import SimplUtils
import FamInstEnv ( FamInstEnv )
import Id
-import MkId ( mkImpossibleExpr, seqId )
+import MkId ( seqId, realWorldPrimId )
+import MkCore ( mkImpossibleExpr )
import Var
import IdInfo
import Name ( mkSystemVarName, isExternalName )
import CoreSyn
import Demand ( isStrictDmd, splitStrictSig )
import PprCore ( pprParendExpr, pprCoreExpr )
-import CoreUnfold ( mkUnfolding, mkCoreUnfolding, mkInlineRule,
- exprIsConApp_maybe, callSiteInline, CallCtxt(..) )
+import CoreUnfold ( mkUnfolding, mkCoreUnfolding
+ , mkInlineUnfolding, mkSimpleUnfolding
+ , exprIsConApp_maybe, callSiteInline, CallCtxt(..) )
import CoreUtils
import qualified CoreSubst
import CoreArity ( exprArity )
import BasicTypes ( isMarkedStrict, Arity )
import CostCentre ( currentCCS, pushCCisNop )
import TysPrim ( realWorldStatePrimTy )
-import PrelInfo ( realWorldPrimId )
import BasicTypes ( TopLevelFlag(..), isTopLevel, RecFlag(..) )
import MonadUtils ( foldlM, mapAccumLM )
import Maybes ( orElse )
expr_ty = exprType expr
bindingOk :: TopLevelFlag -> CoreExpr -> Type -> Bool
--- True iff we can have a binding of this expression at this leve
+-- True iff we can have a binding of this expression at this level
-- Precondition: the type is the type of the expression
bindingOk top_lvl _ expr_ty
| isTopLevel top_lvl = not (isUnLiftedType expr_ty)
-> OccInfo -> OutExpr
-> Unfolding -> SimplM Unfolding
-- Note [Setting the new unfolding]
-simplUnfolding env _ _ _ _ (DFunUnfolding con ops)
- = return (DFunUnfolding con ops')
+simplUnfolding env _ _ _ _ (DFunUnfolding ar con ops)
+ = return (DFunUnfolding ar con ops')
where
ops' = map (substExpr (text "simplUnfolding") env) ops
simplUnfolding env top_lvl id _ _
(CoreUnfolding { uf_tmpl = expr, uf_arity = arity
, uf_src = src, uf_guidance = guide })
- | isInlineRuleSource src
+ | isStableSource src
= do { expr' <- simplExpr rule_env expr
; let src' = CoreSubst.substUnfoldingSource (mkCoreSubst (text "inline-unf") env) src
; return (mkCoreUnfolding (isTopLevel top_lvl) src' expr' arity guide) }
-- See Note [Simplifying gently inside InlineRules] in SimplUtils
simplUnfolding _ top_lvl id _occ_info new_rhs _
- = return (mkUnfolding (isTopLevel top_lvl) (isBottomingId id) new_rhs)
+ = return (mkUnfolding InlineRhs (isTopLevel top_lvl) (isBottomingId id) new_rhs)
-- We make an unfolding *even for loop-breakers*.
