PprC.hs 37.7 KB
Newer Older
1
2
3
4
5
6
7
{-# OPTIONS -w #-}
-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and fix
-- any warnings in the module. See
--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
-- for details

8
9
10
11
-----------------------------------------------------------------------------
--
-- Pretty-printing of Cmm as C, suitable for feeding gcc
--
Simon Marlow's avatar
Simon Marlow committed
12
-- (c) The University of Glasgow 2004-2006
13
14
15
16
17
18
--
-----------------------------------------------------------------------------

--
-- Print Cmm as real C, for -fvia-C
--
19
20
-- See wiki:Commentary/Compiler/Backends/PprC
--
21
22
23
24
25
26
27
28
29
30
31
32
-- This is simpler than the old PprAbsC, because Cmm is "macro-expanded"
-- relative to the old AbstractC, and many oddities/decorations have
-- disappeared from the data type.
--

-- ToDo: save/restore volatile registers around calls.

module PprC (
        writeCs,
        pprStringInCStyle 
  ) where

33
34
#include "HsVersions.h"

35
-- Cmm stuff
36
import BlockId
37
import Cmm
38
import PprCmm	()	-- Instances only
39
40
import CLabel
import ForeignCall
41
import ClosureInfo
42
43

-- Utils
Simon Marlow's avatar
Simon Marlow committed
44
45
import DynFlags
import Unique
46
import UniqSet
Simon Marlow's avatar
Simon Marlow committed
47
import UniqFM
48
49
50
import FastString
import Outputable
import Constants
51
52
import BasicTypes
import CLabel
53
54

-- The rest
Simon Marlow's avatar
Simon Marlow committed
55
56
57
58
import Data.List
import Data.Bits
import Data.Char
import System.IO
59
60
import Data.Map (Map)
import qualified Data.Map as Map
Simon Marlow's avatar
Simon Marlow committed
61
import Data.Word
62
63

import Data.Array.ST
Simon Marlow's avatar
Simon Marlow committed
64
import Control.Monad.ST
65

Simon Marlow's avatar
Simon Marlow committed
66
67
68
69
#if x86_64_TARGET_ARCH
import StaticFlags	( opt_Unregisterised )
#endif

70
71
72
73
#if defined(alpha_TARGET_ARCH) || defined(mips_TARGET_ARCH) || defined(mipsel_TARGET_ARCH) || defined(arm_TARGET_ARCH)
#define BEWARE_LOAD_STORE_ALIGNMENT
#endif

74
75
76
-- --------------------------------------------------------------------------
-- Top level

77
pprCs :: DynFlags -> [RawCmm] -> SDoc
78
79
80
81
pprCs dflags cmms
 = pprCode CStyle (vcat $ map (\c -> split_marker $$ pprC c) cmms)
 where
   split_marker
Ian Lynagh's avatar
Ian Lynagh committed
82
     | dopt Opt_SplitObjs dflags = ptext (sLit "__STG_SPLIT_MARKER")
83
84
     | otherwise     	         = empty

85
writeCs :: DynFlags -> Handle -> [RawCmm] -> IO ()
86
writeCs dflags handle cmms 
87
  = printForC handle (pprCs dflags cmms)
88
89
90
91
92
93
94

-- --------------------------------------------------------------------------
-- Now do some real work
--
-- for fun, we could call cmmToCmm over the tops...
--

95
pprC :: RawCmm -> SDoc
96
pprC (Cmm tops) = vcat $ intersperse blankLine $ map pprTop tops
97
98
99
100

--
-- top level procs
-- 
101
pprTop :: RawCmmTop -> SDoc
102
pprTop (CmmProc info clbl _params (ListGraph blocks)) =
103
    (if not (null info)
104
105
        then pprDataExterns info $$
             pprWordArray (entryLblToInfoLbl clbl) info
106
107
108
109
110
        else empty) $$
    (case blocks of
        [] -> empty
         -- the first block doesn't get a label:
        (BasicBlock _ stmts : rest) -> vcat [
111
	   blankLine,
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
	   extern_decls,
           (if (externallyVisibleCLabel clbl)
                    then mkFN_ else mkIF_) (pprCLabel clbl) <+> lbrace,
           nest 8 temp_decls,
           nest 8 mkFB_,
           nest 8 (vcat (map pprStmt stmts)) $$
              vcat (map pprBBlock rest),
           nest 8 mkFE_,
           rbrace ]
    )
  where
	(temp_decls, extern_decls) = pprTempAndExternDecls blocks 


-- Chunks of static data.

-- We only handle (a) arrays of word-sized things and (b) strings.

pprTop (CmmData _section _ds@[CmmDataLabel lbl, CmmString str]) = 
  hcat [
Ian Lynagh's avatar
Ian Lynagh committed
132
133
    pprLocalness lbl, ptext (sLit "char "), pprCLabel lbl,
    ptext (sLit "[] = "), pprStringInCStyle str, semi
134
135
136
137
  ]

pprTop (CmmData _section _ds@[CmmDataLabel lbl, CmmUninitialised size]) = 
  hcat [
Ian Lynagh's avatar
Ian Lynagh committed
138
    pprLocalness lbl, ptext (sLit "char "), pprCLabel lbl,
139
140
141
142
143
144
145
    brackets (int size), semi
  ]

pprTop top@(CmmData _section (CmmDataLabel lbl : lits)) = 
  pprDataExterns lits $$
  pprWordArray lbl lits  

146
147
148
-- Floating info table for safe a foreign call.
pprTop top@(CmmData _section d@(_ : _))
  | CmmDataLabel lbl : lits <- reverse d = 
149
150
151
  let lits' = reverse lits
  in pprDataExterns lits' $$
     pprWordArray lbl lits'
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
-- these shouldn't appear?
pprTop (CmmData _ _) = panic "PprC.pprTop: can't handle this data"

-- --------------------------------------------------------------------------
-- BasicBlocks are self-contained entities: they always end in a jump.
--
-- Like nativeGen/AsmCodeGen, we could probably reorder blocks to turn
-- as many jumps as possible into fall throughs.
--

pprBBlock :: CmmBasicBlock -> SDoc
pprBBlock (BasicBlock lbl stmts) = 
    if null stmts then
        pprTrace "pprC.pprBBlock: curious empty code block for" 
                        (pprBlockId lbl) empty
    else 
        nest 4 (pprBlockId lbl <> colon) $$
        nest 8 (vcat (map pprStmt stmts))

-- --------------------------------------------------------------------------
-- Info tables. Just arrays of words. 
-- See codeGen/ClosureInfo, and nativeGen/PprMach

pprWordArray :: CLabel -> [CmmStatic] -> SDoc
pprWordArray lbl ds
Ian Lynagh's avatar
Ian Lynagh committed
178
179
  = hcat [ pprLocalness lbl, ptext (sLit "StgWord")
         , space, pprCLabel lbl, ptext (sLit "[] = {") ] 
180
    $$ nest 8 (commafy (pprStatics ds))
Ian Lynagh's avatar
Ian Lynagh committed
181
    $$ ptext (sLit "};")
182
183
184
185
186

