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Diffstat (limited to 'compiler/GHC/CmmToC.hs')
| -rw-r--r-- | compiler/GHC/CmmToC.hs | 1380 |
1 files changed, 1380 insertions, 0 deletions
diff --git a/compiler/GHC/CmmToC.hs b/compiler/GHC/CmmToC.hs new file mode 100644 index 0000000000..a413820e30 --- /dev/null +++ b/compiler/GHC/CmmToC.hs @@ -0,0 +1,1380 @@ +{-# LANGUAGE CPP, DeriveFunctor, GADTs, PatternSynonyms #-} + +----------------------------------------------------------------------------- +-- +-- 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/ppr-c +-- +-- 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 GHC.CmmToC ( + writeC + ) where + +#include "HsVersions.h" + +-- Cmm stuff +import GhcPrelude + +import GHC.Cmm.BlockId +import GHC.Cmm.CLabel +import ForeignCall +import GHC.Cmm hiding (pprBBlock) +import GHC.Cmm.Ppr () -- For Outputable instances +import GHC.Cmm.Dataflow.Block +import GHC.Cmm.Dataflow.Collections +import GHC.Cmm.Dataflow.Graph +import GHC.Cmm.Utils +import GHC.Cmm.Switch + +-- Utils +import CPrim +import DynFlags +import FastString +import Outputable +import GHC.Platform +import UniqSet +import UniqFM +import Unique +import Util + +-- The rest +import Data.ByteString (ByteString) +import qualified Data.ByteString as BS +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 +import Control.Monad (ap) +import qualified Data.Array.Unsafe as U ( castSTUArray ) +import Data.Array.ST + +-- -------------------------------------------------------------------------- +-- Top level + +writeC :: DynFlags -> Handle -> RawCmmGroup -> IO () +writeC dflags handle cmm = printForC dflags handle (pprC cmm $$ blankLine) + +-- -------------------------------------------------------------------------- +-- Now do some real work +-- +-- for fun, we could call cmmToCmm over the tops... +-- + +pprC :: RawCmmGroup -> SDoc +pprC tops = vcat $ intersperse blankLine $ map pprTop tops + +-- +-- top level procs +-- +pprTop :: RawCmmDecl -> SDoc +pprTop (CmmProc infos clbl _in_live_regs graph) = + + (case mapLookup (g_entry graph) infos of + Nothing -> empty + Just (Statics info_clbl info_dat) -> + pprDataExterns info_dat $$ + pprWordArray info_is_in_rodata info_clbl info_dat) $$ + (vcat [ + blankLine, + extern_decls, + (if (externallyVisibleCLabel clbl) + then mkFN_ else mkIF_) (ppr clbl) <+> lbrace, + nest 8 temp_decls, + vcat (map pprBBlock blocks), + rbrace ] + ) + where + -- info tables are always in .rodata + info_is_in_rodata = True + blocks = toBlockListEntryFirst graph + (temp_decls, extern_decls) = pprTempAndExternDecls blocks + + +-- Chunks of static data. + +-- We only handle (a) arrays of word-sized things and (b) strings. + +pprTop (CmmData section (Statics lbl [CmmString str])) = + pprExternDecl lbl $$ + hcat [ + pprLocalness lbl, pprConstness (isSecConstant section), text "char ", ppr lbl, + text "[] = ", pprStringInCStyle str, semi + ] + +pprTop (CmmData section (Statics lbl [CmmUninitialised size])) = + pprExternDecl lbl $$ + hcat [ + pprLocalness lbl, pprConstness (isSecConstant section), text "char ", ppr lbl, + brackets (int size), semi + ] + +pprTop (CmmData section (Statics lbl lits)) = + pprDataExterns lits $$ + pprWordArray (isSecConstant section) 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 :: CmmBlock -> SDoc +pprBBlock block = + nest 4 (pprBlockId (entryLabel block) <> colon) $$ + nest 8 (vcat (map pprStmt (blockToList nodes)) $$ pprStmt last) + where + (_, nodes, last) = blockSplit block + +-- -------------------------------------------------------------------------- +-- Info tables. Just arrays of words. +-- See codeGen/ClosureInfo, and nativeGen/PprMach + +pprWordArray :: Bool -> CLabel -> [CmmStatic] -> SDoc +pprWordArray is_ro lbl ds + = sdocWithDynFlags $ \dflags -> + -- TODO: align closures only + pprExternDecl lbl $$ + hcat [ pprLocalness lbl, pprConstness is_ro, text "StgWord" + , space, ppr lbl, text "[]" + -- See Note [StgWord alignment] + , pprAlignment (wordWidth dflags) + , text "= {" ] + $$ nest 8 (commafy (pprStatics dflags ds)) + $$ text "};" + +pprAlignment :: Width -> SDoc +pprAlignment words = + text "__attribute__((aligned(" <> int (widthInBytes words) <> text ")))" + +-- Note [StgWord alignment] +-- C codegen builds static closures as StgWord C arrays (pprWordArray). +-- Their real C type is 'StgClosure'. Macros like UNTAG_CLOSURE assume +-- pointers to 'StgClosure' are aligned at pointer size boundary: +-- 4 byte boundary on 32 systems +-- and 8 bytes on 64-bit systems +-- see TAG_MASK and TAG_BITS definition and usage. +-- +-- It's a reasonable assumption also known as natural alignment. +-- Although some architectures have different alignment rules. +-- One of known exceptions is m68k (#11395, comment:16) where: +-- __alignof__(StgWord) == 2, sizeof(StgWord) == 4 +-- +-- Thus we explicitly increase alignment by using +-- __attribute__((aligned(4))) +-- declaration. + +-- +-- has to be static, if it isn't globally visible +-- +pprLocalness :: CLabel -> SDoc +pprLocalness lbl | not $ externallyVisibleCLabel lbl = text "static " + | otherwise = empty + +pprConstness :: Bool -> SDoc +pprConstness is_ro | is_ro = text "const " + | otherwise = empty + +-- -------------------------------------------------------------------------- +-- Statements. +-- + +pprStmt :: CmmNode e x -> SDoc + +pprStmt stmt = + sdocWithDynFlags $ \dflags -> + case stmt of + CmmEntry{} -> empty + CmmComment _ -> empty -- (hang (text "/*") 3 (ftext s)) $$ 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. + + CmmTick _ -> empty + CmmUnwind{} -> empty + + CmmAssign dest src -> pprAssign dflags dest src + + CmmStore dest src + | typeWidth rep == W64 && wordWidth dflags /= W64 + -> (if isFloatType rep then text "ASSIGN_DBL" + else ptext (sLit ("ASSIGN_Word64"))) <> + parens (mkP_ <> pprExpr1 dest <> comma <> pprExpr src) <> semi + + | otherwise + -> hsep [ pprExpr (CmmLoad dest rep), equals, pprExpr src <> semi ] + where + rep = cmmExprType dflags src + + CmmUnsafeForeignCall target@(ForeignTarget fn conv) results args -> + fnCall + where + (res_hints, arg_hints) = foreignTargetHints target + hresults = zip results res_hints + hargs = zip args arg_hints + + ForeignConvention cconv _ _ ret = conv + + cast_fn = parens (cCast (pprCFunType (char '*') cconv hresults hargs) fn) + + -- See wiki:commentary/compiler/backends/ppr-c#prototypes + fnCall = + case fn of + CmmLit (CmmLabel lbl) + | StdCallConv <- cconv -> + pprCall (ppr lbl) cconv hresults hargs + -- 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 -> + pprCall