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| author | Tobias Dammers <tdammers@gmail.com> | 2018-04-20 16:38:34 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2018-04-20 18:04:19 -0400 |
| commit | 2a5bdd9adb1cb4afecd3303f0cfcc224be5ce745 (patch) | |
| tree | bc8b6294660537075f811d98f9ff804cc6a6d4fb | |
| parent | da7438526e4bfb1821aa77a22ff66a4a80baf8c6 (diff) | |
| download | haskell-2a5bdd9adb1cb4afecd3303f0cfcc224be5ce745.tar.gz | |
Remove unnecessary check in simplCast
The coercion optimizer will take care of it anyway, and the check is
prohibitively expensive.
See Trac #14737.
Reviewers: bgamari
Subscribers: simonpj, thomie, carter
Differential Revision: https://phabricator.haskell.org/D4568
| -rw-r--r-- | compiler/coreSyn/CoreOpt.hs | 12 | ||||
| -rw-r--r-- | testsuite/tests/perf/compiler/all.T | 12 |
2 files changed, 16 insertions, 8 deletions
diff --git a/compiler/coreSyn/CoreOpt.hs b/compiler/coreSyn/CoreOpt.hs index 372c2ea5aa..f1ff68d133 100644 --- a/compiler/coreSyn/CoreOpt.hs +++ b/compiler/coreSyn/CoreOpt.hs @@ -958,8 +958,10 @@ pushCoTyArg :: CoercionR -> Type -> Maybe (Type, Maybe CoercionR) -- If the returned coercion is Nothing, then it would have been reflexive; -- it's faster not to compute it, though. pushCoTyArg co ty - | tyL `eqType` tyR - = Just (ty, Nothing) + -- The following is inefficient - don't do `eqType` here, the coercion + -- optimizer will take care of it. See Trac #14737. + -- -- | tyL `eqType` tyR + -- -- = Just (ty, Nothing) | isForAllTy tyL = ASSERT2( isForAllTy tyR, ppr co $$ ppr ty ) @@ -991,8 +993,10 @@ pushCoValArg :: CoercionR -> Maybe (Coercion, Maybe Coercion) -- If the second returned Coercion is actually Nothing, then no cast is necessary; -- the returned coercion would have been reflexive. pushCoValArg co - | tyL `eqType` tyR - = Just (mkRepReflCo arg, Nothing) + -- The following is inefficient - don't do `eqType` here, the coercion + -- optimizer will take care of it. See Trac #14737. + -- -- | tyL `eqType` tyR + -- -- = Just (mkRepReflCo arg, Nothing) | isFunTy tyL , (co1, co2) <- decomposeFunCo Representational co diff --git a/testsuite/tests/perf/compiler/all.T b/testsuite/tests/perf/compiler/all.T index ba36b4197e..2001cda637 100644 --- a/testsuite/tests/perf/compiler/all.T +++ b/testsuite/tests/perf/compiler/all.T @@ -747,7 +747,7 @@ test('T9020', # 2014-07-31: 343005716 (Windows) (general round of updates) # 2017-03-24: 249904136 (x86/Linux, 64-bit machine) - (wordsize(64), 423163832, 10)]) + (wordsize(64), 562206104, 10)]) # prev: 795469104 # 2014-07-17: 728263536 (general round of updates) # 2014-09-10: 785871680 post-AMP-cleanup @@ -761,6 +761,7 @@ test('T9020', # Program size collapses in first simplification # 2017-03-31: 493596312 Fix memory leak in simplifier # 2017-04-28: 423163832 Remove exponential behaviour in simplifier + # 2018-04-09: 562206104 Inexplicable, collateral of #14737 ], compile,['']) @@ -1039,7 +1040,7 @@ test('T12227', test('T12425', [ only_ways(['optasm']), compiler_stats_num_field('bytes allocated', - [(wordsize(64), 134780272, 5), + [(wordsize(64), 141952368, 5), # initial: 125831400 # 2017-01-18: 133380960 Allow top-level string literals in Core # 2017-02-17: 153611448 Type-indexed Typeable @@ -1047,6 +1048,7 @@ test('T12425', # 2017-03-21: 134334800 Unclear # 2017-04-28: 127500136 Remove exponential behaviour in simplifier # 2017-05-23: 134780272 Addition of llvm-targets in dynflags (D3352) + # 2018-04-15: 141952368 Collateral of #14737 ]), ], compile, @@ -1116,7 +1118,7 @@ test('T13056', test('T12707', [ compiler_stats_num_field('bytes allocated', - [(wordsize(64), 1163821528, 5), + [(wordsize(64), 1237898376, 5), # initial: 1271577192 # 2017-01-22: 1348865648 Allow top-level strings in Core # 2017-01-31: 1280336112 Join points (#12988) @@ -1124,6 +1126,7 @@ test('T12707', # 2017-02-23: 1386110512 Type-indexed Typeable? (on Darwin) # 2017-03-02: 1231809592 Drift from recent simplifier improvements # 2017-05-14: 1163821528 (amd64/Linux) Two-pass CmmLayoutStack + # 2018-04-09: 1237898376 Inexplicable, collateral of #14737 ]), ], compile, @@ -1235,9 +1238,10 @@ test('T14697', test('T14683', [ compiler_stats_num_field('bytes allocated', - [(wordsize(64), 14675353056, 10), + [(wordsize(64), 10521594688, 10), # initial: 25189145632 # 2018-04-19: 14675353056 Cache NthCo role (#14683) + # 2018-04-20: 10521594688 Remove unnecessary check in simplCast ]), ], multimod_compile, |