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GHC doesn't quite implement the new cost-centre stack semantics correctly. e.g.

{-# NOINLINE f #-}
f :: Int -> Int
f = {-# SCC f #-} g

{-# NOINLINE g #-}
g :: Int -> Int
g x = {-# SCC g #-} x + 1

main = print (f 3)

What we want is

 CAF        Main                    106           0    0.0    0.7     0.0   21.7
  f         Main                    201           1    0.0    0.0     0.0    0.0
  main      Main                    200           1    0.0   20.9     0.0   21.0
   f        Main                    202           0    0.0    0.0     0.0    0.1
    g       Main                    203           1    0.0    0.1     0.0    0.1

but we get

 CAF        Main                    106           0    0.0    0.7     0.0   21.6
  f         Main                    201           1    0.0    0.0     0.0    0.0
  main      Main                    200           1    0.0   20.9     0.0   20.9
   g        Main                    202           1    0.0    0.0     0.0    0.0

The original flat CC profiler used to use IND_PERM indirections to handle this kind of thing, but we aren't doing that now.

Trac metadata

Trac field	Value
Version	7.2.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Profiling
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture