In 8.2.1-rc1 loading a file compiled with -O2 into ghci results in ghci recompiling the file into interpreted byte code. In 8.0.2 it simply loads the compiled object file.

1. 2.1

 ghc -dynamic -O2 eh2.hs
[1 of 1] Compiling Main             ( eh2.hs, eh2.o )
Linking eh2 ...
bash-3.2$ ghci -ignore-dot-ghci
GHCi, version 8.2.0.20170404: http://www.haskell.org/ghc/  :? for help
Prelude> :load eh2
[1 of 1] Compiling Main             ( eh2.hs, interpreted ) [flags changed]
Ok, modules loaded: Main.

1. 0.2

 ghc --version
The Glorious Glasgow Haskell Compilation System, version 8.0.2
bash-3.2$ pwd
/Users/gcolpitts/haskell
bash-3.2$ ghc -dynamic -O2 eh2.hs
[1 of 1] Compiling Main             ( eh2.hs, eh2.o )
Linking eh2 ...
bash-3.2$ ghci -ignore-dot-ghci
GHCi, version 8.0.2: http://www.haskell.org/ghc/  :? for help
Prelude> :load eh2
Ok, modules loaded: Main (eh2.o).