2 -- The above warning supression flag is a temporary kludge.
3 -- While working on this module you are encouraged to remove it and fix
4 -- any warnings in the module. See
5 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
8 -----------------------------------------------------------------------------
10 -- Pretty-printing of Cmm as C, suitable for feeding gcc
12 -- (c) The University of Glasgow 2004-2006
14 -----------------------------------------------------------------------------
17 -- Print Cmm as real C, for -fvia-C
19 -- See wiki:Commentary/Compiler/Backends/PprC
21 -- This is simpler than the old PprAbsC, because Cmm is "macro-expanded"
22 -- relative to the old AbstractC, and many oddities/decorations have
23 -- disappeared from the data type.
26 -- ToDo: save/restore volatile registers around calls.
33 #include "HsVersions.h"
38 import OldPprCmm () -- Instances only
61 import qualified Data.Map as Map
65 import Control.Monad.ST
67 #if defined(alpha_TARGET_ARCH) || defined(mips_TARGET_ARCH) || defined(mipsel_TARGET_ARCH) || defined(arm_TARGET_ARCH)
68 #define BEWARE_LOAD_STORE_ALIGNMENT
71 -- --------------------------------------------------------------------------
74 pprCs :: DynFlags -> [RawCmm] -> SDoc
76 = pprCode CStyle (vcat $ map (\c -> split_marker $$ pprC c) cmms)
79 | dopt Opt_SplitObjs dflags = ptext (sLit "__STG_SPLIT_MARKER")
82 writeCs :: DynFlags -> Handle -> [RawCmm] -> IO ()
83 writeCs dflags handle cmms
84 = printForC handle (pprCs dflags cmms)
86 -- --------------------------------------------------------------------------
87 -- Now do some real work
89 -- for fun, we could call cmmToCmm over the tops...
92 pprC :: RawCmm -> SDoc
93 pprC (Cmm tops) = vcat $ intersperse blankLine $ map pprTop tops
98 pprTop :: RawCmmTop -> SDoc
99 pprTop (CmmProc info clbl (ListGraph blocks)) =
101 then pprDataExterns info $$
102 pprWordArray (entryLblToInfoLbl clbl) info
107 (if (externallyVisibleCLabel clbl)
108 then mkFN_ else mkIF_) (pprCLabel clbl) <+> lbrace,
113 -- the first block doesn't get a label:
114 (BasicBlock _ stmts : rest) ->
115 nest 8 (vcat (map pprStmt stmts)) $$
116 vcat (map pprBBlock rest),
121 (temp_decls, extern_decls) = pprTempAndExternDecls blocks
124 -- Chunks of static data.
126 -- We only handle (a) arrays of word-sized things and (b) strings.
128 pprTop (CmmData _section _ds@[CmmDataLabel lbl, CmmString str]) =
130 pprLocalness lbl, ptext (sLit "char "), pprCLabel lbl,
131 ptext (sLit "[] = "), pprStringInCStyle str, semi
134 pprTop (CmmData _section _ds@[CmmDataLabel lbl, CmmUninitialised size]) =
136 pprLocalness lbl, ptext (sLit "char "), pprCLabel lbl,
137 brackets (int size), semi
140 pprTop top@(CmmData _section (CmmDataLabel lbl : lits)) =
141 pprDataExterns lits $$
142 pprWordArray lbl lits
144 -- Floating info table for safe a foreign call.
145 pprTop top@(CmmData _section d@(_ : _))
146 | CmmDataLabel lbl : lits <- reverse d =
147 let lits' = reverse lits
148 in pprDataExterns lits' $$
149 pprWordArray lbl lits'
151 -- these shouldn't appear?
152 pprTop (CmmData _ _) = panic "PprC.pprTop: can't handle this data"
154 -- --------------------------------------------------------------------------
155 -- BasicBlocks are self-contained entities: they always end in a jump.
157 -- Like nativeGen/AsmCodeGen, we could probably reorder blocks to turn
158 -- as many jumps as possible into fall throughs.
161 pprBBlock :: CmmBasicBlock -> SDoc
162 pprBBlock (BasicBlock lbl stmts) =
164 pprTrace "pprC.pprBBlock: curious empty code block for"
165 (pprBlockId lbl) empty
167 nest 4 (pprBlockId lbl <> colon) $$
168 nest 8 (vcat (map pprStmt stmts))
170 -- --------------------------------------------------------------------------
171 -- Info tables. Just arrays of words.
