Compiled code performance regression
Upgrading from ghc 7.6 to 7.8 has slowed down our main application noticeably. This is with 32-bit Windows.
Here's some 7.2 numbers:
INIT time 0.00s ( 0.00s elapsed)
MUT time 287.78s (290.41s elapsed)
GC time 87.39s ( 88.43s elapsed)
EXIT time 0.00s ( 0.00s elapsed)
Total time 375.63s (378.86s elapsed)
And corresponding 7.8 numbers:
INIT time 0.00s ( 0.00s elapsed)
MUT time 298.34s (301.35s elapsed)
GC time 88.16s ( 89.27s elapsed)
EXIT time 0.00s ( 0.00s elapsed)
Total time 386.93s (390.62s elapsed)
This is not unexpected since every ghc upgrade so far has slowed down our code; it's just following the trend we expect.