binds (addSccs auto_scc exports) binds `thenDs` \ core_prs ->
let
-- Always treat the binds as recursive, because the typechecker
-- makes rather mixed-up dictionary bindings
core_bind = Rec core_prs
-
- -- The mkInline does directly what the
- -- addLocalInlines do in the other cases
- export' = (global, mkInline (idName global `elemNameSet` inlines) $
- mkLams tyvars $ mkLams dicts $
- Let core_bind (Var local))
+ inline_env = mkVarEnv [(global, prag) | prag <- prags, isInlinePrag prag]
in
- returnDs (export' : rest)
+ mappM (dsSpec all_tyvars dicts tyvars global local core_bind)
+ prags `thenDs` \ mb_specs ->
+ let
+ (spec_binds, rules) = unzip (catMaybes mb_specs)
+ global' = addIdSpecialisations global rules
+ rhs' = mkLams tyvars $ mkLams dicts $ Let core_bind (Var local)
+ in
+ returnDs (addInlineInfo inline_env (global', rhs') : spec_binds ++ rest)
-dsHsBind auto_scc rest (AbsBinds all_tyvars dicts exports inlines binds)
- = dsHsBinds (addSccs auto_scc exports) binds []`thenDs` \ core_prs ->
- let
+dsHsBind auto_scc rest (AbsBinds all_tyvars dicts exports binds)
+ = ds_lhs_binds (addSccs auto_scc exports) binds `thenDs` \ core_prs ->
+ let
-- Rec because of mixed-up dictionary bindings
- core_bind = Rec (addLocalInlines exports inlines core_prs)
+ core_bind = Rec (addLocalInlines exports core_prs)
tup_expr = mkTupleExpr locals
tup_ty = exprType tup_expr
poly_tup_expr = mkLams all_tyvars $ mkLams dicts $
Let core_bind tup_expr
- locals = [local | (_, _, local) <- exports]
+ locals = [local | (_, _, local, _) <- exports]
local_tys = map idType locals
in
newSysLocalDs (exprType poly_tup_expr) `thenDs` \ poly_tup_id ->
let
dict_args = map Var dicts
- mk_bind ((tyvars, global, local), n) -- locals !! n == local
+ mk_bind ((tyvars, global, local, prags), n) -- locals !! n == local
= -- Need to make fresh locals to bind in the selector, because
-- some of the tyvars will be bound to voidTy
newSysLocalsDs (map substitute local_tys) `thenDs` \ locals' ->
newSysLocalDs (substitute tup_ty) `thenDs` \ tup_id ->
- returnDs (global, mkLams tyvars $ mkLams dicts $
- mkTupleSelector locals' (locals' !! n) tup_id $
- mkApps (mkTyApps (Var poly_tup_id) ty_args) dict_args)
+ mapM (dsSpec all_tyvars dicts tyvars global local core_bind)
+ prags `thenDs` \ mb_specs ->
+ let
+ (spec_binds, rules) = unzip (catMaybes mb_specs)
+ global' = addIdSpecialisations global rules
+ rhs = mkLams tyvars $ mkLams dicts $
+ mkTupleSelector locals' (locals' !! n) tup_id $
+ mkApps (mkTyApps (Var poly_tup_id) ty_args) dict_args
+ in
+ returnDs ((global', rhs) : spec_binds)
where
mk_ty_arg all_tyvar | all_tyvar `elem` tyvars = mkTyVarTy all_tyvar
| otherwise = voidTy
ty_args = map mk_ty_arg all_tyvars
substitute = substTyWith all_tyvars ty_args
in
- mappM mk_bind (exports `zip` [0..]) `thenDs` \ export_binds ->
+ mappM mk_bind (exports `zip` [0..]) `thenDs` \ export_binds_s ->
-- don't scc (auto-)annotate the tuple itself.
