diff options
| author | Simon Peyton Jones <simonpj@microsoft.com> | 2014-11-03 10:37:59 +0000 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2014-11-04 10:38:07 +0000 |
| commit | ce9d6f251f9764f769f5ebd8c6130809b6b0d159 (patch) | |
| tree | 4c057fda19ba1db2e25d2ffcb1aa100e19958417 | |
| parent | f02c915c1583e40d614dfd97047d5117a9b8a9a5 (diff) | |
| download | haskell-ce9d6f251f9764f769f5ebd8c6130809b6b0d159.tar.gz | |
Compiler performance is much worse in for loopy givens
This is a deliberate choice, to simplify code, invariants, and I think
performance in typical cases. The "loopy givens" case is situations like
[G] a ~ TF (a, Int)
where TF is a type function with TF (a,b) = (TF a, TF b).
See Note [An alternative story for the inert substitution] in TcFlatten.
| -rw-r--r-- | testsuite/tests/perf/compiler/T5837.hs | 40 | ||||
| -rw-r--r-- | testsuite/tests/perf/compiler/all.T | 4 |
2 files changed, 38 insertions, 6 deletions
diff --git a/testsuite/tests/perf/compiler/T5837.hs b/testsuite/tests/perf/compiler/T5837.hs index 1dc3c33cd9..6ebbd65bd5 100644 --- a/testsuite/tests/perf/compiler/T5837.hs +++ b/testsuite/tests/perf/compiler/T5837.hs @@ -10,14 +10,44 @@ t = undefined {- - [G] a ~ TF (a,Int) + [G] a ~ TF (a,Int) -- a = a_am1 --> - TF (a,Int) ~ fsk - fsk ~ a + [G] TF (a,Int) ~ fsk -- fsk = fsk_am8 +inert [G] fsk ~ a + ---> - fsk ~ (TF a, TF Int) - fsk ~ a + [G] fsk ~ (TF a, TF Int) +inert [G] fsk ~ a + ---> a ~ (TF a, TF Int) +inert [G] fsk ~ a + +---> (attempting to flatten (TF a) so that it does not mention a + TF a ~ fsk2 +inert a ~ (fsk2, TF Int) +inert fsk ~ (fsk2, TF Int) + +---> (substitute for a) + TF (fsk2, TF Int) ~ fsk2 +inert a ~ (fsk2, TF Int) +inert fsk ~ (fsk2, TF Int) + +---> (top-level reduction, re-orient) + fsk2 ~ (TF fsk2, TF Int) +inert a ~ (fsk2, TF Int) +inert fsk ~ (fsk2, TF Int) + +---> (attempt to flatten (TF fsk2) to get rid of fsk2 + TF fsk2 ~ fsk3 + fsk2 ~ (fsk3, TF Int) +inert a ~ (fsk2, TF Int) +inert fsk ~ (fsk2, TF Int) + +---> + TF fsk2 ~ fsk3 +inert fsk2 ~ (fsk3, TF Int) +inert a ~ ((fsk3, TF Int), TF Int) +inert fsk ~ ((fsk3, TF Int), TF Int) -}
\ No newline at end of file diff --git a/testsuite/tests/perf/compiler/all.T b/testsuite/tests/perf/compiler/all.T index 76aee352b1..6df8210dee 100644 --- a/testsuite/tests/perf/compiler/all.T +++ b/testsuite/tests/perf/compiler/all.T @@ -455,7 +455,7 @@ test('T5837', # 40000000 (x86/Linux) # 2013-11-13: 45520936 (x86/Windows, 64bit machine) # 2041-09-03: 37096484 (Windows laptop, w/w for INLINABLE things - (wordsize(64), 75765728, 10)]) + (wordsize(64), 651924880, 10)]) # sample: 3926235424 (amd64/Linux, 15/2/2012) # 2012-10-02 81879216 # 2012-09-20 87254264 amd64/Linux @@ -464,6 +464,8 @@ test('T5837', # for constraints solving # 2014-08-29 73639840 amd64/Linux, w/w for INLINABLE things # 2014-10-08 73639840 amd64/Linux, Burning Bridges and other small changes + # 2014-11-02 651924880 Linux, Accept big regression; + # See Note [An alternative story for the inert substitution] in TcFlatten ], compile_fail,['-ftype-function-depth=50']) |