cast_fn cconv hresults hargs <> semi + | not (isMathFun lbl) -> + pprForeignCall (ppr lbl) cconv hresults hargs + _ -> + pprCall cast_fn cconv hresults hargs <> semi + -- for a dynamic call, no declaration is necessary. + + CmmUnsafeForeignCall (PrimTarget MO_Touch) _results _args -> empty + CmmUnsafeForeignCall (PrimTarget (MO_Prefetch_Data _)) _results _args -> empty + + CmmUnsafeForeignCall target@(PrimTarget op) results args -> + fn_call + where + cconv = CCallConv + fn = pprCallishMachOp_for_C op + + (res_hints, arg_hints) = foreignTargetHints target + hresults = zip results res_hints + hargs = zip args arg_hints + + fn_call + -- The mem primops carry an extra alignment arg. + -- We could maybe emit an alignment directive using this info. + -- We also need to cast mem primops to prevent conflicts with GCC + -- builtins (see bug #5967). + | Just _align <- machOpMemcpyishAlign op + = (text ";EFF_(" <> fn <> char ')' <> semi) $$ + pprForeignCall fn cconv hresults hargs + | otherwise + = pprCall fn cconv hresults hargs + + CmmBranch ident -> pprBranch ident + CmmCondBranch expr yes no _ -> pprCondBranch expr yes no + CmmCall { cml_target = expr } -> mkJMP_ (pprExpr expr) <> semi + CmmSwitch arg ids -> sdocWithDynFlags $ \dflags -> + pprSwitch dflags arg ids + + _other -> pprPanic "PprC.pprStmt" (ppr stmt) + +type Hinted a = (a, ForeignHint) + +pprForeignCall :: SDoc -> CCallConv -> [Hinted CmmFormal] -> [Hinted CmmActual] + -> SDoc +pprForeignCall fn cconv results args = fn_call + where + fn_call = braces ( + pprCFunType (char '*' <> text "ghcFunPtr") cconv results args <> semi + $$ text "ghcFunPtr" <+> equals <+> cast_fn <> semi + $$ pprCall (text "ghcFunPtr") cconv results args <> semi + ) + cast_fn = parens (parens (pprCFunType (char '*') cconv results args) <> fn) + +pprCFunType :: SDoc -> CCallConv -> [Hinted CmmFormal] -> [Hinted CmmActual] -> SDoc +pprCFunType ppr_fn cconv ress args + = sdocWithDynFlags $ \dflags -> + let res_type [] = text "void" + res_type [(one, hint)] = machRepHintCType (localRegType one) hint + res_type _ = panic "pprCFunType: only void or 1 return value supported" + + arg_type (expr, hint) = machRepHintCType (cmmExprType dflags expr) hint + in res_type ress <+> + parens (ccallConvAttribute cconv <> ppr_fn) <> + parens (commafy (map arg_type args)) + +-- --------------------------------------------------------------------- +-- unconditional branches +pprBranch :: BlockId -> SDoc +pprBranch ident = text "goto" <+> pprBlockId ident <> semi + + +-- --------------------------------------------------------------------- +-- conditional branches to local labels +pprCondBranch :: CmmExpr -> BlockId -> BlockId -> SDoc +pprCondBranch expr yes no + = hsep [ text "if" , parens(pprExpr expr) , + text "goto", pprBlockId yes <> semi, + text "else goto", pprBlockId no <> semi ] + +-- --------------------------------------------------------------------- +-- a local table branch +-- +-- we find the fall-through cases +-- +pprSwitch :: DynFlags -> CmmExpr -> SwitchTargets -> SDoc +pprSwitch dflags e ids + = (hang (text "switch" <+> parens ( pprExpr e ) <+> lbrace) + 4 (vcat ( map caseify pairs ) $$ def)) $$ rbrace + where + (pairs, mbdef) = switchTargetsFallThrough ids + + -- fall through case + caseify (ix:ixs, ident) = vcat (map do_fallthrough ixs) $$ final_branch ix + where + do_fallthrough ix = + hsep [ text "case" , pprHexVal ix (wordWidth dflags) <> colon , + text "/* fall through */" ] + + final_branch ix = + hsep [ text "case" , pprHexVal ix (wordWidth dflags) <> colon , + text "goto" , (pprBlockId ident) <> semi ] + + caseify (_ , _ ) = panic "pprSwitch: switch with no cases!" + + def | Just l <- mbdef = text "default: goto" <+> pprBlockId l <> semi + | otherwise = empty + +-- --------------------------------------------------------------------- +-- 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 :: CmmExpr -> SDoc +pprExpr e = case e of + CmmLit lit -> pprLit lit + + + CmmLoad e ty -> sdocWithDynFlags $ \dflags -> pprLoad dflags e ty + CmmReg reg -> pprCastReg reg + CmmRegOff reg 0 -> pprCastReg reg + + -- CmmRegOff is an alias of MO_Add + CmmRegOff reg i -> sdocWithDynFlags $ \dflags -> + pprCastReg reg <> char '+' <> + pprHexVal (fromIntegral i) (wordWidth dflags) + + CmmMachOp mop args -> pprMachOpApp mop args + + CmmStackSlot _ _ -> panic "pprExpr: CmmStackSlot not supported!" + + +pprLoad :: DynFlags -> CmmExpr -> CmmType -> SDoc +pprLoad dflags e ty + | width == W64, wordWidth dflags /= W64 + = (if isFloatType ty then text "PK_DBL" + else text "PK_Word64") + <> parens (mkP_ <> pprExpr1 e) + + | otherwise + = case e of + CmmReg r | isPtrReg r && width == wordWidth dflags && not (isFloatType ty) + -> char '*' <> pprAsPtrReg r + + CmmRegOff r 0 | isPtrReg r && width == wordWidth dflags && not (isFloatType ty) + -> char '*' <> pprAsPtrReg r + + CmmRegOff r off | isPtrReg r && width == wordWidth dflags + , off `rem` wORD_SIZE dflags == 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 dflags)) + + _other -> cLoad e ty + where + width = typeWidth ty + +pprExpr1 :: CmmExpr -> SDoc +pprExpr1 (CmmLit lit) = pprLit1 lit +pprExpr1 e@(CmmReg _reg) = pprExpr e +pprExpr1 other = parens (pprExpr other) + +-- -------------------------------------------------------------------------- +-- MachOp applications + +pprMachOpApp :: MachOp -> [CmmExpr] -> SDoc + +pprMachOpApp op args + | isMulMayOfloOp op + = text "mulIntMayOflo" <> parens (commafy (map pprExpr args)) + where isMulMayOfloOp (MO_U_MulMayOflo _) = True + isMulMayOfloOp (MO_S_MulMayOflo _) = True + isMulMayOfloOp _ = False + +pprMachOpApp mop args + | Just ty <- machOpNeedsCast mop + = ty <> parens (pprMachOpApp' mop args) + | otherwise + = pprMachOpApp' mop args + +-- Comparisons in C have type 'int', but we want type W_ (this is what +-- resultRepOfMachOp says). The other C operations inherit their type +-- from their operands, so no casting is required. +machOpNeedsCast :: MachOp -> Maybe SDoc +machOpNeedsCast mop + | isComparisonMachOp mop = Just mkW_ + | otherwise = Nothing + +pprMachOpApp' :: MachOp -> [CmmExpr] -> SDoc +pprMachOpApp' 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 = sdocWithDynFlags $ \dflags -> + cCast (machRep_S_CType (typeWidth (cmmExprType dflags e))) e + | needsFCasts mop = sdocWithDynFlags $ \dflags -> + cCast (machRep_F_CType (typeWidth (cmmExprType dflags e))) e + | otherwise = pprExpr1 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 :: CmmLit -> SDoc +pprLit 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 = text "-INFINITY" + | isInfinite