hsc_env <- getHscEnv
liftIO $ vectoriseIO backend hsc_env guts
+-- | Vectorise a single monad, given its HscEnv (code gen environment).
vectoriseIO :: PackageId -> HscEnv -> ModGuts -> IO ModGuts
vectoriseIO backend hsc_env guts
- = do
+ = do -- Get information about currently loaded external packages.
eps <- hscEPS hsc_env
+
+ -- Combine vectorisation info from the current module, and external ones.
let info = hptVectInfo hsc_env `plusVectInfo` eps_vect_info eps
+
+ -- Run the main VM computation.
Just (info', guts') <- initV backend hsc_env guts info (vectModule guts)
return (guts' { mg_vect_info = info' })
+
+-- | Vectorise a single module, in the VM monad.
vectModule :: ModGuts -> VM ModGuts
vectModule guts
- = do
+ = do -- Vectorise the type environment.
+ -- This may add new TyCons and DataCons.
+ -- TODO: What new binds do we get back here?
(types', fam_insts, tc_binds) <- vectTypeEnv (mg_types guts)
+ -- TODO: What is this?
let fam_inst_env' = extendFamInstEnvList (mg_fam_inst_env guts) fam_insts
updGEnv (setFamInstEnv fam_inst_env')
-- dicts <- mapM buildPADict pa_insts
-- workers <- mapM vectDataConWorkers pa_insts
+
+ -- Vectorise all the top level bindings.
binds' <- mapM vectTopBind (mg_binds guts)
+
return $ guts { mg_types = types'
, mg_binds = Rec tc_binds : binds'
, mg_fam_inst_env = fam_inst_env'
, mg_fam_insts = mg_fam_insts guts ++ fam_insts
}
+
+-- | Try to vectorise a top-level binding.
+-- If it doesn't vectorise then return it unharmed.
+--
+-- For example, for the binding
+--
+-- @
+-- foo :: Int -> Int
+-- foo = \x -> x + x
+-- @
+--
+-- we get
+-- @
+-- foo :: Int -> Int
+-- foo = \x -> vfoo $: x
+--
+-- v_foo :: Closure void vfoo lfoo
+-- v_foo = closure vfoo lfoo void
+--
+-- vfoo :: Void -> Int -> Int
+-- vfoo = ...
+--
+-- lfoo :: PData Void -> PData Int -> PData Int
+-- lfoo = ...
+-- @
+--
+-- @vfoo@ is the "vectorised", or scalar, version that does the same as the original
+-- function foo, but takes an explicit environment.
+--
+-- @lfoo@ is the "lifted" version that works on arrays.
+--
+-- @v_foo@ combines both of these into a `Closure` that also contains the
+-- environment.
+--
+-- The original binding @foo@ is rewritten to call the vectorised version
+-- present in the closure.
+--
vectTopBind :: CoreBind -> VM CoreBind
vectTopBind b@(NonRec var expr)
- = do
- (inline, expr') <- vectTopRhs var expr
- var' <- vectTopBinder var inline expr'
- hs <- takeHoisted
- cexpr <- tryConvert var var' expr
+ = do
+ (inline, expr') <- vectTopRhs var expr
+ var' <- vectTopBinder var inline expr'
+
+ -- Vectorising the body may create other top-level bindings.
+ hs <- takeHoisted
+
+ -- To get the same functionality as the original body we project
+ -- out its vectorised version from the closure.
