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 PprCmm () -- Instances only
63 import Control.Monad.ST
65 #if x86_64_TARGET_ARCH
66 import StaticFlags ( opt_Unregisterised )
69 #if defined(alpha_TARGET_ARCH) || defined(mips_TARGET_ARCH) || defined(mipsel_TARGET_ARCH) || defined(arm_TARGET_ARCH)
70 #define BEWARE_LOAD_STORE_ALIGNMENT
73 -- --------------------------------------------------------------------------
76 pprCs :: DynFlags -> [RawCmm] -> SDoc
78 = pprCode CStyle (vcat $ map (\c -> split_marker $$ pprC c) cmms)
81 | dopt Opt_SplitObjs dflags = ptext (sLit "__STG_SPLIT_MARKER")
84 writeCs :: DynFlags -> Handle -> [RawCmm] -> IO ()
85 writeCs dflags handle cmms
86 = printForC handle (pprCs dflags cmms)
88 -- --------------------------------------------------------------------------
89 -- Now do some real work
91 -- for fun, we could call cmmToCmm over the tops...
94 pprC :: RawCmm -> SDoc
95 pprC (Cmm tops) = vcat $ intersperse blankLine $ map pprTop tops
100 pprTop :: RawCmmTop -> SDoc
101 pprTop (CmmProc info clbl _params (ListGraph blocks)) =
103 then pprDataExterns info $$
104 pprWordArray (entryLblToInfoLbl clbl) info
108 -- the first block doesn't get a label:
109 (BasicBlock _ stmts : rest) -> vcat [
112 (if (externallyVisibleCLabel clbl)
113 then mkFN_ else mkIF_) (pprCLabel clbl) <+> lbrace,
116 nest 8 (vcat (map pprStmt stmts)) $$
117 vcat (map pprBBlock rest),
122 (temp_decls, extern_decls) = pprTempAndExternDecls blocks
125 -- Chunks of static data.
127 -- We only handle (a) arrays of word-sized things and (b) strings.
129 pprTop (CmmData _section _ds@[CmmDataLabel lbl, CmmString str]) =
131 pprLocalness lbl, ptext (sLit "char "), pprCLabel lbl,
132 ptext (sLit "[] = "), pprStringInCStyle str, semi
135 pprTop (CmmData _section _ds@[CmmDataLabel lbl, CmmUninitialised size]) =
137 pprLocalness lbl, ptext (sLit "char "), pprCLabel lbl,
138 brackets (int size), semi
141 pprTop top@(CmmData _section (CmmDataLabel lbl : lits)) =
142 pprDataExterns lits $$
143 pprWordArray lbl lits
145 -- Floating info table for safe a foreign call.
146 pprTop top@(CmmData _section d@(_ : _))
147 | CmmDataLabel lbl : lits <- reverse d =
148 let lits' = reverse lits
149 in pprDataExterns lits' $$
150 pprWordArray lbl lits'
152 -- these shouldn't appear?
153 pprTop (CmmData _ _) = panic "PprC.pprTop: can't handle this data"
155 -- --------------------------------------------------------------------------
156 -- BasicBlocks are self-contained entities: they always end in a jump.
158 -- Like nativeGen/AsmCodeGen, we could probably reorder blocks to turn
159 -- as many jumps as possible into fall throughs.
162 pprBBlock :: CmmBasicBlock -> SDoc
163 pprBBlock (BasicBlock lbl stmts) =
165 pprTrace "pprC.pprBBlock: curious empty code block for"
166 (pprBlockId lbl) empty
168 nest 4 (pprBlockId lbl <> colon) $$
169 nest 8 (vcat (map pprStmt stmts))
171 -- --------------------------------------------------------------------------
172 -- Info tables. Just arrays of words.
173 -- See codeGen/ClosureInfo, and nativeGen/PprMach
175 pprWordArray :: CLabel -> [CmmStatic] -> SDoc
177 = hcat [ pprLocalness lbl, ptext (sLit "StgWord")
178 , space, pprCLabel lbl, ptext (sLit "[] = {") ]
179 $$ nest 8 (commafy (pprStatics ds))
183 -- has to be static, if it isn't globally visible
185 pprLocalness :: CLabel -> SDoc
186 pprLocalness lbl | not $ externallyVisibleCLabel lbl = ptext (sLit "static ")
189 -- --------------------------------------------------------------------------
193 pprStmt :: CmmStmt -> SDoc
195 pprStmt stmt = case stmt of
197 CmmComment s -> empty -- (hang (ptext (sLit "/*")) 3 (ftext s)) $$ ptext (sLit "*/")
198 -- XXX if the string contains "*/", we need to fix it
199 -- XXX we probably want to emit these comments when
200 -- some debugging option is on. They can get quite
203 CmmAssign dest src -> pprAssign dest src
206 | typeWidth rep == W64 && wordWidth /= W64
207 -> (if isFloatType rep then ptext (sLit "ASSIGN_DBL")
208 else ptext (sLit ("ASSIGN_Word64"))) <>
209 parens (mkP_ <> pprExpr1 dest <> comma <> pprExpr src) <> semi
212 -> hsep [ pprExpr (CmmLoad dest rep), equals, pprExpr src <> semi ]
214 rep = cmmExprType src
216 CmmCall (CmmCallee fn cconv) results args safety ret ->
220 cast_fn = parens (cCast (pprCFunType (char '*') cconv results args) fn)
222 real_fun_proto lbl = char ';' <>
223 pprCFunType (pprCLabel lbl) cconv results args <>
224 noreturn_attr <> semi
226 fun_proto lbl = ptext (sLit ";EF_(") <>
227 pprCLabel lbl <> char ')' <> semi
229 noreturn_attr = case ret of
230 CmmNeverReturns -> text "__attribute__ ((noreturn))"
231 CmmMayReturn -> empty
233 -- See wiki:Commentary/Compiler/Backends/PprC#Prototypes
234 (maybe_proto, fnCall) =
236 CmmLit (CmmLabel lbl)
237 | StdCallConv <- cconv ->
238 let myCall = pprCall (pprCLabel lbl) cconv results args safety
239 in (real_fun_proto lbl, myCall)
240 -- stdcall functions must be declared with
241 -- a function type, otherwise the C compiler
242 -- doesn't add the @n suffix to the label. We
243 -- can't add the @n suffix ourselves, because
245 | CmmNeverReturns <- ret ->
246 let myCall = pprCall (pprCLabel lbl) cconv results args safety
247 in (real_fun_proto lbl, myCall)
248 | not (isMathFun lbl) ->
249 let myCall = braces (
250 pprCFunType (char '*' <> text "ghcFunPtr") cconv results args <> semi
251 $$ text "ghcFunPtr" <+> equals <+> cast_fn <> semi
252 $$ pprCall (text "ghcFunPtr") cconv results args safety <> semi
254 in (fun_proto lbl, myCall)
256 (empty {- no proto -},
257 pprCall cast_fn cconv results args safety <> semi)
258 -- for a dynamic call, no declaration is necessary.
260 CmmCall (CmmPrim op) results args safety _ret ->
261 pprCall ppr_fn CCallConv results args safety
263 ppr_fn = pprCallishMachOp_for_C op
265 CmmBranch ident -> pprBranch ident
266 CmmCondBranch expr ident -> pprCondBranch expr ident
267 CmmJump lbl _params -> mkJMP_(pprExpr lbl) <> semi
268 CmmSwitch arg ids -> pprSwitch arg ids
270 pprCFunType :: SDoc -> CCallConv -> HintedCmmFormals -> HintedCmmActuals -> SDoc
271 pprCFunType ppr_fn cconv ress args
273 parens (text (ccallConvAttribute cconv) <> ppr_fn) <>
274 parens (commafy (map arg_type args))
276 res_type [] = ptext (sLit "void")
277 res_type [CmmHinted one hint] = machRepHintCType (localRegType one) hint
279 arg_type (CmmHinted expr hint) = machRepHintCType (cmmExprType expr) hint
281 -- ---------------------------------------------------------------------
282 -- unconditional branches
283 pprBranch :: BlockId -> SDoc
284 pprBranch ident = ptext (sLit "goto") <+> pprBlockId ident <> semi
287 -- ---------------------------------------------------------------------
288 -- conditional branches to local labels
289 pprCondBranch :: CmmExpr -> BlockId -> SDoc
290 pprCondBranch expr ident
291 = hsep [ ptext (sLit "if") , parens(pprExpr expr) ,
292 ptext (sLit "goto") , (pprBlockId ident) <> semi ]
295 -- ---------------------------------------------------------------------
296 -- a local table branch
298 -- we find the fall-through cases
300 -- N.B. we remove Nothing's from the list of branches, as they are
301 -- 'undefined'. However, they may be defined one day, so we better
302 -- document this behaviour.
304 pprSwitch :: CmmExpr -> [ Maybe BlockId ] -> SDoc
305 pprSwitch e maybe_ids
306 = let pairs = [ (ix, ident) | (ix,Just ident) <- zip [0..] maybe_ids ]
307 pairs2 = [ (map fst as, snd (head as)) | as <- groupBy sndEq pairs ]
309 (hang (ptext (sLit "switch") <+> parens ( pprExpr e ) <+> lbrace)
310 4 (vcat ( map caseify pairs2 )))
314 sndEq (_,x) (_,y) = x == y
317 caseify (ix:ixs, ident) = vcat (map do_fallthrough ixs) $$ final_branch ix
320 hsep [ ptext (sLit "case") , pprHexVal ix wordWidth <> colon ,
321 ptext (sLit "/* fall through */") ]
324 hsep [ ptext (sLit "case") , pprHexVal ix wordWidth <> colon ,
325 ptext (sLit "goto") , (pprBlockId ident) <> semi ]
327 -- ---------------------------------------------------------------------
331 -- C Types: the invariant is that the C expression generated by
335 -- has a type in C which is also given by
337 -- machRepCType (cmmExprType e)
339 -- (similar invariants apply to the rest of the pretty printer).
341 pprExpr :: CmmExpr -> SDoc
342 pprExpr e = case e of
343 CmmLit lit -> pprLit lit
346 CmmLoad e ty -> pprLoad e ty
347 CmmReg reg -> pprCastReg reg
348 CmmRegOff reg 0 -> pprCastReg reg
351 | i > 0 -> pprRegOff (char '+') i
352 | otherwise -> pprRegOff (char '-') (-i)
354 pprRegOff op i' = pprCastReg reg <> op <> int i'
356 CmmMachOp mop args -> pprMachOpApp mop args
359 pprLoad :: CmmExpr -> CmmType -> SDoc
361 | width == W64, wordWidth /= W64
362 = (if isFloatType ty then ptext (sLit "PK_DBL")
363 else ptext (sLit "PK_Word64"))
364 <> parens (mkP_ <> pprExpr1 e)
368 CmmReg r | isPtrReg r && width == wordWidth && not (isFloatType ty)
369 -> char '*' <> pprAsPtrReg r
371 CmmRegOff r 0 | isPtrReg r && width == wordWidth && not (isFloatType ty)
372 -> char '*' <> pprAsPtrReg r
374 CmmRegOff r off | isPtrReg r && width == wordWidth
375 , off `rem` wORD_SIZE == 0 && not (isFloatType ty)
376 -- ToDo: check that the offset is a word multiple?