--
-- has to be static, if it isn't globally visible
--
pprLocalness :: CLabel -> SDoc
Ian Lynagh's avatar
Ian Lynagh committed
187
pprLocalness lbl | not $ externallyVisibleCLabel lbl = ptext (sLit "static ")
188
189
190
191
192
193
194
195
196
197
                 | otherwise = empty

-- --------------------------------------------------------------------------
-- Statements.
--

pprStmt :: CmmStmt -> SDoc

pprStmt stmt = case stmt of
    CmmNop       -> empty
Simon Marlow's avatar
Simon Marlow committed
198
199
200
201
202
    CmmComment s -> empty -- (hang (ptext (sLit "/*")) 3 (ftext s)) $$ ptext (sLit "*/")
                          -- XXX if the string contains "*/", we need to fix it
                          -- XXX we probably want to emit these comments when
                          -- some debugging option is on.  They can get quite
                          -- large.
203
204
205
206

    CmmAssign dest src -> pprAssign dest src

    CmmStore  dest src
207
208
209
210
 	| typeWidth rep == W64 && wordWidth /= W64
 	-> (if isFloatType rep then ptext (sLit "ASSIGN_DBL")
 			       else ptext (sLit ("ASSIGN_Word64"))) <> 
 	   parens (mkP_ <> pprExpr1 dest <> comma <> pprExpr src) <> semi
211

212
213
214
 	| otherwise
	-> hsep [ pprExpr (CmmLoad dest rep), equals, pprExpr src <> semi ]
	where
215
	  rep = cmmExprType src
216

217
    CmmCall (CmmCallee fn cconv) results args safety ret ->
218
        maybe_proto $$
219
	fnCall
220
	where
221
222
223
224
225
226
        cast_fn = parens (cCast (pprCFunType (char '*') cconv results args) fn)

        real_fun_proto lbl = char ';' <> 
                        pprCFunType (pprCLabel lbl) cconv results args <> 
                        noreturn_attr <> semi

227
        fun_proto lbl = ptext (sLit ";EF_(") <>
228
229
230
231
232
                         pprCLabel lbl <> char ')' <> semi

        noreturn_attr = case ret of
                          CmmNeverReturns -> text "__attribute__ ((noreturn))"
                          CmmMayReturn    -> empty
233

234
        -- See wiki:Commentary/Compiler/Backends/PprC#Prototypes
235
    	(maybe_proto, fnCall) = 
236
            case fn of
237
	      CmmLit (CmmLabel lbl) 
238
239
240
                | StdCallConv <- cconv ->
                    let myCall = pprCall (pprCLabel lbl) cconv results args safety
                    in (real_fun_proto lbl, myCall)
241
242
243
244
245
                        -- stdcall functions must be declared with
                        -- a function type, otherwise the C compiler
                        -- doesn't add the @n suffix to the label.  We
                        -- can't add the @n suffix ourselves, because
                        -- it isn't valid C.
246
247
248
249
250
251
252
253
254
255
                | CmmNeverReturns <- ret ->
                    let myCall = pprCall (pprCLabel lbl) cconv results args safety
                    in (real_fun_proto lbl, myCall)
                | not (isMathFun lbl) ->
                    let myCall = braces (
                                     pprCFunType (char '*' <> text "ghcFunPtr") cconv results args <> semi
                                  $$ text "ghcFunPtr" <+> equals <+> cast_fn <> semi
                                  $$ pprCall (text "ghcFunPtr") cconv results args safety <> semi
                                 )
                    in (fun_proto lbl, myCall)
256
	      _ -> 
257
258
                   (empty {- no proto -},
                    pprCall cast_fn cconv results args safety <> semi)
259
			-- for a dynamic call, no declaration is necessary.
260

261
    CmmCall (CmmPrim op) results args safety _ret ->
262
	pprCall ppr_fn CCallConv results args safety
263
264
265
266
267
268
269
270
	where
    	ppr_fn = pprCallishMachOp_for_C op

    CmmBranch ident          -> pprBranch ident
    CmmCondBranch expr ident -> pprCondBranch expr ident
    CmmJump lbl _params      -> mkJMP_(pprExpr lbl) <> semi
    CmmSwitch arg ids        -> pprSwitch arg ids

271
pprCFunType :: SDoc -> CCallConv -> HintedCmmFormals -> HintedCmmActuals -> SDoc
272
273
274
275
pprCFunType ppr_fn cconv ress args
  = res_type ress <+>
    parens (text (ccallConvAttribute cconv) <>  ppr_fn) <>
    parens (commafy (map arg_type args))
276
  where
Ian Lynagh's avatar
Ian Lynagh committed
277
	res_type [] = ptext (sLit "void")
278
	res_type [CmmHinted one hint] = machRepHintCType (localRegType one) hint
279

280
	arg_type (CmmHinted expr hint) = machRepHintCType (cmmExprType expr) hint
281
282
283
284

-- ---------------------------------------------------------------------
-- unconditional branches
pprBranch :: BlockId -> SDoc
Ian Lynagh's avatar
Ian Lynagh committed
285
pprBranch ident = ptext (sLit "goto") <+> pprBlockId ident <> semi
286
287
288
289
290
291


-- ---------------------------------------------------------------------
-- conditional branches to local labels
pprCondBranch :: CmmExpr -> BlockId -> SDoc
pprCondBranch expr ident 
Ian Lynagh's avatar
Ian Lynagh committed
292
293
        = hsep [ ptext (sLit "if") , parens(pprExpr expr) ,
                        ptext (sLit "goto") , (pprBlockId ident) <> semi ]
294
295
296
297
298
299
300
301
302
303
304
305
306


-- ---------------------------------------------------------------------
-- a local table branch
--
-- we find the fall-through cases
--
-- N.B. we remove Nothing's from the list of branches, as they are
-- 'undefined'. However, they may be defined one day, so we better
-- document this behaviour.
--
pprSwitch :: CmmExpr -> [ Maybe BlockId ] -> SDoc
pprSwitch e maybe_ids 
307
308
  = let pairs  = [ (ix, ident) | (ix,Just ident) <- zip [0..] maybe_ids ]
	pairs2 = [ (map fst as, snd (head as)) | as <- groupBy sndEq pairs ]
309
    in 
Ian Lynagh's avatar
Ian Lynagh committed
310
        (hang (ptext (sLit "switch") <+> parens ( pprExpr e ) <+> lbrace)
311
                4 (vcat ( map caseify pairs2 )))
312
313
314
        $$ rbrace

  where
315
    sndEq (_,x) (_,y) = x == y
316

317
318
319
320
    -- fall through case
    caseify (ix:ixs, ident) = vcat (map do_fallthrough ixs) $$ final_branch ix
	where 
	do_fallthrough ix =
321
                 hsep [ ptext (sLit "case") , pprHexVal ix wordWidth <> colon ,
Ian Lynagh's avatar
Ian Lynagh committed
322
                        ptext (sLit "/* fall through */") ]
323
324

	final_branch ix = 
325
	        hsep [ ptext (sLit "case") , pprHexVal ix wordWidth <> colon ,
Ian Lynagh's avatar
Ian Lynagh committed
326
                       ptext (sLit "goto") , (pprBlockId ident) <> semi ]
327
328
329
330
331
332
333
334
335
336
337