- returnDs ((poly_tup_id, poly_tup_expr) : (export_binds ++ rest))
+
+ returnDs ((poly_tup_id, poly_tup_expr) : (concat export_binds_s ++ rest))
+
+-- Example:
+-- f :: (Eq a, Ix b) => a -> b -> b
+--
+-- AbsBinds [ab] [d1,d2] [([ab], f, f_mono, prags)] binds
+--
+-- SpecPrag (/\b.\(d:Ix b). f Int b dInt d)
+-- (forall b. Ix b => Int -> b -> b)
+--
+-- Rule: forall b,(d:Ix b). f Int b dInt d = f_spec b d
+--
+-- Spec bind: f_spec = Let f = /\ab \(d1:Eq a)(d2:Ix b). let binds in f_mono
+-- /\b.\(d:Ix b). in f Int b dInt d
+
+dsSpec all_tvs dicts tvs poly_id mono_id mono_bind (InlinePrag {})
+ = return Nothing
+
+dsSpec all_tvs dicts tvs poly_id mono_id mono_bind
+ (SpecPrag spec_expr spec_ty const_dicts)
+ = do { let poly_name = idName poly_id
+ ; spec_name <- newLocalName (idName poly_id)
+ ; ds_spec_expr <- dsExpr spec_expr
+ ; let (bndrs, body) = collectBinders ds_spec_expr
+ mb_lhs = decomposeRuleLhs (bndrs ++ const_dicts) body
+
+ ; case mb_lhs of
+ Nothing -> do { dsWarn msg; return Nothing }
+
+ Just (bndrs', var, args) -> return (Just ((spec_id, spec_rhs), rule))
+ where
+ spec_id = mkLocalId spec_name spec_ty
+ spec_rhs = Let (NonRec poly_id poly_f_body) ds_spec_expr
+ poly_f_body = mkLams (tvs ++ dicts) $
+ fix_up (Let mono_bind (Var mono_id))
+
+ -- Quantify over constant dicts on the LHS, since
+ -- their value depends only on their type
+ -- The ones we are interested in may even be imported
+ -- e.g. GHC.Base.dEqInt
+
+ rule = mkLocalRule (mkFastString ("SPEC " ++ showSDoc (ppr poly_name)))
+ AlwaysActive poly_name
+ bndrs' -- Includes constant dicts
+ args
+ (mkVarApps (Var spec_id) bndrs)
+ }
+ where
+ -- Bind to voidTy any of all_ptvs that aren't
+ -- relevant for this particular function
+ fix_up body | null void_tvs = body
+ | otherwise = mkTyApps (mkLams void_tvs body)
+ (map (const voidTy) void_tvs)
+ void_tvs = all_tvs \\ tvs
+
+ msg = hang (ptext SLIT("Specialisation too complicated to desugar; ignored"))
+ 2 (ppr spec_expr)
\end{code}
%************************************************************************
\begin{code}
-mkInline :: Bool -> CoreExpr -> CoreExpr
-mkInline True body = mkInlineMe body
-mkInline False body = body
+decomposeRuleLhs :: [Var] -> CoreExpr -> Maybe ([Var], Id, [CoreExpr])
+-- Returns Nothing if the LHS isn't of the expected shape
+-- The argument 'all_bndrs' includes the "constant dicts" of the LHS,
+-- and they may be GlobalIds, which we can't forall-ify.
+-- So we substitute them out instead
+decomposeRuleLhs all_bndrs lhs
+ = go init_env (occurAnalyseExpr lhs) -- Occurrence analysis sorts out the dict
+ -- bindings so we know if they are recursive
+ where
-addLocalInlines :: [(a, Id, Id)] -> NameSet -> [(Id,CoreExpr)] -> [(Id,CoreExpr)]
-addLocalInlines exports inlines pairs
- = [(bndr, mkInline (bndr `elemVarSet` local_inlines) rhs) | (bndr,rhs) <- pairs]
+ -- all_bndrs may include top-level imported dicts,
+ -- imported things with a for-all.
