1. 07 Aug, 2012 1 commit
  2. 06 Aug, 2012 1 commit
  3. 24 Jul, 2012 1 commit
  4. 05 Jun, 2012 1 commit
  5. 10 Jan, 2012 1 commit
    • dterei's avatar
      Track STG live register information for use in LLVM · 4384e146
      dterei authored
      We now carry around with CmmJump statements a list of
      the STG registers that are live at that jump site.
      This is used by the LLVM backend so it can avoid
      unnesecarily passing around dead registers, improving
      perfromance. This gives us the framework to finally
      fix trac #4308.
      4384e146
  6. 06 Jan, 2012 1 commit
  7. 04 Nov, 2011 1 commit
  8. 25 Aug, 2011 1 commit
    • Simon Peyton Jones's avatar
      More refactoring (CgRep) · 493c12ff
      Simon Peyton Jones authored and Simon Marlow's avatar Simon Marlow committed
      * Move CgRep (private to old codgen) from SMRep to ClosureInfo
      * Avoid using CgRep in new codegen
      * Move SMRep and Bitmap from codeGen/ to cmm/
      493c12ff
  9. 24 Jan, 2011 1 commit
    • Simon Marlow's avatar
      Merge in new code generator branch. · 889c084e
      Simon Marlow authored
      This changes the new code generator to make use of the Hoopl package
      for dataflow analysis.  Hoopl is a new boot package, and is maintained
      in a separate upstream git repository (as usual, GHC has its own
      lagging darcs mirror in http://darcs.haskell.org/packages/hoopl).
      
      During this merge I squashed recent history into one patch.  I tried
      to rebase, but the history had some internal conflicts of its own
      which made rebase extremely confusing, so I gave up. The history I
      squashed was:
      
        - Update new codegen to work with latest Hoopl
        - Add some notes on new code gen to cmm-notes
        - Enable Hoopl lag package.
        - Add SPJ note to cmm-notes
        - Improve GC calls on new code generator.
      
      Work in this branch was done by:
         - Milan Straka <fox@ucw.cz>
         - John Dias <dias@cs.tufts.edu>
         - David Terei <davidterei@gmail.com>
      
      Edward Z. Yang <ezyang@mit.edu> merged in further changes from GHC HEAD
      and fixed a few bugs.
      889c084e
  10. 09 Jun, 2009 1 commit
    • Duncan Coutts's avatar
      Add PrimCall to the STG layer and update Core -> STG translation · cbbee4e8
      Duncan Coutts authored
      It adds a third case to StgOp which already hold StgPrimOp and StgFCallOp.
      The code generation for the new StgPrimCallOp case is almost exactly the
      same as for out-of-line primops. They now share the tailCallPrim function.
      In the Core -> STG translation we map foreign calls using the "prim"
      calling convention to the StgPrimCallOp case. This is because in Core we
      represent prim calls using the ForeignCall stuff. At the STG level however
      the prim calls are really much more like primops than foreign calls.
      cbbee4e8
  11. 18 Mar, 2009 1 commit
  12. 17 Mar, 2009 2 commits
    • dias@eecs.tufts.edu's avatar
      Calling convention bug and cleanup · e5e7d10b
      dias@eecs.tufts.edu authored
      - yet another wrong calling convention; this one was a special case for returning one
        value.
      e5e7d10b
    • Simon Marlow's avatar
      FIX biographical profiling (#3039, probably #2297) · f8f4cb3f
      Simon Marlow authored
      Since we introduced pointer tagging, we no longer always enter a
      closure to evaluate it.  However, the biographical profiler relies on
      closures being entered in order to mark them as "used", so we were
      getting spurious amounts of data attributed to VOID.  It turns out
      there are various places that need to be fixed, and I think at least
      one of them was also wrong before pointer tagging (CgCon.cgReturnDataCon).
      f8f4cb3f
  13. 18 Dec, 2008 1 commit
  14. 17 Dec, 2008 2 commits
  15. 14 Aug, 2008 1 commit
    • dias@eecs.harvard.edu's avatar
      Merging in the new codegen branch · 176fa33f
      dias@eecs.harvard.edu authored
      This merge does not turn on the new codegen (which only compiles
      a select few programs at this point),
      but it does introduce some changes to the old code generator.
      