-- ---------------------------------------------------------------------
-- Expressions.
--

-- C Types: the invariant is that the C expression generated by
--
--	pprExpr e
--
-- has a type in C which is also given by
--
338
--	machRepCType (cmmExprType e)
339
340
341
342
343
344
345
346
--
-- (similar invariants apply to the rest of the pretty printer).

pprExpr :: CmmExpr -> SDoc
pprExpr e = case e of
    CmmLit lit -> pprLit lit


347
    CmmLoad e ty -> pprLoad e ty
348
349
350
351
352
353
354
355
356
357
358
    CmmReg reg      -> pprCastReg reg
    CmmRegOff reg 0 -> pprCastReg reg

    CmmRegOff reg i
	| i >  0    -> pprRegOff (char '+') i
	| otherwise -> pprRegOff (char '-') (-i)
      where
	pprRegOff op i' = pprCastReg reg <> op <> int i'

    CmmMachOp mop args -> pprMachOpApp mop args

359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384

pprLoad :: CmmExpr -> CmmType -> SDoc
pprLoad e ty
  | width == W64, wordWidth /= W64
  = (if isFloatType ty then ptext (sLit "PK_DBL")
	    	       else ptext (sLit "PK_Word64"))
    <> parens (mkP_ <> pprExpr1 e)

  | otherwise 
  = case e of
	CmmReg r | isPtrReg r && width == wordWidth && not (isFloatType ty)
		 -> char '*' <> pprAsPtrReg r

	CmmRegOff r 0 | isPtrReg r && width == wordWidth && not (isFloatType ty)
		      -> char '*' <> pprAsPtrReg r

	CmmRegOff r off | isPtrReg r && width == wordWidth
			, off `rem` wORD_SIZE == 0 && not (isFloatType ty)
	-- ToDo: check that the offset is a word multiple?
        --       (For tagging to work, I had to avoid unaligned loads. --ARY)
			-> pprAsPtrReg r <> brackets (ppr (off `shiftR` wordShift))

	_other -> cLoad e ty
  where
    width = typeWidth ty

385
386
387
388
389
390
391
392
393
394
395
396
pprExpr1 :: CmmExpr -> SDoc
pprExpr1 (CmmLit lit) 	  = pprLit1 lit
pprExpr1 e@(CmmReg _reg)  = pprExpr e
pprExpr1 other            = parens (pprExpr other)

-- --------------------------------------------------------------------------
-- MachOp applications

pprMachOpApp :: MachOp -> [CmmExpr] -> SDoc

pprMachOpApp op args
  | isMulMayOfloOp op
Ian Lynagh's avatar
Ian Lynagh committed
397
  = ptext (sLit "mulIntMayOflo") <> parens (commafy (map pprExpr args))
398
399
400
401
402
  where isMulMayOfloOp (MO_U_MulMayOflo _) = True
	isMulMayOfloOp (MO_S_MulMayOflo _) = True
	isMulMayOfloOp _ = False

pprMachOpApp mop args
403
404
405
406
407
408
409
410
411
412
413
414
415
416
  | Just ty <- machOpNeedsCast mop 
  = ty <> parens (pprMachOpApp' mop args)
  | otherwise
  = pprMachOpApp' mop args

-- Comparisons in C have type 'int', but we want type W_ (this is what
-- resultRepOfMachOp says).  The other C operations inherit their type
-- from their operands, so no casting is required.
machOpNeedsCast :: MachOp -> Maybe SDoc
machOpNeedsCast mop
  | isComparisonMachOp mop = Just mkW_
  | otherwise              = Nothing

pprMachOpApp' mop args
417
418
419
420
421
422
423
424
425
426
 = case args of
    -- dyadic
    [x,y] -> pprArg x <+> pprMachOp_for_C mop <+> pprArg y

    -- unary
    [x]   -> pprMachOp_for_C mop <> parens (pprArg x)

    _     -> panic "PprC.pprMachOp : machop with wrong number of args"

  where
427
428
429
	-- Cast needed for signed integer ops
    pprArg e | signedOp    mop = cCast (machRep_S_CType (typeWidth (cmmExprType e))) e
             | needsFCasts mop = cCast (machRep_F_CType (typeWidth (cmmExprType e))) e
430
 	     | otherwise    = pprExpr1 e
431
432
433
434
435
    needsFCasts (MO_F_Eq _)   = False
    needsFCasts (MO_F_Ne _)   = False
    needsFCasts (MO_F_Neg _)  = True
    needsFCasts (MO_F_Quot _) = True
    needsFCasts mop  = floatComparison mop
436
437
438
439
440
441

-- --------------------------------------------------------------------------
-- Literals

pprLit :: CmmLit -> SDoc
pprLit lit = case lit of
442
    CmmInt i rep      -> pprHexVal i rep
443

444
    CmmFloat f w       -> parens (machRep_F_CType w) <> str
445
446
447
448
449
450
451
452
        where d = fromRational f :: Double
              str | isInfinite d && d < 0 = ptext (sLit "-INFINITY")
                  | isInfinite d          = ptext (sLit "INFINITY")
                  | isNaN d               = ptext (sLit "NAN")
                  | otherwise             = text (show d)
                -- these constants come from <math.h>
                -- see #1861

453
454
    CmmBlock bid       -> mkW_ <> pprCLabelAddr (infoTblLbl bid)
    CmmHighStackMark   -> panic "PprC printing high stack mark"
455
456
    CmmLabel clbl      -> mkW_ <> pprCLabelAddr clbl
    CmmLabelOff clbl i -> mkW_ <> pprCLabelAddr clbl <> char '+' <> int i
457
458
    CmmLabelDiffOff clbl1 clbl2 i
        -- WARNING:
459
460
        --  * the lit must occur in the info table clbl2
        --  * clbl1 must be an SRT, a slow entry point or a large bitmap
461
462
463
        -- The Mangler is expected to convert any reference to an SRT,
        -- a slow entry point or a large bitmap
        -- from an info table to an offset.
464
465
466
        -> mkW_ <> pprCLabelAddr clbl1 <> char '+' <> int i

pprCLabelAddr lbl = char '&' <> pprCLabel lbl
467
468
469

pprLit1 :: CmmLit -> SDoc
pprLit1 lit@(CmmLabelOff _ _) = parens (pprLit lit)
470
pprLit1 lit@(CmmLabelDiffOff _ _ _) = parens (pprLit lit)
471
472
473
474
475
476
477
478
pprLit1 lit@(CmmFloat _ _)    = parens (pprLit lit)
pprLit1 other = pprLit other

