1. 01 Aug, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-08-01 09:08:25 by simonpj] · fe69f3c1
      simonpj authored
      Simon's Marktoberdorf Commits
      
      1.  Tidy up the renaming story for "system binders", such as
      dictionary functions, default methods, constructor workers etc.  These
      are now documented in HsDecls.  The main effect of the change, apart
      from tidying up, is to make the *type-checker* (instead of the
      renamer) generate names for dict-funs and default-methods.  This is
      good because Sergei's generic-class stuff generates new classes at
      typecheck time.
      
      
      2.  Fix the CSE pass so it does not require the no-shadowing invariant.
      Keith discovered that the simplifier occasionally returns a result
      with shadowing.  After much fiddling around (which has improved the
      code in the simplifier a bit) I found that it is nearly impossible to
      arrange that it really does do no-shadowing.  So I gave up and fixed
      the CSE pass (which is the only one to rely on it) instead.
      
      
      3. Fix a performance bug in the simplifier.  The change is in
      SimplUtils.interestingArg.  It computes whether an argment should 
      be considered "interesting"; if a function is applied to an interesting
      argument, we are more likely to inline that function.
      Consider this case
      	let x = 3 in f x
      The 'x' argument was considered "uninteresting" for a silly reason.
      Since x only occurs once, it was unconditionally substituted, but
      interestingArg didn't take account of that case.  Now it does.
      
      I also made interestingArg a bit more liberal.  Let's see if we
      get too much inlining now.
      
      
      4.  In the occurrence analyser, we were choosing a bad loop breaker.
      Here's the comment that's now in OccurAnal.reOrderRec
      
          score ((bndr, rhs), _, _)
      	| exprIsTrivial rhs 	   = 3	-- Practically certain to be inlined
      		-- Used to have also: && not (isExportedId bndr)
      		-- But I found this sometimes cost an extra iteration when we have
      		--	rec { d = (a,b); a = ...df...; b = ...df...; df = d }
      		-- where df is the exported dictionary. Then df makes a really
      		-- bad choice for loop breaker
      
      I also increased the score for bindings with a non-functional type, so that
      dictionaries have a better chance of getting inlined early
      
      
      5. Add a hash code to the InScopeSet (and make it properly abstract)
      This should make uniqAway a lot more robust.  Simple experiments suggest
      that uniqAway no longer gets into the long iteration chains that it used
      to.
      
      
      6.  Fix a bug in the inliner that made the simplifier tend to get into
      a loop where it would keep iterating ("4 iterations, bailing out" message).
      In SimplUtils.mkRhsTyLam we float bindings out past a big lambda, thus:
      	x = /\ b -> let g = \x -> f x x
      		    in E
      becomes
      	g* = /\a -> \x -> f x x
      	x = /\ b -> let g = g* b in E
      	
      It's essential that we don't simply inling g* back into the RHS of g,
      else we will be back to square 1.  The inliner is meant not to do this
      because there's no benefit to the inlining, but the size calculation
      was a little off in CoreUnfold.
      
      
      7.  In SetLevels we were bogus-ly building a Subst with an empty in-scope
      set, so a WARNING popped up when compiling some modules.  (knights/ChessSetList
      was the example that tickled it.)  Now in fact the warning wasn't an error,
      but the Right Thing to do is to carry down a proper Subst in SetLevels, so
      that is what I have now done.  It is very little more expensive.
      fe69f3c1
  2. 26 Jul, 2000 1 commit
  3. 23 Jul, 2000 1 commit
    • panne's avatar
      [project @ 2000-07-23 10:53:11 by panne] · c8a6996a
      panne authored
      Strictfp-like behaviour is the default now, which can be switched off
      via -fexcess-precision. (Has anybody a better name for this option?)
      c8a6996a
  4. 16 Jul, 2000 1 commit
  5. 11 Jul, 2000 1 commit
  6. 03 Jul, 2000 1 commit
    • panne's avatar
      [project @ 2000-07-03 21:31:28 by panne] · f9e358d0
      panne authored
      Print
         "Interface file unchanged"
      and
         "Module version unchanged, but usages differ; hence need new hi file"
      only when -ddump-rn-trace flag has been given. This is more consistent
      with the rest of GHC and the *nix world, and messes up less tests.
      f9e358d0
  7. 29 Jun, 2000 1 commit
  8. 18 Jun, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-06-18 08:37:17 by simonpj] · 91ef36b9
      simonpj authored
      *** MERGE WITH 4.07 ***
      