377 -- (For tagging to work, I had to avoid unaligned loads. --ARY)
378 -> pprAsPtrReg r <> brackets (ppr (off `shiftR` wordShift))
384 pprExpr1 :: CmmExpr -> SDoc
385 pprExpr1 (CmmLit lit) = pprLit1 lit
386 pprExpr1 e@(CmmReg _reg) = pprExpr e
387 pprExpr1 other = parens (pprExpr other)
389 -- --------------------------------------------------------------------------
390 -- MachOp applications
392 pprMachOpApp :: MachOp -> [CmmExpr] -> SDoc
396 = ptext (sLit "mulIntMayOflo") <> parens (commafy (map pprExpr args))
397 where isMulMayOfloOp (MO_U_MulMayOflo _) = True
398 isMulMayOfloOp (MO_S_MulMayOflo _) = True
399 isMulMayOfloOp _ = False
401 pprMachOpApp mop args
402 | Just ty <- machOpNeedsCast mop
403 = ty <> parens (pprMachOpApp' mop args)
405 = pprMachOpApp' mop args
407 -- Comparisons in C have type 'int', but we want type W_ (this is what
408 -- resultRepOfMachOp says). The other C operations inherit their type
409 -- from their operands, so no casting is required.
410 machOpNeedsCast :: MachOp -> Maybe SDoc
412 | isComparisonMachOp mop = Just mkW_
413 | otherwise = Nothing
415 pprMachOpApp' mop args
418 [x,y] -> pprArg x <+> pprMachOp_for_C mop <+> pprArg y
421 [x] -> pprMachOp_for_C mop <> parens (pprArg x)
423 _ -> panic "PprC.pprMachOp : machop with wrong number of args"
426 -- Cast needed for signed integer ops
427 pprArg e | signedOp mop = cCast (machRep_S_CType (typeWidth (cmmExprType e))) e
428 | needsFCasts mop = cCast (machRep_F_CType (typeWidth (cmmExprType e))) e
429 | otherwise = pprExpr1 e
430 needsFCasts (MO_F_Eq _) = False
431 needsFCasts (MO_F_Ne _) = False
432 needsFCasts (MO_F_Neg _) = True
433 needsFCasts (MO_F_Quot _) = True
434 needsFCasts mop = floatComparison mop
436 -- --------------------------------------------------------------------------
439 pprLit :: CmmLit -> SDoc
440 pprLit lit = case lit of
441 CmmInt i rep -> pprHexVal i rep
443 CmmFloat f w -> parens (machRep_F_CType w) <> str
444 where d = fromRational f :: Double
445 str | isInfinite d && d < 0 = ptext (sLit "-INFINITY")
446 | isInfinite d = ptext (sLit "INFINITY")
447 | isNaN d = ptext (sLit "NAN")
448 | otherwise = text (show d)
449 -- these constants come from <math.h>
452 CmmBlock bid -> mkW_ <> pprCLabelAddr (infoTblLbl bid)
453 CmmHighStackMark -> panic "PprC printing high stack mark"
454 CmmLabel clbl -> mkW_ <> pprCLabelAddr clbl
455 CmmLabelOff clbl i -> mkW_ <> pprCLabelAddr clbl <> char '+' <> int i
456 CmmLabelDiffOff clbl1 clbl2 i
458 -- * the lit must occur in the info table clbl2
459 -- * clbl1 must be an SRT, a slow entry point or a large bitmap
460 -- The Mangler is expected to convert any reference to an SRT,
461 -- a slow entry point or a large bitmap
462 -- from an info table to an offset.
463 -> mkW_ <> pprCLabelAddr clbl1 <> char '+' <> int i
465 pprCLabelAddr lbl = char '&' <> pprCLabel lbl
467 pprLit1 :: CmmLit -> SDoc
468 pprLit1 lit@(CmmLabelOff _ _) = parens (pprLit lit)
469 pprLit1 lit@(CmmLabelDiffOff _ _ _) = parens (pprLit lit)
470 pprLit1 lit@(CmmFloat _ _) = parens (pprLit lit)
471 pprLit1 other = pprLit other
473 -- ---------------------------------------------------------------------------
476 pprStatics :: [CmmStatic] -> [SDoc]
478 pprStatics (CmmStaticLit (CmmFloat f W32) : rest)
479 -- floats are padded to a word, see #1852
480 | wORD_SIZE == 8, CmmStaticLit (CmmInt 0 W32) : rest' <- rest
481 = pprLit1 (floatToWord f) : pprStatics rest'
483 = pprLit1 (floatToWord f) : pprStatics rest
485 = pprPanic "pprStatics: float" (vcat (map (\(CmmStaticLit l) -> ppr (cmmLitType l)) rest))
486 pprStatics (CmmStaticLit (CmmFloat f W64) : rest)
487 = map pprLit1 (doubleToWords f) ++ pprStatics rest
488 pprStatics (CmmStaticLit (CmmInt i W64) : rest)
490 #ifdef WORDS_BIGENDIAN
491 = pprStatics (CmmStaticLit (CmmInt q W32) :
492 CmmStaticLit (CmmInt r W32) : rest)
494 = pprStatics (CmmStaticLit (CmmInt r W32) :
495 CmmStaticLit (CmmInt q W32) : rest)
497 where r = i .&. 0xffffffff
499 pprStatics (CmmStaticLit (CmmInt i w) : rest)
501 = panic "pprStatics: cannot emit a non-word-sized static literal"
502 pprStatics (CmmStaticLit lit : rest)
503 = pprLit1 lit : pprStatics rest
504 pprStatics (other : rest)
505 = pprPanic "pprWord" (pprStatic other)
507 pprStatic :: CmmStatic -> SDoc
508 pprStatic s = case s of
510 CmmStaticLit lit -> nest 4 (pprLit lit)
511 CmmAlign i -> nest 4 (ptext (sLit "/* align */") <+> int i)
512 CmmDataLabel clbl -> pprCLabel clbl <> colon
513 CmmUninitialised i -> nest 4 (mkC_ <> brackets (int i))
515 -- these should be inlined, like the old .hc
516 CmmString s' -> nest 4 (mkW_ <> parens(pprStringInCStyle s'))
519 -- ---------------------------------------------------------------------------
522 pprBlockId :: BlockId -> SDoc
523 pprBlockId b = char '_' <> ppr (getUnique b)
525 -- --------------------------------------------------------------------------
526 -- Print a MachOp in a way suitable for emitting via C.