172 -- See codeGen/ClosureInfo, and nativeGen/PprMach
174 pprWordArray :: CLabel -> [CmmStatic] -> SDoc
176 = hcat [ pprLocalness lbl, ptext (sLit "StgWord")
177 , space, pprCLabel lbl, ptext (sLit "[] = {") ]
178 $$ nest 8 (commafy (pprStatics ds))
182 -- has to be static, if it isn't globally visible
184 pprLocalness :: CLabel -> SDoc
185 pprLocalness lbl | not $ externallyVisibleCLabel lbl = ptext (sLit "static ")
188 -- --------------------------------------------------------------------------
192 pprStmt :: CmmStmt -> SDoc
194 pprStmt stmt = case stmt of
196 CmmComment s -> empty -- (hang (ptext (sLit "/*")) 3 (ftext s)) $$ ptext (sLit "*/")
197 -- XXX if the string contains "*/", we need to fix it
198 -- XXX we probably want to emit these comments when
199 -- some debugging option is on. They can get quite
202 CmmAssign dest src -> pprAssign dest src
205 | typeWidth rep == W64 && wordWidth /= W64
206 -> (if isFloatType rep then ptext (sLit "ASSIGN_DBL")
207 else ptext (sLit ("ASSIGN_Word64"))) <>
208 parens (mkP_ <> pprExpr1 dest <> comma <> pprExpr src) <> semi
211 -> hsep [ pprExpr (CmmLoad dest rep), equals, pprExpr src <> semi ]
213 rep = cmmExprType src
215 CmmCall (CmmCallee fn cconv) results args safety ret ->
219 cast_fn = parens (cCast (pprCFunType (char '*') cconv results args) fn)
221 real_fun_proto lbl = char ';' <>
222 pprCFunType (pprCLabel lbl) cconv results args <>
223 noreturn_attr <> semi
225 fun_proto lbl = ptext (sLit ";EF_(") <>
226 pprCLabel lbl <> char ')' <> semi
228 noreturn_attr = case ret of
229 CmmNeverReturns -> text "__attribute__ ((noreturn))"
230 CmmMayReturn -> empty
232 -- See wiki:Commentary/Compiler/Backends/PprC#Prototypes
233 (maybe_proto, fnCall) =
235 CmmLit (CmmLabel lbl)
236 | StdCallConv <- cconv ->
237 let myCall = pprCall (pprCLabel lbl) cconv results args safety
238 in (real_fun_proto lbl, myCall)
239 -- stdcall functions must be declared with
240 -- a function type, otherwise the C compiler
241 -- doesn't add the @n suffix to the label. We
242 -- can't add the @n suffix ourselves, because
244 | CmmNeverReturns <- ret ->
245 let myCall = pprCall (pprCLabel lbl) cconv results args safety
246 in (real_fun_proto lbl, myCall)
247 | not (isMathFun lbl) ->
248 let myCall = braces (
249 pprCFunType (char '*' <> text "ghcFunPtr") cconv results args <> semi
250 $$ text "ghcFunPtr" <+> equals <+> cast_fn <> semi
251 $$ pprCall (text "ghcFunPtr") cconv results args safety <> semi
253 in (fun_proto lbl, myCall)
255 (empty {- no proto -},
256 pprCall cast_fn cconv results args safety <> semi)
257 -- for a dynamic call, no declaration is necessary.
259 CmmCall (CmmPrim op) results args safety _ret ->
260 pprCall ppr_fn CCallConv results args safety
262 ppr_fn = pprCallishMachOp_for_C op
264 CmmBranch ident -> pprBranch ident
265 CmmCondBranch expr ident -> pprCondBranch expr ident
266 CmmJump lbl _params -> mkJMP_(pprExpr lbl) <> semi
267 CmmSwitch arg ids -> pprSwitch arg ids
269 pprCFunType :: SDoc -> CCallConv -> HintedCmmFormals -> HintedCmmActuals -> SDoc
270 pprCFunType ppr_fn cconv ress args
272 parens (text (ccallConvAttribute cconv) <> ppr_fn) <>
273 parens (commafy (map arg_type args))
275 res_type [] = ptext (sLit "void")
276 res_type [CmmHinted one hint] = machRepHintCType (localRegType one) hint
278 arg_type (CmmHinted expr hint) = machRepHintCType (cmmExprType expr) hint
280 -- ---------------------------------------------------------------------
281 -- unconditional branches
282 pprBranch :: BlockId -> SDoc
283 pprBranch ident = ptext (sLit "goto") <+> pprBlockId ident <> semi
286 -- ---------------------------------------------------------------------
287 -- conditional branches to local labels
288 pprCondBranch :: CmmExpr -> BlockId -> SDoc
289 pprCondBranch expr ident
290 = hsep [ ptext (sLit "if") , parens(pprExpr expr) ,
291 ptext (sLit "goto") , (pprBlockId ident) <> semi ]
294 -- ---------------------------------------------------------------------
295 -- a local table branch
297 -- we find the fall-through cases
299 -- N.B. we remove Nothing's from the list of branches, as they are
300 -- 'undefined'. However, they may be defined one day, so we better
301 -- document this behaviour.
303 pprSwitch :: CmmExpr -> [ Maybe BlockId ] -> SDoc
304 pprSwitch e maybe_ids
305 = let pairs = [ (ix, ident) | (ix,Just ident) <- zip [0..] maybe_ids ]
306 pairs2 = [ (map fst as, snd (head as)) | as <- groupBy sndEq pairs ]
308 (hang (ptext (sLit "switch") <+> parens ( pprExpr e ) <+> lbrace)
309 4 (vcat ( map caseify pairs2 )))
313 sndEq (_,x) (_,y) = x == y
316 caseify (ix:ixs, ident) = vcat (map do_fallthrough ixs) $$ final_branch ix
319 hsep [ ptext (sLit "case") , pprHexVal ix wordWidth <> colon ,
320 ptext (sLit "/* fall through */") ]
323 hsep [ ptext (sLit "case") , pprHexVal ix wordWidth <> colon ,
324 ptext (sLit "goto") , (pprBlockId ident) <> semi ]
326 -- ---------------------------------------------------------------------
330 -- C Types: the invariant is that the C expression generated by
334 -- has a type in C which is also given by
336 -- machRepCType (cmmExprType e)
338 -- (similar invariants apply to the rest of the pretty printer).