      * Fix the ambiguity check in TcMonotype.lhs so that
        it is not carried out for types read from interface 
        files.  Some workers may get ambiguous types but that
        does not matter, and should not make compilation fail.
        More detail in the comments with TcMonoType.tc_type_kind
        (the HsForAll case)
      
      * Don't create specialisations for type applications 
        where there's a matching rule.  The rule should
        clearly take precedence.  (Bug reported by Sven.)
        I havn't tested this fix.
      
      * Run the occurrence analyser after tidyCore, so that
        occurrence info (notably dead-var info) is correct
        for the code generators.  This should fix Erik's problem,
        but again I've not tested the fix.  The extra call 
        is in Main.lhs
      
      * Fix CoreToStg so that it can handle an StgLam in mkStgCase.
        This only shows up in a wierd case, documented in 
        CoreToStg.mkStgCase
      91ef36b9
  9. 15 Jun, 2000 1 commit
    • sewardj's avatar
      [project @ 2000-06-15 08:38:25 by sewardj] · 665229e5
      sewardj authored
      Major thing: new register allocator.  Brief description follows.
      Should correctly handle code with loops in, even though we don't
      generate any such at the moment.  A lot of comments.  The previous
      machinery for spilling is retained, as is the idea of a fast-and-easy
      initial allocation attempt intended to deal with the majority of code
      blocks (about 60% on x86) very cheaply.  Many comments explaining
      in detail how it works :-)
      
      The Stix inliner is now on by default.  Integer code seems to run
      within about 1% of that -fvia-C.  x86 fp code is significantly worse,
      up to about 30% slower, depending on the amount of fp activity.
      
      Minor thing: lazyfication of the top-level NCG plumbing, so that the
      NCG doesn't require any greater residency than compiling to C, just a
      bit more time.  Created lazyThenUs and lazyMapUs for this purpose.
      
      The new allocator is somewhat, although not catastophically, slower
      than the old one.  Fixing of the long-standing NCG space leak more
      than makes up for it; overall hsc run-time is down about 5%, due to
      significantly reduced GC time.
      
      --------------------------------------------------------------------
      
      Instructions are numbered sequentially, starting at zero.
      
      A flow edge (FE) is a pair of insn numbers (MkFE Int Int) denoting
      a possible flow of control from the first insn to the second.
      
      The input to the register allocator is a list of instructions, which
      mention Regs.  A Reg can be a RealReg -- a real machine reg -- or a
      VirtualReg, which carries a unique.  After allocation, all the
      VirtualReg references will have been converted into RealRegs, and
      possibly some spill code will have been inserted.
      
      The heart of the register allocator works in four phases.
      
      1.  (find_flow_edges) Calculate all the FEs for the code list.
          Return them not as a [FE], but implicitly, as a pair of
          Array Int [Int], being the successor and predecessor maps
          for instructions.
      
      2.  (calc_liveness) Returns a FiniteMap FE RegSet.  For each
          FE, indicates the set of registers live on that FE.  Note
          that the set includes both RealRegs and VirtualRegs.  The
          former appear because the code could mention fixed register
          usages, and we need to take them into account from the start.
      
      3.  (calc_live_range_sets) Invert the above mapping, giving a
          FiniteMap Reg FeSet, indicating, for each virtual and real
          reg mentioned in the code, which FEs it is live on.
      