d = text "INFINITY" + | isNaN d = text "NAN" + | otherwise = text (show d) + -- these constants come from <math.h> + -- see #1861 + + CmmVec {} -> panic "PprC printing vector literal" + + 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 _ -- non-word widths not supported via C + -- 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 '&' <> ppr lbl + +pprLit1 :: CmmLit -> SDoc +pprLit1 lit@(CmmLabelOff _ _) = parens (pprLit lit) +pprLit1 lit@(CmmLabelDiffOff _ _ _ _) = parens (pprLit lit) +pprLit1 lit@(CmmFloat _ _) = parens (pprLit lit) +pprLit1 other = pprLit other + +-- --------------------------------------------------------------------------- +-- Static data + +pprStatics :: DynFlags -> [CmmStatic] -> [SDoc] +pprStatics _ [] = [] +pprStatics dflags (CmmStaticLit (CmmFloat f W32) : rest) + -- odd numbers of floats are padded to a word by mkVirtHeapOffsetsWithPadding + | wORD_SIZE dflags == 8, CmmStaticLit (CmmInt 0 W32) : rest' <- rest + = pprLit1 (floatToWord dflags f) : pprStatics dflags rest' + -- adjacent floats aren't padded but combined into a single word + | wORD_SIZE dflags == 8, CmmStaticLit (CmmFloat g W32) : rest' <- rest + = pprLit1 (floatPairToWord dflags f g) : pprStatics dflags rest' + | wORD_SIZE dflags == 4 + = pprLit1 (floatToWord dflags f) : pprStatics dflags rest + | otherwise + = pprPanic "pprStatics: float" (vcat (map ppr' rest)) + where ppr' (CmmStaticLit l) = sdocWithDynFlags $ \dflags -> + ppr (cmmLitType dflags l) + ppr' _other = text "bad static!" +pprStatics dflags (CmmStaticLit (CmmFloat f W64) : rest) + = map pprLit1 (doubleToWords dflags f) ++ pprStatics dflags rest + +pprStatics dflags (CmmStaticLit (CmmInt i W64) : rest) + | wordWidth dflags == W32 + = if wORDS_BIGENDIAN dflags + then pprStatics dflags (CmmStaticLit (CmmInt q W32) : + CmmStaticLit (CmmInt r W32) : rest) + else pprStatics dflags (CmmStaticLit (CmmInt r W32) : + CmmStaticLit (CmmInt q W32) : rest) + where r = i .&. 0xffffffff + q = i `shiftR` 32 +pprStatics dflags (CmmStaticLit (CmmInt a W32) : + CmmStaticLit (CmmInt b W32) : rest) + | wordWidth dflags == W64 + = if wORDS_BIGENDIAN dflags + then pprStatics dflags (CmmStaticLit (CmmInt ((shiftL a 32) .|. b) W64) : + rest) + else pprStatics dflags (CmmStaticLit (CmmInt ((shiftL b 32) .|. a) W64) : + rest) +pprStatics dflags (CmmStaticLit (CmmInt a W16) : + CmmStaticLit (CmmInt b W16) : rest) + | wordWidth dflags == W32 + = if wORDS_BIGENDIAN dflags + then pprStatics dflags (CmmStaticLit (CmmInt ((shiftL a 16) .|. b) W32) : + rest) + else pprStatics dflags (CmmStaticLit (CmmInt ((shiftL b 16) .|. a) W32) : + rest) +pprStatics dflags (CmmStaticLit (CmmInt _ w) : _) + | w /= wordWidth dflags + = pprPanic "pprStatics: cannot emit a non-word-sized static literal" (ppr w) +pprStatics dflags (CmmStaticLit lit : rest) + = pprLit1 lit : pprStatics dflags rest +pprStatics _ (other : _) + = pprPanic "pprStatics: other" (pprStatic other) + +pprStatic :: CmmStatic -> SDoc +pprStatic s = case s of + + CmmStaticLit lit -> nest 4 (pprLit 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 _ -> text "==" + MO_Ne _ -> text "!