-- ---------------------------------------------------------------------------
-- Static data

pprStatics :: [CmmStatic] -> [SDoc]
pprStatics [] = []
479
pprStatics (CmmStaticLit (CmmFloat f W32) : rest) 
480
  -- floats are padded to a word, see #1852
481
  | wORD_SIZE == 8, CmmStaticLit (CmmInt 0 W32) : rest' <- rest
482
483
  = pprLit1 (floatToWord f) : pprStatics rest'
  | wORD_SIZE == 4
484
  = pprLit1 (floatToWord f) : pprStatics rest
485
  | otherwise
486
487
  = pprPanic "pprStatics: float" (vcat (map (\(CmmStaticLit l) -> ppr (cmmLitType l)) rest))
pprStatics (CmmStaticLit (CmmFloat f W64) : rest)
488
  = map pprLit1 (doubleToWords f) ++ pprStatics rest
489
490
pprStatics (CmmStaticLit (CmmInt i W64) : rest)
  | wordWidth == W32
491
#ifdef WORDS_BIGENDIAN
492
493
  = pprStatics (CmmStaticLit (CmmInt q W32) : 
		CmmStaticLit (CmmInt r W32) : rest)
494
#else
495
496
  = pprStatics (CmmStaticLit (CmmInt r W32) : 
		CmmStaticLit (CmmInt q W32) : rest)
497
498
499
#endif
  where r = i .&. 0xffffffff
	q = i `shiftR` 32
500
501
pprStatics (CmmStaticLit (CmmInt i w) : rest)
  | w /= wordWidth
502
  = panic "pprStatics: cannot emit a non-word-sized static literal"
503
504
505
506
507
508
509
510
511
pprStatics (CmmStaticLit lit : rest)
  = pprLit1 lit : pprStatics rest
pprStatics (other : rest)
  = pprPanic "pprWord" (pprStatic other)

pprStatic :: CmmStatic -> SDoc
pprStatic s = case s of

    CmmStaticLit lit   -> nest 4 (pprLit lit)
Ian Lynagh's avatar
Ian Lynagh committed
512
    CmmAlign i         -> nest 4 (ptext (sLit "/* align */") <+> int i)
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
    CmmDataLabel clbl  -> pprCLabel clbl <> colon
    CmmUninitialised i -> nest 4 (mkC_ <> brackets (int i))

    -- these should be inlined, like the old .hc
    CmmString s'       -> nest 4 (mkW_ <> parens(pprStringInCStyle s'))


-- ---------------------------------------------------------------------------
-- Block Ids

pprBlockId :: BlockId -> SDoc
pprBlockId b = char '_' <> ppr (getUnique b)

-- --------------------------------------------------------------------------
-- Print a MachOp in a way suitable for emitting via C.
--

pprMachOp_for_C :: MachOp -> SDoc

pprMachOp_for_C mop = case mop of 

        -- Integer operations
        MO_Add          _ -> char '+'
        MO_Sub          _ -> char '-'
Ian Lynagh's avatar
Ian Lynagh committed
537
538
        MO_Eq           _ -> ptext (sLit "==")
        MO_Ne           _ -> ptext (sLit "!=")
539
540
541
542
543
544
545
546
547
        MO_Mul          _ -> char '*'

        MO_S_Quot       _ -> char '/'
        MO_S_Rem        _ -> char '%'
        MO_S_Neg        _ -> char '-'

        MO_U_Quot       _ -> char '/'
        MO_U_Rem        _ -> char '%'

548
549
550
551
552
553
554
555
        -- & Floating-point operations
        MO_F_Add        _ -> char '+'
        MO_F_Sub        _ -> char '-'
        MO_F_Neg        _ -> char '-'
        MO_F_Mul        _ -> char '*'
        MO_F_Quot       _ -> char '/'

        -- Signed comparisons
Ian Lynagh's avatar
Ian Lynagh committed
556
557
        MO_S_Ge         _ -> ptext (sLit ">=")
        MO_S_Le         _ -> ptext (sLit "<=")
558
559
560
        MO_S_Gt         _ -> char '>'
        MO_S_Lt         _ -> char '<'

561
        -- & Unsigned comparisons
Ian Lynagh's avatar
Ian Lynagh committed
562
563
        MO_U_Ge         _ -> ptext (sLit ">=")
        MO_U_Le         _ -> ptext (sLit "<=")
564
565
566
        MO_U_Gt         _ -> char '>'
        MO_U_Lt         _ -> char '<'

567
568
569
570
571
572
573
574
        -- & Floating-point comparisons
        MO_F_Eq         _ -> ptext (sLit "==")
        MO_F_Ne         _ -> ptext (sLit "!=")
        MO_F_Ge         _ -> ptext (sLit ">=")
        MO_F_Le         _ -> ptext (sLit "<=")
        MO_F_Gt         _ -> char '>'
        MO_F_Lt         _ -> char '<'

575
576
577
578
579
580
        -- Bitwise operations.  Not all of these may be supported at all
        -- sizes, and only integral MachReps are valid.
        MO_And          _ -> char '&'
        MO_Or           _ -> char '|'
        MO_Xor          _ -> char '^'
        MO_Not          _ -> char '~'
Ian Lynagh's avatar
Ian Lynagh committed
581
582
583
        MO_Shl          _ -> ptext (sLit "<<")
        MO_U_Shr        _ -> ptext (sLit ">>") -- unsigned shift right
        MO_S_Shr        _ -> ptext (sLit ">>") -- signed shift right
584

585
586
-- Conversions.  Some of these will be NOPs, but never those that convert
-- between ints and floats.
587
588
589
590
591
-- Floating-point conversions use the signed variant.
-- We won't know to generate (void*) casts here, but maybe from
-- context elsewhere

-- noop casts
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
        MO_UU_Conv from to | from == to -> empty
	MO_UU_Conv _from to  -> parens (machRep_U_CType to)

        MO_SS_Conv from to | from == to -> empty
	MO_SS_Conv _from to  -> parens (machRep_S_CType to)

        -- TEMPORARY: the old code didn't check this case, so let's leave it out
        -- to facilitate comparisons against the old output code.
        --MO_FF_Conv from to | from == to -> empty
	MO_FF_Conv _from to  -> parens (machRep_F_CType to)

