[Git][ghc/ghc][wip/T18502] 13 commits: Improve NegativeLiterals (#18022, GHC Proposal #344)
Simon Peyton Jones
gitlab at gitlab.haskell.org
Tue Jul 28 09:14:56 UTC 2020
Simon Peyton Jones pushed to branch wip/T18502 at Glasgow Haskell Compiler / GHC
Commits:
aee45d9e by Vladislav Zavialov at 2020-07-27T07:06:56-04:00
Improve NegativeLiterals (#18022, GHC Proposal #344)
Before this patch, NegativeLiterals used to parse x-1 as x (-1).
This may not be what the user expects, and now it is fixed:
x-1 is parsed as (-) x 1.
We achieve this by the following requirement:
* When lexing a negative literal,
it must not be preceded by a 'closing token'.
This also applies to unboxed literals, e.g. -1#.
See GHC Proposal #229 for the definition of a closing token.
A nice consequence of this change is that -XNegativeLiterals becomes a
subset of -XLexicalNegation. In other words, enabling both of those
extensions has the same effect as enabling -XLexicalNegation alone.
- - - - -
667ab69e by leiftw at 2020-07-27T07:07:32-04:00
fix typo referring to non-existent `-ohidir` flag, should be `-hidir` I think
- - - - -
6ff89c17 by Vladislav Zavialov at 2020-07-27T07:08:07-04:00
Refactor the parser a little
* Create a dedicated production for type operators
* Create a dedicated type for the UNPACK pragma
* Remove an outdated part of Note [Parsing data constructors is hard]
- - - - -
aa054d32 by Ben Gamari at 2020-07-27T20:09:07-04:00
Drop 32-bit Windows support
As noted in #18487, we have reached the end of this road.
- - - - -
6da73bbf by Michalis Pardalos at 2020-07-27T20:09:44-04:00
Add minimal test for #12492
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47680cb7 by Michalis Pardalos at 2020-07-27T20:09:44-04:00
Use allocate, not ALLOC_PRIM_P for unpackClosure#
ALLOC_PRIM_P fails for large closures, by directly using allocate
we can handle closures which are larger than the block size.
Fixes #12492
- - - - -
3d345c96 by Simon Peyton Jones at 2020-07-27T20:10:19-04:00
Eta-expand the Simplifier monad
This patch eta-expands the Simplifier's monad, using the method
explained in GHC.Core.Unify Note [The one-shot state monad trick].
It's part of the exta-expansion programme in #18202.
It's a tiny patch, but is worth a 1-2% reduction in bytes-allocated
by the compiler. Here's the list, based on the compiler-performance
tests in perf/compiler:
Reduction in bytes allocated
T10858(normal) -0.7%
T12425(optasm) -1.3%
T13056(optasm) -1.8%
T14683(normal) -1.1%
T15164(normal) -1.3%
T15630(normal) -1.4%
T17516(normal) -2.3%
T18282(normal) -1.6%
T18304(normal) -0.8%
T1969(normal) -0.6%
T4801(normal) -0.8%
T5321FD(normal) -0.7%
T5321Fun(normal) -0.5%
T5642(normal) -0.9%
T6048(optasm) -1.1%
T9020(optasm) -2.7%
T9233(normal) -0.7%
T9675(optasm) -0.5%
T9961(normal) -2.9%
WWRec(normal) -1.2%
Metric Decrease:
T12425
T9020
T9961
- - - - -
57aca6bb by Ben Gamari at 2020-07-27T20:10:54-04:00
gitlab-ci: Ensure that Hadrian jobs don't download artifacts
Previously the Hadrian jobs had the default dependencies, meaning that
they would download artifacts from all jobs of earlier stages. This is
unneccessary.
- - - - -
0a815cea by Ben Gamari at 2020-07-27T20:10:54-04:00
gitlab-ci: Bump bootstrap compiler to 8.8.4
Hopefully this will make the Windows jobs a bit more reliable.
- - - - -
0bd60059 by Simon Peyton Jones at 2020-07-28T02:01:49-04:00
This patch addresses the exponential blow-up in the simplifier.
Specifically:
#13253 exponential inlining
#10421 ditto
#18140 strict constructors
#18282 another nested-function call case
This patch makes one really significant changes: change the way that
mkDupableCont handles StrictArg. The details are explained in
GHC.Core.Opt.Simplify Note [Duplicating StrictArg].
Specific changes
* In mkDupableCont, when making auxiliary bindings for the other arguments
of a call, add extra plumbing so that we don't forget the demand on them.
Otherwise we haev to wait for another round of strictness analysis. But
actually all the info is to hand. This change affects:
- Make the strictness list in ArgInfo be [Demand] instead of [Bool],
and rename it to ai_dmds.
