What GHC optimization is responsible for duplicating case expressions?

Given the following code:

{-# OPTIONS_GHC -funbox-strict-fields #-}
module Test where

data X = X !Int !Int

test (X a b) (X c d) = X (max a c) (max b d)

GHC generates this core when compiling with optimizations (renamed to make reading easier):

test
test =
  \ u v ->
    case u of x { X y z ->
    case v of c { X d e ->
    case tagToEnum# (<=# y d) of _ {
      False ->
        case tagToEnum# (<=# z e) of _ {
          False -> x;
          True -> X y e
        };
      True ->
        case tagToEnum# (<=# z e) of _ {
          False -> X d z;
          True -> c
        }
    }
    }
    }

Note how GHC has generated in total 4 different code paths. In general, the number of code paths grows exponentially with the number of conditions.

What GHC optimization leads to that behavior? Is there a flag to control this optimization? In my case, this generates huge code bloat, and makes core dumps very hard to read because of deeply nested case expressions.