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* Module hierarchy: StgToCmm (#13009)Sylvain Henry2019-09-101-992/+0
| | | | | | Add StgToCmm module hierarchy. Platform modules that are used in several other places (NCG, LLVM codegen, Cmm transformations) are put into GHC.Platform.
* Remove unused Unique field from StgFCallOpÖmer Sinan Ağacan2019-06-131-1/+1
| | | | Fixes #16696
* Use a better strategy for determining the offset applied to foreign function ↵Andrew Martin2019-06-041-1/+1
| | | | arguments that have an unlifted boxed type. We used to use the type of the argument. We now use the type of the foreign function. Add a test to confirm that the roundtrip conversion between an unlifted boxed type and Any is sound in the presence of a foreign function call.
* Update Trac ticket URLs to point to GitLabRyan Scott2019-03-151-2/+2
| | | | | This moves all URL references to Trac tickets to their corresponding GitLab counterparts.
* Rip out object splittingBen Gamari2019-03-051-8/+3
| | | | | | | | | | | | | | | The splitter is an evil Perl script that processes assembler code. Its job can be done better by the linker's --gc-sections flag. GHC passes this flag to the linker whenever -split-sections is passed on the command line. This is based on @DemiMarie's D2768. Fixes Trac #11315 Fixes Trac #9832 Fixes Trac #8964 Fixes Trac #8685 Fixes Trac #8629
* Comments onlySimon Peyton Jones2018-11-281-11/+17
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* Add Note [Dead case binders in -O0]Sebastian Graf2018-11-281-1/+13
| | | | | | | | | | | | | | | After reverting Phab:D5358, Simon (Peyton Jones) asked for a Note summarising why we want to keep the dead case binder check in `cgCase`. Summary from mail conversation: * Phab:D5324 means that we no longer /recompute/ dead-ness of case-binders in STG-land * But TidyPgm preserves dead-ness info (see CoreTidy.tidyIdBndr) * And so we can take advantage of it to avoid a redundant load. This load would be eliminated by CmmSink, but that only happens with -O
* Revert "Remove redundant check in cgCase"Ömer Sinan Ağacan2018-11-261-4/+7
| | | | | | This reverts commit d13b7d60650cb84af11ee15b3f51c3511548cfdb. (See discussion in D5358)
* Implement late lambda liftSebastian Graf2018-11-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This implements a selective lambda-lifting pass late in the STG pipeline. Lambda lifting has the effect of avoiding closure allocation at the cost of having to make former free vars available at call sites, possibly enlarging closures surrounding call sites in turn. We identify beneficial cases by means of an analysis that estimates closure growth. There's a Wiki page at https://ghc.haskell.org/trac/ghc/wiki/LateLamLift. Reviewers: simonpj, bgamari, simonmar Reviewed By: simonpj Subscribers: rwbarton, carter GHC Trac Issues: #9476 Differential Revision: https://phabricator.haskell.org/D5224
* Remove redundant check in cgCaseÖmer Sinan Ağacan2018-11-201-7/+4
| | | | | | | | | | | | | D5339 (part of D5324) removed the dead case binder analysis done during CoreToStg so this condition always holds now. Test Plan: Validated locally. Reviewers: sgraf, bgamari, simonmar Subscribers: rwbarton, carter Differential Revision: https://phabricator.haskell.org/D5358
* Don't track free variables in STG syntax by defaultSebastian Graf2018-11-191-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | Summary: Currently, `CoreToStg` annotates `StgRhsClosure`s with their set of non-global free variables. This free variable information is only needed in the final code generation step (i.e. `StgCmm.codeGen`), which leads to transformations such as `StgCse` and `StgUnarise` having to maintain this information. This is tiresome and unnecessary, so this patch introduces a trees-to-grow-like approach that only introduces the free variable set into the syntax tree in the code gen pass, along with a free variable analysis on STG terms to generate that information. Fixes #15754. Reviewers: simonpj, osa1, bgamari, simonmar Reviewed By: osa1 Subscribers: rwbarton, carter GHC Trac Issues: #15754 Differential Revision: https://phabricator.haskell.org/D5324