+ cexpr <- tryConvert var var' expr
+
return . Rec $ (var, cexpr) : (var', expr') : hs
`orElseV`
return b
vectTopBind b@(Rec bs)
- = do
- (vars', _, exprs') <- fixV $ \ ~(_, inlines, rhss) ->
- do
- vars' <- sequence [vectTopBinder var inline rhs
- | (var, ~(inline, rhs))
- <- zipLazy vars (zip inlines rhss)]
- (inlines', exprs') <- mapAndUnzipM (uncurry vectTopRhs) bs
- return (vars', inlines', exprs')
+ = do
+ (vars', _, exprs')
+ <- fixV $ \ ~(_, inlines, rhss) ->
+ do vars' <- sequence [vectTopBinder var inline rhs
+ | (var, ~(inline, rhs)) <- zipLazy vars (zip inlines rhss)]
+ (inlines', exprs')
+ <- mapAndUnzipM (uncurry vectTopRhs) bs
+
+ return (vars', inlines', exprs')
+
hs <- takeHoisted
cexprs <- sequence $ zipWith3 tryConvert vars vars' exprs
return . Rec $ zip vars cexprs ++ zip vars' exprs' ++ hs
where
(vars, exprs) = unzip bs
--- NOTE: vectTopBinder *MUST* be lazy in inline and expr because of how it is
--- used inside of fixV in vectTopBind
-vectTopBinder :: Var -> Inline -> CoreExpr -> VM Var
+
+-- | Make the vectorised version of this top level binder, and add the mapping
+-- between it and the original to the state. For some binder @foo@ the vectorised
+-- version is @$v_foo@
+--
+-- NOTE: vectTopBinder *MUST* be lazy in inline and expr because of how it is
+-- used inside of fixV in vectTopBind
+vectTopBinder
+ :: Var -- ^ Name of the binding.
+ -> Inline -- ^ Whether it should be inlined, used to annotate it.
+ -> CoreExpr -- ^ RHS of the binding, used to set the `Unfolding` of the returned `Var`.
+ -> VM Var -- ^ Name of the vectorised binding.
+
vectTopBinder var inline expr
- = do
+ = do
+ -- Vectorise the type attached to the var.
vty <- vectType (idType var)
var' <- liftM (`setIdUnfolding` unfolding) $ cloneId mkVectOcc var vty
defGlobalVar var var'
Inline arity -> mkInlineRule expr (Just arity)
DontInline -> noUnfolding
-vectTopRhs :: Var -> CoreExpr -> VM (Inline, CoreExpr)
+
+-- | Vectorise the RHS of a top-level binding, in an empty local environment.
+vectTopRhs
+ :: Var -- ^ Name of the binding.
+ -> CoreExpr -- ^ Body of the binding.
+ -> VM (Inline, CoreExpr)
+
vectTopRhs var expr
- = closedV
- $ do
- (inline, vexpr) <- inBind var
- $ vectPolyExpr (isLoopBreaker $ idOccInfo var)
+ = dtrace (vcat [text "vectTopRhs", ppr expr])
+ $ closedV
+ $ do (inline, vexpr) <- inBind var
+ $ vectPolyExpr (isLoopBreaker $ idOccInfo var)
(freeVars expr)
return (inline, vectorised vexpr)
-tryConvert :: Var -> Var -> CoreExpr -> VM CoreExpr
+
+-- | Project out the vectorised version of a binding from some closure,
+-- or return the original body if that doesn't work.
+tryConvert
+ :: Var -- ^ Name of the original binding (eg @foo@)
+ -> Var -- ^ Name of vectorised version of binding (eg @$vfoo@)
+ -> CoreExpr -- ^ The original body of the binding.
+ -> VM CoreExpr
+
tryConvert var vect_var rhs
= fromVect (idType var) (Var vect_var) `orElseV` return rhs
-- ----------------------------------------------------------------------------
-- Bindings
+-- | Vectorise a binder variable, along with its attached type.
vectBndr :: Var -> VM VVar
vectBndr v
= do
where
mapTo vv lv env = env { local_vars = extendVarEnv (local_vars env) v (vv, lv) }
+
+-- | Vectorise a binder variable, along with its attached type,
+-- but give the result a new name.
vectBndrNew :: Var -> FastString -> VM VVar
vectBndrNew v fs
= do
where
upd vv env = env { local_vars = extendVarEnv (local_vars env) v vv }
+
+-- | Vectorise a binder then run a computation with that binder in scope.