529 pprMachOp_for_C :: MachOp -> SDoc
531 pprMachOp_for_C mop = case mop of
533 -- Integer operations
536 MO_Eq _ -> ptext (sLit "==")
537 MO_Ne _ -> ptext (sLit "!=")
540 MO_S_Quot _ -> char '/'
541 MO_S_Rem _ -> char '%'
542 MO_S_Neg _ -> char '-'
544 MO_U_Quot _ -> char '/'
545 MO_U_Rem _ -> char '%'
547 -- & Floating-point operations
548 MO_F_Add _ -> char '+'
549 MO_F_Sub _ -> char '-'
550 MO_F_Neg _ -> char '-'
551 MO_F_Mul _ -> char '*'
552 MO_F_Quot _ -> char '/'
554 -- Signed comparisons
555 MO_S_Ge _ -> ptext (sLit ">=")
556 MO_S_Le _ -> ptext (sLit "<=")
557 MO_S_Gt _ -> char '>'
558 MO_S_Lt _ -> char '<'
560 -- & Unsigned comparisons
561 MO_U_Ge _ -> ptext (sLit ">=")
562 MO_U_Le _ -> ptext (sLit "<=")
563 MO_U_Gt _ -> char '>'
564 MO_U_Lt _ -> char '<'
566 -- & Floating-point comparisons
567 MO_F_Eq _ -> ptext (sLit "==")
568 MO_F_Ne _ -> ptext (sLit "!=")
569 MO_F_Ge _ -> ptext (sLit ">=")
570 MO_F_Le _ -> ptext (sLit "<=")
571 MO_F_Gt _ -> char '>'
572 MO_F_Lt _ -> char '<'
574 -- Bitwise operations. Not all of these may be supported at all
575 -- sizes, and only integral MachReps are valid.
580 MO_Shl _ -> ptext (sLit "<<")
581 MO_U_Shr _ -> ptext (sLit ">>") -- unsigned shift right
582 MO_S_Shr _ -> ptext (sLit ">>") -- signed shift right
584 -- Conversions. Some of these will be NOPs, but never those that convert
585 -- between ints and floats.
586 -- Floating-point conversions use the signed variant.
587 -- We won't know to generate (void*) casts here, but maybe from
591 MO_UU_Conv from to | from == to -> empty
592 MO_UU_Conv _from to -> parens (machRep_U_CType to)
594 MO_SS_Conv from to | from == to -> empty
595 MO_SS_Conv _from to -> parens (machRep_S_CType to)
597 -- TEMPORARY: the old code didn't check this case, so let's leave it out
598 -- to facilitate comparisons against the old output code.
599 --MO_FF_Conv from to | from == to -> empty
600 MO_FF_Conv _from to -> parens (machRep_F_CType to)
602 MO_SF_Conv _from to -> parens (machRep_F_CType to)
603 MO_FS_Conv _from to -> parens (machRep_S_CType to)
605 _ -> pprTrace "offending mop" (ptext $ sLit $ show mop) $
606 panic "PprC.pprMachOp_for_C: unknown machop"
608 signedOp :: MachOp -> Bool -- Argument type(s) are signed ints
609 signedOp (MO_S_Quot _) = True
610 signedOp (MO_S_Rem _) = True
611 signedOp (MO_S_Neg _) = True
612 signedOp (MO_S_Ge _) = True
613 signedOp (MO_S_Le _) = True
614 signedOp (MO_S_Gt _) = True
615 signedOp (MO_S_Lt _) = True
616 signedOp (MO_S_Shr _) = True
617 signedOp (MO_SS_Conv _ _) = True
618 signedOp (MO_SF_Conv _ _) = True
621 floatComparison :: MachOp -> Bool -- comparison between float args
622 floatComparison (MO_F_Eq _) = True
623 floatComparison (MO_F_Ne _) = True
624 floatComparison (MO_F_Ge _) = True
625 floatComparison (MO_F_Le _) = True
626 floatComparison (MO_F_Gt _) = True
627 floatComparison (MO_F_Lt _) = True
628 floatComparison _ = False
630 -- ---------------------------------------------------------------------
631 -- tend to be implemented by foreign calls
633 pprCallishMachOp_for_C :: CallishMachOp -> SDoc
635 pprCallishMachOp_for_C mop
637 MO_F64_Pwr -> ptext (sLit "pow")
638 MO_F64_Sin -> ptext (sLit "sin")
639 MO_F64_Cos -> ptext (sLit "cos")
640 MO_F64_Tan -> ptext (sLit "tan")
641 MO_F64_Sinh -> ptext (sLit "sinh")
642 MO_F64_Cosh -> ptext (sLit "cosh")
643 MO_F64_Tanh -> ptext (sLit "tanh")
644 MO_F64_Asin -> ptext (sLit "asin")
645 MO_F64_Acos -> ptext (sLit "acos")
646 MO_F64_Atan -> ptext (sLit "atan")
647 MO_F64_Log -> ptext (sLit "log")
648 MO_F64_Exp -> ptext (sLit "exp")
649 MO_F64_Sqrt -> ptext (sLit "sqrt")
650 MO_F32_Pwr -> ptext (sLit "powf")
651 MO_F32_Sin -> ptext (sLit "sinf")