340 pprExpr :: CmmExpr -> SDoc
341 pprExpr e = case e of
342 CmmLit lit -> pprLit lit
345 CmmLoad e ty -> pprLoad e ty
346 CmmReg reg -> pprCastReg reg
347 CmmRegOff reg 0 -> pprCastReg reg
350 | i > 0 -> pprRegOff (char '+') i
351 | otherwise -> pprRegOff (char '-') (-i)
353 pprRegOff op i' = pprCastReg reg <> op <> int i'
355 CmmMachOp mop args -> pprMachOpApp mop args
358 pprLoad :: CmmExpr -> CmmType -> SDoc
360 | width == W64, wordWidth /= W64
361 = (if isFloatType ty then ptext (sLit "PK_DBL")
362 else ptext (sLit "PK_Word64"))
363 <> parens (mkP_ <> pprExpr1 e)
367 CmmReg r | isPtrReg r && width == wordWidth && not (isFloatType ty)
368 -> char '*' <> pprAsPtrReg r
370 CmmRegOff r 0 | isPtrReg r && width == wordWidth && not (isFloatType ty)
371 -> char '*' <> pprAsPtrReg r
373 CmmRegOff r off | isPtrReg r && width == wordWidth
374 , off `rem` wORD_SIZE == 0 && not (isFloatType ty)
375 -- ToDo: check that the offset is a word multiple?
376 -- (For tagging to work, I had to avoid unaligned loads. --ARY)
377 -> pprAsPtrReg r <> brackets (ppr (off `shiftR` wordShift))
383 pprExpr1 :: CmmExpr -> SDoc
384 pprExpr1 (CmmLit lit) = pprLit1 lit
385 pprExpr1 e@(CmmReg _reg) = pprExpr e
386 pprExpr1 other = parens (pprExpr other)
388 -- --------------------------------------------------------------------------
389 -- MachOp applications
391 pprMachOpApp :: MachOp -> [CmmExpr] -> SDoc
395 = ptext (sLit "mulIntMayOflo") <> parens (commafy (map pprExpr args))
396 where isMulMayOfloOp (MO_U_MulMayOflo _) = True
397 isMulMayOfloOp (MO_S_MulMayOflo _) = True
398 isMulMayOfloOp _ = False
400 pprMachOpApp mop args
401 | Just ty <- machOpNeedsCast mop
402 = ty <> parens (pprMachOpApp' mop args)
404 = pprMachOpApp' mop args
406 -- Comparisons in C have type 'int', but we want type W_ (this is what
407 -- resultRepOfMachOp says). The other C operations inherit their type
408 -- from their operands, so no casting is required.
409 machOpNeedsCast :: MachOp -> Maybe SDoc
411 | isComparisonMachOp mop = Just mkW_
412 | otherwise = Nothing
414 pprMachOpApp' mop args
417 [x,y] -> pprArg x <+> pprMachOp_for_C mop <+> pprArg y
420 [x] -> pprMachOp_for_C mop <> parens (pprArg x)
422 _ -> panic "PprC.pprMachOp : machop with wrong number of args"
425 -- Cast needed for signed integer ops
426 pprArg e | signedOp mop = cCast (machRep_S_CType (typeWidth (cmmExprType e))) e
427 | needsFCasts mop = cCast (machRep_F_CType (typeWidth (cmmExprType e))) e
428 | otherwise = pprExpr1 e
429 needsFCasts (MO_F_Eq _) = False
430 needsFCasts (MO_F_Ne _) = False
431 needsFCasts (MO_F_Neg _) = True
432 needsFCasts (MO_F_Quot _) = True
433 needsFCasts mop = floatComparison mop
435 -- --------------------------------------------------------------------------
438 pprLit :: CmmLit -> SDoc
439 pprLit lit = case lit of
440 CmmInt i rep -> pprHexVal i rep
442 CmmFloat f w -> parens (machRep_F_CType w) <> str
443 where d = fromRational f :: Double
444 str | isInfinite d && d < 0 = ptext (sLit "-INFINITY")
445 | isInfinite d = ptext (sLit "INFINITY")
446 | isNaN d = ptext (sLit "NAN")
447 | otherwise = text (show d)
448 -- these constants come from <math.h>
451 CmmBlock bid -> mkW_ <> pprCLabelAddr (infoTblLbl bid)
452 CmmHighStackMark -> panic "PprC printing high stack mark"
453 CmmLabel clbl -> mkW_ <> pprCLabelAddr clbl
454 CmmLabelOff clbl i -> mkW_ <> pprCLabelAddr clbl <> char '+' <> int i
455 CmmLabelDiffOff clbl1 clbl2 i
457 -- * the lit must occur in the info table clbl2
458 -- * clbl1 must be an SRT, a slow entry point or a large bitmap
459 -- The Mangler is expected to convert any reference to an SRT,
460 -- a slow entry point or a large bitmap
461 -- from an info table to an offset.