-- Reason: (a) It might be useful to know that they are WHNF
-- (b) In TidyPgm we currently assume that, if we want to
n_params = length bndrs
(bndrs, body) = collectBinders expr
zap | n_args >= n_params = \b -> b
- | otherwise = \b -> if isTyVar b then b
+ | otherwise = \b -> if isTyCoVar b then b
else zapLamIdInfo b
-- NB: we count all the args incl type args
-- so we must count all the binders (incl type lambdas)
-- First deal with type applications and type lets
-- (/\a. e) (Type ty) and (let a = Type ty in e)
simplNonRecE env bndr (Type ty_arg, rhs_se) (bndrs, body) cont
- = ASSERT( isTyVar bndr )
+ = ASSERT( isTyCoVar bndr )
do { ty_arg' <- simplType (rhs_se `setInScope` env) ty_arg
; simplLam (extendTvSubst env bndr ty_arg') bndrs body cont }
(StrictBind bndr bndrs body env cont) }
| otherwise
- = ASSERT( not (isTyVar bndr) )
+ = ASSERT( not (isTyCoVar bndr) )
do { (env1, bndr1) <- simplNonRecBndr env bndr
; let (env2, bndr2) = addBndrRules env1 bndr bndr1
; env3 <- simplLazyBind env2 NotTopLevel NonRecursive bndr bndr2 rhs rhs_se
simplVar :: SimplEnv -> InVar -> SimplM OutExpr
-- Look up an InVar in the environment
simplVar env var
- | isTyVar var
+ | isTyCoVar var
= return (Type (substTyVar env var))
| otherwise
= case substId env var of
rebuildCase env scrut case_bndr [(_, bndrs, rhs)] cont
-- See if we can get rid of the case altogether
- -- See Note [Case eliminiation]
+ -- See Note [Case elimination]
-- mkCase made sure that if all the alternatives are equal,
-- then there is now only one (DEFAULT) rhs
| all isDeadBinder bndrs -- bndrs are [InId]
= go vs the_strs
where
go [] [] = []
- go (v:vs') strs | isTyVar v = v : go vs' strs
+ go (v:vs') strs | isTyCoVar v = v : go vs' strs
go (v:vs') (str:strs)
| isMarkedStrict str = evald_v : go vs' strs
| otherwise = zapped_v : go vs' strs
addBinderUnfolding :: SimplEnv -> Id -> CoreExpr -> SimplEnv
addBinderUnfolding env bndr rhs
- = modifyInScope env (bndr `setIdUnfolding` mkUnfolding False False rhs)
+ = modifyInScope env (bndr `setIdUnfolding` mkSimpleUnfolding rhs)
addBinderOtherCon :: SimplEnv -> Id -> [AltCon] -> SimplEnv
addBinderOtherCon env bndr cons
bind_args env' [] _ = return env'
bind_args env' (b:bs') (Type ty : args)
- = ASSERT( isTyVar b )
+ = ASSERT( isTyCoVar b )
bind_args (extendTvSubst env' b ty) bs' args
bind_args env' (b:bs') (arg : args)
DataAlt dc -> setIdUnfolding case_bndr unf
where
-- See Note [Case binders and join points]
- unf = mkInlineRule rhs Nothing
+ unf = mkInlineUnfolding Nothing rhs
rhs = mkConApp dc (map Type (tyConAppArgs scrut_ty)
++ varsToCoreExprs bndrs')
| otherwise = bndrs' ++ [case_bndr_w_unf]
abstract_over bndr
- | isTyVar bndr = True -- Abstract over all type variables just in case
+ | isTyCoVar bndr = True -- Abstract over all type variables just in case
| otherwise = not (isDeadBinder bndr)
-- The deadness info on the new Ids is preserved by simplBinders
"see" the MkT any more, because it's big and won't get duplicated.
And, what is worse, nothing was gained by the case-of-case transform.
-When should use this case of mkDupableCont?
-However, matching on *any* single-alternative case is a *disaster*;
+So, in circumstances like these, we don't want to build join points
+and push the outer case into the branches of the inner one. Instead,
+don't duplicate the continuation.
+
+When should we use this strategy? We should not use it on *every*
+single-alternative case:
e.g. case (case ....) of (a,b) -> (# a,b #)
- We must push the outer case into the inner one!
+Here we must push the outer case into the inner one!
Other choices:
* Match [(DEFAULT,_,_)], but in the common case of Int,
the *un-simplified* rhs, which is fine. It might get bigger or
smaller after simplification; if it gets smaller, this case might
fire next time round. NB also that we must test contIsDupable
- case_cont *btoo, because case_cont might be big!
+ case_cont *too, because case_cont might be big!
HOWEVER: I found that this version doesn't work well, because
we can get let x = case (...) of { small } in ...case x...