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author | Simon Peyton Jones <simonpj@microsoft.com> | 2017-02-26 21:53:31 -0500 |
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committer | David Feuer <David.Feuer@gmail.com> | 2017-02-26 21:54:30 -0500 |
commit | 4f38fa100091152e6497db384af1fecd628e11e5 (patch) | |
tree | 0c2ab15e62ea6d9023bf6a064e807ca7b16c1f74 /testsuite/tests/perf/should_run | |
parent | e4188b538bfc879b201d416cf1d68ff7072c577f (diff) | |
download | haskell-4f38fa100091152e6497db384af1fecd628e11e5.tar.gz |
Add -fspec-constr-keen
I discovered that the dramatic imprvoement in perf/should_run/T9339
with the introduction of join points was really rather a fluke, and
very fragile.
The real problem (see Note [Making SpecConstr keener]) is that
SpecConstr wasn't specialising a function even though it was applied
to a freshly-allocated constructor. The paper describes plausible
reasons for this, but I think it may well be better to be a bit more
aggressive.
So this patch add -fspec-constr-keen, which makes SpecConstr a bit
keener to specialise, by ignoring whether or not the argument
corresponding to a call pattern is scrutinised in the function body.
Now the gains in T9339 should be robust; and it might even be a
better default.
I'd be interested in what happens if we switched on -fspec-constr-keen
with -O2.
Reviewers: austin, bgamari
Reviewed By: bgamari
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D3186
Diffstat (limited to 'testsuite/tests/perf/should_run')
-rw-r--r-- | testsuite/tests/perf/should_run/all.T | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/testsuite/tests/perf/should_run/all.T b/testsuite/tests/perf/should_run/all.T index efcbb4a30b..2f57613c3a 100644 --- a/testsuite/tests/perf/should_run/all.T +++ b/testsuite/tests/perf/should_run/all.T @@ -462,7 +462,9 @@ test('T9339', # 2016-08-17: 50728 Join points (#12988) only_ways(['normal'])], compile_and_run, - ['-O2']) + ['-O2 -fspec-constr-keen']) + # For the -fspec-constr-keen see Note [Making SpecConstr keener] in SpecConstr + test('T8472', [stats_num_field('bytes allocated', |