1. 20 Aug, 2007 1 commit
  2. 09 Aug, 2007 1 commit
  3. 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
  4. 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
  5. 16 Jul, 2007 1 commit
  6. 17 Jul, 2007 1 commit
  7. 27 Jun, 2007 4 commits
  8. 25 May, 2007 1 commit
    • Michael D. Adams's avatar
      Moved global register saving from the backend to codeGen · bd3a364d
      Michael D. Adams authored
      This frees the Cmm data type from keeping a list of live global registers
      in CmmCall which helps prepare for the CPS conversion phase.
      
      CPS conversion does its own liveness analysis and takes input that should
      not directly refer to parameter registers (e.g. R1, F5, D3, L2).  Since
      these are the only things which could occur in the live global register
      list, CPS conversion makes that field of the CmmCall constructor obsolite.
      
      Once the CPS conversion pass is fully implemented, global register saving
      will move from codeGen into the CPS pass.  Until then, this patch
      is worth scrutinizing and testing to ensure it doesn't cause any performance
      or correctness problems as the code passed to the backends by the CPS
      converting will look very similar to the code that this patch makes codeGen
      pass to the backend.
      bd3a364d
  9. 09 May, 2007 1 commit
  10. 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
  11. 19 Jan, 2007 2 commits
  12. 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
  13. 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
  14. 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
  15. 06 Jan, 2006 1 commit
    • simonmar's avatar
      [project @ 2006-01-06 16:30:17 by simonmar] · 9d7da331
      simonmar authored
      Add support for UTF-8 source files
      
      GHC finally has support for full Unicode in source files.  Source
      files are now assumed to be UTF-8 encoded, and the full range of
      Unicode characters can be used, with classifications recognised using
      the implementation from Data.Char.  This incedentally means that only
      the stage2 compiler will recognise Unicode in source files, because I
      was too lazy to port the unicode classifier code into libcompat.
      
      Additionally, the following synonyms for keywords are now recognised:
      
        forall symbol 	(U+2200)	forall
        right arrow   	(U+2192)	->
        left arrow   		(U+2190)	<-
        horizontal ellipsis 	(U+22EF)	..
      
      there are probably more things we could add here.
      
      This will break some source files if Latin-1 characters are being used.
      In most cases this should result in a UTF-8 decoding error.  Later on
      if we want to support more encodings (perhaps with a pragma to specify
      the encoding), I plan to do it by recoding into UTF-8 before parsing.
      
      Internally, there were some pretty big changes:
      
        - FastStrings are now stored in UTF-8
      
        - Z-encoding has been moved right to the back end.  Previously we
          used to Z-encode every identifier on the way in for simplicity,
          and only decode when we needed to show something to the user.
          Instead, we now keep every string in its UTF-8 encoding, and
          Z-encode right before printing it out.  To avoid Z-encoding the
          same string multiple times, the Z-encoding is cached inside the
          FastString the first time it is requested.
      
          This speeds up the compiler - I've measured some definite
          improvement in parsing at least, and I expect compilations overall
          to be faster too.  It also cleans up a lot of cruft from the
          OccName interface.  Z-encoding is nicely hidden inside the
          Outputable instance for Names & OccNames now.
      
        - StringBuffers are UTF-8 too, and are now represented as
          ForeignPtrs.
      
        - I've put together some test cases, not by any means exhaustive,
          but there are some interesting UTF-8 decoding error cases that
          aren't obvious.  Also, take a look at unicode001.hs for a demo.
      9d7da331
  16. 07 Jul, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-07-07 13:50:40 by simonmar] · cca5f22b
      simonmar authored
      small performance fix: in via-C mode we previously always created a
      switch instead of an conditional-tree for a multi-branch case.  Refine
      this slightly so that 2-branch switches turn into conditionals again,
      since gcc doesn't do a good job of optimising the equivalent switch.
      cca5f22b
  17. 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
  18. 11 Apr, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-04-11 08:52:29 by simonmar] · 5ba806d8
      simonmar authored
      When generating a switch for:
      
        case e of
          0 -> A
          1 -> B
      
      instead of generating
      
        if (e < 1) then goto A
        B
      
      generate
      
        if (e >= 1) then goto B
        A
      
      because this helps the NCG to generate better code.  In particular, if
      e is a comparison, then we don't need to reverse the sense of the
      comparison to eliminate the comparse against 1 (the NCG does try to
      reverse the comparison, but floating-point comparisons can't be
      reversed).
      5ba806d8
  19. 24 Mar, 2005 1 commit
  20. 18 Mar, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-03-18 13:37:27 by simonmar] · d1c1b7d0
      simonmar authored
      Flags cleanup.
      
      Basically the purpose of this commit is to move more of the compiler's
      global state into DynFlags, which is moving in the direction we need
      to go for the GHC API which can have multiple active sessions
      supported by a single GHC instance.
      
      Before:
      
      $ grep 'global_var' */*hs | wc -l
           78
      
      After:
      
      $ grep 'global_var' */*hs | wc -l
           27
      
      Well, it's an improvement.  Most of what's left won't really affect
      our ability to host multiple sessions.
      
      Lots of static flags have become dynamic flags (yay!).  Notably lots
      of flags that we used to think of as "driver" flags, like -I and -L,
      are now dynamic.  The most notable static flags left behind are the
      "way" flags, eg. -prof.  It would be nice to fix this, but it isn't
      urgent.
      
