ghc/runtime/profiling/CHANGES-REQD

   1
   2 Adding @scc@ to the Haskell compiler -- A note of changes required
   3
   4
   5 Haskell Compiler:
   6 ----------------
   7
   8 SCC FRONT END SYNTAX:   scc "label" expr
   9
  10         hslexer.lex     scc recognised as SCC
  11         hsparser.y      scc expression parsed
  12         tree.ugn        new tree construct
  13         printtree.c     print scc (k bytecode)
  14         main.c          -S flag for scc (else warning)
  15
  16 SCC THROUGH COMPILER:
  17         reader          PrefixSyn       new construct (SCC')
  18                         ReadPrefix      read k bytecode
  19                         PrefixToHs      -> AbsSyn
  20
  21         abstractSyn     HsExpr          new construct (SCC)
  22                         BackSubst
  23         rename          RenameExpr4     rename body
  24         typecheck       TcExpr          no unify, use type of body
  25         deSugar         DsExpr          -> CoreSyn
  26
  27     Core Syntax & Transformations:
  28         coreSyn         CoreSyn         new construct (CoSCC) not primop
  29                         AnnCoreSyn      new construct
  30                         FreeVars
  31                         CoreFuns
  32
  33         simplCore0      SubstAnal0
  34                         SimplCore0
  35                         RmTrivLets0
  36
  37         simplCore                               default: not used       n
  38         stranal-sem                             default: not used       n
  39         interpreter                             york:    ???            n
  40
  41     Stg Syntax & Transformations:
  42         stgSyn          CoreToStg       -> StgSyn
  43                         StgSyn          new construct (StgSCC)
  44
  45                         StgInfo (new)   pass gathering CC codegen info
  46
  47                         LetFloat                default: not used       n
  48                         StgToStg                default: not used       n
  49                         FreeVariables           default: not used       n
  50
  51     Abstract C & Code Generation:
  52         main            Main            -scc flag for update flavour    y
  53         codeGen         CgMonad         -scc new Cg info                y
  54         absCSyn         AbsCSyn         new construct (CCostCentre)     y
  55
  56         codeGen         CodeGen         declaring cost centers          y
  57         codeGen         ClosureInfo     closure kind                    y
  58                                                 type                    y
  59         codeGen         CgClosure       closure description             y
  60
  61         abstractC       PprAbsC         info table kind                 y
  62                                                    description          y
  63                                                    type                 y
  64
  65      Real Code Generation Changes
  66         Scc Expression:
  67                 +RCC update frame -- stack space required
  68                 +set new cost centre
  69
  70         Closure Entry:
  71                 !different sizes for STD and CON update frames
  72                 +single entry now requires RCC update frame
  73                 +resume the CC in closure entered
  74
  75         Return in Registers:
  76                 +register return set RetCC (form closure or CCC)
  77                 +register update reset closures CC to RetCC
  78                 +attribute register update allocation to RetCC
  79
  80         CC_ALLOC calls with heap allocation
  81
  82      Optimisations:
  83         update closure entry with scc -- no RCC frame                   ToDo
  84
  85
  86 RTS stuff:
  87 ---------
  88
  89 Time            interupt                                y
  90
  91 Cost centre declaration macros                          y
  92
  93 Info table macros with "description" etc?               y
  94
  95 Modify update frames to include cost centres            y
  96 Dummy update frame return vector                        y
  97 Recognition of dummy ret vect UpdatePAP                 y
  98
  99 Heap profiling (2s)
 100         Cost Centre                                     y
 101         Description                                     y
 102
 103 Profile info reported                                   y
 104
 105 Conditionalise need for timer interupt                  todo
 106
 107
 108
 109 ADDING GRP_NAME to CC and TYPE to CAT:
 110 -------------------------------------
 111
 112 driver          --  -Ggroup flag                        y
 113 main/Main.lhs   --  -Ggroup flag                        y
 114                 --  pass to codegen                     y
 115 codeGen         --  grp_name passed into CCostCentre    y
 116 absCSyn         --  add group to CCostCentre            y
 117                 --  print group with CC decl            y
 118                 --  print type with INFO_TABLE decl     y
 119 uniType         --  getUniTyDescription                 y
 120
 121 runtime         -- Add group to CostCentre              y
 122                 -- Add group to CC_DECALRE              y
 123                 -- Add type to ClCategory               y
 124                 -- Add type to CAT_DECLARE              y
 125                 -- Add type to INFO_TABLEs              y
 126
 127                 -- Report group in profiling report     y
 128
 129                 -- Heap profiling with group/module/type
 130                 -- selection by mod,grp,typ             y
 131                 -- profiling by cc,mod,grp,descr,type   y
 132                     -- always hash on feature           y
 133                 -- report by cc,mod,grp,descr,type      y
 134
 135                 This is different to York as we can have unprofiled
 136                 costs/heap inherited from other modules/groups.
 137
 138                 TESTING TESTING TESTING TESTING         ToDo
 139
 140
 141 AUTO SCCS ...
 142 -------------
 143
 144 driver                  --  -prof-auto                  y
 145 main/Main.lhs           --  -scc-auto                   y
 146                         --  doSCCauto pass (desugared)  Improve?
 147 profiling/SCCauto.lhs   --  sccAutoTop                  Improve?
 148
 149         Need to compare to all explicitly annotated.    ToDo
 150
 151         I think this needs to be incorperated into      ToDo
 152         the desugarer/typechecker? as the dict stuff
 153         currently distorts this.
 154         OK if we are using lexical scoping !!!
 155         eg: See tautclause in clausify1.hs  (cl.*)
 156
 157
 158
 159
 160 EXTENDING SCC ANNOTATIONS ...                           ToDo
 161 -----------------------------
 162
 163 Front End:      let   scc "label"
 164                 where scc "label"
 165                 decl  scc "label"
 166
 167         hsparser.y      extended scc expressions parsed
 168         tree.ugn        new scc language constructs
 169         printtree.c     print new scc bytecode forms
 170
 171 Compiler:
 172         reader          PrefixSyn       new constructs
 173                         ReadPrefix      read bytecodes
 174                         PrefixToHs      -> AbsSyn
 175
 176         abstractSyn     HsExpr          new constructs
 177                         BackSubst
 178         rename          RenameExpr4     rename body
 179         typecheck       TcExpr          no unify, use type of body
 180         deSugar                         desugar new scc constructs -> SCC
 181
 182
 183 LEXICAL/EVALUATION SCOPING ...
 184
 185 driver          --  -prof-eval -prof-lex (def)          y
 186 main/Main.lhs   --  -scc-eval -scc-lex                  y
 187                 --  doSCClex pass (stg_binds')          ToDo
 188 ???             --  lexical scoping transform pass      ToDo
 189
 190
 191
 192 OTHER POSSIBLE STUFF:
 193
 194 codegen/CodeGen.lhs     -- code to declare mod and group strings
 195                         -- use references in CCostCentre
 196
 197 profiling cost report   -- Reporting group / module costs
 198                                 with / without components
 199                            Eg sort on group time
 200                                 with module time sub-sort
 201                                   with label time sub-sort