1 files changed, 15 insertions, 0 deletions
diff --git a/testsuite/tests/perf/should_run/T4830.hs b/testsuite/tests/perf/should_run/T4830.hs
new file mode 100644
index 0000000000..e345ffc9cd
--- /dev/null
+++ b/testsuite/tests/perf/should_run/T4830.hs
@@ -0,0 +1,15 @@
+-- Compile with O2; SpecConstr should fire nicely
+-- and eliminate all allocation in inner loop
+
+module Main where
+
+foo :: Int -> Maybe (Double,Double) -> Double
+foo _ Nothing      = 0
+foo 0 (Just (x,y)) = x+y
+foo n (Just (x,y)) = let r = f x y in r `seq` foo (n-1) (Just r)
+  where
+    f x y | x <= y    = (x,y)
+          | otherwise = (y,x)
+
+main = print (foo 1000000 (Just (1,2)))
+