----------------------------------------------------------------------------- -- -- Pretty-printing of Cmm as C, suitable for feeding gcc -- -- (c) The University of Glasgow 2004-2006 -- -- Print Cmm as real C, for -fvia-C -- -- See wiki:Commentary/Compiler/Backends/PprC -- -- 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. -- -- This code generator is only supported in unregisterised mode. -- ----------------------------------------------------------------------------- module PprC ( writeCs, pprStringInCStyle ) where #include "HsVersions.h" -- Cmm stuff import BlockId import CLabel import ForeignCall import OldCmm import OldPprCmm () -- Utils import Constants import CPrim import DynFlags import FastString import Outputable import Platform import UniqSet import Unique import Util -- The rest import Control.Monad.ST import Data.Bits import Data.Char import Data.List import Data.Map (Map) import Data.Word import System.IO import qualified Data.Map as Map #if __GLASGOW_HASKELL__ >= 703 import Data.Array.Unsafe ( castSTUArray ) import Data.Array.ST hiding ( castSTUArray ) #else import Data.Array.ST #endif -- -------------------------------------------------------------------------- -- Top level pprCs :: DynFlags -> [RawCmmGroup] -> SDoc pprCs dflags cmms = pprCode CStyle (vcat $ map (\c -> split_marker $$ pprC (targetPlatform dflags) c) cmms) where split_marker | dopt Opt_SplitObjs dflags = ptext (sLit "__STG_SPLIT_MARKER") | otherwise = empty writeCs :: DynFlags -> Handle -> [RawCmmGroup] -> IO () writeCs dflags handle cmms = printForC handle (pprCs dflags cmms) -- -------------------------------------------------------------------------- -- Now do some real work -- -- for fun, we could call cmmToCmm over the tops... -- pprC :: Platform -> RawCmmGroup -> SDoc pprC platform tops = vcat $ intersperse blankLine $ map (pprTop platform) tops -- -- top level procs -- pprTop :: Platform -> RawCmmDecl -> SDoc pprTop platform (CmmProc mb_info clbl (ListGraph blocks)) = (case mb_info of Nothing -> empty Just (Statics info_clbl info_dat) -> pprDataExterns platform info_dat $$ pprWordArray platform info_clbl info_dat) $$ (vcat [ blankLine, extern_decls, (if (externallyVisibleCLabel clbl) then mkFN_ else mkIF_) (pprCLabel platform clbl) <+> lbrace, nest 8 temp_decls, nest 8 mkFB_, case blocks of [] -> empty -- the first block doesn't get a label: (BasicBlock _ stmts : rest) -> nest 8 (vcat (map (pprStmt platform) stmts)) $$ vcat (map (pprBBlock platform) rest), nest 8 mkFE_, rbrace ] ) where (temp_decls, extern_decls) = pprTempAndExternDecls platform blocks -- Chunks of static data. -- We only handle (a) arrays of word-sized things and (b) strings. pprTop platform (CmmData _section (Statics lbl [CmmString str])) = hcat [ pprLocalness lbl, ptext (sLit "char "), pprCLabel platform lbl, ptext (sLit "[] = "), pprStringInCStyle str, semi ] pprTop platform (CmmData _section (Statics lbl [CmmUninitialised size])) = hcat [ pprLocalness lbl, ptext (sLit "char "), pprCLabel platform lbl, brackets (int size), semi ] pprTop platform (CmmData _section (Statics lbl lits)) = pprDataExterns platform lits $$ pprWordArray platform lbl lits -- -------------------------------------------------------------------------- -- BasicBlocks are self-contained entities: they always end in a jump. -- -- Like nativeGen/AsmCodeGen, we could probably reorder blocks