+ -- So we localise them and subtitute them out
+ bndr_prs = [ (id, Var (localise id)) | id <- all_bndrs, isGlobalId id ]
+ localise d = mkLocalId (idName d) (idType d)
+
+ init_env = mkVarEnv bndr_prs
+ all_bndrs' = map subst_bndr all_bndrs
+ subst_bndr bndr = case lookupVarEnv init_env bndr of
+ Just (Var bndr') -> bndr'
+ Just other -> panic "decomposeRuleLhs"
+ Nothing -> bndr
+
+ -- Substitute dicts in the LHS args, so that there
+ -- aren't any lets getting in the way
+ go env (Let (NonRec dict rhs) body)
+ = go (extendVarEnv env dict (simpleSubst env rhs)) body
+ go env body
+ = case collectArgs body of
+ (Var fn, args) -> Just (all_bndrs', fn, map (simpleSubst env) args)
+ other -> Nothing
+
+simpleSubst :: IdEnv CoreExpr -> CoreExpr -> CoreExpr
+-- Similar to CoreSubst.substExpr, except that
+-- (a) takes no account of capture; dictionary bindings use new names
+-- (b) can have a GlobalId (imported) in its domain
+-- (c) Ids only; no types are substituted
+
+simpleSubst subst expr
+ = go expr
+ where
+ go (Var v) = lookupVarEnv subst v `orElse` Var v
+ go (Type ty) = Type ty
+ go (Lit lit) = Lit lit
+ go (App fun arg) = App (go fun) (go arg)
+ go (Note note e) = Note note (go e)
+ go (Lam bndr body) = Lam bndr (go body)
+ go (Let (NonRec bndr rhs) body) = Let (NonRec bndr (go rhs)) (go body)
+ go (Let (Rec pairs) body) = Let (Rec (mapSnd go pairs)) (go body)
+ go (Case scrut bndr ty alts) = Case (go scrut) bndr ty
+ [(c,bs,go r) | (c,bs,r) <- alts]
+
+addLocalInlines exports core_prs
+ = map (addInlineInfo inline_env) core_prs
where
- local_inlines = mkVarSet [l | (_,g,l) <- exports, idName g `elemNameSet` inlines]
+ inline_env = mkVarEnv [(mono_id, prag)
+ | (_, _, mono_id, prags) <- exports,
+ prag <- prags, isInlinePrag prag]
+
+addInlineInfo :: IdEnv Prag -> (Id,CoreExpr) -> (Id,CoreExpr)
+addInlineInfo inline_env (bndr,rhs)
+ | Just (InlinePrag is_inline phase) <- lookupVarEnv inline_env bndr
+ = (attach_phase bndr phase, wrap_inline is_inline rhs)
+ | otherwise
+ = (bndr, rhs)
+ where
+ attach_phase bndr phase
+ | isAlwaysActive phase = bndr -- Default phase
+ | otherwise = bndr `setInlinePragma` phase
+
+ wrap_inline True body = mkInlineMe body
+ wrap_inline False body = body
\end{code}
| TopLevelAddSccs (Id -> Maybe Id)
| NoSccs
-addSccs :: AutoScc -> [(a,Id,Id)] -> AutoScc
+addSccs :: AutoScc -> [(a,Id,Id,[Prag])] -> AutoScc
addSccs auto_scc@(TopLevelAddSccs _) exports = auto_scc
addSccs NoSccs exports = NoSccs
addSccs TopLevel exports
- = TopLevelAddSccs (\id -> case [ exp | (_,exp,loc) <- exports, loc == id ] of
+ = TopLevelAddSccs (\id -> case [ exp | (_,exp,loc,_) <- exports, loc == id ] of
(exp:_) | opt_AutoSccsOnAllToplevs ||
(isExportedId exp &&
opt_AutoSccsOnExportedToplevs)
{- DISABLED for now (need to somehow make up a name for the scc) -- SDM
| not ( opt_SccProfilingOn && opt_AutoSccsOnDicts)
- || not (isDictTy (idType var))
+ || not (isDictId var)
= returnDs rhs -- That's easy: do nothing
| otherwise
projects / ghc-hetmet.git / blobdiff