* Remove StgBinderInfo and related computation in CoreToStgÖmer Sinan Ağacan2018-11-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | - The StgBinderInfo type was never used in the code gen, so the type, related computation in CoreToStg, and some comments about it are removed. See #15770 for more details. - Simplified CoreToStg after removing the StgBinderInfo computation: removed StgBinderInfo arguments and mfix stuff. The StgBinderInfo values were not used in the code gen, but I still run nofib just to make sure: 0.0% change in allocations and binary sizes. Test Plan: Validated locally Reviewers: simonpj, simonmar, bgamari, sgraf Reviewed By: sgraf Subscribers: AndreasK, sgraf, rwbarton, carter Differential Revision: https://phabricator.haskell.org/D5232
* Fix dataToTag# argument evaluationÖmer Sinan Ağacan2018-10-101-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | See #15696 for more details. We now always enter dataToTag# argument (done in generated Cmm, in StgCmmExpr). Any high-level optimisations on dataToTag# applications are done by the simplifier. Looking at tag bits (instead of reading the info table) for small types is left to another diff. Incorrect test T14626 is removed. We no longer do this optimisation (see comment:44, comment:45, comment:60). Comments and notes about special cases around dataToTag# are removed. We no longer have any special cases around it in Core. Other changes related to evaluating primops (seq# and dataToTag#) will be pursued in follow-up diffs. Test Plan: Validates with three regression tests Reviewers: simonpj, simonmar, hvr, bgamari, dfeuer Reviewed By: simonmar Subscribers: rwbarton, carter GHC Trac Issues: #15696 Differential Revision: https://phabricator.haskell.org/D5201
* Fix seq# case of exprOkForSpeculationSimon Peyton Jones2018-03-201-6/+9
| | | | | | | | | This subtle patch fixes Trac #5129 (again; comment:20 and following). I took the opportunity to document seq# properly; see Note [seq# magic] in PrelRules, and Note [seq# and expr_ok] in CoreUtils.
* Get rid of more CPP in cmm/ and codeGen/Michal Terepeta2018-03-191-3/+4
| | | | | | | | | | | | | | | | | | This removes a bunch of unnecessary includes of `HsVersions.h` along with unnecessary CPP (e.g., due to checking for DEBUG which can be achieved by looking at `debugIsOn`) Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com> Test Plan: ./validate Reviewers: bgamari, simonmar Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4462
* Simplify, no functionality changeGabor Greif2017-10-171-7/+6
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* compiler: introduce custom "GhcPrelude" PreludeHerbert Valerio Riedel2017-09-191-2/+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
* Use lengthIs and friends in more placesRyan Scott2017-06-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | While investigating #12545, I discovered several places in the code that performed length-checks like so: ``` length ts == 4 ``` This is not ideal, since the length of `ts` could be much longer than 4, and we'd be doing way more work than necessary! There are already a slew of helper functions in `Util` such as `lengthIs` that are designed to do this efficiently, so I found every place where they ought to be used and did just that. I also defined a couple more utility functions for list length that were common patterns (e.g., `ltLength`). Test Plan: ./validate Reviewers: austin, hvr, goldfire, bgamari, simonmar Reviewed By: bgamari, simonmar Subscribers: goldfire, rwbarton, thomie Differential Revision: https://phabricator.haskell.org/D3622
* Improve code generation for conditionalsSimon Peyton Jones2017-04-281-4/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch in in preparation for the fix to Trac #13397 The code generator has a special case for case tagToEnum (a>#b) of False -> e1 True -> e2 but it was not doing nearly so well on case a>#b of DEFAULT -> e1 1# -> e2 This patch arranges to behave essentially identically in both cases. In due course we can eliminate the special case for tagToEnum#, once we've completed Trac #13397. The changes are: * Make CmmSink swizzle the order of a conditional where necessary; see Note [Improving conditionals] in CmmSink * Hack the general case of StgCmmExpr.cgCase so that it use NoGcInAlts for conditionals. This doesn't seem right, but it's the same choice as the tagToEnum version. Without it, code size increases a lot (more heap checks). There's a loose end here. * Add comments in CmmOpt.cmmMachOpFoldM
* Deal with JoinIds before void typesSimon Peyton Jones2017-03-101-3/+4
| | | | | | | | Trac #13394, comment:4 showed up another place where we were testing for the representation of of a type; and it turned out to be a JoinId which can be rep-polymorphic. Just putting the test in the right places solves this easily.