	MO_SF_Conv _from to  -> parens (machRep_F_CType to)
	MO_FS_Conv _from to  -> parens (machRep_S_CType to)

        _ -> pprTrace "offending mop" (ptext $ sLit $ show mop) $
             panic "PprC.pprMachOp_for_C: unknown machop"

signedOp :: MachOp -> Bool	-- Argument type(s) are signed ints
610
611
612
613
614
615
616
617
signedOp (MO_S_Quot _)	 = True
signedOp (MO_S_Rem  _)	 = True
signedOp (MO_S_Neg  _)	 = True
signedOp (MO_S_Ge   _)	 = True
signedOp (MO_S_Le   _)	 = True
signedOp (MO_S_Gt   _)	 = True
signedOp (MO_S_Lt   _)	 = True
signedOp (MO_S_Shr  _)	 = True
618
619
signedOp (MO_SS_Conv _ _) = True
signedOp (MO_SF_Conv _ _) = True
620
621
signedOp _ = False

622
623
624
625
626
627
628
629
630
floatComparison :: MachOp -> Bool  -- comparison between float args
floatComparison (MO_F_Eq   _)	 = True
floatComparison (MO_F_Ne   _)	 = True
floatComparison (MO_F_Ge   _)	 = True
floatComparison (MO_F_Le   _)	 = True
floatComparison (MO_F_Gt   _)	 = True
floatComparison (MO_F_Lt   _)	 = True
floatComparison _ = False

631
632
633
634
635
636
637
-- ---------------------------------------------------------------------
-- tend to be implemented by foreign calls

pprCallishMachOp_for_C :: CallishMachOp -> SDoc

pprCallishMachOp_for_C mop 
    = case mop of
Ian Lynagh's avatar
Ian Lynagh committed
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
        MO_F64_Pwr  -> ptext (sLit "pow")
        MO_F64_Sin  -> ptext (sLit "sin")
        MO_F64_Cos  -> ptext (sLit "cos")
        MO_F64_Tan  -> ptext (sLit "tan")
        MO_F64_Sinh -> ptext (sLit "sinh")
        MO_F64_Cosh -> ptext (sLit "cosh")
        MO_F64_Tanh -> ptext (sLit "tanh")
        MO_F64_Asin -> ptext (sLit "asin")
        MO_F64_Acos -> ptext (sLit "acos")
        MO_F64_Atan -> ptext (sLit "atan")
        MO_F64_Log  -> ptext (sLit "log")
        MO_F64_Exp  -> ptext (sLit "exp")
        MO_F64_Sqrt -> ptext (sLit "sqrt")
        MO_F32_Pwr  -> ptext (sLit "powf")
        MO_F32_Sin  -> ptext (sLit "sinf")
        MO_F32_Cos  -> ptext (sLit "cosf")
        MO_F32_Tan  -> ptext (sLit "tanf")
        MO_F32_Sinh -> ptext (sLit "sinhf")
        MO_F32_Cosh -> ptext (sLit "coshf")
        MO_F32_Tanh -> ptext (sLit "tanhf")
        MO_F32_Asin -> ptext (sLit "asinf")
        MO_F32_Acos -> ptext (sLit "acosf")
        MO_F32_Atan -> ptext (sLit "atanf")
        MO_F32_Log  -> ptext (sLit "logf")
        MO_F32_Exp  -> ptext (sLit "expf")
        MO_F32_Sqrt -> ptext (sLit "sqrtf")
	MO_WriteBarrier -> ptext (sLit "write_barrier")
665
666
667
668
669
670
671

-- ---------------------------------------------------------------------
-- Useful #defines
--

mkJMP_, mkFN_, mkIF_ :: SDoc -> SDoc

Ian Lynagh's avatar
Ian Lynagh committed
672
673
674
mkJMP_ i = ptext (sLit "JMP_") <> parens i
mkFN_  i = ptext (sLit "FN_")  <> parens i -- externally visible function
mkIF_  i = ptext (sLit "IF_")  <> parens i -- locally visible
675
676
677


mkFB_, mkFE_ :: SDoc
Ian Lynagh's avatar
Ian Lynagh committed
678
679
mkFB_ = ptext (sLit "FB_") -- function code begin
mkFE_ = ptext (sLit "FE_") -- function code end
680
681
682

-- from includes/Stg.h
--
Simon Marlow's avatar
Simon Marlow committed
683
mkC_,mkW_,mkP_ :: SDoc
684

Ian Lynagh's avatar
Ian Lynagh committed
685
686
687
mkC_  = ptext (sLit "(C_)")        -- StgChar
mkW_  = ptext (sLit "(W_)")        -- StgWord
mkP_  = ptext (sLit "(P_)")        -- StgWord*
688
689
690
691
692
693
694
695
696
697
698

-- ---------------------------------------------------------------------
--
-- Assignments
--
-- Generating assignments is what we're all about, here
--
pprAssign :: CmmReg -> CmmExpr -> SDoc

-- dest is a reg, rhs is a reg
pprAssign r1 (CmmReg r2)
699
   | isPtrReg r1 && isPtrReg r2
700
701
702
703
   = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, semi ]

-- dest is a reg, rhs is a CmmRegOff
pprAssign r1 (CmmRegOff r2 off)
704
   | isPtrReg r1 && isPtrReg r2 && (off `rem` wORD_SIZE == 0)
705
706
   = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, op, int off', semi ]
  where
707
	off1 = off `shiftR` wordShift
708
709
710
711

	(op,off') | off >= 0  = (char '+', off1)
		  | otherwise = (char '-', -off1)

712
713
714
-- dest is a reg, rhs is anything.
-- We can't cast the lvalue, so we have to cast the rhs if necessary.  Casting
-- the lvalue elicits a warning from new GCC versions (3.4+).
715
pprAssign r1 r2
Ian Lynagh's avatar
Ian Lynagh committed
716
717
718
719
  | isFixedPtrReg r1             = mkAssign (mkP_ <> pprExpr1 r2)
  | Just ty <- strangeRegType r1 = mkAssign (parens ty <> pprExpr1 r2)
  | otherwise                    = mkAssign (pprExpr r2)
    where mkAssign x = if r1 == CmmGlobal BaseReg
Ian Lynagh's avatar
Ian Lynagh committed
720
721
                       then ptext (sLit "ASSIGN_BaseReg") <> parens x <> semi
                       else pprReg r1 <> ptext (sLit " = ") <> x <> semi
722
723
724
725
726
727
728
729

-- ---------------------------------------------------------------------
-- Registers

pprCastReg reg
   | isStrangeTypeReg reg = mkW_ <> pprReg reg
   | otherwise            = pprReg reg

730
731
732
733
734
735
-- True if (pprReg reg) will give an expression with type StgPtr.  We
-- need to take care with pointer arithmetic on registers with type
-- StgPtr.
isFixedPtrReg :: CmmReg -> Bool
isFixedPtrReg (CmmLocal _) = False
isFixedPtrReg (CmmGlobal r) = isFixedPtrGlobalReg r
736

