Record field selectors are not optimized

It seems that record field selectors are not optimized. Usually this doesn't matter, but when there are unpacked fields this leaves suboptimal code. The equivalent code using the data type constructor is optimized.

For example:

module Test where

data Test = Test { getR :: {-# UNPACK #-} !Int }
getC (Test a) = a

Generates the following core (with -O2 -ddump-simpl):

Test.getR :: Test.Test -> GHC.Base.Int
[RecSel]
[Arity 1
 NoCafRefs
 Str: DmdType U(L)m]
Test.getR =
  \ (tpl_B1 :: Test.Test) ->
    case tpl_B1 of tpl1_B2 { Test.Test rb_B4 ->
    let {
      ipv_B3 [Just S] :: GHC.Base.Int
      [Str: DmdType m]
      ipv_B3 = GHC.Base.I# rb_B4
    } in  ipv_B3
    }

Test.getC :: Test.Test -> GHC.Base.Int
[GlobalId]
[Arity 1
 NoCafRefs
 Str: DmdType U(L)m]
Test.getC =
  \ (ds_d5Q :: Test.Test) ->
    case ds_d5Q of wild_B1 { Test.Test rb_d5S -> GHC.Base.I# rb_d5S }

After further investigation, it seems that getR is not passed through the optimizer at all, earlier simplifier passes (-ddump-simpl-iterations, -ddump-cse, -ddump-occur-anal) do not include the function.

Trac metadata

Trac field	Value
Version	6.9
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Unknown
Architecture	Unknown