GHC.Cmm.Info.Build

Documentation

type CAFSet = Set CAFfyLabel

type CAFEnv = LabelMap CAFSet

cafAnal

Arguments

:: Platform

-> LabelSet

The blocks representing continuations, ie. those that will get RET info tables. These labels will get their own SRTs, so we don't aggregate CAFs from references to these labels, we just use the label.

-> CLabel

The top label of the proc

-> 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 :: Platform -> CmmStatics -> CAFSet

Collect possible CAFfy references from a CmmData decl.

doSRTs

Arguments

:: CmmConfig

-> ModuleSRTInfo

-> [(CAFEnv, [CmmDecl])]

CAFEnvs and CmmDecls for code blocks

-> [(CAFSet, CmmDecl)]

static data decls and their CAFSets

-> 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

OutputableP env CLabel => OutputableP env ModuleSRTInfo

Defined in GHC.Cmm.Info.Build

Methods

pdoc :: env -> ModuleSRTInfo -> SDoc

emptySRT :: Module -> ModuleSRTInfo

type SRTMap = Map CAFfyLabel (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.