462 -> mkW_ <> pprCLabelAddr clbl1 <> char '+' <> int i
464 pprCLabelAddr lbl = char '&' <> pprCLabel lbl
466 pprLit1 :: CmmLit -> SDoc
467 pprLit1 lit@(CmmLabelOff _ _) = parens (pprLit lit)
468 pprLit1 lit@(CmmLabelDiffOff _ _ _) = parens (pprLit lit)
469 pprLit1 lit@(CmmFloat _ _) = parens (pprLit lit)
470 pprLit1 other = pprLit other
472 -- ---------------------------------------------------------------------------
475 pprStatics :: [CmmStatic] -> [SDoc]
477 pprStatics (CmmStaticLit (CmmFloat f W32) : rest)
478 -- floats are padded to a word, see #1852
479 | wORD_SIZE == 8, CmmStaticLit (CmmInt 0 W32) : rest' <- rest
480 = pprLit1 (floatToWord f) : pprStatics rest'
482 = pprLit1 (floatToWord f) : pprStatics rest
484 = pprPanic "pprStatics: float" (vcat (map (\(CmmStaticLit l) -> ppr (cmmLitType l)) rest))
485 pprStatics (CmmStaticLit (CmmFloat f W64) : rest)
486 = map pprLit1 (doubleToWords f) ++ pprStatics rest
487 pprStatics (CmmStaticLit (CmmInt i W64) : rest)
489 #ifdef WORDS_BIGENDIAN
490 = pprStatics (CmmStaticLit (CmmInt q W32) :
491 CmmStaticLit (CmmInt r W32) : rest)
493 = pprStatics (CmmStaticLit (CmmInt r W32) :
494 CmmStaticLit (CmmInt q W32) : rest)
496 where r = i .&. 0xffffffff
498 pprStatics (CmmStaticLit (CmmInt i w) : rest)
500 = panic "pprStatics: cannot emit a non-word-sized static literal"
501 pprStatics (CmmStaticLit lit : rest)
502 = pprLit1 lit : pprStatics rest
503 pprStatics (other : rest)
504 = pprPanic "pprWord" (pprStatic other)
506 pprStatic :: CmmStatic -> SDoc
507 pprStatic s = case s of
509 CmmStaticLit lit -> nest 4 (pprLit lit)
510 CmmAlign i -> nest 4 (ptext (sLit "/* align */") <+> int i)
511 CmmDataLabel clbl -> pprCLabel clbl <> colon
512 CmmUninitialised i -> nest 4 (mkC_ <> brackets (int i))
514 -- these should be inlined, like the old .hc
515 CmmString s' -> nest 4 (mkW_ <> parens(pprStringInCStyle s'))
518 -- ---------------------------------------------------------------------------
521 pprBlockId :: BlockId -> SDoc
522 pprBlockId b = char '_' <> ppr (getUnique b)
524 -- --------------------------------------------------------------------------
525 -- Print a MachOp in a way suitable for emitting via C.
528 pprMachOp_for_C :: MachOp -> SDoc
530 pprMachOp_for_C mop = case mop of
532 -- Integer operations
535 MO_Eq _ -> ptext (sLit "==")
536 MO_Ne _ -> ptext (sLit "!=")
539 MO_S_Quot _ -> char '/'
540 MO_S_Rem _ -> char '%'
541 MO_S_Neg _ -> char '-'
543 MO_U_Quot _ -> char '/'
544 MO_U_Rem _ -> char '%'
546 -- & Floating-point operations
547 MO_F_Add _ -> char '+'
548 MO_F_Sub _ -> char '-'
549 MO_F_Neg _ -> char '-'
550 MO_F_Mul _ -> char '*'
551 MO_F_Quot _ -> char '/'
553 -- Signed comparisons
554 MO_S_Ge _ -> ptext (sLit ">=")
555 MO_S_Le _ -> ptext (sLit "<=")
556 MO_S_Gt _ -> char '>'
557 MO_S_Lt _ -> char '<'
559 -- & Unsigned comparisons
560 MO_U_Ge _ -> ptext (sLit ">=")
561 MO_U_Le _ -> ptext (sLit "<=")
562 MO_U_Gt _ -> char '>'
563 MO_U_Lt _ -> char '<'
565 -- & Floating-point comparisons
566 MO_F_Eq _ -> ptext (sLit "==")
567 MO_F_Ne _ -> ptext (sLit "!=")
568 MO_F_Ge _ -> ptext (sLit ">=")
569 MO_F_Le _ -> ptext (sLit "<=")
570 MO_F_Gt _ -> char '>'
571 MO_F_Lt _ -> char '<'
573 -- Bitwise operations. Not all of these may be supported at all
574 -- sizes, and only integral MachReps are valid.
579 MO_Shl _ -> ptext (sLit "<<")
580 MO_U_Shr _ -> ptext (sLit ">>") -- unsigned shift right
581 MO_S_Shr _ -> ptext (sLit ">>") -- signed shift right
583 -- Conversions. Some of these will be NOPs, but never those that convert
584 -- between ints and floats.
585 -- Floating-point conversions use the signed variant.
586 -- We won't know to generate (void*) casts here, but maybe from
590 MO_UU_Conv from to | from == to -> empty
591 MO_UU_Conv _from to -> parens (machRep_U_CType to)
593 MO_SS_Conv from to | from == to -> empty
594 MO_SS_Conv _from to -> parens (machRep_S_CType to)
596 -- TEMPORARY: the old code didn't check this case, so let's leave it out
597 -- to facilitate comparisons against the old output code.