737
-- True if (pprAsPtrReg reg) will give an expression with type StgPtr
738
739
740
-- JD: THIS IS HORRIBLE AND SHOULD BE RENAMED, AT THE VERY LEAST.
-- THE GARBAGE WITH THE VNonGcPtr HELPS MATCH THE OLD CODE GENERATOR'S OUTPUT;
-- I'M NOT SURE IF IT SHOULD REALLY STAY THAT WAY.
741
742
isPtrReg :: CmmReg -> Bool
isPtrReg (CmmLocal _) 		    = False
743
744
isPtrReg (CmmGlobal (VanillaReg n VGcPtr)) = True -- if we print via pprAsPtrReg
isPtrReg (CmmGlobal (VanillaReg n VNonGcPtr)) = False --if we print via pprAsPtrReg
745
746
747
748
749
750
751
752
753
isPtrReg (CmmGlobal reg)	    = isFixedPtrGlobalReg reg

-- True if this global reg has type StgPtr
isFixedPtrGlobalReg :: GlobalReg -> Bool
isFixedPtrGlobalReg Sp 		= True
isFixedPtrGlobalReg Hp 		= True
isFixedPtrGlobalReg HpLim	= True
isFixedPtrGlobalReg SpLim	= True
isFixedPtrGlobalReg _ 		= False
754
755

-- True if in C this register doesn't have the type given by 
756
-- (machRepCType (cmmRegType reg)), so it has to be cast.
757
758
759
760
761
762
763
isStrangeTypeReg :: CmmReg -> Bool
isStrangeTypeReg (CmmLocal _) 	= False
isStrangeTypeReg (CmmGlobal g) 	= isStrangeTypeGlobal g

isStrangeTypeGlobal :: GlobalReg -> Bool
isStrangeTypeGlobal CurrentTSO		= True
isStrangeTypeGlobal CurrentNursery 	= True
764
isStrangeTypeGlobal BaseReg	 	= True
765
isStrangeTypeGlobal r 			= isFixedPtrGlobalReg r
766

767
strangeRegType :: CmmReg -> Maybe SDoc
Ian Lynagh's avatar
Ian Lynagh committed
768
769
770
strangeRegType (CmmGlobal CurrentTSO) = Just (ptext (sLit "struct StgTSO_ *"))
strangeRegType (CmmGlobal CurrentNursery) = Just (ptext (sLit "struct bdescr_ *"))
strangeRegType (CmmGlobal BaseReg) = Just (ptext (sLit "struct StgRegTable_ *"))
771
strangeRegType _ = Nothing
772
773
774
775
776
777
778
779
780

-- pprReg just prints the register name.
--
pprReg :: CmmReg -> SDoc
pprReg r = case r of
        CmmLocal  local  -> pprLocalReg local
        CmmGlobal global -> pprGlobalReg global
		
pprAsPtrReg :: CmmReg -> SDoc
781
782
pprAsPtrReg (CmmGlobal (VanillaReg n gcp)) 
  = WARN( gcp /= VGcPtr, ppr n ) char 'R' <> int n <> ptext (sLit ".p")
783
784
785
786
pprAsPtrReg other_reg = pprReg other_reg

pprGlobalReg :: GlobalReg -> SDoc
pprGlobalReg gr = case gr of
787
788
789
790
    VanillaReg n _ -> char 'R' <> int n  <> ptext (sLit ".w")
	-- pprGlobalReg prints a VanillaReg as a .w regardless
	-- Example:	R1.w = R1.w & (-0x8UL);
	--		JMP_(*R1.p);
791
792
793
    FloatReg   n   -> char 'F' <> int n
    DoubleReg  n   -> char 'D' <> int n
    LongReg    n   -> char 'L' <> int n
Ian Lynagh's avatar
Ian Lynagh committed
794
795
796
797
798
799
800
801
    Sp             -> ptext (sLit "Sp")
    SpLim          -> ptext (sLit "SpLim")
    Hp             -> ptext (sLit "Hp")
    HpLim          -> ptext (sLit "HpLim")
    CurrentTSO     -> ptext (sLit "CurrentTSO")
    CurrentNursery -> ptext (sLit "CurrentNursery")
    HpAlloc        -> ptext (sLit "HpAlloc")
    BaseReg        -> ptext (sLit "BaseReg")
802
    EagerBlackholeInfo -> ptext (sLit "stg_EAGER_BLACKHOLE_info")
Ian Lynagh's avatar
Ian Lynagh committed
803
804
    GCEnter1       -> ptext (sLit "stg_gc_enter_1")
    GCFun          -> ptext (sLit "stg_gc_fun")
805
806

pprLocalReg :: LocalReg -> SDoc
807
pprLocalReg (LocalReg uniq _) = char '_' <> ppr uniq
808
809
810
811

-- -----------------------------------------------------------------------------
-- Foreign Calls

812
pprCall :: SDoc -> CCallConv -> HintedCmmFormals -> HintedCmmActuals -> CmmSafety
813
	-> SDoc
814

815
pprCall ppr_fn cconv results args _
816
  | not (is_cish cconv)
Simon Marlow's avatar
Simon Marlow committed
817
  = panic "pprCall: unknown calling convention"
818
819

  | otherwise
820
  =
821
822
823
824
825
826
827
#if x86_64_TARGET_ARCH
	-- HACK around gcc optimisations.
	-- x86_64 needs a __DISCARD__() here, to create a barrier between
	-- putting the arguments into temporaries and passing the arguments
	-- to the callee, because the argument expressions may refer to
	-- machine registers that are also used for passing arguments in the
	-- C calling convention.
828
    (if (not opt_Unregisterised) 
Ian Lynagh's avatar
Ian Lynagh committed
829
	then ptext (sLit "__DISCARD__();") 
830
	else empty) $$
831
#endif
832
    ppr_assign results (ppr_fn <> parens (commafy (map pprArg args))) <> semi
833
  where 
Simon Marlow's avatar
Simon Marlow committed
834
     ppr_assign []           rhs = rhs
835
     ppr_assign [CmmHinted one hint] rhs
Ian Lynagh's avatar
Ian Lynagh committed
836
	 = pprLocalReg one <> ptext (sLit " = ")
837
		 <> pprUnHint hint (localRegType one) <> rhs
Simon Marlow's avatar
Simon Marlow committed
838
     ppr_assign _other _rhs = panic "pprCall: multiple results"
839

840
841
     pprArg (CmmHinted expr AddrHint)
   	= cCast (ptext (sLit "void *")) expr
842
	-- see comment by machRepHintCType below
843
844
845
846
     pprArg (CmmHinted expr SignedHint)
	= cCast (machRep_S_CType $ typeWidth $ cmmExprType expr) expr
     pprArg (CmmHinted expr _other)
	= pprExpr expr
847

