1. 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
  2. 17 Jan, 2012 1 commit
  3. 05 Nov, 2011 1 commit
  4. 25 Aug, 2011 1 commit
  5. 17 Jun, 2011 3 commits
    • Ian Lynagh's avatar
      Fix build · a07ce419
      Ian Lynagh authored
      I'm not sure what's going on with these warnings, but for now
      I've suppressed them all.
      a07ce419
    • Ian Lynagh's avatar
      Fix the build with GHC 6.12 · 7a80e2dd
      Ian Lynagh authored
      7a80e2dd
    • Edward Z. Yang's avatar
      Port MachOp folding to new code generator. · b8e0ce7b
      Edward Z. Yang authored
          * Rewrote cmmMachOpFold to cmmMachOpFoldM, which returns
            Nothing if no folding took place.
          * Wrote some generic mapping functions which take functions
            of form 'a -> Maybe a' and are smart about sharing.
          * Split up optimizations from PIC and PPC work in the native
            codegen, so they'll be easier to turn off later
            (they are not currently being turned off, however.)
          * Whitespace fixes!
      
      ToDo: Turn off MachOp folding when new codegenerator is being used.
      Signed-off-by: Edward Z. Yang's avatarEdward Z. Yang <ezyang@mit.edu>
      b8e0ce7b
  6. 14 Jun, 2011 4 commits
  7. 13 Jun, 2011 1 commit
  8. 15 May, 2011 4 commits
  9. 15 Apr, 2011 2 commits
  10. 11 Apr, 2011 1 commit
    • Edward Z. Yang's avatar
      Unsafe foreign calls (fat machine instructions) do not kill all registers. · 8a0ab97b
      Edward Z. Yang authored
      The new code generator was doing some interesting spilling across
      unsafe foreign calls:
      
           _c1ao::I32 = Hp - 4;
           I32[Sp - 20] = _c1ao::I32;
           foreign "ccall"
             newCAF((BaseReg, PtrHint), (R1, PtrHint))[_unsafe_call_];
           _c1ao::I32 = I32[Sp - 20];
      
      This is fairly unnecessary, and resulted from over-conservative
      liveness analysis from CmmLive.  We can see that the old code
      generator only saved volatile registers across unsafe foreign calls:
      spilling variables was done by saveVolatileVarsAndRegs, which was
      only performed for ordinary calls.
      
      This commit removes the excess kill from the liveness analysis, as well
      as the *redundant* excess kill from spilling-and-reloading, and adds a
      note to CmmNode to this effect.  The only registers we need to kill
      are the ones that the foreign call assigns to, just like any other
      machine instruction.
      Signed-off-by: Edward Z. Yang's avatarEdward Z. Yang <ezyang@mit.edu>
      8a0ab97b
  11. 28 Jan, 2011 1 commit
  12. 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
  13. 15 Dec, 2010 1 commit
  14. 13 Sep, 2010 2 commits
  15. 12 Nov, 2009 1 commit
  16. 18 Sep, 2009 1 commit
  17. 24 Jul, 2009 1 commit
  18. 07 Jul, 2009 1 commit
  19. 16 Mar, 2009 1 commit
    • dias@eecs.tufts.edu's avatar
      stack overflows and out of memory's · 5dc8b425
      dias@eecs.tufts.edu authored
      1. Stack overflow fixed by making dataflow monad strict in the state.
      2. Out of memory fixed by "forgetting" lastoutfacts in the dataflow monad
         where we should. We were creating an unnecessarily long list that grew
         exponentially...
      5dc8b425
  20. 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
  21. 17 Oct, 2008 1 commit
  22. 16 Oct, 2008 1 commit
    • dias@eecs.harvard.edu's avatar
      Fixed linear regalloc bug, dropped some tracing code · c62b824e
      dias@eecs.harvard.edu authored
      o The linear-scan register allocator sometimes allocated a block
        before allocating one of its predecessors, which could lead
        to inconsistent allocations. Now, we allocate a block only
        if a predecessor has set the "incoming" assignments for the block
        (or if it's the procedure's entry block).
      o Also commented out some tracing code on the new codegen path.
      c62b824e
  23. 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
  24. 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
  25. 29 May, 2008 2 commits
    • dias@eecs.harvard.edu's avatar
      Replacing copyins and copyouts with data-movement instructions · 0d80489c
      dias@eecs.harvard.edu authored
      o Moved BlockId stuff to a new file to avoid module recursion
      o Defined stack areas for parameter-passing locations and spill slots
      o Part way through replacing copy in and copy out nodes
        - added movement instructions for stack pointer
        - added movement instructions for call and return parameters
          (but not with the proper calling conventions)
      o Inserting spills and reloads for proc points is now procpoint-aware
        (it was relying on the presence of a CopyIn node as a proxy for
         procpoint knowledge)
      o Changed ZipDataflow to expect AGraphs (instead of being polymorphic in
         the type of graph)
      0d80489c
    • dias@eecs.harvard.edu's avatar
      Cmm back end upgrades · 25628e27
      dias@eecs.harvard.edu authored
      Several changes in this patch, partially bug fixes, partially new code:
      o bug fixes in ZipDataflow
         - added some checks to verify that facts converge
         - removed some erroneous checks of convergence on entry nodes
         - added some missing applications of transfer functions
      o changed dataflow clients to use ZipDataflow, making ZipDataflow0 obsolete
      o eliminated DFA monad (no need for separate analysis and rewriting monads with ZipDataflow)
      o started stack layout changes
         - no longer generating CopyIn and CopyOut nodes (not yet fully expunged though)
         - still not using proper calling conventions
      o simple new optimizations:
         - common block elimination
            -- have not yet tried to move the Adams opt out of CmmProcPointZ
         - block concatenation
      o piped optimization fuel up to the HscEnv
         - can be limited by a command-line flag
         - not tested, and probably not yet properly used by clients
      o added unique supply to FuelMonad, also lifted unique supply to DFMonad
      25628e27
  26. 03 May, 2008 1 commit
  27. 04 Jan, 2008 1 commit
  28. 26 Dec, 2007 1 commit
    • Isaac Dupree's avatar
      move and generalize another instance (#1405) · 5a7a3110
      Isaac Dupree authored
      was instance Outputable CmmGraph
      type CmmGraph = LGraph Middle Last
      now instance (ctx) => Outputable (LGraph m l),
      in module with LGraph where it belongs
      This also let us reduce the context of DebugNodes to Haskell98,
      leaving that class's only extension being multi-parameter.
      (also Outputable (LGraph M Last) with M = ExtendWithSpills Middle
      was another redundant instance that was then removed)
      5a7a3110
  29. 21 Sep, 2007 1 commit
    • nr@eecs.harvard.edu's avatar
      massive convulsion in ZipDataflow · fee569a6
      nr@eecs.harvard.edu authored
      After my talk, I got the idea of 'shallow rewriting' for the
      dataflow framework.  Here it is implemented, along with
      some related ideas late making Graph and not LGraph primary.
      
      The only bad thing is that the whole bit is stitched together
      out of ill-fitting pieces, kind of like Frankenstein's monster.
      A new ZipDataflow will rise out of the ashes.
      fee569a6