      4.  (calc_vreg_to_rreg_mapping) For virtual reg, try and find
          an allocatable real register for it.  Each real register has
          a "current commitment", indicating the set of FEs it is
          currently live on.  A virtual reg v can be assigned to
          real reg r iff v's live-fe-set does not intersect with r's
          current commitment fe-set.  If the assignment is made,
          v's live-fe-set is union'd into r's current commitment fe-set.
          There is also the minor restriction that v and r must be of
          the same register class (integer or floating).
      
          Once this mapping is established, we simply apply it to the
          input insns, and that's it.
      
          If no suitable real register can be found, the vreg is mapped
          to itself, and we deem allocation to have failed.  The partially
          allocated code is returned.  The higher echelons of the allocator
          (doGeneralAlloc and runRegAlloc) then cooperate to insert spill
          code and re-run allocation, until a successful allocation is found.
      665229e5
  10. 25 May, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-05-25 12:41:14 by simonpj] · 495ef8bd
      simonpj authored
      ~~~~~~~~~~~~
      		Apr/May 2000
      		~~~~~~~~~~~~
      
      This is a pretty big commit!  It adds stuff I've been working on
      over the last month or so.  DO NOT MERGE IT WITH 4.07!
      
      Interface file formats have changed a little; you'll need
      to make clean before remaking.
      
      						Simon PJ
      
      Recompilation checking
      ~~~~~~~~~~~~~~~~~~~~~~
      Substantial improvement in recompilation checking.  The version management
      is now entirely internal to GHC.  ghc-iface.lprl is dead!
      
      The trick is to generate the new interface file in two steps:
        - first convert Types etc to HsTypes etc, and thereby
      	build a new ParsedIface
        - then compare against the parsed (but not renamed) version of the old
      	interface file
      Doing this meant adding code to convert *to* HsSyn things, and to
      compare HsSyn things for equality.  That is the main tedious bit.
      
      Another improvement is that we now track version info for
      fixities and rules, which was missing before.
      
      
      Interface file reading
      ~~~~~~~~~~~~~~~~~~~~~~
      Make interface files reading more robust.
        * If the old interface file is unreadable, don't fail. [bug fix]
      
        * If the old interface file mentions interfaces
          that are unreadable, don't fail. [bug fix]
      
        * When we can't find the interface file,
          print the directories we are looking in.  [feature]
      
      
      Type signatures
      ~~~~~~~~~~~~~~~
        * New flag -ddump-types to print type signatures
      
      
      Type pruning
      ~~~~~~~~~~~~
      When importing
      	data T = T1 A | T2 B | T3 C
      it seems excessive to import the types A, B, C as well, unless
      the constructors T1, T2 etc are used.  A,B,C might be more types,
      and importing them may mean reading more interfaces, and so on.
       So the idea is that the renamer will just import the decl
      	data T
      unless one of the constructors is used.  This turns out to be quite
      easy to implement.  The downside is that we must make sure the
      constructors are always available if they are really needed, so
      I regard this as an experimental feature.
      
      
      Elimininate ThinAir names
      ~~~~~~~~~~~~~~~~~~~~~~~~~
      Eliminate ThinAir.lhs and all its works.  It was always a hack, and now
      the desugarer carries around an environment I think we can nuke ThinAir
      altogether.
      
      As part of this, I had to move all the Prelude RdrName defns from PrelInfo
      to PrelMods --- so I renamed PrelMods as PrelNames.
      
      I also had to move the builtinRules so that they are injected by the renamer
      (rather than appearing out of the blue in SimplCore).  This is if anything simpler.
      
