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* Compute demand signatures assuming idAritySebastian Graf2019-04-301-4/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This does four things: 1. Look at `idArity` instead of manifest lambdas to decide whether to use LetUp 2. Compute the strictness signature in LetDown assuming at least `idArity` incoming arguments 3. Remove the special case for trivial RHSs, which is subsumed by 2 4. Don't perform the W/W split when doing so would eta expand a binding. Otherwise we would eta expand PAPs, causing unnecessary churn in the Simplifier. NoFib Results -------------------------------------------------------------------------------- Program Allocs Instrs -------------------------------------------------------------------------------- fannkuch-redux +0.3% 0.0% gg -0.0% -0.1% maillist +0.2% +0.2% minimax 0.0% +0.8% pretty 0.0% -0.1% reptile -0.0% -1.2% -------------------------------------------------------------------------------- Min -0.0% -1.2% Max +0.3% +0.8% Geometric Mean +0.0% -0.0%
* Update Trac ticket URLs to point to GitLabRyan Scott2019-03-151-4/+4
| | | | | This moves all URL references to Trac tickets to their corresponding GitLab counterparts.
* Always do the worker/wrapper split for NOINLINEsSebastian Graf2019-03-071-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trac #10069 revealed that small NOINLINE functions didn't get split into worker and wrapper. This was due to `certainlyWillInline` saying that any unfoldings with a guidance of `UnfWhen` inline unconditionally. That isn't the case for NOINLINE functions, so we catch this case earlier now. Nofib results: -------------------------------------------------------------------------------- Program Allocs Instrs -------------------------------------------------------------------------------- fannkuch-redux -0.3% 0.0% gg +0.0% +0.1% maillist -0.2% -0.2% minimax 0.0% -0.8% -------------------------------------------------------------------------------- Min -0.3% -0.8% Max +0.0% +0.1% Geometric Mean -0.0% -0.0% Fixes #10069. ------------------------- Metric Increase: T9233 -------------------------
* Define activeAfterInitial, activeDuringFinalSimon Peyton Jones2018-09-051-2/+2
| | | | | | | This is pure refactoring, just adding a couple of definitions to BasicTypes, and using them. Plus some whitespace stuff.
* Revert "Don't inline functions with RULES too early"Ben Gamari2018-08-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit causes significant performance regressions: ``` bytes allocated value is too high: Expected T9872d(normal) bytes allocated: 578498120 +/-5% Lower bound T9872d(normal) bytes allocated: 549573214 Upper bound T9872d(normal) bytes allocated: 607423026 Actual T9872d(normal) bytes allocated: 677179968 Deviation T9872d(normal) bytes allocated: 17.1 % bytes allocated value is too high: Expected T9872c(normal) bytes allocated: 3096670112 +/-5% Lower bound T9872c(normal) bytes allocated: 2941836606 Upper bound T9872c(normal) bytes allocated: 3251503618 Actual T9872c(normal) bytes allocated: 3601872536 Deviation T9872c(normal) bytes allocated: 16.3 % bytes allocated value is too high: Expected T9872b(normal) bytes allocated: 3730686224 +/-5% Lower bound T9872b(normal) bytes allocated: 3544151912 Upper bound T9872b(normal) bytes allocated: 3917220536 Actual T9872b(normal) bytes allocated: 4374298272 Deviation T9872b(normal) bytes allocated: 17.3 % bytes allocated value is too high: Expected T9872a(normal) bytes allocated: 2729927408 +/-5% Lower bound T9872a(normal) bytes allocated: 2593431037 Upper bound T9872a(normal) bytes allocated: 2866423779 Actual T9872a(normal) bytes allocated: 3225788896 Deviation T9872a(normal) bytes allocated: 18.2 % ``` It's not clear that this was intentional so I'm going to revert for now. This reverts commit 2110738b280543698407924a16ac92b6d804dc36.
* Don't inline functions with RULES too earlySimon Peyton Jones2018-07-311-2/+2
| | | | | | | | | Trac #15445 showed that a function with an automatically generated specialisation RULE coudl be inlined before the RULE had a chance to fire. This patch attaches a NOINLINE[2] activation to the Id, to stop this happening.
