1. 30 Oct, 2012 1 commit
  2. 08 Oct, 2012 1 commit
    • Simon Marlow's avatar
      Produce new-style Cmm from the Cmm parser · a7c0387d
      Simon Marlow authored
      The main change here is that the Cmm parser now allows high-level cmm
      code with argument-passing and function calls.  For example:
      
      foo ( gcptr a, bits32 b )
      {
        if (b > 0) {
           // we can make tail calls passing arguments:
           jump stg_ap_0_fast(a);
        }
      
        return (x,y);
      }
      
      More details on the new cmm syntax are in Note [Syntax of .cmm files]
      in CmmParse.y.
      
      The old syntax is still more-or-less supported for those occasional
      code fragments that really need to explicitly manipulate the stack.
      However there are a couple of differences: it is now obligatory to
      give a list of live GlobalRegs on every jump, e.g.
      
        jump %ENTRY_CODE(Sp(0)) [R1];
      
      Again, more details in Note [Syntax of .cmm files].
      
      I have rewritten most of the .cmm files in the RTS into the new
      syntax, except for AutoApply.cmm which is generated by the genapply
      program: this file could be generated in the new syntax instead and
      would probably be better off for it, but I ran out of enthusiasm.
      
      Some other changes in this batch:
      
       - The PrimOp calling convention is gone, primops now use the ordinary
         NativeNodeCall convention.  This means that primops and "foreign
         import prim" code must be written in high-level cmm, but they can
         now take more than 10 arguments.
      
       - CmmSink now does constant-folding (should fix #7219)
      
       - .cmm files now go through the cmmPipeline, and as a result we
         generate better code in many cases.  All the object files generated
         for the RTS .cmm files are now smaller.  Performance should be
         better too, but I haven't measured it yet.
      
       - RET_DYN frames are removed from the RTS, lots of code goes away
      
       - we now have some more canned GC points to cover unboxed-tuples with
         2-4 pointers, which will reduce code size a little.
      a7c0387d
  3. 12 Sep, 2012 1 commit
  4. 04 Sep, 2012 1 commit
  5. 09 Aug, 2012 1 commit
  6. 07 Aug, 2012 1 commit
  7. 06 Aug, 2012 2 commits
  8. 02 Aug, 2012 1 commit
    • Simon Marlow's avatar
      Explicitly share some return continuations · 6ede0067
      Simon Marlow authored
      Instead of relying on common-block-elimination to share return
      continuations in the common case (case-alternative heap checks) we do
      it explicitly.  This isn't hard to do, is more robust, and saves some
      compilation time.  Full commentary in Note [sharing continuations].
      6ede0067
  9. 30 Jul, 2012 1 commit
    • Simon Marlow's avatar
      New codegen: do not split proc-points when using the NCG · f1ed6a10
      Simon Marlow authored
      Proc-point splitting is only required by backends that do not support
      having proc-points within a code block (that is, everything except the
      native backend, i.e. LLVM and C).
      
      Not doing proc-point splitting saves some compilation time, and might
      produce slightly better code in some cases.
      f1ed6a10
  10. 06 Jul, 2012 1 commit
  11. 13 Jun, 2012 1 commit
    • Ian Lynagh's avatar
      Remove PlatformOutputable · d06edb8e
      Ian Lynagh authored
      We can now get the Platform from the DynFlags inside an SDoc, so we
      no longer need to pass the Platform in.
      d06edb8e
  12. 06 Mar, 2012 1 commit
    • Simon Marlow's avatar
      Lower safe foreign calls in the new CmmLayoutStack · 93e42a68
      Simon Marlow authored
      We also generate much better code for safe foreign calls (and maybe
      also unsafe foreign calls) than previously.  See the two new Notes:
      
      Note [lower safe foreign calls]
      Note [safe foreign call convention]
      93e42a68
  13. 08 Feb, 2012 1 commit
    • Simon Marlow's avatar
      New stack layout algorithm · 76999b60
      Simon Marlow authored
      Also:
       - improvements to code generation: push slow-call continuations
         on the stack instead of generating explicit continuations
      
       - remove unused CmmInfo wrapper type (replace with CmmInfoTable)
      
       - squash Area and AreaId together, remove now-unused RegSlot
      
       - comment out old unused stack-allocation code that no longer
         compiles after removal of RegSlot
      76999b60
  14. 26 Jan, 2012 1 commit
  15. 25 Jan, 2012 1 commit
  16. 19 Dec, 2011 1 commit
    • Ian Lynagh's avatar
      Add a class HasDynFlags(getDynFlags) · 06c6d970
      Ian Lynagh authored
      We no longer have many separate, clashing getDynFlags functions
      
      I've given each GhcMonad its own HasDynFlags instance, rather than
      using UndecidableInstances to make a GhcMonad m => HasDynFlags m
      instance.
      06c6d970
  17. 04 Nov, 2011 1 commit
  18. 02 Oct, 2011 1 commit
  19. 25 Aug, 2011 3 commits
  20. 05 Jul, 2011 1 commit
    • batterseapower's avatar
      Refactoring: use a structured CmmStatics type rather than [CmmStatic] · 54843b5b
      batterseapower authored
      I observed that the [CmmStatics] within CmmData uses the list in a very stylised way.
      The first item in the list is almost invariably a CmmDataLabel. Many parts of the
      compiler pattern match on this list and fail if this is not true.
      