      Miscellaneous
      ~~~~~~~~~~~~~
      * Tidy up the data types involved in Rules
      
      * Eliminate RnEnv.better_provenance; use Name.hasBetterProv instead
      
      * Add Unique.hasKey :: Uniquable a => a -> Unique -> Bool
        It's useful in a lot of places
      
      * Fix a bug in interface file parsing for __U[!]
      495ef8bd
  11. 24 May, 2000 2 commits
    • simonmar's avatar
      [project @ 2000-05-24 16:04:38 by simonmar] · efdcccf6
      simonmar authored
      Fix compilation errors when OMIT_NATIVE_CODEGEN is on.
      efdcccf6
    • simonpj's avatar
      [project @ 2000-05-24 15:47:13 by simonpj] · 95929be0
      simonpj authored
      MERGE 4.07
      
      * This fix cures the weird 'ifaceBinds' error that
        Sven and George tripped over.  It was quite obscure!
      
        Basically, there was a top level binding
      	f = x
        lying around, which CoreToStg didn't like.  Why hadn't
        it been substituted away?  Because it had a NOINLINE
        pragma.  Why did it have a NOINLINE pragma?  Because
        it's an always-diverging function, so we never want to
        inline it.
      95929be0
  12. 23 May, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-05-23 11:35:36 by simonpj] · bb91427f
      simonpj authored
      *** MERGE WITH 4.07 (once I've checked it works) ***
      
      * Fix result type signatures.  Note that a consequential change is that
        an ordinary binding with a variable on the left
      	f = e
        is now treated as a FunMonoBind, not a PatMonoBind.  This makes
        a few things a bit simpler (eg rnMethodBinds)
      
      * Fix warnings for unused imports.  This meant moving where provenances
        are improved in RnNames.  Move mkExportAvails from RnEnv to RnNames.
      
      * Print module names right (small change in Module.lhs and Rename.lhs)
      
      * Remove a few unused bindings
        
      * Add a little hack to let us print info about join points that turn
        out not to be let-no-escaped.  The idea is to call them "$j" and report
        any such variables that are not let-no-escaped.
      
      * Some small things aiming towards -ddump-types (harmless but incomplete)
      bb91427f
  13. 15 May, 2000 1 commit
  14. 21 Apr, 2000 2 commits
    • simonpj's avatar
      [project @ 2000-04-21 14:40:48 by simonpj] · 0666c3bb
      simonpj authored
      Remove a way to make the simplifier go into an
      infinite loop.   This has been there for some weeks;
      and George's UniForm tickled it.  I'm amazed nothing
      else has done so.  I'll add a test.
      
      The bad case happened when you go
      
      	let xs = 1:xs
      	in
      	foldr k z xs
      
      Then we kept firing the foldr/cons rule.
      
      Solution: we don't attach an unfolding *at all* to
      loop breakers (Simplify.completeBinding)
      0666c3bb
    • simonpj's avatar
      [project @ 2000-04-21 12:57:54 by simonpj] · c30bd911
      simonpj authored
      /home/simonpj/tmp/msg
      c30bd911
  15. 14 Apr, 2000 1 commit
  16. 13 Apr, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-04-13 11:56:35 by simonpj] · 9579283c
      simonpj authored
      Add support for 'packages'.
      
      * A package is a group of modules.
      
      * A package has a name (e.g. std)
      
      * A package is built into a single library (Unix; e.g. libHSstd.a)
                             or a single DLL     (Windows; e.g. HSstd.dll)
      
      * The '-package-name foo' flag tells GHC that the module being compiled
        is destined for package foo.
      
      * The '-package foo' flag tells GHC to make available modules
        from package 'foo'.  It replaces '-syslib foo' which is now deprecated.
      
      * Cross-package references cost an extra indirection in Windows,
        but not Unix
      
      * GHC does not maintain detailed cross-package dependency information.
        It does remember which modules in other packages the current module
        depends on, but not which things within those imported things.
      