vectBndrIn :: Var -> VM a -> VM (VVar, a)
vectBndrIn v p
= localV
x <- p
return (vv, x)
+
+-- | Vectorise a binder, give it a new name, then run a computation with that binder in scope.
vectBndrNewIn :: Var -> FastString -> VM a -> VM (VVar, a)
vectBndrNewIn v fs p
= localV
x <- p
return (vv, x)
+-- | Vectorise some binders, then run a computation with them in scope.
vectBndrsIn :: [Var] -> VM a -> VM ([VVar], a)
vectBndrsIn vs p
= localV
x <- p
return (vvs, x)
+
-- ----------------------------------------------------------------------------
-- Expressions
+-- | Vectorise a variable, producing the vectorised and lifted versions.
vectVar :: Var -> VM VExpr
vectVar v
- = do
+ = do
+ -- lookup the variable from the environment.
r <- lookupVar v
+
case r of
Local (vv,lv) -> return (Var vv, Var lv)
Global vv -> do
lexpr <- liftPD vexpr
return (vexpr, lexpr)
+-- | Like `vectVar` but also add type applications to the variables.
vectPolyVar :: Var -> [Type] -> VM VExpr
vectPolyVar v tys
= do
- vtys <- mapM vectType tys
- r <- lookupVar v
+ vtys <- mapM vectType tys
+ r <- lookupVar v
case r of
- Local (vv, lv) -> liftM2 (,) (polyApply (Var vv) vtys)
- (polyApply (Var lv) vtys)
- Global poly -> do
- vexpr <- polyApply (Var poly) vtys
- lexpr <- liftPD vexpr
- return (vexpr, lexpr)
+ Local (vv, lv)
+ -> liftM2 (,) (polyApply (Var vv) vtys)
+ (polyApply (Var lv) vtys)
+
+ Global poly
+ -> do vexpr <- polyApply (Var poly) vtys
+ lexpr <- liftPD vexpr
+ return (vexpr, lexpr)
+
+-- | Lifted literals are created by replicating them.
vectLiteral :: Literal -> VM VExpr
vectLiteral lit
= do
lexpr <- liftPD (Lit lit)
return (Lit lit, lexpr)
-vectPolyExpr :: Bool -> CoreExprWithFVs -> VM (Inline, VExpr)
+
+-- | Vectorise a polymorphic expression
+vectPolyExpr
+ :: Bool -- ^ When vectorising the RHS of a binding, whether that
+ -- binding is a loop breaker.
+ -> CoreExprWithFVs
+ -> VM (Inline, VExpr)
+
vectPolyExpr loop_breaker (_, AnnNote note expr)
- = do
- (inline, expr') <- vectPolyExpr loop_breaker expr
+ = do (inline, expr') <- vectPolyExpr loop_breaker expr
return (inline, vNote note expr')
+
vectPolyExpr loop_breaker expr
= do
arity <- polyArity tvs
where
(tvs, mono) = collectAnnTypeBinders expr
+
+-- | Vectorise a core expression.
vectExpr :: CoreExprWithFVs -> VM VExpr
vectExpr (_, AnnType ty)
= liftM vType (vectType ty)
-vectExpr (_, AnnVar v) = vectVar v
+vectExpr (_, AnnVar v)
+ = vectVar v
-vectExpr (_, AnnLit lit) = vectLiteral lit
+vectExpr (_, AnnLit lit)
+ = vectLiteral lit
vectExpr (_, AnnNote note expr)
= liftM (vNote note) (vectExpr expr)
is_special_con con = con `elem` [intDataCon, floatDataCon, doubleDataCon]
+-- TODO: Avoid using closure application for dictionaries.
+-- vectExpr (_, AnnApp fn arg)
+-- | if is application of dictionary
+-- just use regular app instead of closure app.
