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| author | Sebastian Graf <sebastian.graf@kit.edu> | 2022-12-02 16:46:45 +0100 |
|---|---|---|
| committer | Sebastian Graf <sebastian.graf@kit.edu> | 2022-12-06 16:23:53 +0100 |
| commit | 4bb308efc01bf290269d776c74deb4ede7b24902 (patch) | |
| tree | b7b00e163463a26cfb5d088eb9d877f75b215ed2 /testsuite/tests/perf/should_run | |
| parent | a9d9b8c0458e838f331ead62dca272665ecbf20d (diff) | |
| download | haskell-4bb308efc01bf290269d776c74deb4ede7b24902.tar.gz | |
Make `drop` and `dropWhile` fuse (#18964)wip/T18964
I copied the fusion framework we have in place for `take`.
T18964 asserts that we regress neither when fusion fires nor when it doesn't.
Fixes #18964.
Diffstat (limited to 'testsuite/tests/perf/should_run')
| -rw-r--r-- | testsuite/tests/perf/should_run/T18964.hs | 15 | ||||
| -rw-r--r-- | testsuite/tests/perf/should_run/T18964.stdout | 4 | ||||
| -rw-r--r-- | testsuite/tests/perf/should_run/all.T | 2 |
3 files changed, 21 insertions, 0 deletions
diff --git a/testsuite/tests/perf/should_run/T18964.hs b/testsuite/tests/perf/should_run/T18964.hs new file mode 100644 index 0000000000..e9c7b915e7 --- /dev/null +++ b/testsuite/tests/perf/should_run/T18964.hs @@ -0,0 +1,15 @@ +import GHC.Exts +import Data.Int + +main :: IO () +main = do + -- drop should fuse away and the program should consume O(1) space + -- If fusion fails, this allocates about 640MB. + print $ sum $ drop 10 [0..10000000::Int64] + -- Here, drop can't fuse. This asserts that we don't regress in allocations in that case either + -- If we don't do a good job here, we'll see more than 6.4MB of allocs. + print $ lazy $ sum $ lazy $ drop 10 $ lazy [0..100000::Int64] + + -- and once more with dropWhile + print $ sum $ dropWhile (< 10) [0..10000000::Int64] + print $ lazy $ sum $ lazy $ dropWhile (< 10) $ lazy [0..100000::Int64] diff --git a/testsuite/tests/perf/should_run/T18964.stdout b/testsuite/tests/perf/should_run/T18964.stdout new file mode 100644 index 0000000000..b1c0d38f19 --- /dev/null +++ b/testsuite/tests/perf/should_run/T18964.stdout @@ -0,0 +1,4 @@ +50000004999955 +5000049955 +50000004999955 +5000049955 diff --git a/testsuite/tests/perf/should_run/all.T b/testsuite/tests/perf/should_run/all.T index 59ad878a4c..ba75906c7d 100644 --- a/testsuite/tests/perf/should_run/all.T +++ b/testsuite/tests/perf/should_run/all.T @@ -408,3 +408,5 @@ test('T21839r', only_ways(['normal'])], compile_and_run, ['-O']) + +test('T18964', [collect_stats('bytes allocated', 1), only_ways(['normal'])], compile_and_run, ['-O']) |