652 MO_F32_Cos -> ptext (sLit "cosf")
653 MO_F32_Tan -> ptext (sLit "tanf")
654 MO_F32_Sinh -> ptext (sLit "sinhf")
655 MO_F32_Cosh -> ptext (sLit "coshf")
656 MO_F32_Tanh -> ptext (sLit "tanhf")
657 MO_F32_Asin -> ptext (sLit "asinf")
658 MO_F32_Acos -> ptext (sLit "acosf")
659 MO_F32_Atan -> ptext (sLit "atanf")
660 MO_F32_Log -> ptext (sLit "logf")
661 MO_F32_Exp -> ptext (sLit "expf")
662 MO_F32_Sqrt -> ptext (sLit "sqrtf")
663 MO_WriteBarrier -> ptext (sLit "write_barrier")
665 -- ---------------------------------------------------------------------
669 mkJMP_, mkFN_, mkIF_ :: SDoc -> SDoc
671 mkJMP_ i = ptext (sLit "JMP_") <> parens i
672 mkFN_ i = ptext (sLit "FN_") <> parens i -- externally visible function
673 mkIF_ i = ptext (sLit "IF_") <> parens i -- locally visible
677 mkFB_ = ptext (sLit "FB_") -- function code begin
678 mkFE_ = ptext (sLit "FE_") -- function code end
680 -- from includes/Stg.h
682 mkC_,mkW_,mkP_ :: SDoc
684 mkC_ = ptext (sLit "(C_)") -- StgChar
685 mkW_ = ptext (sLit "(W_)") -- StgWord
686 mkP_ = ptext (sLit "(P_)") -- StgWord*
688 -- ---------------------------------------------------------------------
692 -- Generating assignments is what we're all about, here
694 pprAssign :: CmmReg -> CmmExpr -> SDoc
696 -- dest is a reg, rhs is a reg
697 pprAssign r1 (CmmReg r2)
698 | isPtrReg r1 && isPtrReg r2
699 = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, semi ]
701 -- dest is a reg, rhs is a CmmRegOff
702 pprAssign r1 (CmmRegOff r2 off)
703 | isPtrReg r1 && isPtrReg r2 && (off `rem` wORD_SIZE == 0)
704 = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, op, int off', semi ]
706 off1 = off `shiftR` wordShift
708 (op,off') | off >= 0 = (char '+', off1)
709 | otherwise = (char '-', -off1)
711 -- dest is a reg, rhs is anything.
712 -- We can't cast the lvalue, so we have to cast the rhs if necessary. Casting
713 -- the lvalue elicits a warning from new GCC versions (3.4+).
715 | isFixedPtrReg r1 = mkAssign (mkP_ <> pprExpr1 r2)
716 | Just ty <- strangeRegType r1 = mkAssign (parens ty <> pprExpr1 r2)
717 | otherwise = mkAssign (pprExpr r2)
718 where mkAssign x = if r1 == CmmGlobal BaseReg
719 then ptext (sLit "ASSIGN_BaseReg") <> parens x <> semi
720 else pprReg r1 <> ptext (sLit " = ") <> x <> semi
722 -- ---------------------------------------------------------------------
726 | isStrangeTypeReg reg = mkW_ <> pprReg reg
727 | otherwise = pprReg reg
729 -- True if (pprReg reg) will give an expression with type StgPtr. We
730 -- need to take care with pointer arithmetic on registers with type
732 isFixedPtrReg :: CmmReg -> Bool
733 isFixedPtrReg (CmmLocal _) = False
734 isFixedPtrReg (CmmGlobal r) = isFixedPtrGlobalReg r
736 -- True if (pprAsPtrReg reg) will give an expression with type StgPtr
737 -- JD: THIS IS HORRIBLE AND SHOULD BE RENAMED, AT THE VERY LEAST.
738 -- THE GARBAGE WITH THE VNonGcPtr HELPS MATCH THE OLD CODE GENERATOR'S OUTPUT;
739 -- I'M NOT SURE IF IT SHOULD REALLY STAY THAT WAY.
740 isPtrReg :: CmmReg -> Bool
741 isPtrReg (CmmLocal _) = False
742 isPtrReg (CmmGlobal (VanillaReg n VGcPtr)) = True -- if we print via pprAsPtrReg
743 isPtrReg (CmmGlobal (VanillaReg n VNonGcPtr)) = False --if we print via pprAsPtrReg
744 isPtrReg (CmmGlobal reg) = isFixedPtrGlobalReg reg
746 -- True if this global reg has type StgPtr
747 isFixedPtrGlobalReg :: GlobalReg -> Bool
748 isFixedPtrGlobalReg Sp = True
749 isFixedPtrGlobalReg Hp = True
750 isFixedPtrGlobalReg HpLim = True
751 isFixedPtrGlobalReg SpLim = True
752 isFixedPtrGlobalReg _ = False
754 -- True if in C this register doesn't have the type given by
755 -- (machRepCType (cmmRegType reg)), so it has to be cast.
