[commit: testsuite] master: Add a performance test for #2762 (8749522)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/testsuite

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/87495227dfa630173bf503ad393439ac7a3d0da3

>---------------------------------------------------------------

commit 87495227dfa630173bf503ad393439ac7a3d0da3
Author: Ian Lynagh <igloo at earth.li>
Date:   Sun Apr 17 13:34:31 2011 +0100

    Add a performance test for #2762

>---------------------------------------------------------------

 tests/ghc-regress/perf/space_leaks/T2762.hs  |   18 ++++++++++++++++++
 tests/ghc-regress/perf/space_leaks/T2762A.hs |   15 +++++++++++++++
 tests/ghc-regress/perf/space_leaks/all.T     |    8 ++++++++
 3 files changed, 41 insertions(+), 0 deletions(-)

diff --git a/tests/ghc-regress/perf/space_leaks/T2762.hs b/tests/ghc-regress/perf/space_leaks/T2762.hs
new file mode 100644
index 0000000..76ab045
--- /dev/null
+++ b/tests/ghc-regress/perf/space_leaks/T2762.hs
@@ -0,0 +1,18 @@
+
+module Main (main) where
+
+import T2762A
+
+main :: IO ()
+main = do
+          let content1 = concat (replicate 1000000 "1x") ++ "0"
+          let i1 = fst $ input content1
+          view i1
+
+          let content2 = concat (replicate 1000001 "1y") ++ "0"
+          let i2 = fst $ input content2
+          view i2
+
+view :: [Char] -> IO ()
+view [] = return ()
+view (i : is) = i `seq` view is
diff --git a/tests/ghc-regress/perf/space_leaks/T2762A.hs b/tests/ghc-regress/perf/space_leaks/T2762A.hs
new file mode 100644
index 0000000..665fa6e
--- /dev/null
+++ b/tests/ghc-regress/perf/space_leaks/T2762A.hs
@@ -0,0 +1,15 @@
+
+module T2762A (input) where
+
+class InputOutput a where
+    input :: String -> (a, String)
+
+instance InputOutput Char where
+    input (x : bs) = (x, bs)
+
+instance InputOutput a => InputOutput [a] where
+    input ('0':bs) = ([], bs)
+    input ('1':bs) = case input bs of
+                     (x, bs') ->
+                         case input bs' of
+                         ~(xs, bs'') -> (x : xs, bs'')
diff --git a/tests/ghc-regress/perf/space_leaks/all.T b/tests/ghc-regress/perf/space_leaks/all.T
index 7be1aaa..809ec01 100644
--- a/tests/ghc-regress/perf/space_leaks/all.T
+++ b/tests/ghc-regress/perf/space_leaks/all.T
@@ -29,3 +29,11 @@ test('T4334',
       omit_ways(['profasm','profthreaded'])
       ],
      compile_and_run, [''])
+
+test('T2762',
+     [# peak_megabytes_allocated is 2 with 7.0.2.
+      # Was 57 with 6.12.3.
+      stats_num_field('peak_megabytes_allocated', 1, 3),
+      only_ways(['normal']),
+      extra_clean(['T2762A.hi', 'T2762A.o'])],
+     compile_and_run, ['-O'])