* Spelling only [ci skip]Gabor Greif2017-02-231-1/+1
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* Update levity polymorphismRichard Eisenberg2017-01-191-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit implements the proposal in https://github.com/ghc-proposals/ghc-proposals/pull/29 and https://github.com/ghc-proposals/ghc-proposals/pull/35. Here are some of the pieces of that proposal: * Some of RuntimeRep's constructors have been shortened. * TupleRep and SumRep are now parameterized over a list of RuntimeReps. * This means that two types with the same kind surely have the same representation. Previously, all unboxed tuples had the same kind, and thus the fact above was false. * RepType.typePrimRep and friends now return a *list* of PrimReps. These functions can now work successfully on unboxed tuples. This change is necessary because we allow abstraction over unboxed tuple types and so cannot always handle unboxed tuples specially as we did before. * We sometimes have to create an Id from a PrimRep. I thus split PtrRep * into LiftedRep and UnliftedRep, so that the created Ids have the right strictness. * The RepType.RepType type was removed, as it didn't seem to help with * much. * The RepType.repType function is also removed, in favor of typePrimRep. * I have waffled a good deal on whether or not to keep VoidRep in TyCon.PrimRep. In the end, I decided to keep it there. PrimRep is *not* represented in RuntimeRep, and typePrimRep will never return a list including VoidRep. But it's handy to have in, e.g., ByteCodeGen and friends. I can imagine another design choice where we have a PrimRepV type that is PrimRep with an extra constructor. That seemed to be a heavier design, though, and I'm not sure what the benefit would be. * The last, unused vestiges of # (unliftedTypeKind) have been removed. * There were several pretty-printing bugs that this change exposed; * these are fixed. * We previously checked for levity polymorphism in the types of binders. * But we also must exclude levity polymorphism in function arguments. This is hard to check for, requiring a good deal of care in the desugarer. See Note [Levity polymorphism checking] in DsMonad. * In order to efficiently check for levity polymorphism in functions, it * was necessary to add a new bit of IdInfo. See Note [Levity info] in IdInfo. * It is now safe for unlifted types to be unsaturated in Core. Core Lint * is updated accordingly. * We can only know strictness after zonking, so several checks around * strictness in the type-checker (checkStrictBinds, the check for unlifted variables under a ~ pattern) have been moved to the desugarer. * Along the way, I improved the treatment of unlifted vs. banged * bindings. See Note [Strict binds checks] in DsBinds and #13075. * Now that we print type-checked source, we must be careful to print * ConLikes correctly. This is facilitated by a new HsConLikeOut constructor to HsExpr. Particularly troublesome are unlifted pattern synonyms that get an extra void# argument. * Includes a submodule update for haddock, getting rid of #. * New testcases: typecheck/should_fail/StrictBinds typecheck/should_fail/T12973 typecheck/should_run/StrictPats typecheck/should_run/T12809 typecheck/should_fail/T13105 patsyn/should_fail/UnliftedPSBind typecheck/should_fail/LevPolyBounded typecheck/should_compile/T12987 typecheck/should_compile/T11736 * Fixed tickets: #12809 #12973 #11736 #13075 #12987 * This also adds a test case for #13105. This test case is * "compile_fail" and succeeds, because I want the testsuite to monitor the error message. When #13105 is fixed, the test case will compile cleanly.
* Use newBlockId instead of newLabelCBen Gamari2016-11-291-3/+3
| | | | | | | | | | | | | | | This seems like a clearer name and the fewer functions that one needs to remember, the better. Test Plan: validate Reviewers: austin, simonmar, michalt Reviewed By: simonmar, michalt Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2735
* Fix comment about pointer taggingAlex Biehl2016-11-101-1/+1
| | | | | | | | | | | | | | | `Lcall` enters the closure. If it has tags we jump directly to `Lret`. Confirmed with some generated cmm code: ``` R1 = _s2pP::P64; Sp = Sp - 8; if (R1 & 7 != 0) goto c2x0; else goto c2x1; c2x1: call (I64[R1])(R1) returns to c2x0, args: 8, res: 8, upd: 8; c2x0: _s2pQ::P64 = R1; ```
* Codegen for case: Remove redundant void id checksÖmer Sinan Ağacan2016-09-201-11/+15
| | | | | | | | | | | | | | | | New unarise (714bebf) eliminates void binders in patterns already, so no need to eliminate them here. I leave assertions to make sure this is the case. Assertion failure -> bug in unarise Reviewers: bgamari, simonpj, austin, simonmar, hvr Reviewed By: simonpj Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2416