756 isStrangeTypeReg :: CmmReg -> Bool
757 isStrangeTypeReg (CmmLocal _) = False
758 isStrangeTypeReg (CmmGlobal g) = isStrangeTypeGlobal g
760 isStrangeTypeGlobal :: GlobalReg -> Bool
761 isStrangeTypeGlobal CurrentTSO = True
762 isStrangeTypeGlobal CurrentNursery = True
763 isStrangeTypeGlobal BaseReg = True
764 isStrangeTypeGlobal r = isFixedPtrGlobalReg r
766 strangeRegType :: CmmReg -> Maybe SDoc
767 strangeRegType (CmmGlobal CurrentTSO) = Just (ptext (sLit "struct StgTSO_ *"))
768 strangeRegType (CmmGlobal CurrentNursery) = Just (ptext (sLit "struct bdescr_ *"))
769 strangeRegType (CmmGlobal BaseReg) = Just (ptext (sLit "struct StgRegTable_ *"))
770 strangeRegType _ = Nothing
772 -- pprReg just prints the register name.
774 pprReg :: CmmReg -> SDoc
776 CmmLocal local -> pprLocalReg local
777 CmmGlobal global -> pprGlobalReg global
779 pprAsPtrReg :: CmmReg -> SDoc
780 pprAsPtrReg (CmmGlobal (VanillaReg n gcp))
781 = WARN( gcp /= VGcPtr, ppr n ) char 'R' <> int n <> ptext (sLit ".p")
782 pprAsPtrReg other_reg = pprReg other_reg
784 pprGlobalReg :: GlobalReg -> SDoc
785 pprGlobalReg gr = case gr of
786 VanillaReg n _ -> char 'R' <> int n <> ptext (sLit ".w")
787 -- pprGlobalReg prints a VanillaReg as a .w regardless
788 -- Example: R1.w = R1.w & (-0x8UL);
790 FloatReg n -> char 'F' <> int n
791 DoubleReg n -> char 'D' <> int n
792 LongReg n -> char 'L' <> int n
793 Sp -> ptext (sLit "Sp")
794 SpLim -> ptext (sLit "SpLim")
795 Hp -> ptext (sLit "Hp")
796 HpLim -> ptext (sLit "HpLim")
797 CurrentTSO -> ptext (sLit "CurrentTSO")
798 CurrentNursery -> ptext (sLit "CurrentNursery")
799 HpAlloc -> ptext (sLit "HpAlloc")
800 BaseReg -> ptext (sLit "BaseReg")
801 EagerBlackholeInfo -> ptext (sLit "stg_EAGER_BLACKHOLE_info")
802 GCEnter1 -> ptext (sLit "stg_gc_enter_1")
803 GCFun -> ptext (sLit "stg_gc_fun")
805 pprLocalReg :: LocalReg -> SDoc
806 pprLocalReg (LocalReg uniq _) = char '_' <> ppr uniq
808 -- -----------------------------------------------------------------------------
811 pprCall :: SDoc -> CCallConv -> HintedCmmFormals -> HintedCmmActuals -> CmmSafety
814 pprCall ppr_fn cconv results args _
815 | not (is_cish cconv)
816 = panic "pprCall: unknown calling convention"
820 #if x86_64_TARGET_ARCH
821 -- HACK around gcc optimisations.
822 -- x86_64 needs a __DISCARD__() here, to create a barrier between
823 -- putting the arguments into temporaries and passing the arguments
824 -- to the callee, because the argument expressions may refer to
825 -- machine registers that are also used for passing arguments in the
826 -- C calling convention.
827 (if (not opt_Unregisterised)
828 then ptext (sLit "__DISCARD__();")
831 ppr_assign results (ppr_fn <> parens (commafy (map pprArg args))) <> semi
833 ppr_assign [] rhs = rhs
834 ppr_assign [CmmHinted one hint] rhs
835 = pprLocalReg one <> ptext (sLit " = ")
836 <> pprUnHint hint (localRegType one) <> rhs
837 ppr_assign _other _rhs = panic "pprCall: multiple results"
839 pprArg (CmmHinted expr AddrHint)
840 = cCast (ptext (sLit "void *")) expr
841 -- see comment by machRepHintCType below
842 pprArg (CmmHinted expr SignedHint)
843 = cCast (machRep_S_CType $ typeWidth $ cmmExprType expr) expr
844 pprArg (CmmHinted expr _other)
847 pprUnHint AddrHint rep = parens (machRepCType rep)
848 pprUnHint SignedHint rep = parens (machRepCType rep)
849 pprUnHint _ _ = empty
851 pprGlobalRegName :: GlobalReg -> SDoc
852 pprGlobalRegName gr = case gr of
853 VanillaReg n _ -> char 'R' <> int n -- without the .w suffix
856 -- Currently we only have these two calling conventions, but this might
857 -- change in the future...
