summaryrefslogtreecommitdiff
path: root/compiler/codeGen/StgCmm.hs
blob: 6cdb14880a0ac0a6c5a972fcf99b5af991242e4b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
{-# LANGUAGE CPP #-}
{-# LANGUAGE DataKinds #-}

-----------------------------------------------------------------------------
--
-- Stg to C-- code generation
--
-- (c) The University of Glasgow 2004-2006
--
-----------------------------------------------------------------------------

module StgCmm ( codeGen ) where

#include "HsVersions.h"

import GhcPrelude as Prelude

import StgCmmProf (initCostCentres, ldvEnter)
import StgCmmMonad
import StgCmmEnv
import StgCmmBind
import StgCmmCon
import StgCmmLayout
import StgCmmUtils
import StgCmmClosure
import StgCmmHpc
import StgCmmTicky

import Cmm
import CmmUtils
import CLabel

import StgSyn
import DynFlags

import HscTypes
import CostCentre
import Id
import IdInfo
import RepType
import DataCon
import TyCon
import Module
import Outputable
import Stream
import BasicTypes
import VarSet ( isEmptyDVarSet )

import OrdList
import MkGraph

import Data.IORef
import Control.Monad (when,void)
import Util

codeGen :: DynFlags
        -> Module
        -> [TyCon]
        -> CollectedCCs                -- (Local/global) cost-centres needing declaring/registering.
        -> [CgStgTopBinding]           -- Bindings to convert
        -> HpcInfo
        -> Stream IO CmmGroup ()       -- Output as a stream, so codegen can
                                       -- be interleaved with output

codeGen dflags this_mod data_tycons
        cost_centre_info stg_binds hpc_info
  = do  {     -- cg: run the code generator, and yield the resulting CmmGroup
              -- Using an IORef to store the state is a bit crude, but otherwise
              -- we would need to add a state monad layer.
        ; cgref <- liftIO $ newIORef =<< initC
        ; let cg :: FCode () -> Stream IO CmmGroup ()
              cg fcode = do
                cmm <- liftIO $ do
                         st <- readIORef cgref
                         let (a,st') = runC dflags this_mod st (getCmm fcode)

                         -- NB. stub-out cgs_tops and cgs_stmts.  This fixes
                         -- a big space leak.  DO NOT REMOVE!
                         writeIORef cgref $! st'{ cgs_tops = nilOL,
                                                  cgs_stmts = mkNop }
                         return a
                yield cmm

               -- Note [codegen-split-init] the cmm_init block must come
               -- FIRST.  This is because when -split-objs is on we need to
               -- combine this block with its initialisation routines; see
               -- Note [pipeline-split-init].
        ; cg (mkModuleInit cost_centre_info this_mod hpc_info)

        ; mapM_ (cg . cgTopBinding dflags) stg_binds

                -- Put datatype_stuff after code_stuff, because the
                -- datatype closure table (for enumeration types) to
                -- (say) PrelBase_True_closure, which is defined in
                -- code_stuff
        ; let do_tycon tycon = do
                -- Generate a table of static closures for an
                -- enumeration type Note that the closure pointers are
                -- tagged.
                 when (isEnumerationTyCon tycon) $ cg (cgEnumerationTyCon tycon)
                 mapM_ (cg . cgDataCon) (tyConDataCons tycon)

        ; mapM_ do_tycon data_tycons
        }

---------------------------------------------------------------
--      Top-level bindings
---------------------------------------------------------------

{- 'cgTopBinding' is only used for top-level bindings, since they need
to be allocated statically (not in the heap) and need to be labelled.
No unboxed bindings can happen at top level.