to turn -- as many jumps as possible into fall throughs. -- pprBBlock :: Platform -> CmmBasicBlock -> SDoc pprBBlock platform (BasicBlock lbl stmts) = if null stmts then pprTrace "pprC.pprBBlock: curious empty code block for" (pprBlockId lbl) empty else nest 4 (pprBlockId lbl <> colon) $$ nest 8 (vcat (map (pprStmt platform) stmts)) -- -------------------------------------------------------------------------- -- Info tables. Just arrays of words. -- See codeGen/ClosureInfo, and nativeGen/PprMach pprWordArray :: Platform -> CLabel -> [CmmStatic] -> SDoc pprWordArray platform lbl ds = hcat [ pprLocalness lbl, ptext (sLit "StgWord") , space, pprCLabel platform lbl, ptext (sLit "[] = {") ] $$ nest 8 (commafy (pprStatics platform ds)) $$ ptext (sLit "};") -- -- has to be static, if it isn't globally visible -- pprLocalness :: CLabel -> SDoc pprLocalness lbl | not $ externallyVisibleCLabel lbl = ptext (sLit "static ") | otherwise = empty -- -------------------------------------------------------------------------- -- Statements. -- pprStmt :: Platform -> CmmStmt -> SDoc pprStmt platform stmt = case stmt of CmmReturn -> panic "pprStmt: return statement should have been cps'd away" CmmNop -> empty CmmComment _ -> empty -- (hang (ptext (sLit "/*")) 3 (ftext s)) $$ ptext (sLit "*/") -- XXX if the string contains "*/", we need to fix it -- XXX we probably want to emit these comments when -- some debugging option is on. They can get quite -- large. CmmAssign dest src -> pprAssign platform dest src CmmStore dest src | typeWidth rep == W64 && wordWidth /= W64 -> (if isFloatType rep then ptext (sLit "ASSIGN_DBL") else ptext (sLit ("ASSIGN_Word64"))) <> parens (mkP_ <> pprExpr1 platform dest <> comma <> pprExpr platform src) <> semi | otherwise -> hsep [ pprExpr platform (CmmLoad dest rep), equals, pprExpr platform src <> semi ] where rep = cmmExprType src CmmCall (CmmCallee fn cconv) results args ret -> maybe_proto $$ fnCall where cast_fn = parens (cCast platform (pprCFunType (char '*') cconv results args) fn) real_fun_proto lbl = char ';' <> pprCFunType (pprCLabel platform lbl) cconv results args <> noreturn_attr <> semi fun_proto lbl = ptext (sLit ";EF_(") <> pprCLabel platform lbl <> char ')' <> semi noreturn_attr = case ret of CmmNeverReturns -> text "__attribute__ ((noreturn))" CmmMayReturn -> empty -- See wiki:Commentary/Compiler/Backends/PprC#Prototypes (maybe_proto, fnCall) = case fn of CmmLit (CmmLabel lbl) | StdCallConv <- cconv -> let myCall = pprCall platform (pprCLabel platform lbl) cconv results args in (real_fun_proto lbl, myCall) -- 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. | CmmNeverReturns <- ret -> let myCall = pprCall platform (pprCLabel platform lbl) cconv results args 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 platform (text "ghcFunPtr") cconv results args <> semi ) in (fun_proto lbl, myCall) _ -> (empty {- no proto -}, pprCall platform cast_fn cconv results args <> semi) -- for a dynamic call, no declaration is necessary. CmmCall (CmmPrim op) results args _ret -> pprCall platform ppr_fn CCallConv results args' where ppr_fn = pprCallishMachOp_for_C op -- The mem primops carry an extra alignment arg, must drop it. -- We could maybe emit an alignment directive using this info. args' | op == MO_Memcpy || op == MO_Memset || op == MO_Memmove = init args | otherwise = args CmmBranch ident -> pprBranch