      
      All of this tidies up the Prelude enormously.  The Prelude and
      Standard Libraries are built into a singl package called 'std'.  (This
      is a change; the library is now called libHSstd.a instead of libHS.a)
      9579283c
  17. 05 Apr, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-04-05 16:25:51 by simonpj] · d4e0a55c
      simonpj authored
      * Add new flag -fddump-minimal-imports, which dumps a file
        M.imports that contains the (allegedly) minimal bunch of
        imports that make the system work.
        It's done by Rename.printMinimalImports
      
      * Extend foreign import/export to handle
      	* Booleans
      	* newtypes
        as requested by the FFI team
      
      * Tidy up DsCCall quite a bit
        Remove maybeBoxedPrimTy from TcHsSyn
      d4e0a55c
  18. 03 Apr, 2000 2 commits
  19. 27 Mar, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-03-27 13:24:12 by simonpj] · a127213c
      simonpj authored
      a) Move Unfolding and UnfoldingGuidance to CoreSyn
         As a result, remove several SOURCE imports
         Shrink CoreSyn.hi-boot considerably
         Delete CoreUnfold.hi-boot altogether
      
      b) Add CoreUtils.exprIsConApp_maybe
         Use in PrelRules to fix a bug in the dataToTag rule
      
      c) Fix boolean polarity error in Simplify.lhs
      a127213c
  20. 24 Mar, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-03-24 17:49:29 by simonpj] · 6c872fff
      simonpj authored
      a) Small wibbles to do with inlining and floating
      
      b) Implement Ralf's request, so that one can write
      
      	type F = forall a. a -> a
      
      	f :: Int -> F
      	f = ...
      
         The for-alls inside F are hoisted out to the top of
         the type signature for f.  This applies uniformly to
         all user-written types
      6c872fff
  21. 23 Mar, 2000 2 commits
    • simonpj's avatar
      [project @ 2000-03-23 17:45:17 by simonpj] · 111cee3f
      simonpj authored
      This utterly gigantic commit is what I've been up to in background
      mode in the last couple of months.  Originally the main goal
      was to get rid of Con (staturated constant applications)
      in the CoreExpr type, but one thing led to another, and I kept
      postponing actually committing.   Sorry.
      
      	Simon, 23 March 2000
      
      
      I've tested it pretty thoroughly, but doubtless things will break.
      
      Here are the highlights
      
      * Con is gone; the CoreExpr type is simpler
      * NoRepLits have gone
      * Better usage info in interface files => less recompilation
      * Result type signatures work
      * CCall primop is tidied up
      * Constant folding now done by Rules
      * Lots of hackery in the simplifier
      * Improvements in CPR and strictness analysis
      
      Many bug fixes including
      
      * Sergey's DoCon compiles OK; no loop in the strictness analyser
      * Volker Wysk's programs don't crash the CPR analyser
      
      I have not done much on measuring compilation times and binary sizes;
      they could have got worse.  I think performance has got significantly
      better, though, in most cases.
      
      
      Removing the Con form of Core expressions
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      The big thing is that
      
        For every constructor C there are now *two* Ids:
      
      	C is the constructor's *wrapper*. It evaluates and unboxes arguments
      	before calling $wC.  It has a perfectly ordinary top-level defn
      	in the module defining the data type.
      
      	$wC is the constructor's *worker*.  It is like a primop that simply
      	allocates and builds the constructor value.  Its arguments are the
      	actual representation arguments of the constructor.
      	Its type may be different to C, because:
      		- useless dict args are dropped
      		- strict args may be flattened
      
        For every primop P there is *one* Id, its (curried) Id
      
        Neither contructor worker Id nor the primop Id have a defminition anywhere.
        Instead they are saturated during the core-to-STG pass, and the code generator
        generates code for them directly. The STG language still has saturated
        primops and constructor applications.
      
      * The Const type disappears, along with Const.lhs.  The literal part
        of Const.lhs reappears as Literal.lhs.  Much tidying up in here,
        to bring all the range checking into this one module.
      
      * I got rid of NoRep literals entirely.  They just seem to be too much trouble.
      
      * Because Con's don't exist any more, the funny C { args } syntax
        disappears from inteface files.
      