858 is_cish CCallConv = True
859 is_cish StdCallConv = True
861 -- ---------------------------------------------------------------------
862 -- Find and print local and external declarations for a list of
865 pprTempAndExternDecls :: [CmmBasicBlock] -> (SDoc{-temps-}, SDoc{-externs-})
866 pprTempAndExternDecls stmts
867 = (vcat (map pprTempDecl (uniqSetToList temps)),
868 vcat (map (pprExternDecl False{-ToDo-}) (keysFM lbls)))
869 where (temps, lbls) = runTE (mapM_ te_BB stmts)
871 pprDataExterns :: [CmmStatic] -> SDoc
872 pprDataExterns statics
873 = vcat (map (pprExternDecl False{-ToDo-}) (keysFM lbls))
874 where (_, lbls) = runTE (mapM_ te_Static statics)
876 pprTempDecl :: LocalReg -> SDoc
877 pprTempDecl l@(LocalReg _ rep)
878 = hcat [ machRepCType rep, space, pprLocalReg l, semi ]
880 pprExternDecl :: Bool -> CLabel -> SDoc
881 pprExternDecl in_srt lbl
882 -- do not print anything for "known external" things
883 | not (needsCDecl lbl) = empty
884 | Just sz <- foreignLabelStdcallInfo lbl = stdcall_decl sz
886 hcat [ visibility, label_type lbl,
887 lparen, pprCLabel lbl, text ");" ]
889 label_type lbl | isCFunctionLabel lbl = ptext (sLit "F_")
890 | otherwise = ptext (sLit "I_")
893 | externallyVisibleCLabel lbl = char 'E'
894 | otherwise = char 'I'
896 -- If the label we want to refer to is a stdcall function (on Windows) then
897 -- we must generate an appropriate prototype for it, so that the C compiler will
898 -- add the @n suffix to the label (#2276)
900 ptext (sLit "extern __attribute__((stdcall)) void ") <> pprCLabel lbl
901 <> parens (commafy (replicate (sz `quot` wORD_SIZE) (machRep_U_CType wordWidth)))
904 type TEState = (UniqSet LocalReg, FiniteMap CLabel ())
905 newtype TE a = TE { unTE :: TEState -> (a, TEState) }
907 instance Monad TE where
908 TE m >>= k = TE $ \s -> case m s of (a, s') -> unTE (k a) s'
909 return a = TE $ \s -> (a, s)
911 te_lbl :: CLabel -> TE ()
912 te_lbl lbl = TE $ \(temps,lbls) -> ((), (temps, addToFM lbls lbl ()))
914 te_temp :: LocalReg -> TE ()
915 te_temp r = TE $ \(temps,lbls) -> ((), (addOneToUniqSet temps r, lbls))
917 runTE :: TE () -> TEState
918 runTE (TE m) = snd (m (emptyUniqSet, emptyFM))
920 te_Static :: CmmStatic -> TE ()
921 te_Static (CmmStaticLit lit) = te_Lit lit
922 te_Static _ = return ()
924 te_BB :: CmmBasicBlock -> TE ()
925 te_BB (BasicBlock _ ss) = mapM_ te_Stmt ss
927 te_Lit :: CmmLit -> TE ()
928 te_Lit (CmmLabel l) = te_lbl l
929 te_Lit (CmmLabelOff l _) = te_lbl l
930 te_Lit (CmmLabelDiffOff l1 l2 _) = te_lbl l1
933 te_Stmt :: CmmStmt -> TE ()
934 te_Stmt (CmmAssign r e) = te_Reg r >> te_Expr e
935 te_Stmt (CmmStore l r) = te_Expr l >> te_Expr r
936 te_Stmt (CmmCall _ rs es _ _) = mapM_ (te_temp.hintlessCmm) rs >>
937 mapM_ (te_Expr.hintlessCmm) es
938 te_Stmt (CmmCondBranch e _) = te_Expr e
939 te_Stmt (CmmSwitch e _) = te_Expr e
940 te_Stmt (CmmJump e _) = te_Expr e
941 te_Stmt _ = return ()
943 te_Expr :: CmmExpr -> TE ()
944 te_Expr (CmmLit lit) = te_Lit lit
945 te_Expr (CmmLoad e _) = te_Expr e
946 te_Expr (CmmReg r) = te_Reg r
947 te_Expr (CmmMachOp _ es) = mapM_ te_Expr es
948 te_Expr (CmmRegOff r _) = te_Reg r
950 te_Reg :: CmmReg -> TE ()
951 te_Reg (CmmLocal l) = te_temp l
955 -- ---------------------------------------------------------------------
956 -- C types for MachReps
958 cCast :: SDoc -> CmmExpr -> SDoc
959 cCast ty expr = parens ty <> pprExpr1 expr
961 cLoad :: CmmExpr -> CmmType -> SDoc
962 #ifdef BEWARE_LOAD_STORE_ALIGNMENT
964 let decl = machRepCType rep <+> ptext (sLit "x") <> semi
965 struct = ptext (sLit "struct") <+> braces (decl)
966 packed_attr = ptext (sLit "__attribute__((packed))")
967 cast = parens (struct <+> packed_attr <> char '*')
968 in parens (cast <+> pprExpr1 expr) <> ptext (sLit "->x")
970 cLoad expr rep = char '*' <> parens (cCast (machRepPtrCType rep) expr)
973 isCmmWordType :: CmmType -> Bool
974 -- True of GcPtrReg/NonGcReg of native word size
975 isCmmWordType ty = not (isFloatType ty)
976 && typeWidth ty == wordWidth
978 -- This is for finding the types of foreign call arguments. For a pointer
979 -- argument, we always cast the argument to (void *), to avoid warnings from
981 machRepHintCType :: CmmType -> ForeignHint -> SDoc
982 machRepHintCType rep AddrHint = ptext (sLit "void *")
983 machRepHintCType rep SignedHint = machRep_S_CType (typeWidth rep)
984 machRepHintCType rep _other = machRepCType rep
986 machRepPtrCType :: CmmType -> SDoc
987 machRepPtrCType r | isCmmWordType r = ptext (sLit "P_")
988 | otherwise = machRepCType r <> char '*'
990 machRepCType :: CmmType -> SDoc
991 machRepCType ty | isFloatType ty = machRep_F_CType w
992 | otherwise = machRep_U_CType w
996 machRep_F_CType :: Width -> SDoc
997 machRep_F_CType W32 = ptext (sLit "StgFloat") -- ToDo: correct?