ident CmmCondBranch expr ident -> pprCondBranch platform expr ident CmmJump lbl _ -> mkJMP_(pprExpr platform lbl) <> semi CmmSwitch arg ids -> pprSwitch platform arg ids pprCFunType :: SDoc -> CCallConv -> [HintedCmmFormal] -> [HintedCmmActual] -> SDoc pprCFunType ppr_fn cconv ress args = res_type ress <+> parens (ccallConvAttribute cconv <> ppr_fn) <> parens (commafy (map arg_type args)) where res_type [] = ptext (sLit "void") res_type [CmmHinted one hint] = machRepHintCType (localRegType one) hint res_type _ = panic "pprCFunType: only void or 1 return value supported" arg_type (CmmHinted expr hint) = machRepHintCType (cmmExprType expr) hint -- --------------------------------------------------------------------- -- unconditional branches pprBranch :: BlockId -> SDoc pprBranch ident = ptext (sLit "goto") <+> pprBlockId ident <> semi -- --------------------------------------------------------------------- -- conditional branches to local labels pprCondBranch :: Platform -> CmmExpr -> BlockId -> SDoc pprCondBranch platform expr ident = hsep [ ptext (sLit "if") , parens(pprExpr platform expr) , ptext (sLit "goto") , (pprBlockId ident) <> semi ] -- --------------------------------------------------------------------- -- 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 :: Platform -> CmmExpr -> [ Maybe BlockId ] -> SDoc pprSwitch platform e maybe_ids = let pairs = [ (ix, ident) | (ix,Just ident) <- zip [0..] maybe_ids ] pairs2 = [ (map fst as, snd (head as)) | as <- groupBy sndEq pairs ] in (hang (ptext (sLit "switch") <+> parens ( pprExpr platform e ) <+> lbrace) 4 (vcat ( map caseify pairs2 ))) $$ rbrace where sndEq (_,x) (_,y) = x == y -- fall through case caseify (ix:ixs, ident) = vcat (map do_fallthrough ixs) $$ final_branch ix where do_fallthrough ix = hsep [ ptext (sLit "case") , pprHexVal ix wordWidth <> colon , ptext (sLit "/* fall through */") ] final_branch ix = hsep [ ptext (sLit "case") , pprHexVal ix wordWidth <> colon , ptext (sLit "goto") , (pprBlockId ident) <> semi ] caseify (_ , _ ) = panic "pprSwtich: swtich with no cases!" -- --------------------------------------------------------------------- -- Expressions. -- -- C Types: the invariant is that the C expression generated by -- -- pprExpr e -- -- has a type in C which is also given by -- -- machRepCType (cmmExprType e) -- -- (similar invariants apply to the rest of the pretty printer). pprExpr :: Platform -> CmmExpr -> SDoc pprExpr platform e = case e of CmmLit lit -> pprLit platform lit CmmLoad e ty -> pprLoad platform e ty 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 platform mop args CmmStackSlot _ _ -> panic "pprExpr: CmmStackSlot not supported!" pprLoad :: Platform -> CmmExpr -> CmmType -> SDoc pprLoad platform e ty | width == W64, wordWidth /= W64 = (if isFloatType ty then ptext (sLit "PK_DBL") else ptext (sLit "PK_Word64")) <> parens (mkP_ <> pprExpr1 platform 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 platform e ty where width = typeWidth ty pprExpr1 :: Platform -> CmmExpr -> SDoc pprExpr1 platform (CmmLit lit) = pprLit1 platform lit pprExpr1 platform e@(CmmReg _reg) = pprExpr platform e pprExpr1 platform other = parens (pprExpr platform other) -- -------------------------------------------------------------------------- -- MachOp applications pprMachOpApp :: Platform -> MachOp -> [CmmExpr] -> SDoc pprMachOpApp platform