Add compiler perf regression test for #9198wip/9198

2 files changed, 16 insertions, 0 deletions

diff --git a/testsuite/tests/perf/compiler/T9198.hs b/testsuite/tests/perf/compiler/T9198.hs
new file mode 100644
index 0000000000..11d3ae4a0d
--- /dev/null
+++ b/testsuite/tests/perf/compiler/T9198.hs
@@ -0,0 +1,12 @@
+-- Type checking time for this test used to be quadratic in the number of `a`s
+-- in `main` from GHC 7.8 to 8.6. It appears to have been fixed in 8.8.
+begin :: Monad m => (m () -> t) -> t
+begin cont = cont (return ())
+
+a :: IO a -> (IO () -> t) -> t
+a m cont = cont (m >> putStrLn "a")
+
+end :: t -> t
+end m = m
+
+main = begin a a a a a a a a a a a a a a a a a a end
diff --git a/testsuite/tests/perf/compiler/all.T b/testsuite/tests/perf/compiler/all.T
index 5fde44d7ea..937858c2a7 100644
--- a/testsuite/tests/perf/compiler/all.T
+++ b/testsuite/tests/perf/compiler/all.T
@@ -448,3 +448,7 @@ test ('T16577',
       [ collect_compiler_stats('bytes allocated',2) ],
       compile,
       ['-v0 -O'])
+test ('T9198',
+      [ collect_compiler_stats('bytes allocated',2) ],
+      compile,
+      [''])