      
      Parsing
      ~~~~~~~
      * Result type signatures now work
      	f :: Int -> Int = \x -> x
      	-- The Int->Int is the type of f
      
      	g x y :: Int = x+y
      	-- The Int is the type of the result of (g x y)
      
      
      Recompilation checking and make
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      * The .hi file for a modules is not touched if it doesn't change.  (It used to
        be touched regardless, forcing a chain of recompilations.)  The penalty for this
        is that we record exported things just as if they were mentioned in the body of
        the module.  And the penalty for that is that we may recompile a module when
        the only things that have changed are the things it is passing on without using.
        But it seems like a good trade.
      
      * -recomp is on by default
      
      Foreign declarations
      ~~~~~~~~~~~~~~~~~~~~
      * If you say
      	foreign export zoo :: Int -> IO Int
        then you get a C produre called 'zoo', not 'zzoo' as before.
        I've also added a check that complains if you export (or import) a C
        procedure whose name isn't legal C.
      
      
      Code generation and labels
      ~~~~~~~~~~~~~~~~~~~~~~~~~~
      * Now that constructor workers and wrappers have distinct names, there's
        no need to have a Foo_static_closure and a Foo_closure for constructor Foo.
        I nuked the entire StaticClosure story.  This has effects in some of
        the RTS headers (i.e. s/static_closure/closure/g)
      
      
      Rules, constant folding
      ~~~~~~~~~~~~~~~~~~~~~~~
      * Constant folding becomes just another rewrite rule, attached to the Id for the
        PrimOp.   To achieve this, there's a new form of Rule, a BuiltinRule (see CoreSyn.lhs).
        The prelude rules are in prelude/PrelRules.lhs, while simplCore/ConFold.lhs has gone.
      
      * Appending of constant strings now works, using fold/build fusion, plus
        the rewrite rule
      	unpack "foo" c (unpack "baz" c n)  =  unpack "foobaz" c n
        Implemented in PrelRules.lhs
      
      * The CCall primop is tidied up quite a bit.  There is now a data type CCall,
        defined in PrimOp, that packages up the info needed for a particular CCall.
        There is a new Id for each new ccall, with an big "occurrence name"
      	{__ccall "foo" gc Int# -> Int#}
        In interface files, this is parsed as a single Id, which is what it is, really.
      
      Miscellaneous
      ~~~~~~~~~~~~~
      * There were numerous places where the host compiler's
        minInt/maxInt was being used as the target machine's minInt/maxInt.
        I nuked all of these; everything is localised to inIntRange and inWordRange,
        in Literal.lhs
      
      * Desugaring record updates was broken: it didn't generate correct matches when
        used withe records with fancy unboxing etc.  It now uses matchWrapper.
      
      * Significant tidying up in codeGen/SMRep.lhs
      
      * Add __word, __word64, __int64 terminals to signal the obvious types
        in interface files.  Add the ability to print word values in hex into
        C code.
      
      * PrimOp.lhs is no longer part of a loop.  Remove PrimOp.hi-boot*
      
      
      Types
      ~~~~~
      * isProductTyCon no longer returns False for recursive products, nor
        for unboxed products; you have to test for these separately.
        There's no reason not to do CPR for recursive product types, for example.
        Ditto splitProductType_maybe.
      
      Simplification
      ~~~~~~~~~~~~~~~
      * New -fno-case-of-case flag for the simplifier.  We use this in the first run
        of the simplifier, where it helps to stop messing up expressions that
        the (subsequent) full laziness pass would otherwise find float out.
        It's much more effective than previous half-baked hacks in inlining.
      
        Actually, it turned out that there were three places in Simplify.lhs that
        needed to know use this flag.
      
      * Make the float-in pass push duplicatable bindings into the branches of
        a case expression, in the hope that we never have to allocate them.
        (see FloatIn.sepBindsByDropPoint)
      
      * Arrange that top-level bottoming Ids get a NOINLINE pragma
        This reduced gratuitous inlining of error messages.
        But arrange that such things still get w/w'd.
      