848
     pprUnHint AddrHint   rep = parens (machRepCType rep)
849
850
851
     pprUnHint SignedHint rep = parens (machRepCType rep)
     pprUnHint _          _   = empty

852
853
pprGlobalRegName :: GlobalReg -> SDoc
pprGlobalRegName gr = case gr of
854
855
    VanillaReg n _  -> char 'R' <> int n  -- without the .w suffix
    _               -> pprGlobalReg gr
856

857
858
-- Currently we only have these two calling conventions, but this might
-- change in the future...
859
860
861
862
863
864
865
866
867
is_cish CCallConv   = True
is_cish StdCallConv = True

-- ---------------------------------------------------------------------
-- Find and print local and external declarations for a list of
-- Cmm statements.
-- 
pprTempAndExternDecls :: [CmmBasicBlock] -> (SDoc{-temps-}, SDoc{-externs-})
pprTempAndExternDecls stmts 
868
  = (vcat (map pprTempDecl (uniqSetToList temps)), 
869
     vcat (map (pprExternDecl False{-ToDo-}) (Map.keys lbls)))
870
871
872
873
  where (temps, lbls) = runTE (mapM_ te_BB stmts)

pprDataExterns :: [CmmStatic] -> SDoc
pprDataExterns statics
874
  = vcat (map (pprExternDecl False{-ToDo-}) (Map.keys lbls))
875
876
877
  where (_, lbls) = runTE (mapM_ te_Static statics)

pprTempDecl :: LocalReg -> SDoc
878
pprTempDecl l@(LocalReg _ rep)
879
880
881
882
883
884
  = hcat [ machRepCType rep, space, pprLocalReg l, semi ]

pprExternDecl :: Bool -> CLabel -> SDoc
pprExternDecl in_srt lbl
  -- do not print anything for "known external" things
  | not (needsCDecl lbl) = empty
885
886
  | Just sz <- foreignLabelStdcallInfo lbl = stdcall_decl sz
  | otherwise =
887
	hcat [ visibility, label_type lbl,
888
	       lparen, pprCLabel lbl, text ");" ]
889
 where
890
891
  label_type lbl | isCFunctionLabel lbl = ptext (sLit "F_")
		 | otherwise		= ptext (sLit "I_")
892
893
894
895
896

  visibility
     | externallyVisibleCLabel lbl = char 'E'
     | otherwise		   = char 'I'

897
898
899
900
901
  -- If the label we want to refer to is a stdcall function (on Windows) then
  -- we must generate an appropriate prototype for it, so that the C compiler will
  -- add the @n suffix to the label (#2276)
  stdcall_decl sz =
        ptext (sLit "extern __attribute__((stdcall)) void ") <> pprCLabel lbl
902
        <> parens (commafy (replicate (sz `quot` wORD_SIZE) (machRep_U_CType wordWidth)))
903
        <> semi
904

905
type TEState = (UniqSet LocalReg, Map CLabel ())
906
907
908
909
910
911
912
newtype TE a = TE { unTE :: TEState -> (a, TEState) }

instance Monad TE where
   TE m >>= k  = TE $ \s -> case m s of (a, s') -> unTE (k a) s'
   return a    = TE $ \s -> (a, s)

te_lbl :: CLabel -> TE ()
913
te_lbl lbl = TE $ \(temps,lbls) -> ((), (temps, Map.insert lbl () lbls))
914
915
916
917
918

te_temp :: LocalReg -> TE ()
te_temp r = TE $ \(temps,lbls) -> ((), (addOneToUniqSet temps r, lbls))

runTE :: TE () -> TEState
919
runTE (TE m) = snd (m (emptyUniqSet, Map.empty))
920
921
922
923
924
925
926
927
928
929

te_Static :: CmmStatic -> TE ()
te_Static (CmmStaticLit lit) = te_Lit lit
te_Static _ = return ()

te_BB :: CmmBasicBlock -> TE ()
te_BB (BasicBlock _ ss)		= mapM_ te_Stmt ss

te_Lit :: CmmLit -> TE ()
te_Lit (CmmLabel l) = te_lbl l
930
931
te_Lit (CmmLabelOff l _) = te_lbl l
te_Lit (CmmLabelDiffOff l1 l2 _) = te_lbl l1
932
933
934
935
936
te_Lit _ = return ()

te_Stmt :: CmmStmt -> TE ()
te_Stmt (CmmAssign r e)		= te_Reg r >> te_Expr e
te_Stmt (CmmStore l r)		= te_Expr l >> te_Expr r
937
938
te_Stmt (CmmCall _ rs es _ _)	= mapM_ (te_temp.hintlessCmm) rs >>
				  mapM_ (te_Expr.hintlessCmm) es
939
940
941
942
943
944
945
946
te_Stmt (CmmCondBranch e _)	= te_Expr e
te_Stmt (CmmSwitch e _)		= te_Expr e
te_Stmt (CmmJump e _)		= te_Expr e
te_Stmt _			= return ()

te_Expr :: CmmExpr -> TE ()
te_Expr (CmmLit lit)		= te_Lit lit
te_Expr (CmmLoad e _)		= te_Expr e
947
te_Expr (CmmReg r)		= te_Reg r
948
949
950
951
952
953
954
955
956
957
958
959
960
961
te_Expr (CmmMachOp _ es) 	= mapM_ te_Expr es
te_Expr (CmmRegOff r _) 	= te_Reg r

te_Reg :: CmmReg -> TE ()
te_Reg (CmmLocal l) = te_temp l
te_Reg _            = return ()


-- ---------------------------------------------------------------------
-- C types for MachReps

cCast :: SDoc -> CmmExpr -> SDoc
cCast ty expr = parens ty <> pprExpr1 expr

962
cLoad :: CmmExpr -> CmmType -> SDoc
963
964
#ifdef BEWARE_LOAD_STORE_ALIGNMENT
cLoad expr rep =
Ian Lynagh's avatar
Ian Lynagh committed
965
966
967
    let decl = machRepCType rep <+> ptext (sLit "x") <> semi
        struct = ptext (sLit "struct") <+> braces (decl)
        packed_attr = ptext (sLit "__attribute__((packed))")
968
        cast = parens (struct <+> packed_attr <> char '*')
Ian Lynagh's avatar
Ian Lynagh committed
969
    in parens (cast <+> pprExpr1 expr) <> ptext (sLit "->x")
970
971
972
973
#else
cLoad expr rep = char '*' <> parens (cCast (machRepPtrCType rep) expr)
#endif

974
975
976
977
978
isCmmWordType :: CmmType -> Bool
-- True of GcPtrReg/NonGcReg of native word size
isCmmWordType ty = not (isFloatType ty) 
		   && typeWidth ty == wordWidth