      This patch makes the invariant explicit by introducing a structured type CmmStatics
      that holds the label and the list of remaining [CmmStatic].
      
      There is one wrinkle: the x86 backend sometimes wants to output an alignment directive just
      before the label. However, this can be easily fixed up by parameterising the native codegen
      over the type of CmmStatics (though the GenCmmTop parameterisation) and using a pair
      (Alignment, CmmStatics) there instead.
      
      As a result, I think we will be able to remove CmmAlign and CmmDataLabel from the CmmStatic
      data type, thus nuking a lot of code and failing pattern matches. This change will come as part
      of my next patch.
      54843b5b
  21. 13 Jun, 2011 1 commit
  22. 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
  23. 26 Oct, 2010 1 commit
  24. 21 Oct, 2010 2 commits
  25. 04 Mar, 2010 1 commit
  26. 01 Jul, 2009 1 commit
  27. 23 Mar, 2009 2 commits
  28. 03 Mar, 2009 1 commit
    • dias@eecs.harvard.edu's avatar
      A few bug fixes; some improvements spurred by paper writing · 31a9d048
      dias@eecs.harvard.edu authored
      Among others:
      - Fixed Stg->C-- translation of let-no-escapes -- it's important to use the
        right continuation...
      - Fixed infinite recursion in X86 backend (shortcutJump mishandled infinite loops)
      - Fixed yet another wrong calling convention -- primops take args only in vanilla regs,
        but they may return results on the stack!
      - Removed StackInfo from LGraph and Block -- now in LastCall and CmmZ
      - Updated avail-variable and liveness code
      31a9d048
  29. 14 Oct, 2008 1 commit
    • dias@eecs.harvard.edu's avatar
      Don't adjust hp up when the case scrutinee won't allocate · 309f64a0
      dias@eecs.harvard.edu authored
      If the case scrutinee can't allocate, we don't need to do a heap
      check in the case alternatives. (A previous patch got that right.)
      In that case, we had better not adjust the heap pointer to recover
      unused stack space before evaluating the scrutinee -- because we
      aren't going to reallocate for the case alternative.
      309f64a0
  30. 13 Oct, 2008 1 commit
    • dias@eecs.harvard.edu's avatar
      Big collection of patches for the new codegen branch. · e6243a81
      dias@eecs.harvard.edu authored
      o Fixed bug that emitted the copy-in code for closure entry
        in the wrong place -- at the initialization of the closure.
      o Refactored some of the closure entry code.
      o Added code to check that no LocalRegs are live-in to a procedure
         -- trip up some buggy programs earlier
      o Fixed environment bindings for thunks
         -- we weren't (re)binding the free variables in a thunk
      o Fixed a bug in proc-point splitting that dropped some updates
        to the entry block in a procedure.
      o Fixed improper calls to code that generates CmmLit's for strings
      o New invariant on cg_loc in CgIdInfo: the expression is always tagged
      o Code to load free vars on entry to a thunk was (wrongly) placed before
        the heap check.
      o Some of the StgCmm code was redundantly passing around Id's
        along with CgIdInfo's; no more.
      o Initialize the LocalReg's that point to a closure before allocating and
        initializing the closure itself -- otherwise, we have problems with
        recursive closure bindings
      o BlockEnv and BlockSet types are now abstract.
      o Update frames:
        - push arguments in Old call area
        - keep track of the return sp in the FCode monad
        - keep the return sp in every call, tail call, and return
            (because it might be different at different call sites,
             e.g. tail calls to the gc after a heap check are performed
                  before pushing the update frame)
        - set the sp appropriately on returns and tail calls
      o Reduce call, tail call, and return to a single LastCall node
      o Added slow entry code, using different calling conventions on entry and tail call
      o More fixes to the calling convention code.
        The tricky stuff is all about the closure environment: it must be passed in R1,
        but in non-closures, there is no such argument, so we can't treat all arguments
        the same way: the closure environment is special. Maybe the right step forward
        would be to define a different calling convention for closure arguments.
      o Let-no-escapes need to be emitted out-of-line -- otherwise, we drop code.
      o Respect RTS requirement of word alignment for pointers
        My stack allocation can pack sub-word values into a single word on the stack,
        but it wasn't requiring word-alignment for pointers. It does now,
        by word-aligning both pointer registers and call areas.
      o CmmLint was over-aggresively ruling out non-word-aligned memory references,
        which may be kosher now that we can spill small values into a single word.
      o Wrong label order on a conditional branch when compiling switches.
      o void args weren't dropped in many cases.
        To help prevent this kind of mistake, I defined a NonVoid wrapper,
        which I'm applying only to Id's for now, although there are probably
        other good candidates.
      o A little code refactoring: separate modules for procpoint analysis splitting, 
        stack layout, and building infotables.
      o Stack limit check: insert along with the heap limit check, using a symbolic