      The high bits:
      1. The Rep Swamp patch is finally here.
         The highlight is that the representation of types at the
         machine level has changed.
         Consequently, this patch contains updates across several back ends.
      2. The new Stg -> Cmm path is here, although it appears to have a
         fair number of bugs lurking.
      3. Many improvements along the CmmCPSZ path, including:
         o stack layout
         o some code for infotables, half of which is right and half wrong
         o proc-point splitting
      176fa33f
  16. 29 Mar, 2008 1 commit
  17. 06 Sep, 2007 1 commit
    • nr@eecs.harvard.edu's avatar
      massive changes to add a 'zipper' representation of C-- · 16a2f6a8
      nr@eecs.harvard.edu authored
      Changes too numerous to comment on, but here is some old history that
      I saved: 
      
      
      Wed Aug 15 11:07:13 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * type synonyms made consistent with new Cmm types
      
          M ./compiler/nativeGen/MachInstrs.hs -2 +2
      
      Mon Aug 20 19:22:14 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * pushing return info beyond cmm into codegen
      
          M ./compiler/codeGen/Bitmap.hs r3
          M ./compiler/codeGen/CgBindery.lhs r3
          M ./compiler/codeGen/CgCallConv.hs r3
          M ./compiler/codeGen/CgCase.lhs r3
          M ./compiler/codeGen/CgClosure.lhs r3
          M ./compiler/codeGen/CgCon.lhs r3
          M ./compiler/codeGen/CgExpr.lhs r3
          M ./compiler/codeGen/CgForeignCall.hs -6 +7 r3
          M ./compiler/codeGen/CgHeapery.lhs r3
          M ./compiler/codeGen/CgHpc.hs +1 r3
          M ./compiler/codeGen/CgInfoTbls.hs r3
          M ./compiler/codeGen/CgLetNoEscape.lhs r3
          M ./compiler/codeGen/CgMonad.lhs r3
          M ./compiler/codeGen/CgParallel.hs r3
          M ./compiler/codeGen/CgPrimOp.hs +3 r3
          M ./compiler/codeGen/CgProf.hs r3
          M ./compiler/codeGen/CgStackery.lhs r3
          M ./compiler/codeGen/CgTailCall.lhs r3
          M ./compiler/codeGen/CgTicky.hs r3
          M ./compiler/codeGen/CgUtils.hs -1 +1 r3
          M ./compiler/codeGen/ClosureInfo.lhs r3
          M ./compiler/codeGen/CodeGen.lhs r3
          M ./compiler/codeGen/SMRep.lhs r3
          M ./compiler/nativeGen/AsmCodeGen.lhs -2 +2 r1
          M ./compiler/nativeGen/MachCodeGen.hs -3 +3 r1
          M ./compiler/nativeGen/MachInstrs.hs r1
          M ./compiler/nativeGen/MachRegs.lhs r1
          M ./compiler/nativeGen/NCGMonad.hs r1
          M ./compiler/nativeGen/PositionIndependentCode.hs r1
          M ./compiler/nativeGen/PprMach.hs r1
          M ./compiler/nativeGen/RegAllocInfo.hs r1
          M ./compiler/nativeGen/RegisterAlloc.hs r1
      
      Mon Aug 20 20:54:41 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * put CmmReturnInfo into a CmmCall (and related types)
      
          M ./compiler/cmm/Cmm.hs -2 +1 r3
          M ./compiler/cmm/CmmBrokenBlock.hs -13 +12 r1
          M ./compiler/cmm/CmmCPS.hs -3 +3
          M ./compiler/cmm/CmmCPSGen.hs -8 +6 r1
          M ./compiler/cmm/CmmLint.hs -1 +1
          M ./compiler/cmm/CmmLive.hs -1 +1
          M ./compiler/cmm/CmmOpt.hs -3 +3
          M ./compiler/cmm/CmmParse.y -6 +6 r3
          M ./compiler/cmm/PprC.hs -3 +3
          M ./compiler/cmm/PprCmm.hs -7 +4 r2
          M ./compiler/codeGen/CgForeignCall.hs -7 +6 r2
          M ./compiler/codeGen/CgHpc.hs -1 r1
          M ./compiler/codeGen/CgPrimOp.hs -3 r1
          M ./compiler/codeGen/CgUtils.hs -1 +1 r1
          M ./compiler/nativeGen/AsmCodeGen.lhs -2 +2
          M ./compiler/nativeGen/MachCodeGen.hs -3 +3 r1
      
