GHC.Cmm.Info.Build

Documentation

type CAFSet = Set CAFLabel

type CAFEnv = LabelMap CAFSet

cafAnal :: LabelSet -> CLabel -> CmmGraph -> CAFEnv

For each code block: - collect the references reachable from this code block to FUN, THUNK or RET labels for which hasCAF == True

This gives us a CAFEnv: a mapping from code block to sets of labels

cafAnalData :: CmmStatics -> CAFSet

doSRTs :: DynFlags -> ModuleSRTInfo -> [(CAFEnv, [CmmDecl])] -> [(CAFSet, CmmDecl)] -> IO (ModuleSRTInfo, [CmmDeclSRTs])

Attach SRTs to all info tables in the CmmDecls, and add SRT declarations to the ModuleSRTInfo.

data ModuleSRTInfo

Constructors

ModuleSRTInfo

Fields

• thisModule :: Module

  Current module being compiled. Required for calling labelDynamic.

• dedupSRTs :: Map (Set SRTEntry) SRTEntry

  previous SRTs we've emitted, so we can de-duplicate. Used to implement the [Common] optimisation.

• flatSRTs :: Map SRTEntry (Set SRTEntry)

  The reverse mapping, so that we can remove redundant entries. e.g. if we have an SRT [a,b,c], and we know that b points to [c,d], we can omit c and emit [a,b]. Used to implement the [Filter] optimisation.

• moduleSRTMap :: SRTMap

Instances

Outputable ModuleSRTInfo

Defined in GHC.Cmm.Info.Build

Methods

ppr :: ModuleSRTInfo -> SDoc

pprPrec :: Rational -> ModuleSRTInfo -> SDoc

emptySRT :: Module -> ModuleSRTInfo

type SRTMap = Map CAFLabel (Maybe SRTEntry)

Maps labels from cafAnal to the final CLabel that will appear in the SRT. - closures with singleton SRTs resolve to their single entry - closures with larger SRTs map to the label for that SRT - CAFs must not map to anything! - if a labels maps to Nothing, we found that this label's SRT is empty, so we don't need to refer to it from other SRTs.

srtMapNonCAFs :: SRTMap -> NonCaffySet

Given SRTMap of a module, returns the set of non-CAFFY names in the module. Any Names not in the set are CAFFY.