summaryrefslogtreecommitdiff
path: root/compiler/cmm/PprCmmExpr.hs
blob: 7bf73f1ca69a53ce5d17f44428e39064598791b9 (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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
----------------------------------------------------------------------------
--
-- Pretty-printing of common Cmm types
--
-- (c) The University of Glasgow 2004-2006
--
-----------------------------------------------------------------------------

--
-- This is where we walk over Cmm emitting an external representation,
-- suitable for parsing, in a syntax strongly reminiscent of C--. This
-- is the "External Core" for the Cmm layer.
--
-- As such, this should be a well-defined syntax: we want it to look nice.
-- Thus, we try wherever possible to use syntax defined in [1],
-- "The C-- Reference Manual", http://www.cs.tufts.edu/~nr/c--/index.html. We
-- differ slightly, in some cases. For one, we use I8 .. I64 for types, rather
-- than C--'s bits8 .. bits64.
--
-- We try to ensure that all information available in the abstract
-- syntax is reproduced, or reproducible, in the concrete syntax.
-- Data that is not in printed out can be reconstructed according to
-- conventions used in the pretty printer. There are at least two such
-- cases:
--      1) if a value has wordRep type, the type is not appended in the
--      output.
--      2) MachOps that operate over wordRep type are printed in a
--      C-style, rather than as their internal MachRep name.
--
-- These conventions produce much more readable Cmm output.
--
-- A useful example pass over Cmm is in nativeGen/MachCodeGen.hs
--

{-# OPTIONS_GHC -fno-warn-orphans #-}
module PprCmmExpr
    ( pprExpr, pprLit
    )
where

import GhcPrelude

import CmmExpr

import Outputable
import DynFlags

import Data.Maybe
import Numeric ( fromRat )

-----------------------------------------------------------------------------

instance Outputable CmmExpr where
    ppr e = pprExpr e

instance Outputable CmmReg where
    ppr e = pprReg e

instance Outputable CmmLit where
    ppr l = pprLit l

instance Outputable LocalReg where
    ppr e = pprLocalReg e

instance Outputable Area where
    ppr e = pprArea e

instance Outputable GlobalReg where
    ppr e = pprGlobalReg e

-- --------------------------------------------------------------------------
-- Expressions
--

pprExpr :: CmmExpr -> SDoc
pprExpr e
    = sdocWithDynFlags $ \dflags ->
      case e of
        CmmRegOff reg i ->
                pprExpr (CmmMachOp (MO_Add rep)
                           [CmmReg reg, CmmLit (CmmInt (fromIntegral i) rep)])
                where rep = typeWidth (cmmRegType dflags reg)
        CmmLit lit -> pprLit lit
        _other     -> pprExpr1 e

-- Here's the precedence table from CmmParse.y:
-- %nonassoc '>=' '>' '<=' '<' '!=' '=='
-- %left '|'
-- %left '^'
-- %left '&'
-- %left '>>' '<<'
-- %left '-' '+'
-- %left '/' '*' '%'
-- %right '~'

-- We just cope with the common operators for now, the rest will get
-- a default conservative behaviour.

-- %nonassoc '>=' '>' '<=' '<' '!=' '=='
pprExpr1, pprExpr7, pprExpr8 :: CmmExpr -> SDoc
pprExpr1 (CmmMachOp op [x,y]) | Just doc <- infixMachOp1 op
   = pprExpr7 x <+> doc <+> pprExpr7 y
pprExpr1 e = pprExpr7 e

infixMachOp1, infixMachOp7, infixMachOp8 :: MachOp -> Maybe SDoc

infixMachOp1 (MO_Eq     _) = Just (text "==")
infixMachOp1 (MO_Ne     _) = Just (text "!=")
infixMachOp1 (MO_Shl    _) = Just (text "<<")
infixMachOp1 (MO_U_Shr  _) = Just (text ">>")
infixMachOp1 (MO_U_Ge   _) = Just (text ">=")
infixMachOp1 (MO_U_Le   _) = Just (text "<=")
infixMachOp1 (MO_U_Gt   _) = Just (char '>')
infixMachOp1 (MO_U_Lt   _) = Just (char '<')
infixMachOp1 _             = Nothing