      Tue Aug 21 18:09:13 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * add call info in nativeGen
      
          M ./compiler/nativeGen/AsmCodeGen.lhs r1
          M ./compiler/nativeGen/MachInstrs.hs r1
          M ./compiler/nativeGen/MachRegs.lhs r1
          M ./compiler/nativeGen/NCGMonad.hs r1
          M ./compiler/nativeGen/PositionIndependentCode.hs r1
          M ./compiler/nativeGen/PprMach.hs r1
          M ./compiler/nativeGen/RegAllocInfo.hs r1
      
      Wed Aug 22 16:41:58 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * ListGraph is now a newtype, not a synonym
        The resultant bookkeepping is unenviable, but the change
        greatly simplifies our ability to make Cmm things propertly
        Outputable for both list-graph and zipper-graph representations.
      
          M ./compiler/cmm/Cmm.hs -5 +3
          M ./compiler/cmm/CmmCPS.hs -2 +2
          M ./compiler/cmm/CmmCPSGen.hs -1 +1
          M ./compiler/cmm/CmmContFlowOpt.hs -3 +3
          M ./compiler/cmm/CmmCvt.hs -2 +2
          M ./compiler/cmm/CmmInfo.hs -2 +3
          M ./compiler/cmm/CmmLint.hs -1 +1
          M ./compiler/cmm/CmmOpt.hs -2 +2
          M ./compiler/cmm/PprC.hs -1 +1
          M ./compiler/cmm/PprCmm.hs -5 +8
          M ./compiler/cmm/PprCmmZ.hs -7 +1
          M ./compiler/codeGen/CgMonad.lhs -1 +1
          M ./compiler/nativeGen/AsmCodeGen.lhs -15 +15
          M ./compiler/nativeGen/MachCodeGen.hs -2 +2
          M ./compiler/nativeGen/PositionIndependentCode.hs -6 +6
          M ./compiler/nativeGen/PprMach.hs -3 +2
          M ./compiler/nativeGen/RegAllocColor.hs +1
          M ./compiler/nativeGen/RegAllocLinear.hs -4 +5
          M ./compiler/nativeGen/RegCoalesce.hs -6 +6
          M ./compiler/nativeGen/RegLiveness.hs -12 +12
      
      Thu Aug 23 13:44:49 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * diagnostic assistance in case fromJust fails
      
          M ./compiler/nativeGen/MachCodeGen.hs -2 +5
      
      Thu Aug 23 14:07:28 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * give every block, even the first, a label
          With branch-chain elimination, the first block of a procedure
          might be the target of a branch.  This actually happens to 
          a dozen or more procedures in the run-time system.
      
          M ./compiler/nativeGen/PprMach.hs -8 +3
      
      Fri Aug 24 17:27:04 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * clean up the code in PprMach
      
          M ./compiler/nativeGen/PprMach.hs -16 +14
      
      Fri Aug 24 19:35:03 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * a bunch of impedance matching to get the compiler to build, plus 
         * the plus is diagnostics for unreachable code, which required
           moving a lot of prettyprinting code
      
          M ./compiler/cmm/Cmm.hs -7 +5
          M ./compiler/cmm/CmmCPSZ.hs -1 +1
          M ./compiler/cmm/CmmCvt.hs -8 +8
          M ./compiler/cmm/CmmParse.y -4 +3
          M ./compiler/cmm/MkZipCfg.hs -19 +9
          M ./compiler/cmm/PprCmmZ.hs -118 +4
          M ./compiler/cmm/ZipCfg.hs -1 +13
          M ./compiler/cmm/ZipCfgCmm.hs -10 +129
          M ./compiler/main/HscMain.lhs -4 +4
          M ./compiler/nativeGen/NCGMonad.hs -2 +2
          M ./compiler/nativeGen/RegAllocInfo.hs -3 +3
      