998 machRep_F_CType W64 = ptext (sLit "StgDouble")
999 machRep_F_CType _ = panic "machRep_F_CType"
1001 machRep_U_CType :: Width -> SDoc
1002 machRep_U_CType w | w == wordWidth = ptext (sLit "W_")
1003 machRep_U_CType W8 = ptext (sLit "StgWord8")
1004 machRep_U_CType W16 = ptext (sLit "StgWord16")
1005 machRep_U_CType W32 = ptext (sLit "StgWord32")
1006 machRep_U_CType W64 = ptext (sLit "StgWord64")
1007 machRep_U_CType _ = panic "machRep_U_CType"
1009 machRep_S_CType :: Width -> SDoc
1010 machRep_S_CType w | w == wordWidth = ptext (sLit "I_")
1011 machRep_S_CType W8 = ptext (sLit "StgInt8")
1012 machRep_S_CType W16 = ptext (sLit "StgInt16")
1013 machRep_S_CType W32 = ptext (sLit "StgInt32")
1014 machRep_S_CType W64 = ptext (sLit "StgInt64")
1015 machRep_S_CType _ = panic "machRep_S_CType"
1018 -- ---------------------------------------------------------------------
1019 -- print strings as valid C strings
1021 pprStringInCStyle :: [Word8] -> SDoc
1022 pprStringInCStyle s = doubleQuotes (text (concatMap charToC s))
1024 charToC :: Word8 -> String
1026 case chr (fromIntegral w) of
1030 c | c >= ' ' && c <= '~' -> [c]
1031 | otherwise -> ['\\',
1032 chr (ord '0' + ord c `div` 64),
1033 chr (ord '0' + ord c `div` 8 `mod` 8),
1034 chr (ord '0' + ord c `mod` 8)]
1036 -- ---------------------------------------------------------------------------
1037 -- Initialising static objects with floating-point numbers. We can't
1038 -- just emit the floating point number, because C will cast it to an int
1039 -- by rounding it. We want the actual bit-representation of the float.
1041 -- This is a hack to turn the floating point numbers into ints that we
1042 -- can safely initialise to static locations.
1045 | widthInBytes W64 == 2 * wORD_SIZE = True
1046 | widthInBytes W64 == wORD_SIZE = False
1047 | otherwise = panic "big_doubles"
1049 castFloatToIntArray :: STUArray s Int Float -> ST s (STUArray s Int Int)
1050 castFloatToIntArray = castSTUArray
1052 castDoubleToIntArray :: STUArray s Int Double -> ST s (STUArray s Int Int)
1053 castDoubleToIntArray = castSTUArray
1055 -- floats are always 1 word
1056 floatToWord :: Rational -> CmmLit
1059 arr <- newArray_ ((0::Int),0)
1060 writeArray arr 0 (fromRational r)
1061 arr' <- castFloatToIntArray arr
1062 i <- readArray arr' 0
1063 return (CmmInt (toInteger i) wordWidth)
1066 doubleToWords :: Rational -> [CmmLit]
1068 | big_doubles -- doubles are 2 words
1070 arr <- newArray_ ((0::Int),1)
1071 writeArray arr 0 (fromRational r)
1072 arr' <- castDoubleToIntArray arr
1073 i1 <- readArray arr' 0
1074 i2 <- readArray arr' 1
1075 return [ CmmInt (toInteger i1) wordWidth
1076 , CmmInt (toInteger i2) wordWidth
1079 | otherwise -- doubles are 1 word
1081 arr <- newArray_ ((0::Int),0)
1082 writeArray arr 0 (fromRational r)
1083 arr' <- castDoubleToIntArray arr
1084 i <- readArray arr' 0
1085 return [ CmmInt (toInteger i) wordWidth ]
1088 -- ---------------------------------------------------------------------------
1092 wordShift = widthInLog wordWidth
1094 commafy :: [SDoc] -> SDoc
1095 commafy xs = hsep $ punctuate comma xs
1097 -- Print in C hex format: 0x13fa
1098 pprHexVal :: Integer -> Width -> SDoc
1099 pprHexVal 0 _ = ptext (sLit "0x0")
1101 | w < 0 = parens (char '-' <> ptext (sLit "0x") <> go (-w) <> repsuffix rep)
1102 | otherwise = ptext (sLit "0x") <> go w <> repsuffix rep
1104 -- type suffix for literals:
1105 -- Integer literals are unsigned in Cmm/C. We explicitly cast to
1106 -- signed values for doing signed operations, but at all other
1107 -- times values are unsigned. This also helps eliminate occasional
1108 -- warnings about integer overflow from gcc.
1110 -- on 32-bit platforms, add "ULL" to 64-bit literals
1111 repsuffix W64 | wORD_SIZE == 4 = ptext (sLit "ULL")
1112 -- on 64-bit platforms with 32-bit int, add "L" to 64-bit literals
1113 repsuffix W64 | cINT_SIZE == 4 = ptext (sLit "UL")
1114 repsuffix _ = char 'U'
1119 (q,r) = w' `quotRem` 16
1120 dig | r < 10 = char (chr (fromInteger r + ord '0'))
1121 | otherwise = char (chr (fromInteger r - 10 + ord 'a'))