- Add as_dmd to ValArg
- Simplify.makeTrivial takes a Demand
- mkDupableContWithDmds takes a [Demand]
There are a number of other small changes
1. For Ids that are used at most once in each branch of a case, make
the occurrence analyser record the total number of syntactic
occurrences. Previously we recorded just OneBranch or
MultipleBranches.
I thought this was going to be useful, but I ended up barely
using it; see Note [Note [Suppress exponential blowup] in
GHC.Core.Opt.Simplify.Utils
Actual changes:
* See the occ_n_br field of OneOcc.
* postInlineUnconditionally
2. I found a small perf buglet in SetLevels; see the new
function GHC.Core.Opt.SetLevels.hasFreeJoin
3. Remove the sc_cci field of StrictArg. I found I could get
its information from the sc_fun field instead. Less to get
wrong!
4. In ArgInfo, arrange that ai_dmds and ai_discs have a simpler
invariant: they line up with the value arguments beyond ai_args
This allowed a bit of nice refactoring; see isStrictArgInfo,
lazyArgcontext, strictArgContext
There is virtually no difference in nofib. (The runtime numbers
are bogus -- I tried a few manually.)
Program Size Allocs Runtime Elapsed TotalMem
--------------------------------------------------------------------------------
fft +0.0% -2.0% -48.3% -49.4% 0.0%
multiplier +0.0% -2.2% -50.3% -50.9% 0.0%
--------------------------------------------------------------------------------
Min -0.4% -2.2% -59.2% -60.4% 0.0%
Max +0.0% +0.1% +3.3% +4.9% 0.0%
Geometric Mean +0.0% -0.0% -33.2% -34.3% -0.0%
Test T18282 is an existing example of these deeply-nested strict calls.
We get a big decrease in compile time (-85%) because so much less
inlining takes place.
Metric Decrease:
T18282
- - - - -
6ee07b49 by Sylvain Henry at 2020-07-28T02:02:27-04:00
Bignum: add support for negative shifts (fix #18499)
shiftR/shiftL support negative arguments despite Haskell 2010 report
saying otherwise. We explicitly test for negative values which is bad
(it gets in the way of constant folding, etc.). Anyway, for consistency
we fix Bits instancesof Integer/Natural.
- - - - -
f305bbfd by Peter Trommler at 2020-07-28T02:03:02-04:00
config: Fix Haskell platform constructor w/ params
Fixes #18505
- - - - -
49d8597c by Simon Peyton Jones at 2020-07-28T10:14:32+01:00
Add two bangs to improve perf of flattening
This tiny patch improves the compile time of flatten-heavy
programs by 1-2%, by adding two bangs.
Addresses (somewhat) #18502
This reduces allocation by
T9872b -1.1%
T9872d -3.3%
T5321Fun -0.2%
T5631 -0.2%
T5837 +0.1%
T6048 +0.1%
Metric Decrease:
T9872b
T9872d
- - - - -
30 changed files:
- .gitlab-ci.yml
- aclocal.m4
- compiler/GHC/Core/Coercion.hs
- compiler/GHC/Core/Opt/OccurAnal.hs
- compiler/GHC/Core/Opt/SetLevels.hs
- compiler/GHC/Core/Opt/Simplify.hs
- compiler/GHC/Core/Opt/Simplify/Monad.hs
- compiler/GHC/Core/Opt/Simplify/Utils.hs
- compiler/GHC/Core/SimpleOpt.hs
- compiler/GHC/Parser.y
- compiler/GHC/Parser/Lexer.x
- compiler/GHC/Parser/PostProcess.hs
- compiler/GHC/Types/Basic.hs
- compiler/GHC/Types/Demand.hs
- compiler/GHC/Types/Id/Info.hs
- docs/users_guide/8.12.1-notes.rst
- docs/users_guide/exts/negative_literals.rst
- docs/users_guide/separate_compilation.rst
- libraries/base/Data/Bits.hs
- rts/PrimOps.cmm
- testsuite/tests/numeric/should_compile/T14465.stdout
- testsuite/tests/numeric/should_compile/T7116.stdout
- + testsuite/tests/numeric/should_run/T18499.hs
- + testsuite/tests/numeric/should_run/T18499.stdout
- testsuite/tests/numeric/should_run/all.T
- − testsuite/tests/parser/should_compile/LexNegVsNegLit.hs
- + testsuite/tests/parser/should_compile/NegativeLiterals.hs
- + testsuite/tests/parser/should_compile/NegativeLiteralsNoExt.hs
- testsuite/tests/parser/should_compile/all.T
- + testsuite/tests/perf/compiler/T10421.hs
The diff was not included because it is too large.
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/65ef562cf75fe22b2437af994ec0c8610a85e34b...49d8597c9da32a5b674987cdc6ee227bcb627bb2
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/65ef562cf75fe22b2437af994ec0c8610a85e34b...49d8597c9da32a5b674987cdc6ee227bcb627bb2
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