598 --MO_FF_Conv from to | from == to -> empty
599 MO_FF_Conv _from to -> parens (machRep_F_CType to)
601 MO_SF_Conv _from to -> parens (machRep_F_CType to)
602 MO_FS_Conv _from to -> parens (machRep_S_CType to)
604 _ -> pprTrace "offending mop" (ptext $ sLit $ show mop) $
605 panic "PprC.pprMachOp_for_C: unknown machop"
607 signedOp :: MachOp -> Bool -- Argument type(s) are signed ints
608 signedOp (MO_S_Quot _) = True
609 signedOp (MO_S_Rem _) = True
610 signedOp (MO_S_Neg _) = True
611 signedOp (MO_S_Ge _) = True
612 signedOp (MO_S_Le _) = True
613 signedOp (MO_S_Gt _) = True
614 signedOp (MO_S_Lt _) = True
615 signedOp (MO_S_Shr _) = True
616 signedOp (MO_SS_Conv _ _) = True
617 signedOp (MO_SF_Conv _ _) = True
620 floatComparison :: MachOp -> Bool -- comparison between float args
621 floatComparison (MO_F_Eq _) = True
622 floatComparison (MO_F_Ne _) = True
623 floatComparison (MO_F_Ge _) = True
624 floatComparison (MO_F_Le _) = True
625 floatComparison (MO_F_Gt _) = True
626 floatComparison (MO_F_Lt _) = True
627 floatComparison _ = False
629 -- ---------------------------------------------------------------------
630 -- tend to be implemented by foreign calls
632 pprCallishMachOp_for_C :: CallishMachOp -> SDoc
634 pprCallishMachOp_for_C mop
636 MO_F64_Pwr -> ptext (sLit "pow")
637 MO_F64_Sin -> ptext (sLit "sin")
638 MO_F64_Cos -> ptext (sLit "cos")
639 MO_F64_Tan -> ptext (sLit "tan")
640 MO_F64_Sinh -> ptext (sLit "sinh")
641 MO_F64_Cosh -> ptext (sLit "cosh")
642 MO_F64_Tanh -> ptext (sLit "tanh")
643 MO_F64_Asin -> ptext (sLit "asin")
644 MO_F64_Acos -> ptext (sLit "acos")
645 MO_F64_Atan -> ptext (sLit "atan")
646 MO_F64_Log -> ptext (sLit "log")
647 MO_F64_Exp -> ptext (sLit "exp")
648 MO_F64_Sqrt -> ptext (sLit "sqrt")
649 MO_F32_Pwr -> ptext (sLit "powf")
650 MO_F32_Sin -> ptext (sLit "sinf")
651 MO_F32_Cos -> ptext (sLit "cosf")
652 MO_F32_Tan -> ptext (sLit "tanf")
653 MO_F32_Sinh -> ptext (sLit "sinhf")
654 MO_F32_Cosh -> ptext (sLit "coshf")
655 MO_F32_Tanh -> ptext (sLit "tanhf")
656 MO_F32_Asin -> ptext (sLit "asinf")
657 MO_F32_Acos -> ptext (sLit "acosf")
658 MO_F32_Atan -> ptext (sLit "atanf")
659 MO_F32_Log -> ptext (sLit "logf")
660 MO_F32_Exp -> ptext (sLit "expf")
661 MO_F32_Sqrt -> ptext (sLit "sqrtf")
662 MO_WriteBarrier -> ptext (sLit "write_barrier")
664 -- ---------------------------------------------------------------------
668 mkJMP_, mkFN_, mkIF_ :: SDoc -> SDoc
670 mkJMP_ i = ptext (sLit "JMP_") <> parens i
671 mkFN_ i = ptext (sLit "FN_") <> parens i -- externally visible function
672 mkIF_ i = ptext (sLit "IF_") <> parens i -- locally visible
676 mkFB_ = ptext (sLit "FB_") -- function code begin
677 mkFE_ = ptext (sLit "FE_") -- function code end
679 -- from includes/Stg.h
681 mkC_,mkW_,mkP_ :: SDoc
683 mkC_ = ptext (sLit "(C_)") -- StgChar
684 mkW_ = ptext (sLit "(W_)") -- StgWord
685 mkP_ = ptext (sLit "(P_)") -- StgWord*
687 -- ---------------------------------------------------------------------
691 -- Generating assignments is what we're all about, here
693 pprAssign :: CmmReg -> CmmExpr -> SDoc
695 -- dest is a reg, rhs is a reg
696 pprAssign r1 (CmmReg r2)
697 | isPtrReg r1 && isPtrReg r2
698 = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, semi ]
700 -- dest is a reg, rhs is a CmmRegOff
701 pprAssign r1 (CmmRegOff r2 off)
702 | isPtrReg r1 && isPtrReg r2 && (off `rem` wORD_SIZE == 0)
703 = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, op, int off', semi ]
705 off1 = off `shiftR` wordShift
707 (op,off') | off >= 0 = (char '+', off1)
708 | otherwise = (char '-', -off1)
710 -- dest is a reg, rhs is anything.
711 -- We can't cast the lvalue, so we have to cast the rhs if necessary. Casting
712 -- the lvalue elicits a warning from new GCC versions (3.4+).
714 | isFixedPtrReg r1 = mkAssign (mkP_ <> pprExpr1 r2)
715 | Just ty <- strangeRegType r1 = mkAssign (parens ty <> pprExpr1 r2)
716 | otherwise = mkAssign (pprExpr r2)
717 where mkAssign x = if r1 == CmmGlobal BaseReg
718 then ptext (sLit "ASSIGN_BaseReg") <> parens x <> semi
719 else pprReg r1 <> ptext (sLit " = ") <> x <> semi
721 -- ---------------------------------------------------------------------
725 | isStrangeTypeReg reg = mkW_ <> pprReg reg
726 | otherwise = pprReg reg
728 -- True if (pprReg reg) will give an expression with type StgPtr. We
729 -- need to take care with pointer arithmetic on registers with type
731 isFixedPtrReg :: CmmReg -> Bool
732 isFixedPtrReg (CmmLocal _) = False
733 isFixedPtrReg (CmmGlobal r) = isFixedPtrGlobalReg r
735 -- True if (pprAsPtrReg reg) will give an expression with type StgPtr
736 -- JD: THIS IS HORRIBLE AND SHOULD BE RENAMED, AT THE VERY LEAST.
737 -- THE GARBAGE WITH THE VNonGcPtr HELPS MATCH THE OLD CODE GENERATOR'S OUTPUT;
738 -- I'M NOT SURE IF IT SHOULD REALLY STAY THAT WAY.
