1 files changed, 39 insertions, 0 deletions
diff --git a/testsuite/tests/simplCore/should_run/T4814.hs b/testsuite/tests/simplCore/should_run/T4814.hs
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+++ b/testsuite/tests/simplCore/should_run/T4814.hs
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+-- This test exposes the bug in GHC 7.0.1 (and earlier)
+-- which did the following rule rewrite:
+--
+--    f (let v = 2 in g v) (let v = 3 in g v)
+--    --->  let v = 2 in let v = 3 in g v + g v
+--
+-- which is wrong because of the shadowing of v
+
+module Main where
+foo :: Int -> Int
+{-# INLINE foo #-}
+foo x = g (bar (x,x))
+
+bar :: (Int,Int) -> Int
+{-# NOINLINE bar #-}
+bar (x,y) = x
+
+baz :: Int -> Int
+{-# NOINLINE baz #-}
+baz x = x
+
+f :: Int -> Int -> Int
+{-# NOINLINE f #-}
+f x y = x+y
+
+g :: Int -> Int
+{-# NOINLINE g #-}
+g x = x
+
+{-# RULES
+
+ "f/g" [1] forall x y. f (g x) (g y) = x + y
+
+ #-}
+
+main = print $ f (foo (baz 1)) (foo (baz 2))
+-- Should print 3
+-- Bug means that it prints 4
+