979
980
981
-- This is for finding the types of foreign call arguments.  For a pointer
-- argument, we always cast the argument to (void *), to avoid warnings from
-- the C compiler.
982
983
984
machRepHintCType :: CmmType -> ForeignHint -> SDoc
machRepHintCType rep AddrHint    = ptext (sLit "void *")
machRepHintCType rep SignedHint = machRep_S_CType (typeWidth rep)
985
986
machRepHintCType rep _other     = machRepCType rep

987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
machRepPtrCType :: CmmType -> SDoc
machRepPtrCType r | isCmmWordType r = ptext (sLit "P_")
	          | otherwise       = machRepCType r <> char '*'

machRepCType :: CmmType -> SDoc
machRepCType ty | isFloatType ty = machRep_F_CType w
		| otherwise	 = machRep_U_CType w
		where
		  w = typeWidth ty

machRep_F_CType :: Width -> SDoc
machRep_F_CType W32 = ptext (sLit "StgFloat") -- ToDo: correct?
machRep_F_CType W64 = ptext (sLit "StgDouble")
machRep_F_CType _   = panic "machRep_F_CType"

machRep_U_CType :: Width -> SDoc
machRep_U_CType w | w == wordWidth = ptext (sLit "W_")
machRep_U_CType W8  = ptext (sLit "StgWord8")
machRep_U_CType W16 = ptext (sLit "StgWord16")
machRep_U_CType W32 = ptext (sLit "StgWord32")
machRep_U_CType W64 = ptext (sLit "StgWord64")
machRep_U_CType _   = panic "machRep_U_CType"

machRep_S_CType :: Width -> SDoc
machRep_S_CType w | w == wordWidth = ptext (sLit "I_")
machRep_S_CType W8  = ptext (sLit "StgInt8")
machRep_S_CType W16 = ptext (sLit "StgInt16")
machRep_S_CType W32 = ptext (sLit "StgInt32")
machRep_S_CType W64 = ptext (sLit "StgInt64")
machRep_S_CType _   = panic "machRep_S_CType"
  
1018
1019
1020
1021

-- ---------------------------------------------------------------------
-- print strings as valid C strings

1022
pprStringInCStyle :: [Word8] -> SDoc
1023
1024
pprStringInCStyle s = doubleQuotes (text (concatMap charToC s))

1025
1026
1027
1028
1029
1030
1031
1032
charToC :: Word8 -> String
charToC w = 
  case chr (fromIntegral w) of
	'\"' -> "\\\""
	'\'' -> "\\\'"
	'\\' -> "\\\\"
	c | c >= ' ' && c <= '~' -> [c]
          | otherwise -> ['\\',
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
                         chr (ord '0' + ord c `div` 64),
                         chr (ord '0' + ord c `div` 8 `mod` 8),
                         chr (ord '0' + ord c         `mod` 8)]

-- ---------------------------------------------------------------------------
-- Initialising static objects with floating-point numbers.  We can't
-- just emit the floating point number, because C will cast it to an int
-- by rounding it.  We want the actual bit-representation of the float.

-- This is a hack to turn the floating point numbers into ints that we
-- can safely initialise to static locations.

big_doubles 
1046
1047
  | widthInBytes W64 == 2 * wORD_SIZE  = True
  | widthInBytes W64 == wORD_SIZE      = False
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
  | otherwise = panic "big_doubles"

castFloatToIntArray :: STUArray s Int Float -> ST s (STUArray s Int Int)
castFloatToIntArray = castSTUArray

castDoubleToIntArray :: STUArray s Int Double -> ST s (STUArray s Int Int)
castDoubleToIntArray = castSTUArray

-- floats are always 1 word
floatToWord :: Rational -> CmmLit
floatToWord r
  = runST (do
1060
1061
	arr <- newArray_ ((0::Int),0)
	writeArray arr 0 (fromRational r)
1062
	arr' <- castFloatToIntArray arr
1063
	i <- readArray arr' 0
1064
	return (CmmInt (toInteger i) wordWidth)
1065
1066
1067
1068
1069
1070
    )

doubleToWords :: Rational -> [CmmLit]
doubleToWords r
  | big_doubles				-- doubles are 2 words
  = runST (do
1071
1072
	arr <- newArray_ ((0::Int),1)
	writeArray arr 0 (fromRational r)
1073
	arr' <- castDoubleToIntArray arr
1074
1075
	i1 <- readArray arr' 0
	i2 <- readArray arr' 1
1076
1077
	return [ CmmInt (toInteger i1) wordWidth
	       , CmmInt (toInteger i2) wordWidth
1078
1079
1080
1081
	       ]
    )
  | otherwise				-- doubles are 1 word
  = runST (do
1082
1083
	arr <- newArray_ ((0::Int),0)
	writeArray arr 0 (fromRational r)
1084
	arr' <- castDoubleToIntArray arr
1085
	i <- readArray arr' 0
1086
	return [ CmmInt (toInteger i) wordWidth ]
1087
1088
1089
1090
1091
1092
    )

-- ---------------------------------------------------------------------------
-- Utils

wordShift :: Int
1093
wordShift = widthInLog wordWidth
1094
1095
1096
1097
1098

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

-- Print in C hex format: 0x13fa
1099
pprHexVal :: Integer -> Width -> SDoc
Ian Lynagh's avatar
Ian Lynagh committed
1100
pprHexVal 0 _ = ptext (sLit "0x0")
1101
pprHexVal w rep
Ian Lynagh's avatar
Ian Lynagh committed
1102
1103
  | w < 0     = parens (char '-' <> ptext (sLit "0x") <> go (-w) <> repsuffix rep)
  | otherwise = ptext (sLit "0x") <> go w <> repsuffix rep
1104
  where
1105
  	-- type suffix for literals:
1106
1107
1108
1109
1110
1111
	-- Integer literals are unsigned in Cmm/C.  We explicitly cast to
	-- signed values for doing signed operations, but at all other
	-- times values are unsigned.  This also helps eliminate occasional
	-- warnings about integer overflow from gcc.

	-- on 32-bit platforms, add "ULL" to 64-bit literals
1112
      repsuffix W64 | wORD_SIZE == 4 = ptext (sLit "ULL")
1113
      	-- on 64-bit platforms with 32-bit int, add "L" to 64-bit literals
1114
      repsuffix W64 | cINT_SIZE == 4 = ptext (sLit "UL")
1115
      repsuffix _ = char 'U'
1116
      
1117
1118
1119
1120
1121
1122
1123
      go 0 = empty
      go w' = go q <> dig
           where
             (q,r) = w' `quotRem` 16
             dig | r < 10    = char (chr (fromInteger r + ord '0'))
                 | otherwise = char (chr (fromInteger r - 10 + ord 'a'))