* Remove StgRubbishArg and CmmArgÖmer Sinan Ağacan2016-08-101-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea behind adding special "rubbish" arguments was in unboxed sum types depending on the tag some arguments are not used and we don't want to move some special values (like 0 for literals and some special pointer for boxed slots) for those arguments (to stack locations or registers). "StgRubbishArg" was an indicator to the code generator that the value won't be used. During Stg-to-Cmm we were then not generating any move or store instructions at all. This caused problems in the register allocator because some variables were only initialized in some code paths. As an example, suppose we have this STG: (after unarise) Lib.$WT = \r [dt_sit] case case dt_sit of { Lib.F dt_siv [Occ=Once] -> (#,,#) [1# dt_siv StgRubbishArg::GHC.Prim.Int#]; Lib.I dt_siw [Occ=Once] -> (#,,#) [2# StgRubbishArg::GHC.Types.Any dt_siw]; } of dt_six { (#,,#) us_giC us_giD us_giE -> Lib.T [us_giC us_giD us_giE]; }; This basically unpacks a sum type to an unboxed sum with 3 fields, and then moves the unboxed sum to a constructor (`Lib.T`). This is the Cmm for the inner case expression (case expression in the scrutinee position of the outer case): ciN: ... -- look at dt_sit's tag if (_ciT::P64 != 1) goto ciS; else goto ciR; ciS: -- Tag is 2, i.e. Lib.F _siw::I64 = I64[_siu::P64 + 6]; _giE::I64 = _siw::I64; _giD::P64 = stg_RUBBISH_ENTRY_info; _giC::I64 = 2; goto ciU; ciR: -- Tag is 1, i.e. Lib.I _siv::P64 = P64[_siu::P64 + 7]; _giD::P64 = _siv::P64; _giC::I64 = 1; goto ciU; Here one of the blocks `ciS` and `ciR` is executed and then the execution continues to `ciR`, but only `ciS` initializes `_giE`, in the other branch `_giE` is not initialized, because it's "rubbish" in the STG and so we don't generate an assignment during code generator. The code generator then panics during the register allocations: ghc-stage1: panic! (the 'impossible' happened) (GHC version 8.1.20160722 for x86_64-unknown-linux): LocalReg's live-in to graph ciY {_giE::I64} (`_giD` is also "rubbish" in `ciS`, but it's still initialized because it's a pointer slot, we have to initialize it otherwise garbage collector follows the pointer to some random place. So we only remove assignment if the "rubbish" arg has unboxed type.) This patch removes `StgRubbishArg` and `CmmArg`. We now always initialize rubbish slots. If the slot is for boxed types we use the existing `absentError`, otherwise we initialize the slot with literal 0. Reviewers: simonpj, erikd, austin, simonmar, bgamari Reviewed By: erikd Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2446
* StgCmm: Remove unused Bool field of Return sequelÖmer Sinan Ağacan2016-08-051-1/+1
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* Some typos in commentsGabor Greif2016-07-261-2/+2
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* Implement unboxed sum primitive typeÖmer Sinan Ağacan2016-07-211-13/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This patch implements primitive unboxed sum types, as described in https://ghc.haskell.org/trac/ghc/wiki/UnpackedSumTypes. Main changes are: - Add new syntax for unboxed sums types, terms and patterns. Hidden behind `-XUnboxedSums`. - Add unlifted unboxed sum type constructors and data constructors, extend type and pattern checkers and desugarer. - Add new RuntimeRep for unboxed sums. - Extend unarise pass to translate unboxed sums to unboxed tuples right before code generation. - Add `StgRubbishArg` to `StgArg`, and a new type `CmmArg` for better code generation when sum values are involved. - Add user manual section for unboxed sums. Some other changes: - Generalize `UbxTupleRep` to `MultiRep` and `UbxTupAlt` to `MultiValAlt` to be able to use those with both sums and tuples. - Don't use `tyConPrimRep` in `isVoidTy`: `tyConPrimRep` is really wrong, given an `Any` `TyCon`, there's no way to tell what its kind is, but `kindPrimRep` and in turn `tyConPrimRep` returns `PtrRep`. - Fix some bugs on the way: #12375. Not included in this patch: - Update Haddock for new the new unboxed sum syntax. - `TemplateHaskell` support is left as future work. For reviewers: - Front-end code is mostly trivial and adapted from unboxed tuple code for type checking, pattern checking, renaming, desugaring etc. - Main translation routines are in `RepType` and `UnariseStg`. Documentation in `UnariseStg` should be enough for understanding what's going on. Credits: - Johan Tibell wrote the initial front-end and interface file extensions. - Simon Peyton Jones reviewed this patch many times, wrote some code, and helped with debugging. Reviewers: bgamari, alanz, goldfire, RyanGlScott, simonpj, austin, simonmar, hvr, erikd Reviewed By: simonpj Subscribers: Iceland_jack, ggreif, ezyang, RyanGlScott, goldfire, thomie, mpickering Differential Revision: https://phabricator.haskell.org/D2259