      Fri Aug 31 14:38:02 BST 2007  Norman Ramsey <nr@eecs.harvard.edu>
        * fix a warning about an import
      
          M ./compiler/nativeGen/RegAllocColor.hs -1 +1
      16a2f6a8
  18. 04 Sep, 2007 1 commit
  19. 03 Sep, 2007 1 commit
  20. 01 Sep, 2007 1 commit
  21. 25 Aug, 2007 1 commit
    • Ian Lynagh's avatar
      Add a missing "entryCode" · 06c7fd3f
      Ian Lynagh authored
      This was causing us to try to jump to the address of an infotable when
      unregisterised, leading to a segfault.
      06c7fd3f
  22. 31 Jul, 2007 1 commit
    • Clemens Fruhwirth's avatar
      Change the strategy to determine dynamic data access · 81b2276f
      Clemens Fruhwirth authored
      Instead of attaching the information whether a Label is going to be
      accessed dynamically or not (distinction between IdLabel/DynLabel and
      additional flags in ModuleInitLabel and PlainModuleInitLabel), we hand
      dflags through the CmmOpt monad and the NatM monad. Before calling
      labelDynamic in PositionIndependentCode, we extract thisPackage from
      dflags and supply the current package to labelDynamic, so it can take
      this information into account instead of extracting it from the labels
      itself. This simplifies a lot of code in codeGen that just hands
      through this_pkg.
      81b2276f
  23. 27 Jul, 2007 1 commit
    • Simon Marlow's avatar
      Pointer Tagging · 6015a94f
      Simon Marlow authored
        
      This patch implements pointer tagging as per our ICFP'07 paper "Faster
      laziness using dynamic pointer tagging".  It improves performance by
      10-15% for most workloads, including GHC itself.
      
      The original patches were by Alexey Rodriguez Yakushev
      <mrchebas@gmail.com>, with additions and improvements by me.  I've
      re-recorded the development as a single patch.
      
      The basic idea is this: we use the low 2 bits of a pointer to a heap
      object (3 bits on a 64-bit architecture) to encode some information
      about the object pointed to.  For a constructor, we encode the "tag"
      of the constructor (e.g. True vs. False), for a function closure its
      arity.  This enables some decisions to be made without dereferencing
      the pointer, which speeds up some common operations.  In particular it
      enables us to avoid costly indirect jumps in many cases.
      
      More information in the commentary:
      
      http://hackage.haskell.org/trac/ghc/wiki/Commentary/Rts/HaskellExecution/PointerTagging
      6015a94f
  24. 28 Feb, 2007 1 commit
  25. 22 Jan, 2007 2 commits
    • Simon Marlow's avatar
      Semi-tagging optimisation · a2d78ebe
      Simon Marlow authored
      In the generated code for case-of-variable, test the tag of the
      scrutinee closure and only enter if it is unevaluated.  Also turn
      *off* vectored returns.
      a2d78ebe
    • Simon Marlow's avatar
      Semi-tagging optimisation · 7f1bc015
      Simon Marlow authored
      In the generated code for case-of-variable, test the tag of the
      scrutinee closure and only enter if it is unevaluated.  Also turn
      *off* vectored returns.
      7f1bc015
  26. 11 Oct, 2006 1 commit
    • Simon Marlow's avatar
      Module header tidyup, phase 1 · 49c98d14
      Simon Marlow authored
      This patch is a start on removing import lists and generally tidying
      up the top of each module.  In addition to removing import lists:
      
         - Change DATA.IOREF -> Data.IORef etc.
         - Change List -> Data.List etc.
         - Remove $Id$
         - Update copyrights
         - Re-order imports to put non-GHC imports last
         - Remove some unused and duplicate imports
      49c98d14
  27. 25 Jul, 2006 1 commit
    • Simon Marlow's avatar
      Generalise Package Support · 61d2625a
      Simon Marlow authored
      This patch pushes through one fundamental change: a module is now
      identified by the pair of its package and module name, whereas
      previously it was identified by its module name alone.  This means
      that now a program can contain multiple modules with the same name, as
      long as they belong to different packages.
      