* WorkWrap: Rip out unsafeGlobalDynFlags usage in mkWwInlineRuleBen Gamari2018-06-071-1/+1
| | | | | | Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4775
* Do not unpack class dictionaries with INLINABLESimon Peyton Jones2018-04-261-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Matthew Pickering uncovered a bad performance hole in the way that single-method dictionaries work, described in Trac #14955. See Note [Do not unpack class dictionaries] in WwLib. I tried to fix this 6 years ago, but got it slightly wrong. This patch fixes it, which makes a dramatic improvement in the test case. Nofib highlights: not much happening: Program Size Allocs Runtime Elapsed TotalMem ----------------------------------------------------------------- VSM -0.3% +2.7% -7.4% -7.4% 0.0% cacheprof -0.0% +0.1% +0.3% +0.7% 0.0% integer -0.0% +1.1% +7.5% +7.5% 0.0% tak -0.1% -0.2% 0.024 0.024 0.0% ----------------------------------------------------------------- Min -4.4% -0.2% -7.4% -7.4% -8.0% Max +0.6% +2.7% +7.5% +7.5% 0.0% Geom Mean -0.1% +0.0% +0.1% +0.1% -0.2% I investigated VSM. The patch unpacks class dictionaries a bit more than before (i.e. does so if there is no INLINABLE pragma). And that gives better code in VSM (less dictionary selection etc), but one closure gets one word bigger. I'll accept these changes in exchange for more robust performance. Some ghci.debugger output wobbled around (order of bindings being displayed). I have no idea why; but I accepted the changes.
* Inline wrappers earlierSimon Peyton Jones2018-04-201-53/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch has a single significant change: strictness wrapper functions are inlined earlier, in phase 2 rather than phase 0. As shown by Trac #15056, this gives a better chance for RULEs to fire. Before this change, a function that would have inlined early without strictness analyss was instead inlining late. Result: applying "optimisation" made the program worse. This does not make too much difference in nofib, but I've stumbled over the problem more than once, so even a "no-change" result would be quite acceptable. Here are the headlines: -------------------------------------------------------------------------------- Program Size Allocs Runtime Elapsed TotalMem -------------------------------------------------------------------------------- cacheprof -0.5% -0.5% +2.5% +2.5% 0.0% fulsom -1.0% +2.6% -0.1% -0.1% 0.0% mate -0.6% +2.4% -0.9% -0.9% 0.0% veritas -0.7% -23.2% 0.002 0.002 0.0% -------------------------------------------------------------------------------- Min -1.4% -23.2% -12.5% -15.3% 0.0% Max +0.6% +2.6% +4.4% +4.3% +19.0% Geometric Mean -0.7% -0.2% -1.4% -1.7% +0.2% * A worthwhile reduction in binary size. * Runtimes are not to be trusted much but look as if they are moving the right way. * A really big win in veritas, described in comment:1 of Trac #15056; more fusion rules fired. * I investigated the losses in 'mate' and 'fulsom'; see #15056.
* Comments onlySimon Peyton Jones2017-10-031-1/+1
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* A bunch of typofixesGabor Greif2017-09-261-1/+1
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* compiler: introduce custom "GhcPrelude" PreludeHerbert Valerio Riedel2017-09-191-0/+2
| | | | | | | | | | | | | | | | | | This switches the compiler/ component to get compiled with -XNoImplicitPrelude and a `import GhcPrelude` is inserted in all modules. This is motivated by the upcoming "Prelude" re-export of `Semigroup((<>))` which would cause lots of name clashes in every modulewhich imports also `Outputable` Reviewers: austin, goldfire, bgamari, alanz, simonmar Reviewed By: bgamari Subscribers: goldfire, rwbarton, thomie, mpickering, bgamari Differential Revision: https://phabricator.haskell.org/D3989
* Allow CSE'ing of work-wrapped bindings (#14186)Joachim Breitner2017-09-121-1/+5
| | | | | | | | the worker/wrapper creates an artificial INLINE pragma, which caused CSE to not do its work. We now recognize such artificial pragmas by using `NoUserInline` instead of `Inline` as the `InlineSpec`. Differential Revision: https://phabricator.haskell.org/D3939
