--------------------------------
-- Remove a = b bindings from let expressions everywhere
letremovetop :: Transform
-letremovetop = everywhere ("letremove", inlinebind (\(b, e) -> case e of (Var v) | not $ Id.isDataConWorkId v -> True; otherwise -> False))
+letremovetop = everywhere ("letremove", inlinebind (\(b, e) -> case e of (Var v) | not $ Id.isDataConWorkId v -> return True; otherwise -> return False))
--------------------------------
-- Function inlining
-- will just not work on those function-typed values at first, but the other
-- transformations (in particular β-reduction) should make sure that the type
-- of those values eventually becomes primitive.
-inlinefuntop :: Transform
-inlinefuntop = everywhere ("inlinefun", inlinebind (is_applicable . snd))
+inlinenonreptop :: Transform
+inlinenonreptop = everywhere ("inlinenonrep", inlinebind ((Monad.liftM not) . isRepr . snd))
--------------------------------
-- Scrutinee simplification
appsimpl, appsimpltop :: Transform
-- Don't simplify arguments that are already simple.
appsimpl expr@(App f (Var v)) = return expr
--- Simplify all non-applicable (to prevent loops with inlinefun) arguments,
--- except for type arguments (since a let can't bind type vars, only a lambda
--- can). Do this by introducing a new Let that binds the argument and passing
--- the new binder in the application.
-appsimpl (App f expr) | (not $ is_applicable expr) && (not $ CoreSyn.isTypeArg expr) = do
- id <- mkInternalVar "arg" (CoreUtils.exprType expr)
- change $ Let (Rec [(id, expr)]) (App f (Var id))
+-- Simplify all representable arguments. Do this by introducing a new Let
+-- that binds the argument and passing the new binder in the application.
+appsimpl expr@(App f arg) = do
+ -- Check runtime representability
+ repr <- isRepr arg
+ if repr
+ then do -- Extract representable arguments
+ id <- mkInternalVar "arg" (CoreUtils.exprType arg)
+ change $ Let (Rec [(id, arg)]) (App f (Var id))
+ else -- Leave non-representable arguments unchanged
+ return expr
-- Leave all other expressions unchanged
appsimpl expr = return expr
-- Perform this transform everywhere
appsimpltop = everywhere ("appsimpl", appsimpl)
-
---------------------------------
--- Type argument propagation
---------------------------------
--- Remove all applications to type arguments, by duplicating the function
--- called with the type application in its new definition. We leave
--- dictionaries that might be associated with the type untouched, the funprop
--- transform should propagate these later on.
-typeprop, typeproptop :: Transform
--- Transform any function that is applied to a type argument. Since type
--- arguments are always the first ones to apply and we'll remove all type
--- arguments, we can simply do them one by one. We only propagate type
--- arguments without any free tyvars, since tyvars those wouldn't be in scope
--- in the new function.
-typeprop expr@(App (Var f) arg@(Type ty)) | not $ has_free_tyvars arg = do
- body_maybe <- Trans.lift $ getGlobalBind f
- case body_maybe of
- Just body -> do
- let newbody = App body (Type ty)
- -- Create a new function with the same name but a new body
- newf <- mkFunction f newbody
- -- Replace the application with this new function
- change (Var newf)
- -- If we don't have a body for the function called, leave it unchanged (it
- -- should be a primitive function then).
- Nothing -> return expr
--- Leave all other expressions unchanged
-typeprop expr = return expr
--- Perform this transform everywhere
-typeproptop = everywhere ("typeprop", typeprop)
-
-
--------------------------------
-- Function-typed argument propagation
--------------------------------
-- Remove all applications to function-typed arguments, by duplication the
-- function called with the function-typed parameter replaced by the free
-- variables of the argument passed in.
-funprop, funproptop :: Transform
+argprop, argproptop :: Transform
-- Transform any application of a named function (i.e., skip applications of
-- lambda's). Also skip applications that have arguments with free type
-- variables, since we can't inline those.
-funprop expr@(App _ _) | is_var fexpr && not (any has_free_tyvars args) = do
+argprop expr@(App _ _) | is_var fexpr = do
-- Find the body of the function called
body_maybe <- Trans.lift $ getGlobalBind f
case body_maybe of
-- in the new function body, and arg is the argument to apply to the old
-- function body.
doarg :: CoreExpr -> TransformMonad ([CoreExpr], [CoreBndr], CoreExpr)
- doarg arg | is_fun arg = do
+ doarg arg = do
+ repr <- isRepr arg
bndrs <- Trans.lift getGlobalBinders
- -- Find interesting free variables, each of which should be passed to
- -- the new function instead of the original function argument.
- --
- -- Interesting vars are those that are local, but not available from the
- -- top level scope (functions from this module are defined as local, but
- -- they're not local to this function, so we can freely move references
- -- to them into another function).
let interesting var = Var.isLocalVar var && (not $ var `elem` bndrs)
- let free_vars = VarSet.varSetElems $ CoreFVs.exprSomeFreeVars interesting arg
- -- Mark the current expression as changed
- setChanged
- return (map Var free_vars, free_vars, arg)
- -- Non-functiontyped arguments can be unchanged. Note that this handles
- -- both values and types.