      This is a language change - the Haskell report says nothing about
      packages, but it is now necessary to understand packages in order to
      understand GHC's module system.  For example, a type T from module M
      in package P is different from a type T from module M in package Q.
      Previously this wasn't an issue because there could only be a single
      module M in the program.
      
      The "module restriction" on combining packages has therefore been
      lifted, and a program can contain multiple versions of the same
      package.
      
      Note that none of the proposed syntax changes have yet been
      implemented, but the architecture is geared towards supporting import
      declarations qualified by package name, and that is probably the next
      step.
      
      It is now necessary to specify the package name when compiling a
      package, using the -package-name flag (which has been un-deprecated).
      Fortunately Cabal still uses -package-name.
      
      Certain packages are "wired in".  Currently the wired-in packages are:
      base, haskell98, template-haskell and rts, and are always referred to
      by these versionless names.  Other packages are referred to with full
      package IDs (eg. "network-1.0").  This is because the compiler needs
      to refer to entities in the wired-in packages, and we didn't want to
      bake the version of these packages into the comiler.  It's conceivable
      that someone might want to upgrade the base package independently of
      GHC.
      
      Internal changes:
      
        - There are two module-related types:
      
              ModuleName      just a FastString, the name of a module
              Module          a pair of a PackageId and ModuleName
      
          A mapping from ModuleName can be a UniqFM, but a mapping from Module
          must be a FiniteMap (we provide it as ModuleEnv).
      
        - The "HomeModules" type that was passed around the compiler is now
          gone, replaced in most cases by the current package name which is
          contained in DynFlags.  We can tell whether a Module comes from the
          current package by comparing its package name against the current
          package.
      
        - While I was here, I changed PrintUnqual to be a little more useful:
          it now returns the ModuleName that the identifier should be qualified
          with according to the current scope, rather than its original
          module.  Also, PrintUnqual tells whether to qualify module names with
          package names (currently unused).
      
      Docs to follow.
      61d2625a
  28. 07 Apr, 2006 1 commit
    • Simon Marlow's avatar
      Reorganisation of the source tree · 0065d5ab
      Simon Marlow authored
      Most of the other users of the fptools build system have migrated to
      Cabal, and with the move to darcs we can now flatten the source tree
      without losing history, so here goes.
      
      The main change is that the ghc/ subdir is gone, and most of what it
      contained is now at the top level.  The build system now makes no
      pretense at being multi-project, it is just the GHC build system.
      
      No doubt this will break many things, and there will be a period of
      instability while we fix the dependencies.  A straightforward build
      should work, but I haven't yet fixed binary/source distributions.
      Changes to the Building Guide will follow, too.
      0065d5ab
  29. 28 Feb, 2006 1 commit
    • Simon Marlow's avatar
      pass arguments to unknown function calls in registers · 04db0e9f
      Simon Marlow authored
      We now have more stg_ap entry points: stg_ap_*_fast, which take
      arguments in registers according to the platform calling convention.
      This is faster if the function being called is evaluated and has the
      right arity, which is the common case (see the eval/apply paper for
      measurements).  
      
      We still need the stg_ap_*_info entry points for stack-based
      application, such as an overflows when a function is applied to too
      many argumnets.  The stg_ap_*_fast functions actually just check for
      an evaluated function, and if they don't find one, push the args on
      the stack and invoke stg_ap_*_info.  (this might be slightly slower in
      some cases, but not the common case).
      04db0e9f
  30. 21 Jun, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-06-21 10:44:37 by simonmar] · 0c53bd0e
      simonmar authored
      Relax the restrictions on conflicting packages.  This should address
      many of the traps that people have been falling into with the current
      package story.
      
      Now, a local module can shadow a module in an exposed package, as long
      as the package is not otherwise required by the program.  GHC checks
      for conflicts when it knows the dependencies of the module being
      compiled.
      
      Also, we now check for module conflicts in exposed packages only when
      importing a module: if an import can be satisfied from multiple
      packages, that's an error.  It's not possible to prevent GHC from
      starting by installing packages now (unless you install another base
      package).
      