In the code below, the static bindings are accumulated in the
@MkCgState@, and transferred into the ``statics'' slot by @forkStatics@.
This is so that we can write the top level processing in a compositional
style, with the increasing static environment being plumbed as a state
variable. -}

cgTopBinding :: DynFlags -> CgStgTopBinding -> FCode ()
cgTopBinding dflags (StgTopLifted (StgNonRec id rhs))
  = do  { let (info, fcode) = cgTopRhs dflags NonRecursive id rhs
        ; fcode
        ; addBindC info
        }

cgTopBinding dflags (StgTopLifted (StgRec pairs))
  = do  { let (bndrs, rhss) = unzip pairs
        ; let pairs' = zip bndrs rhss
              r = unzipWith (cgTopRhs dflags Recursive) pairs'
              (infos, fcodes) = unzip r
        ; addBindsC infos
        ; sequence_ fcodes
        }

cgTopBinding dflags (StgTopStringLit id str)
  = do  { let label = mkBytesLabel (idName id)
        ; let (lit, decl) = mkByteStringCLit label str
        ; emitDecl decl
        ; addBindC (litIdInfo dflags id mkLFStringLit lit)
        }

cgTopRhs :: DynFlags -> RecFlag -> Id -> CgStgRhs -> (CgIdInfo, FCode ())
        -- The Id is passed along for setting up a binding...

cgTopRhs dflags _rec bndr (StgRhsCon _cc con args)
  = cgTopRhsCon dflags bndr con (assertNonVoidStgArgs args)
      -- con args are always non-void,
      -- see Note [Post-unarisation invariants] in UnariseStg

cgTopRhs dflags rec bndr (StgRhsClosure fvs cc upd_flag args body)
  = ASSERT(isEmptyDVarSet fvs)    -- There should be no free variables
    cgTopRhsClosure dflags rec bndr cc upd_flag args body


---------------------------------------------------------------
--      Module initialisation code
---------------------------------------------------------------

mkModuleInit
        :: CollectedCCs         -- cost centre info
        -> Module
        -> HpcInfo
        -> FCode ()

mkModuleInit cost_centre_info this_mod hpc_info
  = do  { initHpc this_mod hpc_info
        ; initCostCentres cost_centre_info
        }


---------------------------------------------------------------
--      Generating static stuff for algebraic data types
---------------------------------------------------------------


cgEnumerationTyCon :: TyCon -> FCode ()
cgEnumerationTyCon tycon
  = do dflags <- getDynFlags
       emitRODataLits (mkLocalClosureTableLabel (tyConName tycon) NoCafRefs)
             [ CmmLabelOff (mkLocalClosureLabel (dataConName con) NoCafRefs)
                           (tagForCon dflags con)
             | con <- tyConDataCons tycon]


cgDataCon :: DataCon -> FCode ()
-- Generate the entry code, info tables, and (for niladic constructor)
-- the static closure, for a constructor.
cgDataCon data_con
  = do  { dflags <- getDynFlags
        ; let
            (tot_wds, --  #ptr_wds + #nonptr_wds
             ptr_wds) --  #ptr_wds
              = mkVirtConstrSizes dflags arg_reps

            nonptr_wds   = tot_wds - ptr_wds

            dyn_info_tbl =
              mkDataConInfoTable dflags data_con False ptr_wds nonptr_wds

            -- We're generating info tables, so we don't know and care about
            -- what the actual arguments are. Using () here as the place holder.
            arg_reps :: [NonVoid PrimRep]
            arg_reps = [ NonVoid rep_ty
                       | ty <- dataConRepArgTys data_con
                       , rep_ty <- typePrimRep ty
                       , not (isVoidRep rep_ty) ]

        ; emitClosureAndInfoTable dyn_info_tbl NativeDirectCall [] $
            -- NB: the closure pointer is assumed *untagged* on
            -- entry to a constructor.  If the pointer is tagged,
            -- then we should not be entering it.  This assumption
            -- is used in ldvEnter and when tagging the pointer to
            -- return it.
            -- NB 2: We don't set CC when entering data (WDP 94/06)
            do { tickyEnterDynCon
               ; ldvEnter (CmmReg nodeReg)
               ; tickyReturnOldCon (length arg_reps)
               ; void $ emitReturn [cmmOffsetB dflags (CmmReg nodeReg) (tagForCon dflags data_con)]
               }
                    -- The case continuation code expects a tagged pointer
        }