* Do Worker/Wrapper for NOINLINE thingsEric Seidel2017-02-051-12/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Disabling worker/wrapper for NOINLINE things can cause unnecessary reboxing of values. Consider {-# NOINLINE f #-} f :: Int -> a f x = error (show x) g :: Bool -> Bool -> Int -> Int g True True p = f p g False True p = p + 1 g b False p = g b True p the strictness analysis will discover f and g are strict, but because f has no wrapper, the worker for g will rebox p. So we get $wg x y p# = let p = I# p# in -- Yikes! Reboxing! case x of False -> case y of False -> $wg False True p# True -> +# p# 1# True -> case y of False -> $wg True True p# True -> case f p of { } g x y p = case p of (I# p#) -> $wg x y p# Now, in this case the reboxing will float into the True branch, an so the allocation will only happen on the error path. But it won't float inwards if there are multiple branches that call (f p), so the reboxing will happen on every call of g. Disaster. Solution: do worker/wrapper even on NOINLINE things; but move the NOINLINE pragma to the worker. Test Plan: make test TEST="13143" Reviewers: simonpj, bgamari, dfeuer, austin Reviewed By: simonpj, bgamari Subscribers: dfeuer, thomie Differential Revision: https://phabricator.haskell.org/D3046
* Join pointsLuke Maurer2017-02-011-9/+65
| | | | | | | | | | | | | | | | | | | This major patch implements Join Points, as described in https://ghc.haskell.org/trac/ghc/wiki/SequentCore. You have to read that page, and especially the paper it links to, to understand what's going on; but it is very cool. It's Luke Maurer's work, but done in close collaboration with Simon PJ. This Phab is a squash-merge of wip/join-points branch of http://github.com/lukemaurer/ghc. There are many, many interdependent changes. Reviewers: goldfire, mpickering, bgamari, simonmar, dfeuer, austin Subscribers: simonpj, dfeuer, mpickering, Mikolaj, thomie Differential Revision: https://phabricator.haskell.org/D2853
* Never apply worker/wrapper to DFunsSimon Peyton Jones2016-12-211-7/+3
| | | | | | | | | While fixing Trac #12444 I found an occasion on which we applied worker/wrapper to a DFunId. This is bad: it destroys the magic DFunUnfolding. This patch is a minor refactoring that stops this corner case happening, and tidies up the code a bit too.
* Add HsSyn prettyprinter testsAlan Zimmerman2016-12-071-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Add prettyprinter tests, which take a file, parse it, pretty print it, re-parse the pretty printed version and then compare the original and new ASTs (ignoring locations) Updates haddock submodule to match the AST changes. There are three issues outstanding 1. Extra parens around a context are not reproduced. This will require an AST change and will be done in a separate patch. 2. Currently if an `HsTickPragma` is found, this is not pretty-printed, to prevent noise in the output. I am not sure what the desired behaviour in this case is, so have left it as before. Test Ppr047 is marked as expected fail for this. 3. Apart from in a context, the ParsedSource AST keeps all the parens from the original source. Something is happening in the renamer to remove the parens around visible type application, causing T12530 to fail, as the dumped splice decl is after the renamer. This needs to be fixed by keeping the parens, but I do not know where they are being removed. I have amended the test to pass, by removing the parens in the expected output. Test Plan: ./validate Reviewers: goldfire, mpickering, simonpj, bgamari, austin Reviewed By: simonpj, bgamari Subscribers: simonpj, goldfire, thomie, mpickering Differential Revision: https://phabricator.haskell.org/D2752 GHC Trac Issues: #3384
* Fix shadowing in mkWwBodiesSimon Peyton Jones2016-10-171-1/+3
| | | | | | | | | | | | | | | | | | This bug, exposed by Trac #12562 was very obscure, and has been lurking for a long time. What happened was that, in the worker/wrapper split a tyvar binder for a worker function accidentally shadowed an in-scope term variable that was mentioned in the body of the function It's jolly hard to provoke, so I have not even attempted to make a test case. There's a Note [Freshen WW arguments] to explain. Interestingly, fixing the bug (which meant fresher type variables) revealed a second lurking bug: I'd failed to apply the substitution to the coercion in the second last case of mkWWArgs, which introduces a Cast.