      It seems to be possible to confuse GHCi by having a local module
      shadowing a package module that goes away and comes back again.  I
      think it's nearly right, but strange happenings have been observed.
      
      I'll try to merge this into the STABLE branch.
      0c53bd0e
  31. 31 Mar, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-03-31 10:16:33 by simonmar] · 853e20a3
      simonmar authored
      Tweaks to get the GHC sources through Haddock.  Doesn't quite work
      yet, because Haddock complains about the recursive modules.  Haddock
      needs to understand SOURCE imports (it can probably just ignore them
      as a first attempt).
      853e20a3
  32. 26 Nov, 2004 1 commit
    • simonmar's avatar
      [project @ 2004-11-26 16:19:45 by simonmar] · ef5b4b14
      simonmar authored
      Further integration with the new package story.  GHC now supports
      pretty much everything in the package proposal.
      
        - GHC now works in terms of PackageIds (<pkg>-<version>) rather than
          just package names.  You can still specify package names without
          versions on the command line, as long as the name is unambiguous.
      
        - GHC understands hidden/exposed modules in a package, and will refuse
          to import a hidden module.  Also, the hidden/eposed status of packages
          is taken into account.
      
        - I had to remove the old package syntax from ghc-pkg, backwards
          compatibility isn't really practical.
      
        - All the package.conf.in files have been rewritten in the new syntax,
          and contain a complete list of modules in the package.  I've set all
          the versions to 1.0 for now - please check your package(s) and fix the
          version number & other info appropriately.
      
        - New options:
      
      	-hide-package P    sets the expose flag on package P to False
      	-ignore-package P  unregisters P for this compilation
      
      	For comparison, -package P sets the expose flag on package P
              to True, and also causes P to be linked in eagerly.
      
              -package-name is no longer officially supported.  Unofficially, it's
      	a synonym for -ignore-package, which has more or less the same effect
      	as -package-name used to.
      
      	Note that a package may be hidden and yet still be linked into
      	the program, by virtue of being a dependency of some other package.
      	To completely remove a package from the compiler's internal database,
              use -ignore-package.
      
      	The compiler will complain if any two packages in the
              transitive closure of exposed packages contain the same
              module.
      
      	You *must* use -ignore-package P when compiling modules for
              package P, if package P (or an older version of P) is already
              registered.  The compiler will helpfully complain if you don't.
      	The fptools build system does this.
      
         - Note: the Cabal library won't work yet.  It still thinks GHC uses
           the old package config syntax.
      
      Internal changes/cleanups:
      
         - The ModuleName type has gone away.  Modules are now just (a
           newtype of) FastStrings, and don't contain any package information.
           All the package-related knowledge is in DynFlags, which is passed
           down to where it is needed.
      
         - DynFlags manipulation has been cleaned up somewhat: there are no
           global variables holding DynFlags any more, instead the DynFlags
           are passed around properly.
      
         - There are a few less global variables in GHC.  Lots more are
           scheduled for removal.
      
         - -i is now a dynamic flag, as are all the package-related flags (but
           using them in {-# OPTIONS #-} is Officially Not Recommended).
      
         - make -j now appears to work under fptools/libraries/.  Probably
           wouldn't take much to get it working for a whole build.
      ef5b4b14
  33. 30 Sep, 2004 1 commit
    • simonpj's avatar
      [project @ 2004-09-30 10:35:15 by simonpj] · 23f40f0e
      simonpj authored
      ------------------------------------
      	Add Generalised Algebraic Data Types
      	------------------------------------
      
      This rather big commit adds support for GADTs.  For example,
      
          data Term a where
       	  Lit :: Int -> Term Int
      	  App :: Term (a->b) -> Term a -> Term b
      	  If  :: Term Bool -> Term a -> Term a
      	  ..etc..
      
          eval :: Term a -> a
          eval (Lit i) = i
          eval (App a b) = eval a (eval b)
          eval (If p q r) | eval p    = eval q
          		    | otherwise = eval r
      
      
      Lots and lots of of related changes throughout the compiler to make
      this fit nicely.
      
      One important change, only loosely related to GADTs, is that skolem
      constants in the typechecker are genuinely immutable and constant, so
      we often get better error messages from the type checker.  See
      TcType.TcTyVarDetails.
      