- doarg arg = do
- -- TODO: preserve original naming?
- id <- mkBinderFor arg "param"
- -- Just pass the original argument to the new function, which binds it
- -- to a new id and just pass that new id to the old function body.
- return ([arg], [id], mkReferenceTo id)
+ if not repr && not (is_var arg && interesting (exprToVar arg)) && not (has_free_tyvars arg)
+ then do
+ -- Propagate all complex arguments that are not representable, but not
+ -- arguments with free type variables (since those would require types
+ -- not known yet, which will always be known eventually).
+ -- Find interesting free variables, each of which should be passed to
+ -- the new function instead of the original function argument.
+ --
+ -- Interesting vars are those that are local, but not available from the
+ -- top level scope (functions from this module are defined as local, but
+ -- they're not local to this function, so we can freely move references
+ -- to them into another function).
+ let free_vars = VarSet.varSetElems $ CoreFVs.exprSomeFreeVars interesting arg
+ -- Mark the current expression as changed
+ setChanged
+ return (map Var free_vars, free_vars, arg)
+ else do
+ -- Representable types will not be propagated, and arguments with free
+ -- type variables will be propagated later.
+ -- TODO: preserve original naming?
+ id <- mkBinderFor arg "param"
+ -- Just pass the original argument to the new function, which binds it
+ -- to a new id and just pass that new id to the old function body.
+ return ([arg], [id], mkReferenceTo id)
-- Leave all other expressions unchanged
-funprop expr = return expr
+argprop expr = return expr
-- Perform this transform everywhere
-funproptop = everywhere ("funprop", funprop)
+argproptop = everywhere ("argprop", argprop)
--------------------------------
-- Function-typed argument extraction
-- What transforms to run?
-transforms = [typeproptop, funproptop, funextracttop, etatop, betatop, castproptop, letremovetop, letrectop, letsimpltop, letflattop, casewildtop, scrutsimpltop, casevalsimpltop, caseremovetop, inlinefuntop, appsimpltop]
+transforms = [argproptop, funextracttop, etatop, betatop, castproptop, letremovetop, letrectop, letsimpltop, letflattop, casewildtop, scrutsimpltop, casevalsimpltop, caseremovetop, inlinenonreptop, appsimpltop]
-- Turns the given bind into VHDL
normalizeModule ::
import Debug.Trace
import qualified List
import qualified Data.Monoid as Monoid
+import qualified Data.Either as Either
import qualified Control.Arrow as Arrow
import qualified Control.Monad as Monad
import qualified Control.Monad.Trans.State as State
import qualified "transformers" Control.Monad.Trans as Trans
import qualified Data.Map as Map
import Data.Accessor
+import Data.Accessor.MonadState as MonadState
-- GHC API
import CoreSyn
-- Local imports
import NormalizeTypes
+import Pretty
+import qualified VHDLTools
-- Create a new internal var with the given name and type. A Unique is
-- appended to the given name, to ensure uniqueness (not strictly neccesary,
if Monoid.getAny changed then dotransforms transs expr' else return expr'
-- Inline all let bindings that satisfy the given condition
-inlinebind :: ((CoreBndr, CoreExpr) -> Bool) -> Transform
-inlinebind condition (Let (Rec binds) expr) | not $ null replace =
- change newexpr
+inlinebind :: ((CoreBndr, CoreExpr) -> TransformMonad Bool) -> Transform
+inlinebind condition expr@(Let (Rec binds) res) = do
+ -- Find all bindings that adhere to the condition
+ res_eithers <- mapM docond binds
+ case Either.partitionEithers res_eithers of
+ -- No replaces? No change
+ ([], _) -> return expr
+ (replace, others) -> do
+ -- Substitute the to be replaced binders with their expression
+ let newexpr = substitute replace (Let (Rec others) res)
+ change newexpr
where
- -- Find all simple bindings
- (replace, others) = List.partition condition binds
- -- Substitute the to be replaced binders with their expression
- newexpr = substitute replace (Let (Rec others) expr)
+ docond :: (CoreBndr, CoreExpr) -> TransformMonad (Either (CoreBndr, CoreExpr) (CoreBndr, CoreExpr))
+ docond b = do
+ res <- condition b
+ return $ case res of True -> Left b; False -> Right b
+
-- Leave all other expressions unchanged
inlinebind _ expr = return expr
-- an initial state.
runTransformSession :: UniqSupply.UniqSupply -> TransformSession a -> a
runTransformSession uniqSupply session = State.evalState session (emptyTransformState uniqSupply)
+
+-- Is the given expression representable at runtime, based on the type?
+isRepr :: CoreSyn.CoreExpr -> TransformMonad Bool
+isRepr (Type ty) = return False
+isRepr expr = Trans.lift $ MonadState.lift tsType $ VHDLTools.isReprType (CoreUtils.exprType expr)
projects / matthijs / master-project / cλash.git / commitdiff