* Comments onlySimon Peyton Jones2016-04-151-8/+5
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* Add a final demand analyzer run right before TidyCoreJoachim Breitner2016-04-141-20/+59
| | | | | | | | | | | | | | | | | | in order to have precise used-once information in the exported strictness signatures, as well as precise used-once information on thunks. This avoids the bad effects of #11731. The subsequent worker-wrapper pass is responsible for removing the demand environment part of the strictness signature. It does not run after the final demand analyzer pass, so remove this also in CoreTidy. The subsequent worker-wrapper pass is also responsible for removing used-once-information from the demands and strictness signatures, as these might not be preserved by the simplifier. This is _not_ done by CoreTidy, because we _do_ want this information, as produced by the last round of the demand analyzer, to be available to the code generator. Differential Revision: https://phabricator.haskell.org/D2073
* Demand Analyzer: Do not set OneShot information (second try)Joachim Breitner2016-04-061-15/+45
| | | | | | | | | | | | | | | | | | | | | as suggested in ticket:11770#comment:1. This code was buggy (#11770), and the occurrence analyzer does the same job anyways. This also elaborates the notes in the occurrence analyzer accordingly. Previously, the worker/wrapper code would go through lengths to transfer the oneShot annotations from the original function to both the worker and the wrapper. We now simply transfer the demand on the worker, and let the subsequent occurrence analyzer push this onto the lambda binders. This also requires the occurrence analyzer to do this more reliably. Previously, it would not hand out OneShot annotatoins to things that would not `certainly_inline` (and it might not have mattered, as the Demand Analysis might have handed out the annotations). Now we hand out one-shot annotations unconditionally. Differential Revision: https://phabricator.haskell.org/D2085
* Work SourceText in for all integer literalsAlan Zimmerman2016-01-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Certain syntactic elements have integers in them, such as fixity specifications, SPECIALISE pragmas and so on. The lexer will accept mult-radix literals, with arbitrary leading zeros in these. Bring in a SourceText field to each affected AST element to capture the original literal text for use with API Annotations. Affected hsSyn elements are ``` -- See note [Pragma source text] data Activation = NeverActive | AlwaysActive | ActiveBefore SourceText PhaseNum -- Active only *strictly before* this phase | ActiveAfter SourceText PhaseNum -- Active in this phase and later deriving( Eq, Data, Typeable ) -- Eq used in comparing rules in HsDecls data Fixity = Fixity SourceText Int FixityDirection -- Note [Pragma source text] deriving (Data, Typeable) ``` and ``` | HsTickPragma -- A pragma introduced tick SourceText -- Note [Pragma source text] in BasicTypes (StringLiteral,(Int,Int),(Int,Int)) -- external span for this tick ((SourceText,SourceText),(SourceText,SourceText)) -- Source text for the four integers used in the span. -- See note [Pragma source text] in BasicTypes (LHsExpr id) ``` Updates haddock submodule Test Plan: ./validate Reviewers: goldfire, bgamari, austin Reviewed By: bgamari Subscribers: thomie, mpickering Differential Revision: https://phabricator.haskell.org/D1781 GHC Trac Issues: #11430
* Make demand analysis understand catchSimon Peyton Jones2016-01-071-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As Trac #11222, and #10712 note, the strictness analyser needs to be rather careful about exceptions. Previously it treated them as identical to divergence, but that won't quite do. See Note [Exceptions and strictness] in Demand, which explains the deal. Getting more strictness in 'catch' and friends is a very good thing. Here is the nofib summary, keeping only the big ones. -------------------------------------------------------------------------------- Program Size Allocs Runtime Elapsed TotalMem -------------------------------------------------------------------------------- fasta -0.1% -6.9% -3.0% -3.0% +0.0% hpg -0.1% -2.0% -6.2% -6.2% +0.0% maillist -0.1% -0.3% 0.08 0.09 +1.2% reverse-complem -0.1% -10.9% -6.0% -5.9% +0.0% sphere -0.1% -4.3% 0.08 0.08 +0.0% x2n1 -0.1% -0.0% 0.00 0.00 +0.0% -------------------------------------------------------------------------------- Min -0.2% -10.9% -17.4% -17.3% +0.0% Max -0.0% +0.0% +4.3% +4.4% +1.2% Geometric Mean -0.1% -0.3% -2.9% -3.0% +0.0% On the way I did quite a bit of refactoring in Demand.hs
* API Annotations tweaks.Alan Zimmerman2015-01-161-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: HsTyLit now has SourceText Update documentation of HsSyn to reflect which annotations are attached to which element. Ensure that the parser always keeps HsSCC and HsTickPragma values, to be ignored in the desugar phase if not needed Bringing in SourceText for pragmas Add Location in NPlusKPat Add Location in FunDep Make RecCon payload Located Explicitly add AnnVal to RdrName where it is compound Add Location in IPBind Add Location to name in IEThingAbs Add Maybe (Located id,Bool) to Match to track fun_id,infix This includes converting Match into a record and adding a note about why the fun_id needs to be replicated in the Match. Add Location in KindedTyVar Sort out semi-colons for parsing - import statements - stmts - decls - decls_cls - decls_inst This updates the haddock submodule. Test Plan: ./validate Reviewers: hvr, austin, goldfire, simonpj Reviewed By: simonpj Subscribers: thomie, carter Differential Revision: https://phabricator.haskell.org/D538
* unlit compiler/stranal/ modulesHerbert Valerio Riedel2014-12-011-0/+476
Reviewed By: austin Differential Revision: https://phabricator.haskell.org/D541