-- %left '-' '+'
pprExpr7 (CmmMachOp (MO_Add rep1) [x, CmmLit (CmmInt i rep2)]) | i < 0
   = pprExpr7 (CmmMachOp (MO_Sub rep1) [x, CmmLit (CmmInt (negate i) rep2)])
pprExpr7 (CmmMachOp op [x,y]) | Just doc <- infixMachOp7 op
   = pprExpr7 x <+> doc <+> pprExpr8 y
pprExpr7 e = pprExpr8 e

infixMachOp7 (MO_Add _)  = Just (char '+')
infixMachOp7 (MO_Sub _)  = Just (char '-')
infixMachOp7 _           = Nothing

-- %left '/' '*' '%'
pprExpr8 (CmmMachOp op [x,y]) | Just doc <- infixMachOp8 op
   = pprExpr8 x <+> doc <+> pprExpr9 y
pprExpr8 e = pprExpr9 e

infixMachOp8 (MO_U_Quot _) = Just (char '/')
infixMachOp8 (MO_Mul _)    = Just (char '*')
infixMachOp8 (MO_U_Rem _)  = Just (char '%')
infixMachOp8 _             = Nothing

pprExpr9 :: CmmExpr -> SDoc
pprExpr9 e =
   case e of
        CmmLit    lit       -> pprLit1 lit
        CmmLoad   expr rep  -> ppr rep <> brackets (ppr expr)
        CmmReg    reg       -> ppr reg
        CmmRegOff  reg off  -> parens (ppr reg <+> char '+' <+> int off)
        CmmStackSlot a off  -> parens (ppr a   <+> char '+' <+> int off)
        CmmMachOp mop args  -> genMachOp mop args

genMachOp :: MachOp -> [CmmExpr] -> SDoc
genMachOp mop args
   | Just doc <- infixMachOp mop = case args of
        -- dyadic
        [x,y] -> pprExpr9 x <+> doc <+> pprExpr9 y

        -- unary
        [x]   -> doc <> pprExpr9 x

        _     -> pprTrace "PprCmm.genMachOp: machop with strange number of args"
                          (pprMachOp mop <+>
                            parens (hcat $ punctuate comma (map pprExpr args)))
                          empty

   | isJust (infixMachOp1 mop)
   || isJust (infixMachOp7 mop)
   || isJust (infixMachOp8 mop)  = parens (pprExpr (CmmMachOp mop args))

   | otherwise = char '%' <> ppr_op <> parens (commafy (map pprExpr args))
        where ppr_op = text (map (\c -> if c == ' ' then '_' else c)
                                 (show mop))
                -- replace spaces in (show mop) with underscores,

--
-- Unsigned ops on the word size of the machine get nice symbols.
-- All else get dumped in their ugly format.
--
infixMachOp :: MachOp -> Maybe SDoc
infixMachOp mop
        = case mop of
            MO_And    _ -> Just $ char '&'
            MO_Or     _ -> Just $ char '|'
            MO_Xor    _ -> Just $ char '^'
            MO_Not    _ -> Just $ char '~'
            MO_S_Neg  _ -> Just $ char '-' -- there is no unsigned neg :)
            _ -> Nothing

-- --------------------------------------------------------------------------
-- Literals.
--  To minimise line noise we adopt the convention that if the literal
--  has the natural machine word size, we do not append the type
--
pprLit :: CmmLit -> SDoc
pprLit lit = sdocWithDynFlags $ \dflags ->
             case lit of
    CmmInt i rep ->
        hcat [ (if i < 0 then parens else id)(integer i)
             , ppUnless (rep == wordWidth dflags) $
               space <> dcolon <+> ppr rep ]