* Whitespace onlyÖmer Sinan Ağacan2016-06-031-3/+3
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* Remove unused FAST_STRING_NOT_NEEDED macro defsÖmer Sinan Ağacan2016-05-311-1/+0
| | | | | | | | | | Reviewers: austin, bgamari, simonmar, hvr Reviewed By: hvr Subscribers: hvr, thomie Differential Revision: https://phabricator.haskell.org/D2285
* StgCmmExpr: Remove a redundant listÖmer Sinan Ağacan2016-05-271-1/+1
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* StgCmmExpr: Fix a duplicationÖmer Sinan Ağacan2016-05-261-2/+2
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* Fix histograms for ticky codeMateusz Lenik2016-05-181-0/+1
| | | | | | | | | | | | | | | | | | | | This patch fixes Cmm generation required to produce histograms when compiling with -ticky flag, strips dead code from rts/Ticky.c and reworks it to use a shared constant in both C and Haskell code. Fixes #8308. Test Plan: T8308 Reviewers: jstolarek, simonpj, austin Reviewed By: simonpj Subscribers: mpickering, simonpj, bgamari, mlen, thomie, jstolarek Differential Revision: https://phabricator.haskell.org/D931 GHC Trac Issues: #8308
* Remove "use mask" from StgAlt syntaxÖmer Sinan Ağacan2016-02-241-5/+5
| | | | | | | | | | Reviewers: austin, bgamari, simonpj Reviewed By: simonpj Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1933
* Remove unused LiveVars and SRT fields of StgCaseÖmer Sinan Ağacan2016-02-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | We also need to update `stgBindHasCafRefs` assertion with this change, as we no longer have the pre-computed SRT, LiveVars etc. We rename it to `topStgBindHasCafRefs` and implement it like this: A non-updatable top-level binding may refer to a CAF by referring to a top-level definition with CAFs. A top-level definition may have CAFs if it's updatable. At this point (because this is done after TidyPgm) top-level Ids (whether imported or defined in this module) are GlobalIds, so the top-levelness test is easy. (see also comments in the code) Reviewers: bgamari, simonpj, austin Reviewed By: simonpj Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1889 GHC Trac Issues: #11550
* Revert "Remove unused LiveVars and SRT fields of StgCase and StgLetNoEscape"Ömer Sinan Ağacan2016-02-061-3/+3
| | | | This reverts commit 4f9967aa3d1f7cfd539d0c173cafac0fe290e26f.
* Remove unused LiveVars and SRT fields of StgCase and StgLetNoEscapeÖmer Sinan Ağacan2016-02-041-3/+3
| | | | | | | | | | | | | | | | | | Also remove the functions and types that became useless after removing the fields: - SRT functions - LiveInfo type and functions - freeVarsToLiveVars - unariseLives and unariseSRT Reviewers: bgamari, simonpj, austin Reviewed By: simonpj Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1880
* s/unLifted/unlifted for consistencyÖmer Sinan Ağacan2016-01-271-1/+1
| | | | | | | | | | | | | This was causing trouble as we had to remember when to use "unLifted" and when to use "unlifted". "unlifted" is used instead of "unLifted" as it's a single word. Reviewers: austin, hvr, goldfire, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1852
* Do not count void arguments when considering a function for loopification.Jonas Scholl2016-01-221-5/+29
| | | | | | | | | | | | | | | | | | | | | | | This fixes #11372 by omitting arguments with a void-type when checking whether a self-recursive tail call can be optimized to a local jump. Previously, a function taking a real argument and a State# token would report an arity of 1 in the SelfLoopInfo in getCallMethod, but a self-recursive call would apply it to 2 arguments, one of them being the State# token, thus no local jump would be generated. As the State# token is not represented by anything at runtime, we can ignore it and thus trigger the loopification optimization. Test Plan: ./validate Reviewers: austin, bgamari, simonmar Reviewed By: bgamari Subscribers: simonmar, thomie Differential Revision: https://phabricator.haskell.org/D1767 GHC Trac Issues: #11372
* Drop pre-AMP compatibility CPP conditionalsHerbert Valerio Riedel2015-12-311-2/+0
| | | | | | | | | | | | Since GHC 8.1/8.2 only needs to be bootstrap-able by GHC 7.10 and GHC 8.0 (and GHC 8.2), we can now finally drop all that pre-AMP compatibility CPP-mess for good! Reviewers: austin, goldfire, bgamari Subscribers: goldfire, thomie, erikd Differential Revision: https://phabricator.haskell.org/D1724