      * Arrange that a strict argument position is regarded as an 'interesting'
        context, so that if we see
      	foldr k z (g x)
        then we'll be inclined to inline g; this can expose a build.
      
      * There was a missing case in CoreUtils.exprEtaExpandArity that meant
        we were missing some obvious cases for eta expansion
        Also improve the code when handling applications.
      
      * Make record selectors (identifiable by their IdFlavour) into "cheap" operations.
      	  [The change is a 2-liner in CoreUtils.exprIsCheap]
        This means that record selection may be inlined into function bodies, which
        greatly improves the arities of overloaded functions.
      
      * Make a cleaner job of inlining "lone variables".  There was some distributed
        cunning, but I've centralised it all now in SimplUtils.analyseCont, which
        analyses the context of a call to decide whether it is "interesting".
      
      * Don't specialise very small functions in Specialise.specDefn
        It's better to inline it.  Rather like the worker/wrapper case.
      
      * Be just a little more aggressive when floating out of let rhss.
        See comments with Simplify.wantToExpose
        A small change with an occasional big effect.
      
      * Make the inline-size computation think that
      	case x of I# x -> ...
        is *free*.
      
      
      CPR analysis
      ~~~~~~~~~~~~
      * Fix what was essentially a bug in CPR analysis.  Consider
      
      	letrec f x = let g y = let ... in f e1
      		     in
      		     if ... then (a,b) else g x
      
        g has the CPR property if f does; so when generating the final annotated
        RHS for f, we must use an envt in which f is bound to its final abstract
        value.  This wasn't happening.  Instead, f was given the CPR tag but g
        wasn't; but of course the w/w pass gives rotten results in that case!!
        (Because f's CPR-ness relied on g's.)
      
        On they way I tidied up the code in CprAnalyse.  It's quite a bit shorter.
      
        The fact that some data constructors return a constructed product shows
        up in their CPR info (MkId.mkDataConId) not in CprAnalyse.lhs
      
      
      
      Strictness analysis and worker/wrapper
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      * BIG THING: pass in the demand to StrictAnal.saExpr.  This affects situations
        like
      	f (let x = e1 in (x,x))
        where f turns out to have strictness u(SS), say.  In this case we can
        mark x as demanded, and use a case expression for it.
      
        The situation before is that we didn't "know" that there is the u(SS)
        demand on the argument, so we simply computed that the body of the let
        expression is lazy in x, and marked x as lazily-demanded.  Then even after
        f was w/w'd we got
      
      	let x = e1 in case (x,x) of (a,b) -> $wf a b
      
        and hence
      
      	let x = e1 in $wf a b
      
        I found a much more complicated situation in spectral/sphere/Main.shade,
        which improved quite a bit with this change.
      
      * Moved the StrictnessInfo type from IdInfo to Demand.  It's the logical
        place for it, and helps avoid module loops
      
      * Do worker/wrapper for coerces even if the arity is zero.  Thus:
      	stdout = coerce Handle (..blurg..)
        ==>
      	wibble = (...blurg...)
      	stdout = coerce Handle wibble
        This is good because I found places where we were saying
      	case coerce t stdout of { MVar a ->
      	...
      	case coerce t stdout of { MVar b ->
      	...
        and the redundant case wasn't getting eliminated because of the coerce.
      111cee3f
    • sewardj's avatar
      [project @ 2000-03-23 12:22:04 by sewardj] · 1e5271f1
      sewardj authored
      In interface files, don't forget to mention the names of modules imported
      via hi-boot files.  This is needed so that Hugs can use the import decls
      in interface files to safely overestimate the dependency sets which it will
      encounter when linking object code.
      1e5271f1
  22. 08 Mar, 2000 1 commit
    • simonmar's avatar
      [project @ 2000-03-08 17:48:24 by simonmar] · de896403
      simonmar authored
      - generalise the per-module initialisation stubs so that we use it
        in normal (non-profiled) code too.  The initialisation stubs are
        now called '__init_<module>' rather than '_reg<module>'.
      