+
+-- for lifted version.
+-- do liftPD (sub a dNumber)
+-- lift the result of the selection, not sub and dNumber seprately.
+
vectExpr (_, AnnApp fn arg)
= do
arg_ty' <- vectType arg_ty
res_ty' <- vectType res_ty
fn' <- vectExpr fn
arg' <- vectExpr arg
+
mkClosureApp arg_ty' res_ty' fn' arg'
where
(arg_ty, res_ty) = splitFunTy . exprType $ deAnnotate fn
vectExpr e = cantVectorise "Can't vectorise expression" (ppr $ deAnnotate e)
-vectFnExpr :: Bool -> Bool -> CoreExprWithFVs -> VM (Inline, VExpr)
+
+-- | Vectorise an expression with an outer lambda abstraction.
+vectFnExpr
+ :: Bool -- ^ When the RHS of a binding, whether that binding should be inlined.
+ -> Bool -- ^ Whether the binding is a loop breaker.
+ -> CoreExprWithFVs -- ^ Expression to vectorise. Must have an outer `AnnLam`.
+ -> VM (Inline, VExpr)
+
vectFnExpr inline loop_breaker e@(fvs, AnnLam bndr _)
| isId bndr = onlyIfV (isEmptyVarSet fvs)
(mark DontInline . vectScalarLam bs $ deAnnotate body)
mark :: Inline -> VM a -> VM (Inline, a)
mark b p = do { x <- p; return (b,x) }
-vectScalarLam :: [Var] -> CoreExpr -> VM VExpr
+
+-- | Vectorise a function where are the args have scalar type, that is Int, Float or Double.
+vectScalarLam
+ :: [Var] -- ^ Bound variables of function.
+ -> CoreExpr -- ^ Function body.
+ -> VM VExpr
vectScalarLam args body
= do
scalars <- globalScalars
&& is_scalar (extendVarSetList scalars args) body
&& uses scalars body)
$ do
- fn_var <- hoistExpr (fsLit "fn") (mkLams args body) DontInline
- zipf <- zipScalars arg_tys res_ty
- clo <- scalarClosure arg_tys res_ty (Var fn_var)
+ fn_var <- hoistExpr (fsLit "fn") (mkLams args body) DontInline
+ zipf <- zipScalars arg_tys res_ty
+ clo <- scalarClosure arg_tys res_ty (Var fn_var)
(zipf `App` Var fn_var)
clo_var <- hoistExpr (fsLit "clo") clo DontInline
- lclo <- liftPD (Var clo_var)
+ lclo <- liftPD (Var clo_var)
return (Var clo_var, lclo)
where
arg_tys = map idType args
res_ty = exprType body
- is_scalar_ty ty | Just (tycon, []) <- splitTyConApp_maybe ty
- = tycon == intTyCon
- || tycon == floatTyCon
- || tycon == doubleTyCon
+ is_scalar_ty ty
+ | Just (tycon, []) <- splitTyConApp_maybe ty
+ = tycon == intTyCon
+ || tycon == floatTyCon
+ || tycon == doubleTyCon
- | otherwise = False
+ | otherwise = False
is_scalar vs (Var v) = v `elemVarSet` vs
is_scalar _ e@(Lit _) = is_scalar_ty $ exprType e
uses funs (App e1 e2) = uses funs e1 || uses funs e2
uses _ _ = False
-vectLam :: Bool -> Bool -> VarSet -> [Var] -> CoreExprWithFVs -> VM VExpr
+
+vectLam
+ :: Bool -- ^ When the RHS of a binding, whether that binding should be inlined.
+ -> Bool -- ^ Whether the binding is a loop breaker.
+ -> VarSet -- ^ The free variables in the body.
+ -> [Var] --
+ -> CoreExprWithFVs
+ -> VM VExpr
+
vectLam inline loop_breaker fvs bs body
= do
tyvars <- localTyVars