op args | isMulMayOfloOp op = ptext (sLit "mulIntMayOflo") <> parens (commafy (map (pprExpr platform) args)) where isMulMayOfloOp (MO_U_MulMayOflo _) = True isMulMayOfloOp (MO_S_MulMayOflo _) = True isMulMayOfloOp _ = False pprMachOpApp platform mop args | Just ty <- machOpNeedsCast mop = ty <> parens (pprMachOpApp' platform mop args) | otherwise = pprMachOpApp' platform 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' :: Platform -> MachOp -> [CmmExpr] -> SDoc pprMachOpApp' platform mop args = 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 -- Cast needed for signed integer ops pprArg e | signedOp mop = cCast platform (machRep_S_CType (typeWidth (cmmExprType e))) e | needsFCasts mop = cCast platform (machRep_F_CType (typeWidth (cmmExprType e))) e | otherwise = pprExpr1 platform e needsFCasts (MO_F_Eq _) = False needsFCasts (MO_F_Ne _) = False needsFCasts (MO_F_Neg _) = True needsFCasts (MO_F_Quot _) = True needsFCasts mop = floatComparison mop -- -------------------------------------------------------------------------- -- Literals pprLit :: Platform -> CmmLit -> SDoc pprLit platform lit = case lit of CmmInt i rep -> pprHexVal i rep CmmFloat f w -> parens (machRep_F_CType w) <> str 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 -- see #1861 CmmBlock bid -> mkW_ <> pprCLabelAddr (infoTblLbl bid) CmmHighStackMark -> panic "PprC printing high stack mark" CmmLabel clbl -> mkW_ <> pprCLabelAddr clbl CmmLabelOff clbl i -> mkW_ <> pprCLabelAddr clbl <> char '+' <> int i CmmLabelDiffOff clbl1 _ i -- WARNING: -- * the lit must occur in the info table clbl2 -- * clbl1 must be an SRT, a slow entry point or a large bitmap -> mkW_ <> pprCLabelAddr clbl1 <> char '+' <> int i where pprCLabelAddr lbl = char '&' <> pprCLabel platform lbl pprLit1 :: Platform -> CmmLit -> SDoc pprLit1 platform lit@(CmmLabelOff _ _) = parens (pprLit platform lit) pprLit1 platform lit@(CmmLabelDiffOff _ _ _) = parens (pprLit platform lit) pprLit1 platform lit@(CmmFloat _ _) = parens (pprLit platform lit) pprLit1 platform other = pprLit platform other -- --------------------------------------------------------------------------- -- Static data pprStatics :: Platform -> [CmmStatic] -> [SDoc] pprStatics _ [] = [] pprStatics platform (CmmStaticLit (CmmFloat f W32) : rest) -- floats are padded to a word, see #1852 | wORD_SIZE == 8, CmmStaticLit (CmmInt 0 W32) : rest' <- rest = pprLit1 platform (floatToWord f) : pprStatics platform rest' | wORD_SIZE == 4 = pprLit1 platform (floatToWord f) : pprStatics platform rest | otherwise = pprPanic "pprStatics: float" (vcat (map ppr' rest)) where ppr' (CmmStaticLit l) = ppr (cmmLitType l) ppr' _other = ptext (sLit "bad static!") pprStatics platform (CmmStaticLit (CmmFloat f W64) : rest) = map (pprLit1 platform) (doubleToWords f) ++ pprStatics platform rest pprStatics platform (CmmStaticLit (CmmInt i W64) : rest) | wordWidth == W32 #ifdef WORDS_BIGENDIAN = pprStatics platform (CmmStaticLit (CmmInt q W32) : CmmStaticLit (CmmInt r W32) : rest) #else = pprStatics platform (CmmStaticLit (CmmInt r W32) : CmmStaticLit (CmmInt q W32) : rest) #endif where r = i .&. 