        constant (a special CmmLit), then replace it when the stack layout is known.
      o Removed last node: MidAddToContext 
      o Adding block id as a literal: means that the lowering of the calling conventions
        no longer has to produce labels early, which was inhibiting common-block elimination.
        Will also make it easier for the non-procpoint-splitting path.
      o Info tables: don't try to describe the update frame!
      o Over aggressive use of NonVoid!!!!
        Don't drop the non-void args before setting the type of the closure!!!
      o Sanity checking:
        Added a pass to stub dead dead slots on the stack
        (only ~10 lines with the dataflow framework)
      o More sanity checking:
        Check that incoming pointer arguments are non-stubbed.
        Note: these checks are still subject to dead-code removal, but they should
        still be quite helpful.
      o Better sanity checking: why stop at function arguments?
        Instead, in mkAssign, check that _any_ assignment to a pointer type is non-null
        -- the sooner the crash, the easier it is to debug.
        Still need to add the debugging flag to turn these checks on explicitly.
      o Fixed yet another calling convention bug.
        This time, the calls to the GC were wrong. I've added a new convention
        for GC calls and invoked it where appropriate.
        We should really straighten out the calling convention stuff:
          some of the code (and documentation) is spread across the compiler,
          and there's some magical use of the node register that should really
          be handled (not avoided) by calling conventions.
      o Switch bug: the arms in mkCmmLitSwitch weren't returning to a single join point.
      o Environment shadowing problem in Stg->Cmm:
        When a closure f is bound at the top-level, we should not bind f to the
        node register on entry to the closure.
        Why? Because if the body of f contains a let-bound closure g that refers
        to f, we want to make sure that it refers to the static closure for f.
        Normally, this would all be fine, because when we compile a closure,
        we rebind free variables in the environment. But f doesn't look like
        a free variable because it's a static value. So, the binding for f
        remains in the environment when we compile g, inconveniently referring
        to the wrong thing.
        Now, I bind the variable in the local environment only if the closure is not
        bound at the top level. It's still okay to make assumptions about the
        node holding the closure environment; we just won't find the binding
        in the environment, so code that names the closure will now directly
        get the label of the static closure, not the node register holding a
        pointer to the static closure.
      o Don't generate bogus Cmm code containing SRTs during the STG -> Cmm pass!
        The tables made reference to some labels that don't exist when we compute and
        generate the tables in the back end.
      o Safe foreign calls need some special treatment (at least until we have the integrated
        codegen). In particular:
        o they need info tables
        o they are not procpoints -- the successor had better be in the same procedure
        o we cannot (yet) implement the calling conventions early, which means we have
          to carry the calling-conv info all the way to the end
      o We weren't following the old convention when registering a module.
        Now, we use update frames to push any new modules that have to be registered
        and enter the youngest one on the stack.
        We also use the update frame machinery to specify that the return should pop
        the return address off the stack.
      o At each safe foreign call, an infotable must be at the bottom of the stack,
        and the TSO->sp must point to it.
      o More problems with void args in a direct call to a function:
        We were checking the args (minus voids) to check whether the call was saturated,
        which caused problems when the function really wasn't saturated because it
        took an extra void argument.
      o Forgot to distinguish integer != from floating != during Stg->Cmm
      o Updating slotEnv and areaMap to include safe foreign calls
        The dataflow analyses that produce the slotEnv and areaMap give
        results for each basic block, but we also need the results for
        a safe foreign call, which is a middle node.
        After running the dataflow analysis, we have another pass that
        updates the results to includ any safe foreign calls.
      o Added a static flag for the debugging technique that inserts
        instructions to stub dead slots on the stack and crashes when
        a stubbed value is loaded into a pointer-typed LocalReg.
      o C back end expects to see return continuations before their call sites.
        Sorted the flowgraphs appropriately after splitting.
      o PrimOp calling conventions are special -- unlimited registers, no stack
        Yet another calling convention...
      o More void value problems: if the RHS of a case arm is a void-typed variable,
        don't try to return it.
      o When calling some primOp, they may allocate memory; if so, we need to
        do a heap check when we return from the call.
      e6243a81
  31. 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