X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FcoreSyn%2FCoreSyn.lhs;h=25d2cdb3bafebca528b41f17903902890b548d70;hp=79e25a2be0d0201ae821f60dd2c545d7f99837cd;hb=d95ce839533391e7118257537044f01cbb1d6694;hpb=2e06595241350a6548b6ab6430c65d6458f7c197 diff --git a/compiler/coreSyn/CoreSyn.lhs b/compiler/coreSyn/CoreSyn.lhs index 79e25a2..25d2cdb 100644 --- a/compiler/coreSyn/CoreSyn.lhs +++ b/compiler/coreSyn/CoreSyn.lhs @@ -41,9 +41,10 @@ module CoreSyn ( noUnfolding, evaldUnfolding, mkOtherCon, -- ** Predicates and deconstruction on 'Unfolding' - unfoldingTemplate, maybeUnfoldingTemplate, otherCons, + unfoldingTemplate, setUnfoldingTemplate, + maybeUnfoldingTemplate, otherCons, isValueUnfolding, isEvaldUnfolding, isCheapUnfolding, isCompulsoryUnfolding, - hasUnfolding, hasSomeUnfolding, neverUnfold, + isInlineRule, isClosedUnfolding, hasSomeUnfolding, canUnfold, neverUnfoldGuidance, -- * Strictness seqExpr, seqExprs, seqUnfolding, @@ -271,21 +272,7 @@ See #type_let# -- | Allows attaching extra information to points in expressions rather than e.g. identifiers. data Note = SCC CostCentre -- ^ A cost centre annotation for profiling - - | InlineMe -- ^ Instructs the core simplifer to treat the enclosed expression - -- as very small, and inline it at its call sites - | CoreNote String -- ^ A generic core annotation, propagated but not used by GHC - --- NOTE: we also treat expressions wrapped in InlineMe as --- 'cheap' and 'dupable' (in the sense of exprIsCheap, exprIsDupable) --- What this means is that we obediently inline even things that don't --- look like valuse. This is sometimes important: --- {-# INLINE f #-} --- f = g . h --- Here, f looks like a redex, and we aren't going to inline (.) because it's --- inside an INLINE, so it'll stay looking like a redex. Nevertheless, we --- should inline f even inside lambdas. In effect, we should trust the programmer. \end{code} @@ -404,45 +391,73 @@ data Unfolding -- -- Here, @f@ gets an @OtherCon []@ unfolding. - | CompulsoryUnfolding CoreExpr -- ^ There is /no original definition/, - -- so you'd better unfold. + | CompulsoryUnfolding { -- There is /no original definition/, so you'd better unfold. + uf_tmpl :: CoreExpr -- The unfolding is guaranteed to have no free variables + } -- so no need to think about it during dependency analysis + + | InlineRule { -- The function has an INLINE pragma, with the specified (original) RHS + -- (The inline phase, if any, is in the InlinePragInfo for this Id.) + -- Inline when (a) applied to at least this number of args + -- (b) if there is something interesting about args or context + uf_tmpl :: CoreExpr, -- The *original* RHS; occurrence info is correct + -- (The actual RHS of the function may be different by now, + -- but what we inline is still the original RHS (kept in the InlineRule).) + uf_is_top :: Bool, + + uf_arity :: Arity, -- Don't inline unless applied to this number of *value* args + uf_is_value :: Bool, -- True <=> exprIsHNF is true; save to discard a `seq` + uf_worker :: Maybe Id -- Just wrk_id <=> this unfolding is a the wrapper in a worker/wrapper + -- split from the strictness analyser + -- Used to abbreviate the uf_tmpl in interface files + -- In the Just case, interface files don't actually + -- need to contain the RHS; it can be derived from + -- the strictness info + -- Also used in CoreUnfold to guide inlining decisions + } - | CoreUnfolding - CoreExpr - Bool - Bool - Bool - UnfoldingGuidance + | CoreUnfolding { -- An unfolding for an Id with no pragma, or perhaps a NOINLINE pragma + -- (For NOINLINE, the phase, if any, is in the InlinePragInfo for this Id.) + uf_tmpl :: CoreExpr, -- Template; binder-info is correct + uf_is_top :: Bool, -- True <=> top level binding + uf_is_value :: Bool, -- exprIsHNF template (cached); it is ok to discard a `seq` on + -- this variable + uf_is_cheap :: Bool, -- True <=> doesn't waste (much) work to expand inside an inlining + -- Basically it's exprIsCheap + uf_guidance :: UnfoldingGuidance -- Tells about the *size* of the template. + } -- ^ An unfolding with redundant cached information. Parameters: -- - -- 1) Template used to perform unfolding; binder-info is correct + -- uf_tmpl: Template used to perform unfolding; binder-info is correct -- - -- 2) Is this a top level binding? + -- uf_is_top: Is this a top level binding? -- - -- 3) 'exprIsHNF' template (cached); it is ok to discard a 'seq' on + -- uf_is_valiue: 'exprIsHNF' template (cached); it is ok to discard a 'seq' on -- this variable -- - -- 4) Does this waste only a little work if we expand it inside an inlining? + -- uf_is_cheap: Does this waste only a little work if we expand it inside an inlining? -- Basically this is a cached version of 'exprIsCheap' -- - -- 5) Tells us about the /size/ of the unfolding template + -- uf_guidance: Tells us about the /size/ of the unfolding template --- | When unfolding should take place +------------------------------------------------ +-- | 'UnfoldingGuidance' says when unfolding should take place data UnfoldingGuidance = UnfoldNever - | UnfoldIfGoodArgs Int -- and "n" value args + | UnfoldIfGoodArgs { + ug_arity :: Arity, -- "n" value args - [Int] -- Discount if the argument is evaluated. - -- (i.e., a simplification will definitely - -- be possible). One elt of the list per *value* arg. + ug_args :: [Int], -- Discount if the argument is evaluated. + -- (i.e., a simplification will definitely + -- be possible). One elt of the list per *value* arg. - Int -- The "size" of the unfolding; to be elaborated - -- later. ToDo + ug_size :: Int, -- The "size" of the unfolding; to be elaborated + -- later. ToDo - Int -- Scrutinee discount: the discount to substract if the thing is in - -- a context (case (thing args) of ...), - -- (where there are the right number of arguments.) + ug_res :: Int -- Scrutinee discount: the discount to substract if the thing is in + } -- a context (case (thing args) of ...), + -- (where there are the right number of arguments.) +------------------------------------------------ noUnfolding :: Unfolding -- ^ There is no known 'Unfolding' evaldUnfolding :: Unfolding @@ -455,7 +470,8 @@ mkOtherCon :: [AltCon] -> Unfolding mkOtherCon = OtherCon seqUnfolding :: Unfolding -> () -seqUnfolding (CoreUnfolding e top b1 b2 g) +seqUnfolding (CoreUnfolding { uf_tmpl = e, uf_is_top = top, + uf_is_value = b1, uf_is_cheap = b2, uf_guidance = g}) = seqExpr e `seq` top `seq` b1 `seq` b2 `seq` seqGuidance g seqUnfolding _ = () @@ -467,15 +483,17 @@ seqGuidance _ = () \begin{code} -- | Retrieves the template of an unfolding: panics if none is known unfoldingTemplate :: Unfolding -> CoreExpr -unfoldingTemplate (CoreUnfolding expr _ _ _ _) = expr -unfoldingTemplate (CompulsoryUnfolding expr) = expr -unfoldingTemplate _ = panic "getUnfoldingTemplate" +unfoldingTemplate = uf_tmpl + +setUnfoldingTemplate :: Unfolding -> CoreExpr -> Unfolding +setUnfoldingTemplate unf rhs = unf { uf_tmpl = rhs } -- | Retrieves the template of an unfolding if possible maybeUnfoldingTemplate :: Unfolding -> Maybe CoreExpr -maybeUnfoldingTemplate (CoreUnfolding expr _ _ _ _) = Just expr -maybeUnfoldingTemplate (CompulsoryUnfolding expr) = Just expr -maybeUnfoldingTemplate _ = Nothing +maybeUnfoldingTemplate (CoreUnfolding { uf_tmpl = expr }) = Just expr +maybeUnfoldingTemplate (CompulsoryUnfolding { uf_tmpl = expr }) = Just expr +maybeUnfoldingTemplate (InlineRule { uf_tmpl = expr }) = Just expr +maybeUnfoldingTemplate _ = Nothing -- | The constructors that the unfolding could never be: -- returns @[]@ if no information is available @@ -486,45 +504,53 @@ otherCons _ = [] -- | Determines if it is certainly the case that the unfolding will -- yield a value (something in HNF): returns @False@ if unsure isValueUnfolding :: Unfolding -> Bool -isValueUnfolding (CoreUnfolding _ _ is_evald _ _) = is_evald -isValueUnfolding _ = False + -- Returns False for OtherCon +isValueUnfolding (CoreUnfolding { uf_is_value = is_evald }) = is_evald +isValueUnfolding (InlineRule { uf_is_value = is_evald }) = is_evald +isValueUnfolding _ = False -- | Determines if it possibly the case that the unfolding will -- yield a value. Unlike 'isValueUnfolding' it returns @True@ -- for 'OtherCon' isEvaldUnfolding :: Unfolding -> Bool -isEvaldUnfolding (OtherCon _) = True -isEvaldUnfolding (CoreUnfolding _ _ is_evald _ _) = is_evald -isEvaldUnfolding _ = False + -- Returns True for OtherCon +isEvaldUnfolding (OtherCon _) = True +isEvaldUnfolding (CoreUnfolding { uf_is_value = is_evald }) = is_evald +isEvaldUnfolding (InlineRule { uf_is_value = is_evald }) = is_evald +isEvaldUnfolding _ = False -- | Is the thing we will unfold into certainly cheap? isCheapUnfolding :: Unfolding -> Bool -isCheapUnfolding (CoreUnfolding _ _ _ is_cheap _) = is_cheap -isCheapUnfolding _ = False +isCheapUnfolding (CoreUnfolding { uf_is_cheap = is_cheap }) = is_cheap +isCheapUnfolding _ = False + +isInlineRule :: Unfolding -> Bool +isInlineRule (InlineRule {}) = True +isInlineRule _ = False -- | Must this unfolding happen for the code to be executable? isCompulsoryUnfolding :: Unfolding -> Bool -isCompulsoryUnfolding (CompulsoryUnfolding _) = True +isCompulsoryUnfolding (CompulsoryUnfolding {}) = True isCompulsoryUnfolding _ = False --- | Do we have an available or compulsory unfolding? -hasUnfolding :: Unfolding -> Bool -hasUnfolding (CoreUnfolding _ _ _ _ _) = True -hasUnfolding (CompulsoryUnfolding _) = True -hasUnfolding _ = False +isClosedUnfolding :: Unfolding -> Bool -- No free variables +isClosedUnfolding (CoreUnfolding {}) = False +isClosedUnfolding (InlineRule {}) = False +isClosedUnfolding _ = True -- | Only returns False if there is no unfolding information available at all hasSomeUnfolding :: Unfolding -> Bool hasSomeUnfolding NoUnfolding = False hasSomeUnfolding _ = True --- | Similar to @not . hasUnfolding@, but also returns @True@ --- if it has an unfolding that says it should never occur -neverUnfold :: Unfolding -> Bool -neverUnfold NoUnfolding = True -neverUnfold (OtherCon _) = True -neverUnfold (CoreUnfolding _ _ _ _ UnfoldNever) = True -neverUnfold _ = False +neverUnfoldGuidance :: UnfoldingGuidance -> Bool +neverUnfoldGuidance UnfoldNever = True +neverUnfoldGuidance _ = False + +canUnfold :: Unfolding -> Bool +canUnfold (InlineRule {}) = True +canUnfold (CoreUnfolding { uf_guidance = g }) = not (neverUnfoldGuidance g) +canUnfold _ = False \end{code}