{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE FlexibleContexts #-}

-- | Perform copy propagation.  This is done by invoking the
-- simplifier with no rules, so hoisting and dead-code elimination may
-- also take place.
module Futhark.Transform.CopyPropagate
  ( copyPropagateInProg,
    copyPropagateInStms,
    copyPropagateInFun,
  )
where

import qualified Futhark.Analysis.SymbolTable as ST
import Futhark.IR
import Futhark.MonadFreshNames
import Futhark.Optimise.Simplify
import Futhark.Optimise.Simplify.Lore (Wise)
import Futhark.Pass

-- | Run copy propagation on an entire program.
copyPropagateInProg ::
  SimplifiableLore lore =>
  SimpleOps lore ->
  Prog lore ->
  PassM (Prog lore)
copyPropagateInProg simpl = simplifyProg simpl mempty neverHoist

-- | Run copy propagation on some statements.
copyPropagateInStms ::
  (MonadFreshNames m, SimplifiableLore lore) =>
  SimpleOps lore ->
  Scope lore ->
  Stms lore ->
  m (ST.SymbolTable (Wise lore), Stms lore)
copyPropagateInStms simpl = simplifyStms simpl mempty neverHoist

-- | Run copy propagation on a function.
copyPropagateInFun ::
  (MonadFreshNames m, SimplifiableLore lore) =>
  SimpleOps lore ->
  ST.SymbolTable (Wise lore) ->
  FunDef lore ->
  m (FunDef lore)
copyPropagateInFun simpl = simplifyFun simpl mempty neverHoist