    CmmFloat f rep     -> hsep [ double (fromRat f), dcolon, ppr rep ]
    CmmVec lits        -> char '<' <> commafy (map pprLit lits) <> char '>'
    CmmLabel clbl      -> ppr clbl
    CmmLabelOff clbl i -> ppr clbl <> ppr_offset i
    CmmLabelDiffOff clbl1 clbl2 i _ -> ppr clbl1 <> char '-'
                                  <> ppr clbl2 <> ppr_offset i
    CmmBlock id        -> ppr id
    CmmHighStackMark -> text "<highSp>"

pprLit1 :: CmmLit -> SDoc
pprLit1 lit@(CmmLabelOff {}) = parens (pprLit lit)
pprLit1 lit                  = pprLit lit

ppr_offset :: Int -> SDoc
ppr_offset i
    | i==0      = empty
    | i>=0      = char '+' <> int i
    | otherwise = char '-' <> int (-i)

-- --------------------------------------------------------------------------
-- Registers, whether local (temps) or global
--
pprReg :: CmmReg -> SDoc
pprReg r
    = case r of
        CmmLocal  local  -> pprLocalReg  local
        CmmGlobal global -> pprGlobalReg global

--
-- We only print the type of the local reg if it isn't wordRep
--
pprLocalReg :: LocalReg -> SDoc
pprLocalReg (LocalReg uniq rep) = sdocWithDynFlags $ \dflags ->
--   = ppr rep <> char '_' <> ppr uniq
-- Temp Jan08
    char '_' <> pprUnique dflags uniq <>
       (if isWord32 rep -- && not (isGcPtrType rep) -- Temp Jan08               -- sigh
                    then dcolon <> ptr <> ppr rep
                    else dcolon <> ptr <> ppr rep)
   where
     pprUnique dflags unique =
        if gopt Opt_SuppressUniques dflags
            then text "_locVar_"
            else ppr unique
     ptr = empty
         --if isGcPtrType rep
         --      then doubleQuotes (text "ptr")
         --      else empty

-- Stack areas
pprArea :: Area -> SDoc
pprArea Old        = text "old"
pprArea (Young id) = hcat [ text "young<", ppr id, text ">" ]

-- needs to be kept in syn with CmmExpr.hs.GlobalReg
--
pprGlobalReg :: GlobalReg -> SDoc
pprGlobalReg gr
    = case gr of
        VanillaReg n _ -> char 'R' <> int n
-- Temp Jan08
--        VanillaReg n VNonGcPtr -> char 'R' <> int n
--        VanillaReg n VGcPtr    -> char 'P' <> int n
        FloatReg   n   -> char 'F' <> int n
        DoubleReg  n   -> char 'D' <> int n
        LongReg    n   -> char 'L' <> int n
        XmmReg     n   -> text "XMM" <> int n
        YmmReg     n   -> text "YMM" <> int n
        ZmmReg     n   -> text "ZMM" <> int n
        Sp             -> text "Sp"
        SpLim          -> text "SpLim"
        Hp             -> text "Hp"
        HpLim          -> text "HpLim"
        MachSp         -> text "MachSp"
        UnwindReturnReg-> text "UnwindReturnReg"
        CCCS           -> text "CCCS"
        CurrentTSO     -> text "CurrentTSO"
        CurrentNursery -> text "CurrentNursery"
        HpAlloc        -> text "HpAlloc"
        EagerBlackholeInfo -> text "stg_EAGER_BLACKHOLE_info"
        GCEnter1       -> text "stg_gc_enter_1"
        GCFun          -> text "stg_gc_fun"
        BaseReg        -> text "BaseReg"
        PicBaseReg     -> text "PicBaseReg"

-----------------------------------------------------------------------------

commafy :: [SDoc] -> SDoc
commafy xs = fsep $ punctuate comma xs