739 isPtrReg :: CmmReg -> Bool
740 isPtrReg (CmmLocal _) = False
741 isPtrReg (CmmGlobal (VanillaReg n VGcPtr)) = True -- if we print via pprAsPtrReg
742 isPtrReg (CmmGlobal (VanillaReg n VNonGcPtr)) = False --if we print via pprAsPtrReg
743 isPtrReg (CmmGlobal reg) = isFixedPtrGlobalReg reg
745 -- True if this global reg has type StgPtr
746 isFixedPtrGlobalReg :: GlobalReg -> Bool
747 isFixedPtrGlobalReg Sp = True
748 isFixedPtrGlobalReg Hp = True
749 isFixedPtrGlobalReg HpLim = True
750 isFixedPtrGlobalReg SpLim = True
751 isFixedPtrGlobalReg _ = False
753 -- True if in C this register doesn't have the type given by
754 -- (machRepCType (cmmRegType reg)), so it has to be cast.
755 isStrangeTypeReg :: CmmReg -> Bool
756 isStrangeTypeReg (CmmLocal _) = False
757 isStrangeTypeReg (CmmGlobal g) = isStrangeTypeGlobal g
759 isStrangeTypeGlobal :: GlobalReg -> Bool
760 isStrangeTypeGlobal CurrentTSO = True
761 isStrangeTypeGlobal CurrentNursery = True
762 isStrangeTypeGlobal BaseReg = True
763 isStrangeTypeGlobal r = isFixedPtrGlobalReg r
765 strangeRegType :: CmmReg -> Maybe SDoc
766 strangeRegType (CmmGlobal CurrentTSO) = Just (ptext (sLit "struct StgTSO_ *"))
767 strangeRegType (CmmGlobal CurrentNursery) = Just (ptext (sLit "struct bdescr_ *"))
768 strangeRegType (CmmGlobal BaseReg) = Just (ptext (sLit "struct StgRegTable_ *"))
769 strangeRegType _ = Nothing
771 -- pprReg just prints the register name.
773 pprReg :: CmmReg -> SDoc
775 CmmLocal local -> pprLocalReg local
776 CmmGlobal global -> pprGlobalReg global
778 pprAsPtrReg :: CmmReg -> SDoc
779 pprAsPtrReg (CmmGlobal (VanillaReg n gcp))
780 = WARN( gcp /= VGcPtr, ppr n ) char 'R' <> int n <> ptext (sLit ".p")
781 pprAsPtrReg other_reg = pprReg other_reg
783 pprGlobalReg :: GlobalReg -> SDoc
784 pprGlobalReg gr = case gr of
785 VanillaReg n _ -> char 'R' <> int n <> ptext (sLit ".w")
786 -- pprGlobalReg prints a VanillaReg as a .w regardless
787 -- Example: R1.w = R1.w & (-0x8UL);
789 FloatReg n -> char 'F' <> int n
790 DoubleReg n -> char 'D' <> int n
791 LongReg n -> char 'L' <> int n
792 Sp -> ptext (sLit "Sp")
793 SpLim -> ptext (sLit "SpLim")
794 Hp -> ptext (sLit "Hp")
795 HpLim -> ptext (sLit "HpLim")
796 CurrentTSO -> ptext (sLit "CurrentTSO")
797 CurrentNursery -> ptext (sLit "CurrentNursery")
798 HpAlloc -> ptext (sLit "HpAlloc")
799 BaseReg -> ptext (sLit "BaseReg")
800 EagerBlackholeInfo -> ptext (sLit "stg_EAGER_BLACKHOLE_info")
801 GCEnter1 -> ptext (sLit "stg_gc_enter_1")
802 GCFun -> ptext (sLit "stg_gc_fun")
804 pprLocalReg :: LocalReg -> SDoc
805 pprLocalReg (LocalReg uniq _) = char '_' <> ppr uniq
807 -- -----------------------------------------------------------------------------
810 pprCall :: SDoc -> CCallConv -> HintedCmmFormals -> HintedCmmActuals -> CmmSafety
813 pprCall ppr_fn cconv results args _
814 | not (is_cish cconv)
815 = panic "pprCall: unknown calling convention"
819 ppr_assign results (ppr_fn <> parens (commafy (map pprArg args))) <> semi
821 ppr_assign [] rhs = rhs
822 ppr_assign [CmmHinted one hint] rhs
823 = pprLocalReg one <> ptext (sLit " = ")
824 <> pprUnHint hint (localRegType one) <> rhs
825 ppr_assign _other _rhs = panic "pprCall: multiple results"
827 pprArg (CmmHinted expr AddrHint)
828 = cCast (ptext (sLit "void *")) expr
829 -- see comment by machRepHintCType below
830 pprArg (CmmHinted expr SignedHint)
831 = cCast (machRep_S_CType $ typeWidth $ cmmExprType expr) expr
832 pprArg (CmmHinted expr _other)
835 pprUnHint AddrHint rep = parens (machRepCType rep)
836 pprUnHint SignedHint rep = parens (machRepCType rep)
837 pprUnHint _ _ = empty
839 pprGlobalRegName :: GlobalReg -> SDoc
840 pprGlobalRegName gr = case gr of
841 VanillaReg n _ -> char 'R' <> int n -- without the .w suffix
844 -- Currently we only have these two calling conventions, but this might
845 -- change in the future...