* minor: use unless instead of (when . not)Ömer Sinan Ağacan2015-11-081-3/+3
| | | | | | | | | | Reviewers: bgamari, austin Reviewed By: austin Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1438
* Annotate CmmBranch with an optional likely targetSimon Marlow2015-09-231-1/+2
| | | | | | | | | | | | | | | | | Summary: This allows the code generator to give hints to later code generation steps about which branch is most likely to be taken. Right now it is only taken into account in one place: a special case in CmmContFlowOpt that swapped branches over to maximise the chance of fallthrough, which is now disabled when there is a likelihood setting. Test Plan: validate Reviewers: austin, simonpj, bgamari, ezyang, tibbe Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1273
* Fix comments, and a little reformattingSimon Marlow2015-02-241-26/+26
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* Add a bizarre corner-case to cgExpr (Trac #9964)Simon Peyton Jones2015-02-201-23/+55
| | | | | | | | | | | David Feuer managed to tickle a corner case in the code generator. See Note [Scrutinising VoidRep] in StgCmmExpr. I rejigged the comments in that area of the code generator Note [Dodgy unsafeCoerce 1] Note [Dodgy unsafeCoerce 2] but I can't say I fully understand them, alas.
* Replace .lhs with .hs in compiler commentsYuri de Wit2015-02-091-1/+1
| | | | | | | | | | | | | | Summary: It looks like during .lhs -> .hs switch the comments were not updated. So doing exactly that. Reviewers: austin, jstolarek, hvr, goldfire Reviewed By: austin, jstolarek Subscribers: thomie, goldfire Differential Revision: https://phabricator.haskell.org/D621 GHC Trac Issues: #9986
* Improve an ASSERTSimon Peyton Jones2014-12-171-1/+1
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* Tick scopesPeter Wortmann2014-12-161-9/+11
| | | | | | | | | | | | | | | | | | | | | | This patch solves the scoping problem of CmmTick nodes: If we just put CmmTicks into blocks we have no idea what exactly they are meant to cover. Here we introduce tick scopes, which allow us to create sub-scopes and merged scopes easily. Notes: * Given that the code often passes Cmm around "head-less", we have to make sure that its intended scope does not get lost. To keep the amount of passing-around to a minimum we define a CmmAGraphScoped type synonym here that just bundles the scope with a portion of Cmm to be assembled later. * We introduce new scopes at somewhat random places, aligning with getCode calls. This works surprisingly well, but we might have to add new scopes into the mix later on if we find things too be too coarse-grained. (From Phabricator D169)
* Source notes (Cmm support)Peter Wortmann2014-12-161-0/+1
| | | | | | | | | | | | | | | | | | | | This patch adds CmmTick nodes to Cmm code. This is relatively straight-forward, but also not very useful, as many blocks will simply end up with no annotations whatosever. Notes: * We use this design over, say, putting ticks into the entry node of all blocks, as it seems to work better alongside existing optimisations. Now granted, the reason for this is that currently GHC's main Cmm optimisations seem to mainly reorganize and merge code, so this might change in the future. * We have the Cmm parser generate a few source notes as well. This is relatively easy to do - worst part is that it complicates the CmmParse implementation a bit. (From Phabricator D169)
* Source notes (CorePrep and Stg support)Peter Wortmann2014-12-161-4/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is basically just about continuing maintaining source notes after the Core stage. Unfortunately, this is more involved as it might seem, as there are more restrictions on where ticks are allowed to show up. Notes: * We replace the StgTick / StgSCC constructors with a unified StgTick that can carry any tickish. * For handling constructor or lambda applications, we generally float ticks out. * Note that thanks to the NonLam placement, we know that source notes can never appear on lambdas. This means that as long as we are careful to always use mkTick, we will never violate CorePrep invariants. * This is however not automatically true for eta expansion, which needs to somewhat awkwardly strip, then re-tick the expression in question. * Where CorePrep floats out lets, we make sure to wrap them in the same spirit as FloatOut. * Detecting selector thunks becomes a bit more involved, as we can run into ticks at multiple points. (From Phabricator D169)
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