0xffffffff q = i `shiftR` 32 pprStatics _ (CmmStaticLit (CmmInt _ w) : _) | w /= wordWidth = panic "pprStatics: cannot emit a non-word-sized static literal" pprStatics platform (CmmStaticLit lit : rest) = pprLit1 platform lit : pprStatics platform rest pprStatics platform (other : _) = pprPanic "pprWord" (pprStatic platform other) pprStatic :: Platform -> CmmStatic -> SDoc pprStatic platform s = case s of CmmStaticLit lit -> nest 4 (pprLit platform lit) 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 '-' MO_Eq _ -> ptext (sLit "==") MO_Ne _ -> ptext (sLit "!=") MO_Mul _ -> char '*' MO_S_Quot _ -> char '/' MO_S_Rem _ -> char '%' MO_S_Neg _ -> char '-' MO_U_Quot _ -> char '/' MO_U_Rem _ -> char '%' -- & 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 MO_S_Ge _ -> ptext (sLit ">=") MO_S_Le _ -> ptext (sLit "<=") MO_S_Gt _ -> char '>' MO_S_Lt _ -> char '<' -- & Unsigned comparisons MO_U_Ge _ -> ptext (sLit ">=") MO_U_Le _ -> ptext (sLit "<=") MO_U_Gt _ -> char '>' MO_U_Lt _ -> char '<' -- & 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 '<' -- 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 '~' MO_Shl _ -> ptext (sLit "<<") MO_U_Shr _ -> ptext (sLit ">>") -- unsigned shift right MO_S_Shr _ -> ptext (sLit ">>") -- signed shift right -- Conversions. Some of these will be NOPs, but never those that convert -- between ints and floats. -- Floating-point conversions use the signed variant. -- We won't know to generate (void*) casts here, but maybe from -- context elsewhere -- noop casts 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) 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) MO_S_MulMayOflo _ -> pprTrace "offending mop:" (ptext $ sLit "MO_S_MulMayOflo") (panic $ "PprC.pprMachOp_for_C: MO_S_MulMayOflo" ++ " should have been handled earlier!") MO_U_MulMayOflo _ -> pprTrace "offending mop:" (ptext $ sLit "MO_U_MulMayOflo") (panic $ "PprC.pprMachOp_for_C: MO_U_MulMayOflo" ++ " should have been handled earlier!") signedOp :: MachOp -> Bool -- Argument type(s) are signed ints 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 signedOp (MO_SS_Conv _ _) = True signedOp (MO_SF_Conv _ _) = True signedOp _ = False 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 -- --------------------------------------------------------------------- -- tend to be implemented by foreign calls pprCallishMachOp_for_C :: CallishMachOp -> SDoc pprCallishMachOp_for_C mop = case mop of 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") MO_Memcpy -> ptext (sLit "memcpy") MO_Memset -> ptext (sLit "memset") MO_Memmove -> ptext (sLit "memmove") (MO_PopCnt w) -> ptext (sLit $ popCntLabel w) MO_Touch -> panic $ "pprCallishMachOp_for_C: MO_Touch not supported!" -- --------------------------------------------------------------------- -- Useful #defines -- mkJMP_, mkFN_, mkIF_ :: SDoc -> SDoc 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 mkFB_, mkFE_ :: SDoc mkFB_ = ptext (sLit "FB_") -- function code begin mkFE_ = ptext (sLit "FE_") -- function code end -- from includes/Stg.h -- mkC_,mkW_,mkP_ :: SDoc mkC_ = ptext (sLit "(C_)") -- StgChar mkW_ = ptext (sLit "(W_)") -- StgWord mkP_ = ptext (sLit "(P_)") -- StgWord* -- --------------------------------------------------------------------- -- -- Assignments -- -- Generating assignments is what we're all about, here -- pprAssign :: Platform -> CmmReg -> CmmExpr -> SDoc -- dest is a reg, rhs is a reg pprAssign _ r1 (CmmReg r2) | isPtrReg r1 && isPtrReg r2 = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, semi ] -- dest is a reg, rhs is a CmmRegOff pprAssign _ r1 (CmmRegOff r2 off) | isPtrReg r1 && isPtrReg