846 is_cish CCallConv = True
847 is_cish StdCallConv = True
849 -- ---------------------------------------------------------------------
850 -- Find and print local and external declarations for a list of
853 pprTempAndExternDecls :: [CmmBasicBlock] -> (SDoc{-temps-}, SDoc{-externs-})
854 pprTempAndExternDecls stmts
855 = (vcat (map pprTempDecl (uniqSetToList temps)),
856 vcat (map (pprExternDecl False{-ToDo-}) (Map.keys lbls)))
857 where (temps, lbls) = runTE (mapM_ te_BB stmts)
859 pprDataExterns :: [CmmStatic] -> SDoc
860 pprDataExterns statics
861 = vcat (map (pprExternDecl False{-ToDo-}) (Map.keys lbls))
862 where (_, lbls) = runTE (mapM_ te_Static statics)
864 pprTempDecl :: LocalReg -> SDoc
865 pprTempDecl l@(LocalReg _ rep)
866 = hcat [ machRepCType rep, space, pprLocalReg l, semi ]
868 pprExternDecl :: Bool -> CLabel -> SDoc
869 pprExternDecl in_srt lbl
870 -- do not print anything for "known external" things
871 | not (needsCDecl lbl) = empty
872 | Just sz <- foreignLabelStdcallInfo lbl = stdcall_decl sz
874 hcat [ visibility, label_type lbl,
875 lparen, pprCLabel lbl, text ");" ]
877 label_type lbl | isCFunctionLabel lbl = ptext (sLit "F_")
878 | otherwise = ptext (sLit "I_")
881 | externallyVisibleCLabel lbl = char 'E'
882 | otherwise = char 'I'
884 -- If the label we want to refer to is a stdcall function (on Windows) then
885 -- we must generate an appropriate prototype for it, so that the C compiler will
886 -- add the @n suffix to the label (#2276)
888 ptext (sLit "extern __attribute__((stdcall)) void ") <> pprCLabel lbl
889 <> parens (commafy (replicate (sz `quot` wORD_SIZE) (machRep_U_CType wordWidth)))
892 type TEState = (UniqSet LocalReg, Map CLabel ())
893 newtype TE a = TE { unTE :: TEState -> (a, TEState) }
895 instance Monad TE where
896 TE m >>= k = TE $ \s -> case m s of (a, s') -> unTE (k a) s'
897 return a = TE $ \s -> (a, s)
899 te_lbl :: CLabel -> TE ()
900 te_lbl lbl = TE $ \(temps,lbls) -> ((), (temps, Map.insert lbl () lbls))
902 te_temp :: LocalReg -> TE ()
903 te_temp r = TE $ \(temps,lbls) -> ((), (addOneToUniqSet temps r, lbls))
905 runTE :: TE () -> TEState
906 runTE (TE m) = snd (m (emptyUniqSet, Map.empty))
908 te_Static :: CmmStatic -> TE ()
909 te_Static (CmmStaticLit lit) = te_Lit lit
910 te_Static _ = return ()
912 te_BB :: CmmBasicBlock -> TE ()
913 te_BB (BasicBlock _ ss) = mapM_ te_Stmt ss
915 te_Lit :: CmmLit -> TE ()
916 te_Lit (CmmLabel l) = te_lbl l
917 te_Lit (CmmLabelOff l _) = te_lbl l
918 te_Lit (CmmLabelDiffOff l1 l2 _) = te_lbl l1
921 te_Stmt :: CmmStmt -> TE ()
922 te_Stmt (CmmAssign r e) = te_Reg r >> te_Expr e
923 te_Stmt (CmmStore l r) = te_Expr l >> te_Expr r
924 te_Stmt (CmmCall _ rs es _ _) = mapM_ (te_temp.hintlessCmm) rs >>
925 mapM_ (te_Expr.hintlessCmm) es
926 te_Stmt (CmmCondBranch e _) = te_Expr e
927 te_Stmt (CmmSwitch e _) = te_Expr e
928 te_Stmt (CmmJump e _) = te_Expr e
929 te_Stmt _ = return ()
931 te_Expr :: CmmExpr -> TE ()
932 te_Expr (CmmLit lit) = te_Lit lit
933 te_Expr (CmmLoad e _) = te_Expr e
934 te_Expr (CmmReg r) = te_Reg r
935 te_Expr (CmmMachOp _ es) = mapM_ te_Expr es
936 te_Expr (CmmRegOff r _) = te_Reg r
938 te_Reg :: CmmReg -> TE ()
939 te_Reg (CmmLocal l) = te_temp l
943 -- ---------------------------------------------------------------------
944 -- C types for MachReps
946 cCast :: SDoc -> CmmExpr -> SDoc
947 cCast ty expr = parens ty <> pprExpr1 expr
949 cLoad :: CmmExpr -> CmmType -> SDoc
950 #ifdef BEWARE_LOAD_STORE_ALIGNMENT
952 let decl = machRepCType rep <+> ptext (sLit "x") <> semi
953 struct = ptext (sLit "struct") <+> braces (decl)
954 packed_attr = ptext (sLit "__attribute__((packed))")
955 cast = parens (struct <+> packed_attr <> char '*')
956 in parens (cast <+> pprExpr1 expr) <> ptext (sLit "->x")
958 cLoad expr rep = char '*' <> parens (cCast (machRepPtrCType rep) expr)
961 isCmmWordType :: CmmType -> Bool
962 -- True of GcPtrReg/NonGcReg of native word size
963 isCmmWordType ty = not (isFloatType ty)
964 && typeWidth ty == wordWidth
966 -- This is for finding the types of foreign call arguments. For a pointer
967 -- argument, we always cast the argument to (void *), to avoid warnings from
969 machRepHintCType :: CmmType -> ForeignHint -> SDoc
970 machRepHintCType rep AddrHint = ptext (sLit "void *")
971 machRepHintCType rep SignedHint = machRep_S_CType (typeWidth rep)
972 machRepHintCType rep _other = machRepCType rep
974 machRepPtrCType :: CmmType -> SDoc
975 machRepPtrCType r | isCmmWordType r = ptext (sLit "P_")
976 | otherwise = machRepCType r <> char '*'
978 machRepCType :: CmmType -> SDoc
979 machRepCType ty | isFloatType ty = machRep_F_CType w
980 | otherwise = machRep_U_CType w
984 machRep_F_CType :: Width -> SDoc
985 machRep_F_CType W32 = ptext (sLit "StgFloat") -- ToDo: correct?