      - Register foreign exported functions as stable pointers in the
        initialisation code for the module.  This fixes the foreign export
        problems reported by several people.
      
      - remove the concept of "module groups" from the profiling subsystem.
      
      - change the profiling semantics slightly; it should be unnecessary
        to use '-caf-all' to get reasonable profiles now.
      de896403
  23. 02 Mar, 2000 1 commit
  24. 25 Feb, 2000 1 commit
    • panne's avatar
      [project @ 2000-02-25 14:55:31 by panne] · f83a5a68
      panne authored
      Deprecations of variables now works, although the source location is
      not yet reported correctly and the code needs some cleanup. Added a
      new flag -fwarn-deprecations to the set of standard warnings. The
      syntax of deprecations has been extended to deprecate types, classes,
      or even constructors, although this does not work yet.
      f83a5a68
  25. 22 Feb, 2000 1 commit
  26. 21 Feb, 2000 1 commit
  27. 20 Feb, 2000 1 commit
  28. 15 Feb, 2000 1 commit
    • panne's avatar
      [project @ 2000-02-15 22:18:16 by panne] · 06619533
      panne authored
      First steps towards DEPRECATED before Rosebank (12yrs) takes its toll.
      Nothing very functional yet, but at least hsc can be compiled and it
      still compiles the Prelude.
      
      Parsing the pragma turned out to be a little bit more complicated than
      expected, here the comment from Parser.y:
      
         The place for module deprecation is really too restrictive, but if it
         was allowed at its natural place just before 'module', we get an ugly
         s/r conflict with the second alternative. Another solution would be the
         introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
         either, and DEPRECATED is only expected to be used by people who really
         know what they are doing. :-)
      
      Net result: Module deprecation is allowed exactly behind the module's
      name and nowhere else. I probably have to think a little bit more
      about this some day...
      06619533
  29. 09 Feb, 2000 1 commit
  30. 31 Jan, 2000 1 commit
  31. 28 Jan, 2000 1 commit
    • lewie's avatar
      [project @ 2000-01-28 20:52:37 by lewie] · 266fadd9
      lewie authored
      First pass at implicit parameters.  Honest, I didn't really go in *intending*
      to modify every file in the typechecker... ;-)  The breadth of the change
      is partly due to generalizing contexts so that they are not hardwired to
      be (Class, [Type]) pairs.  See types/Type.lhs for details (look for PredType).
      266fadd9
  32. 24 Jan, 2000 1 commit
    • sewardj's avatar
      [project @ 2000-01-24 18:22:07 by sewardj] · 9ac31f7c
      sewardj authored
      ARR_HDR_SIZE --> ARR_WORDS_HDR_SIZE, and derived quantities in
      Constants.h, Constants.lhs et al are similarly renamed.
      
      new constant ARR_PTRS_HDR_SIZE, with corresponding derivatives.
      9ac31f7c
  33. 13 Jan, 2000 3 commits
  34. 04 Jan, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-01-04 17:40:46 by simonpj] · 5ca77490
      simonpj authored
      This commit arranges that literal strings will fuse
      nicely, by expressing them as an application of build.
      
      * NoRepStr is now completely redundant, though I havn't removed it yet.
      
      * The unpackStr stuff moves from PrelPack to PrelBase.
      
      * There's a new form of Rule, a BuiltinRule, for rules that
        can't be expressed in Haskell.  The string-fusion rule is one
        such.  It's defined in prelude/PrelRules.lhs.
      
      * PrelRules.lhs also contains a great deal of code that
        implements constant folding.  In due course this will replace
        ConFold.lhs, but for the moment it simply duplicates it.
      5ca77490