r2 && (off `rem` wORD_SIZE == 0) = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, op, int off', semi ] where off1 = off `shiftR` wordShift (op,off') | off >= 0 = (char '+', off1) | otherwise = (char '-', -off1) -- 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+). pprAssign platform r1 r2 | isFixedPtrReg r1 = mkAssign (mkP_ <> pprExpr1 platform r2) | Just ty <- strangeRegType r1 = mkAssign (parens ty <> pprExpr1 platform r2) | otherwise = mkAssign (pprExpr platform r2) where mkAssign x = if r1 == CmmGlobal BaseReg then ptext (sLit "ASSIGN_BaseReg") <> parens x <> semi else pprReg r1 <> ptext (sLit " = ") <> x <> semi -- --------------------------------------------------------------------- -- Registers pprCastReg :: CmmReg -> SDoc pprCastReg reg | isStrangeTypeReg reg = mkW_ <> pprReg reg | otherwise = pprReg reg -- 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 -- True if (pprAsPtrReg reg) will give an expression with type StgPtr -- 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. isPtrReg :: CmmReg -> Bool isPtrReg (CmmLocal _) = False isPtrReg (CmmGlobal (VanillaReg _ VGcPtr)) = True -- if we print via pprAsPtrReg isPtrReg (CmmGlobal (VanillaReg _ VNonGcPtr)) = False -- if we print via pprAsPtrReg 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 -- True if in C this register doesn't have the type given by -- (machRepCType (cmmRegType reg)), so it has to be cast. isStrangeTypeReg :: CmmReg -> Bool isStrangeTypeReg (CmmLocal _) = False isStrangeTypeReg (CmmGlobal g) = isStrangeTypeGlobal g isStrangeTypeGlobal :: GlobalReg -> Bool isStrangeTypeGlobal CCCS = True isStrangeTypeGlobal CurrentTSO = True isStrangeTypeGlobal CurrentNursery = True isStrangeTypeGlobal BaseReg = True isStrangeTypeGlobal r = isFixedPtrGlobalReg r strangeRegType :: CmmReg -> Maybe SDoc strangeRegType (CmmGlobal CCCS) = Just (ptext (sLit "struct CostCentreStack_ *")) strangeRegType (CmmGlobal CurrentTSO) = Just (ptext (sLit "struct StgTSO_ *")) strangeRegType (CmmGlobal CurrentNursery) = Just (ptext (sLit "struct bdescr_ *")) strangeRegType (CmmGlobal BaseReg) = Just (ptext (sLit "struct StgRegTable_ *")) strangeRegType _ = Nothing -- 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 pprAsPtrReg (CmmGlobal (VanillaReg n gcp)) = WARN( gcp /= VGcPtr, ppr n ) char 'R' <> int n <> ptext (sLit ".p") pprAsPtrReg other_reg = pprReg other_reg pprGlobalReg :: GlobalReg -> SDoc pprGlobalReg gr = case gr of 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); FloatReg n -> char 'F' <> int n DoubleReg n -> char 'D' <> int n LongReg n -> char 'L' <> int n Sp -> ptext (sLit "Sp") SpLim -> ptext (sLit "SpLim") Hp -> ptext (sLit "Hp") HpLim -> ptext (sLit "HpLim") CCCS -> ptext (sLit "CCCS") CurrentTSO -> ptext (sLit "CurrentTSO") CurrentNursery -> ptext (sLit "CurrentNursery") HpAlloc -> ptext (sLit "HpAlloc") BaseReg -> ptext (sLit "BaseReg") EagerBlackholeInfo -> ptext (sLit "stg_EAGER_BLACKHOLE_info") GCEnter1 -> ptext (sLit "stg_gc_enter_1") GCFun -> ptext (sLit "stg_gc_fun") other -> panic $ "pprGlobalReg: Unsupported register: " ++ show other pprLocalReg :: LocalReg -> SDoc pprLocalReg (LocalReg uniq _) = char '_' <> ppr uniq -- ----------------------------------------------------------------------------- -- Foreign Calls pprCall :: Platform -> SDoc -> CCallConv -> [HintedCmmFormal] -> [HintedCmmActual] -> SDoc pprCall