986 machRep_F_CType W64 = ptext (sLit "StgDouble")
987 machRep_F_CType _ = panic "machRep_F_CType"
989 machRep_U_CType :: Width -> SDoc
990 machRep_U_CType w | w == wordWidth = ptext (sLit "W_")
991 machRep_U_CType W8 = ptext (sLit "StgWord8")
992 machRep_U_CType W16 = ptext (sLit "StgWord16")
993 machRep_U_CType W32 = ptext (sLit "StgWord32")
994 machRep_U_CType W64 = ptext (sLit "StgWord64")
995 machRep_U_CType _ = panic "machRep_U_CType"
997 machRep_S_CType :: Width -> SDoc
998 machRep_S_CType w | w == wordWidth = ptext (sLit "I_")
999 machRep_S_CType W8 = ptext (sLit "StgInt8")
1000 machRep_S_CType W16 = ptext (sLit "StgInt16")
1001 machRep_S_CType W32 = ptext (sLit "StgInt32")
1002 machRep_S_CType W64 = ptext (sLit "StgInt64")
1003 machRep_S_CType _ = panic "machRep_S_CType"
1006 -- ---------------------------------------------------------------------
1007 -- print strings as valid C strings
1009 pprStringInCStyle :: [Word8] -> SDoc
1010 pprStringInCStyle s = doubleQuotes (text (concatMap charToC s))
1012 -- ---------------------------------------------------------------------------
1013 -- Initialising static objects with floating-point numbers. We can't
1014 -- just emit the floating point number, because C will cast it to an int
1015 -- by rounding it. We want the actual bit-representation of the float.
1017 -- This is a hack to turn the floating point numbers into ints that we
1018 -- can safely initialise to static locations.
1021 | widthInBytes W64 == 2 * wORD_SIZE = True
1022 | widthInBytes W64 == wORD_SIZE = False
1023 | otherwise = panic "big_doubles"
1025 castFloatToIntArray :: STUArray s Int Float -> ST s (STUArray s Int Int)
1026 castFloatToIntArray = castSTUArray
1028 castDoubleToIntArray :: STUArray s Int Double -> ST s (STUArray s Int Int)
1029 castDoubleToIntArray = castSTUArray
1031 -- floats are always 1 word
1032 floatToWord :: Rational -> CmmLit
1035 arr <- newArray_ ((0::Int),0)
1036 writeArray arr 0 (fromRational r)
1037 arr' <- castFloatToIntArray arr
1038 i <- readArray arr' 0
1039 return (CmmInt (toInteger i) wordWidth)
1042 doubleToWords :: Rational -> [CmmLit]
1044 | big_doubles -- doubles are 2 words
1046 arr <- newArray_ ((0::Int),1)
1047 writeArray arr 0 (fromRational r)
1048 arr' <- castDoubleToIntArray arr
1049 i1 <- readArray arr' 0
1050 i2 <- readArray arr' 1
1051 return [ CmmInt (toInteger i1) wordWidth
1052 , CmmInt (toInteger i2) wordWidth
1055 | otherwise -- doubles are 1 word
1057 arr <- newArray_ ((0::Int),0)
1058 writeArray arr 0 (fromRational r)
1059 arr' <- castDoubleToIntArray arr
1060 i <- readArray arr' 0
1061 return [ CmmInt (toInteger i) wordWidth ]
1064 -- ---------------------------------------------------------------------------
1068 wordShift = widthInLog wordWidth
1070 commafy :: [SDoc] -> SDoc
1071 commafy xs = hsep $ punctuate comma xs
1073 -- Print in C hex format: 0x13fa
1074 pprHexVal :: Integer -> Width -> SDoc
1075 pprHexVal 0 _ = ptext (sLit "0x0")
1077 | w < 0 = parens (char '-' <> ptext (sLit "0x") <> go (-w) <> repsuffix rep)
1078 | otherwise = ptext (sLit "0x") <> go w <> repsuffix rep
1080 -- type suffix for literals:
1081 -- Integer literals are unsigned in Cmm/C. We explicitly cast to
1082 -- signed values for doing signed operations, but at all other
1083 -- times values are unsigned. This also helps eliminate occasional
1084 -- warnings about integer overflow from gcc.
1086 -- on 32-bit platforms, add "ULL" to 64-bit literals
1087 repsuffix W64 | wORD_SIZE == 4 = ptext (sLit "ULL")
1088 -- on 64-bit platforms with 32-bit int, add "L" to 64-bit literals
1089 repsuffix W64 | cINT_SIZE == 4 = ptext (sLit "UL")
1090 repsuffix _ = char 'U'
1095 (q,r) = w' `quotRem` 16
1096 dig | r < 10 = char (chr (fromInteger r + ord '0'))
1097 | otherwise = char (chr (fromInteger r - 10 + ord 'a'))