      On the way, lots of cleanup has happened.  Everything related to
      static and dynamic flags lives in StaticFlags and DynFlags
      respectively, and they share a common command-line parser library in
      CmdLineParser.  The flags related to modes (--makde, --interactive
      etc.) are now private to the front end: in fact private to Main
      itself, for now.
      d1c1b7d0
  21. 22 Feb, 2005 1 commit
  22. 28 Jan, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-01-28 12:55:17 by simonmar] · 153b9cb9
      simonmar authored
      Rationalise the BUILD,HOST,TARGET defines.
      
      Recall that:
      
        - build is the platform we're building on
        - host is the platform we're running on
        - target is the platform we're generating code for
      
      The change is that now we take these definitions as applying from the
      point of view of the particular source code being built, rather than
      the point of view of the whole build tree.
      
      For example, in RTS and library code, we were previously testing the
      TARGET platform.  But under the new rule, the platform on which this
      code is going to run is the HOST platform.  TARGET only makes sense in
      the compiler sources.
      
      In practical terms, this means that the values of BUILD, HOST & TARGET
      may vary depending on which part of the build tree we are in.
      
      Actual changes:
      
       - new file: includes/ghcplatform.h contains platform defines for
         the RTS and library code.
      
       - new file: includes/ghcautoconf.h contains the autoconf settings
         only (HAVE_BLAH).  This is so that we can get hold of these
         settings independently of the platform defines when necessary
         (eg. in GHC).
      
       - ghcconfig.h now #includes both ghcplatform.h and ghcautoconf.h.
      
       - MachRegs.h, which is included into both the compiler and the RTS,
         now has to cope with the fact that it might need to test either
         _TARGET_ or _HOST_ depending on the context.
      
       - the compiler's Makefile now generates
           stage{1,2,3}/ghc_boot_platform.h
         which contains platform defines for the compiler.  These differ
         depending on the stage, of course: in stage2, the HOST is the
         TARGET of stage1.  This was wrong before.
      
       - The compiler doesn't get platform info from Config.hs any more.
         Previously it did (sometimes), but unless we want to generate
         a new Config.hs for each stage we can't do this.
      
       - GHC now helpfully defines *_{BUILD,HOST}_{OS,ARCH} automatically
         in CPP'd Haskell source.
      
       - ghcplatform.h defines *_TARGET_* for backwards compatibility
         (ghcplatform.h is included by ghcconfig.h, which is included by
         config.h, so code which still #includes config.h will get the TARGET
         settings as before).
      
       - The Users's Guide is updated to mention *_HOST_* rather than
         *_TARGET_*.
      
       - coding-style.html in the commentary now contains a section on
         platform defines.  There are further doc updates to come.
      
      Thanks to Wolfgang Thaller for pointing me in the right direction.
      153b9cb9
  23. 23 Jan, 2005 1 commit
    • wolfgang's avatar
      [project @ 2005-01-23 18:50:40 by wolfgang] · e171a977
      wolfgang authored
      Make the NCG distinguish between the read-only data section and the
      "relocatable read-only data" section.
      Read-only data is supposed to be _really_ read-only, whereas "relrodata"
      can have relocations, but should not be modified by the program at runtime.
      
      For Linux, put relrodata into ".data" by default, as the dynamic linker
      tends to do evil things to avoid relocating things in read-only sections.
      e171a977
  24. 12 Jan, 2005 1 commit
  25. 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
  26. 17 Sep, 2004 1 commit
  27. 15 Sep, 2004 2 commits
    • simonmar's avatar
      [project @ 2004-09-15 12:06:08 by simonmar] · 39439207
      simonmar authored
      Oops, fix bugs in previous commit.
      39439207
    • simonmar's avatar
      [project @ 2004-09-15 11:45:24 by simonmar] · f220cc51
      simonmar authored
      Add a couple of cases to mk_switch to catch the case when we have a
      tag range that has a lot of default cases at either end, and we're not
      using a single switch.  In situations like this we want to eliminate
      the default cases with an if-statement, before dealing with the rest
      of the branches, which might then be suitable for a switch.
      
      Also, ignore empty tag slots at either end of the range if there is no
      default case.
      
      This might work around a gcc 2.95 bug that we tickled with the
      code being generated before.
      f220cc51
  28. 20 Aug, 2004 2 commits
    • simonmar's avatar
      [project @ 2004-08-20 12:21:03 by simonmar] · 557d889d
      simonmar authored
      Simplify the "impossible branch" handling, and fix a bug in the
      process.  CmmSwitch encodes the possibility of having impossible
      branches (the destinations are Maybe BlockId rather than just BlockId)
      so we don't need to encode impossible branches as dummy blocks
      containing a jump to an impossible location (currently 0).
      
      However, PprC and PprCmm weren't set up to cope with Nothings in a
      CmmSwitch, so this commit fixes that too.
      557d889d
    • simonmar's avatar
      [project @ 2004-08-20 11:20:16 by simonmar] · fa93dff5
      simonmar authored
      Give literal string labels a _str suffix, to make it less likely that
      they'll clash with a symbol in scope in a C file.
      fa93dff5
  29. 17 Aug, 2004 1 commit
    • simonpj's avatar
      [project @ 2004-08-17 15:23:47 by simonpj] · 59c796f8
      simonpj authored
      -------------------------------
      	Use merge-sort not quicksort
      	Nuke quicksort altogether
      	-------------------------------
      
      Quicksort has O(n**2) behaviour worst case, and this occasionally bites.
      In particular, when compiling large files consisting only of static data,
      we get loads of top-level delarations -- and that led to more than half the
      total compile time being spent in the strongly connected component analysis
      for the occurrence analyser.  Switching to merge sort completely solved the
      problem.
      
      I've nuked quicksort altogether to make sure this does not happen again.
      59c796f8
  30. 13 Aug, 2004 1 commit