      There's a new module types/Unify.lhs, which has purely-functional
      unification and matching for Type. This is used both in the typechecker
      (for type refinement of GADTs) and in Core Lint (also for type refinement).
      23f40f0e
  34. 13 Aug, 2004 1 commit
  35. 02 Jun, 2003 1 commit
  36. 14 May, 2003 1 commit
    • simonmar's avatar
      [project @ 2003-05-14 09:13:52 by simonmar] · 7a236a56
      simonmar authored
      Change the way SRTs are represented:
      
      Previously, the SRT associated with a function or thunk would be a
      sub-list of the enclosing top-level function's SRT.  But this approach
      can lead to lots of duplication: if a CAF is referenced in several
      different thunks, then it may appear several times in the SRT.
      Let-no-escapes compound the problem, because the occurrence of a
      let-no-escape-bound variable would expand to all the CAFs referred to
      by the let-no-escape.
      
      The new way is to describe the SRT associated with a function or thunk
      as a (pointer+offset,bitmap) pair, where the pointer+offset points
      into some SRT table (the enclosing function's SRT), and the bitmap
      indicates which entries in this table are "live" for this closure.
      The bitmap is stored in the 16 bits previously used for the length
      field, but this rarely overflows.  When it does overflow, we store the
      bitmap externally in a new "SRT descriptor".
      
      Now the enclosing SRT can be a set, hence eliminating the duplicates.
      
      Also, we now have one SRT per top-level function in a recursive group,
      where previously we used to have one SRT for the whole group.  This
      helps keep the size of SRTs down.
      
      Bottom line: very little difference most of the time.  GHC itself got
      slightly smaller.  One bad case of a module in GHC which had a huge
      SRT has gone away.
      
      While I was in the area:
      
        - Several parts of the back-end require bitmaps.  Functions for
          creating bitmaps are now centralised in the Bitmap module.
      
        - We were trying to be independent of word-size in a couple of
          places in the back end, but we've now abandoned that strategy so I
          simplified things a bit.
      7a236a56
  37. 11 Dec, 2002 1 commit
    • simonmar's avatar
      [project @ 2002-12-11 15:36:20 by simonmar] · 0bffc410
      simonmar authored
      Merge the eval-apply-branch on to the HEAD
      ------------------------------------------
      
      This is a change to GHC's evaluation model in order to ultimately make
      GHC more portable and to reduce complexity in some areas.
      
      At some point we'll update the commentary to describe the new state of
      the RTS.  Pending that, the highlights of this change are:
      
        - No more Su.  The Su register is gone, update frames are one
          word smaller.
      
        - Slow-entry points and arg checks are gone.  Unknown function calls
          are handled by automatically-generated RTS entry points (AutoApply.hc,
          generated by the program in utils/genapply).
      
        - The stack layout is stricter: there are no "pending arguments" on
          the stack any more, the stack is always strictly a sequence of
          stack frames.
      
          This means that there's no need for LOOKS_LIKE_GHC_INFO() or
          LOOKS_LIKE_STATIC_CLOSURE() any more, and GHC doesn't need to know
          how to find the boundary between the text and data segments (BIG WIN!).
      
        - A couple of nasty hacks in the mangler caused by the neet to
          identify closure ptrs vs. info tables have gone away.
      
        - Info tables are a bit more complicated.  See InfoTables.h for the
          details.
      
        - As a side effect, GHCi can now deal with polymorphic seq.  Some bugs
          in GHCi which affected primitives and unboxed tuples are now
          fixed.
      
        - Binary sizes are reduced by about 7% on x86.  Performance is roughly
          similar, some programs get faster while some get slower.  I've seen
          GHCi perform worse on some examples, but haven't investigated
          further yet (GHCi performance *should* be about the same or better
          in theory).
      
        - Internally the code generator is rather better organised.  I've moved
          info-table generation from the NCG into the main codeGen where it is
          shared with the C back-end; info tables are now emitted as arrays
          of words in both back-ends.  The NCG is one step closer to being able
          to support profiling.
      
      This has all been fairly thoroughly tested, but no doubt I've messed
      up the commit in some way.
      0bffc410