platform ppr_fn cconv results args | not (is_cishCC cconv) = panic $ "pprCall: unknown calling convention" | otherwise = ppr_assign results (ppr_fn <> parens (commafy (map pprArg args))) <> semi where ppr_assign [] rhs = rhs ppr_assign [CmmHinted one hint] rhs = pprLocalReg one <> ptext (sLit " = ") <> pprUnHint hint (localRegType one) <> rhs ppr_assign _other _rhs = panic "pprCall: multiple results" pprArg (CmmHinted expr AddrHint) = cCast platform (ptext (sLit "void *")) expr -- see comment by machRepHintCType below pprArg (CmmHinted expr SignedHint) = cCast platform (machRep_S_CType $ typeWidth $ cmmExprType expr) expr pprArg (CmmHinted expr _other) = pprExpr platform expr pprUnHint AddrHint rep = parens (machRepCType rep) pprUnHint SignedHint rep = parens (machRepCType rep) pprUnHint _ _ = empty -- Currently we only have these two calling conventions, but this might -- change in the future... is_cishCC :: CCallConv -> Bool is_cishCC CCallConv = True is_cishCC CApiConv = True is_cishCC StdCallConv = True is_cishCC CmmCallConv = False is_cishCC PrimCallConv = False -- --------------------------------------------------------------------- -- Find and print local and external declarations for a list of -- Cmm statements. -- pprTempAndExternDecls :: Platform -> [CmmBasicBlock] -> (SDoc{-temps-}, SDoc{-externs-}) pprTempAndExternDecls platform stmts = (vcat (map pprTempDecl (uniqSetToList temps)), vcat (map (pprExternDecl platform False{-ToDo-}) (Map.keys lbls))) where (temps, lbls) = runTE (mapM_ te_BB stmts) pprDataExterns :: Platform -> [CmmStatic] -> SDoc pprDataExterns platform statics = vcat (map (pprExternDecl platform False{-ToDo-}) (Map.keys lbls)) where (_, lbls) = runTE (mapM_ te_Static statics) pprTempDecl :: LocalReg -> SDoc pprTempDecl l@(LocalReg _ rep) = hcat [ machRepCType rep, space, pprLocalReg l, semi ] pprExternDecl :: Platform -> Bool -> CLabel -> SDoc pprExternDecl platform _in_srt lbl -- do not print anything for "known external" things | not (needsCDecl lbl) = empty | Just sz <- foreignLabelStdcallInfo lbl = stdcall_decl sz | otherwise = hcat [ visibility, label_type lbl, lparen, pprCLabel platform lbl, text ");" ] where label_type lbl | isCFunctionLabel lbl = ptext (sLit "F_") | otherwise = ptext (sLit "I_") visibility | externallyVisibleCLabel lbl = char 'E' | otherwise = char 'I' -- 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 platform lbl <> parens (commafy (replicate (sz `quot` wORD_SIZE) (machRep_U_CType wordWidth))) <> semi type TEState = (UniqSet LocalReg, Map CLabel ()) 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 () te_lbl lbl = TE $ \(temps,lbls) -> ((), (temps, Map.insert lbl () lbls)) te_temp :: LocalReg -> TE () te_temp r = TE $ \(temps,lbls) -> ((), (addOneToUniqSet temps r, lbls)) runTE :: TE () -> TEState runTE (TE m) = snd (m (emptyUniqSet, Map.empty)) 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 te_Lit (CmmLabelOff l _) = te_lbl l te_Lit (CmmLabelDiffOff l1 _ _) = te_lbl l1 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 te_Stmt (CmmCall _ rs es _) = mapM_ (te_temp.hintlessCmm) rs >> mapM_ (te_Expr.hintlessCmm) es 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 te_Expr (CmmReg r) = te_Reg r te_Expr (CmmMachOp _ es) = mapM_ te_Expr es te_Expr (CmmRegOff r _) = te_Reg r te_Expr (CmmStackSlot _ _) = panic "te_Expr: CmmStackSlot not supported!" te_Reg :: CmmReg -> TE () te_Reg (CmmLocal l) = te_temp l te_Reg _ = return () -- --------------------------------------------------------------------- -- C types for MachReps cCast :: Platform -> SDoc -> CmmExpr -> SDoc cCast platform ty expr = parens ty <> pprExpr1 platform expr cLoad :: Platform -> CmmExpr -> CmmType -> SDoc cLoad platform expr rep | bewareLoadStoreAlignment (platformArch platform) = let decl = machRepCType rep <+> ptext (sLit "x") <> semi struct = ptext (sLit "struct") <+> braces (decl) packed_attr = ptext (sLit "__attribute__((packed))") cast = parens (struct <+> packed_attr <> char '*') in parens (cast <+> pprExpr1 platform expr) <> ptext (sLit "->x") | otherwise = char '*' <> parens (cCast platform (machRepPtrCType rep) expr) where -- On these platforms, unaligned loads are known to cause problems bewareLoadStoreAlignment (ArchARM {}) = True bewareLoadStoreAlignment _ = False isCmmWordType :: CmmType -> Bool -- True of GcPtrReg/NonGcReg of native word size isCmmWordType ty = not (isFloatType ty) && typeWidth ty == wordWidth -- 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. machRepHintCType :: CmmType -> ForeignHint -> SDoc machRepHintCType _ AddrHint = ptext (sLit "void *") machRepHintCType rep SignedHint = machRep_S_CType (typeWidth rep) machRepHintCType rep _other = machRepCType rep 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" -- --------------------------------------------------------------------- -- print strings as valid C strings pprStringInCStyle :: [Word8] -> SDoc pprStringInCStyle s = doubleQuotes (text (concatMap charToC s)) -- --------------------------------------------------------------------------- -- 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 :: Bool big_doubles | widthInBytes W64 == 2 * wORD_SIZE = True | widthInBytes W64 == wORD_SIZE = False | 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 arr <- newArray_ ((0::Int),0) writeArray arr 0 (fromRational r) arr' <- castFloatToIntArray arr i <- readArray arr' 0 return (CmmInt (toInteger i) wordWidth) ) doubleToWords :: Rational -> [CmmLit] doubleToWords r | big_doubles -- doubles are 2 words = runST (do arr <- newArray_ ((0::Int),1) writeArray arr 0 (fromRational r) arr' <- castDoubleToIntArray arr i1 <- readArray arr' 0 i2 <- readArray arr' 1 return [ CmmInt (toInteger i1) wordWidth , CmmInt (toInteger i2) wordWidth ] ) | otherwise -- doubles are 1 word = runST (do arr <- newArray_ ((0::Int),0) writeArray arr 0 (fromRational r) arr' <- castDoubleToIntArray arr i <- readArray arr' 0 return [ CmmInt (toInteger i) wordWidth ] ) -- --------------------------------------------------------------------------- -- Utils wordShift :: Int wordShift = widthInLog wordWidth commafy :: [SDoc] -> SDoc commafy xs = hsep $ punctuate comma xs -- Print in C hex format: 0x13fa pprHexVal :: Integer -> Width -> SDoc pprHexVal 0 _ = ptext (sLit "0x0") pprHexVal w rep | w < 0 = parens (char '-' <> ptext (sLit "0x") <> go (-w) <> repsuffix rep) | otherwise = ptext (sLit "0x") <> go w <> repsuffix rep where -- type suffix for literals: -- 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 repsuffix W64 | wORD_SIZE == 4 = ptext (sLit "ULL") -- on 64-bit platforms with 32-bit int, add "L" to 64-bit literals repsuffix W64 | cINT_SIZE == 4 = ptext (sLit "UL") repsuffix _ = char 'U' 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'))