=" + 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 _ -> text ">=" + MO_S_Le _ -> text "<=" + MO_S_Gt _ -> char '>' + MO_S_Lt _ -> char '<' + + -- & Unsigned comparisons + MO_U_Ge _ -> text ">=" + MO_U_Le _ -> text "<=" + MO_U_Gt _ -> char '>' + MO_U_Lt _ -> char '<' + + -- & Floating-point comparisons + MO_F_Eq _ -> text "==" + MO_F_Ne _ -> text "!=" + MO_F_Ge _ -> text ">=" + MO_F_Le _ -> text "<=" + 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 _ -> text "<<" + MO_U_Shr _ -> text ">>" -- unsigned shift right + MO_S_Shr _ -> text ">>" -- 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_XX_Conv from to | from == to -> empty + MO_XX_Conv _from to -> parens (machRep_U_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:" + (text "MO_S_MulMayOflo") + (panic $ "PprC.pprMachOp_for_C: MO_S_MulMayOflo" + ++ " should have been handled earlier!") + MO_U_MulMayOflo _ -> pprTrace "offending mop:" + (text "MO_U_MulMayOflo") + (panic $ "PprC.pprMachOp_for_C: MO_U_MulMayOflo" + ++ " should have been handled earlier!") + + MO_V_Insert {} -> pprTrace "offending mop:" + (text "MO_V_Insert") + (panic $ "PprC.pprMachOp_for_C: MO_V_Insert" + ++ " should have been handled earlier!") + MO_V_Extract {} -> pprTrace "offending mop:" + (text "MO_V_Extract") + (panic $ "PprC.pprMachOp_for_C: MO_V_Extract" + ++ " should have been handled earlier!") + + MO_V_Add {} -> pprTrace "offending mop:" + (text "MO_V_Add") + (panic $ "PprC.pprMachOp_for_C: MO_V_Add" + ++ " should have been handled earlier!") + MO_V_Sub {} -> pprTrace "offending mop:" + (text "MO_V_Sub") + (panic $ "PprC.pprMachOp_for_C: MO_V_Sub" + ++ " should have been handled earlier!") + MO_V_Mul {} -> pprTrace "offending mop:" + (text "MO_V_Mul") + (panic $ "PprC.pprMachOp_for_C: MO_V_Mul" + ++ " should have been handled earlier!") + + MO_VS_Quot {} -> pprTrace "offending mop:" + (text "MO_VS_Quot") + (panic $ "PprC.pprMachOp_for_C: MO_VS_Quot" + ++ " should have been handled earlier!") + MO_VS_Rem {} -> pprTrace "offending mop:" + (text "MO_VS_Rem") + (panic $ "PprC.pprMachOp_for_C: MO_VS_Rem" + ++ " should have been handled earlier!") + MO_VS_Neg {} -> pprTrace "offending mop:" + (text "MO_VS_Neg") + (panic $ "PprC.pprMachOp_for_C: MO_VS_Neg" + ++ " should have been handled earlier!") + + MO_VU_Quot {} -> pprTrace "offending mop:" + (text "MO_VU_Quot") + (panic $ "PprC.pprMachOp_for_C: MO_VU_Quot" + ++ " should have been handled earlier!") + MO_VU_Rem {} -> pprTrace "offending mop:" + (text "MO_VU_Rem") + (panic $ "PprC.pprMachOp_for_C: MO_VU_Rem" + ++ " should have been handled earlier!") + + MO_VF_Insert {} -> pprTrace "offending mop:" + (text "MO_VF_Insert") + (panic $ "PprC.pprMachOp_for_C: MO_VF_Insert" + ++ " should have been handled earlier!") + MO_VF_Extract {} -> pprTrace "offending mop:" + (text "MO_VF_Extract") + (panic $ "PprC.pprMachOp_for_C: MO_VF_Extract" + ++ " should have been handled earlier!") + + MO_VF_Add {} -> pprTrace "offending mop:" + (text "MO_VF_Add") + (panic $ "PprC.pprMachOp_for_C: MO_VF_Add" + ++ " should have been handled earlier!") + MO_VF_Sub {} -> pprTrace "offending mop:" + (text "MO_VF_Sub") + (panic $ "PprC.pprMachOp_for_C: MO_VF_Sub" + ++ " should have been handled earlier!") + MO_VF_Neg {} -> pprTrace "offending mop:" + (text "MO_VF_Neg") + (panic $ "PprC.pprMachOp_for_C: MO_VF_Neg" + ++ " should have been handled earlier!") + MO_VF_Mul {} -> pprTrace "offending mop:" + (text "MO_VF_Mul") + (panic $ "PprC.pprMachOp_for_C: MO_VF_Mul" + ++ " should have been handled earlier!") + MO_VF_Quot {} -> pprTrace "offending mop:" + (text "MO_VF_Quot") + (panic $ "PprC.pprMachOp_for_C: MO_VF_Quot" + ++ " should have been handled earlier!") + + MO_AlignmentCheck {} -> panic "-falignment-santisation not supported by unregisterised backend" + +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 -> text "pow" + MO_F64_Sin -> text "sin" + MO_F64_Cos -> text "cos" + MO_F64_Tan -> text "tan" + MO_F64_Sinh -> text "sinh" + MO_F64_Cosh -> text "cosh" + MO_F64_Tanh -> text "tanh" + MO_F64_Asin -> text "asin" + MO_F64_Acos -> text "acos" + MO_F64_Atanh -> text "atanh" + MO_F64_Asinh -> text "asinh" + MO_F64_Acosh -> text "acosh" + MO_F64_Atan -> text "atan" + MO_F64_Log -> text "log" + MO_F64_Log1P -> text "log1p" + MO_F64_Exp -> text "exp" + MO_F64_ExpM1 -> text "expm1" + MO_F64_Sqrt -> text "sqrt" + MO_F64_Fabs -> text "fabs" + MO_F32_Pwr -> text "powf" + MO_F32_Sin -> text "sinf" + MO_F32_Cos -> text "cosf" + MO_F32_Tan -> text "tanf" + MO_F32_Sinh -> text "sinhf" + MO_F32_Cosh -> text "coshf" + MO_F32_Tanh -> text "tanhf" + MO_F32_Asin -> text "asinf" + MO_F32_Acos -> text "acosf" + MO_F32_Atan -> text "atanf" + MO_F32_Asinh -> text "asinhf" + MO_F32_Acosh -> text "acoshf" + MO_F32_Atanh -> text "atanhf" + MO_F32_Log -> text "logf" + MO_F32_Log1P -> text "log1pf" + MO_F32_Exp -> text "expf" + MO_F32_ExpM1 -> text "expm1f" + MO_F32_Sqrt -> text "sqrtf" + MO_F32_Fabs -> text "fabsf" + MO_ReadBarrier -> text "load_load_barrier" + MO_WriteBarrier -> text "write_barrier" + MO_Memcpy _ -> text "memcpy" + MO_Memset _ -> text "memset" + MO_Memmove _ -> text "memmove" + MO_Memcmp _ -> text "memcmp" + (MO_BSwap w) -> ptext (sLit $ bSwapLabel w) + (MO_BRev w) -> ptext (sLit $ bRevLabel w) + (MO_PopCnt w) -> ptext (sLit $ popCntLabel w) + (MO_Pext w) -> ptext (sLit $ pextLabel w) + (MO_Pdep w) -> ptext (sLit $ pdepLabel w) + (MO_Clz w) -> ptext (sLit $ clzLabel w) + (MO_Ctz w) -> ptext (sLit $ ctzLabel w) + (MO_AtomicRMW w amop) -> ptext (sLit $ atomicRMWLabel w amop) + (MO_Cmpxchg w) -> ptext (sLit $ cmpxchgLabel w) + (MO_AtomicRead w) -> ptext (sLit $ atomicReadLabel w) + (MO_AtomicWrite w) -> ptext (sLit $ atomicWriteLabel w) + (MO_UF_Conv w) -> ptext (sLit $ word2FloatLabel w) + + MO_S_Mul2 {} -> unsupported + MO_S_QuotRem {} -> unsupported + MO_U_QuotRem {} -> unsupported + MO_U_QuotRem2 {} -> unsupported + MO_Add2 {} -> unsupported + MO_AddWordC {} -> unsupported + MO_SubWordC {} -> unsupported + MO_AddIntC {} -> unsupported + MO_SubIntC {} -> unsupported + MO_U_Mul2 {} -> unsupported + MO_Touch -> unsupported + (MO_Prefetch_Data _ ) -> unsupported + --- we could support prefetch via "__builtin_prefetch" + --- Not adding it for now + where unsupported = panic ("pprCallishMachOp_for_C: " ++ show mop + ++ " not supported!") + +-- --------------------------------------------------------------------- +-- Useful #defines +-- + +mkJMP_, mkFN_, mkIF_ :: SDoc -> SDoc + +mkJMP_ i = text "JMP_" <> parens i +mkFN_ i = text "FN_" <> parens i -- externally visible function +mkIF_ i = text "IF_" <> parens i -- locally visible + +-- from includes/Stg.h +-- +mkC_,mkW_,mkP_ :: SDoc + +mkC_ = text "(C_)" -- StgChar +mkW_ = text "(W_)" -- StgWord +mkP_ = text "(P_)" -- StgWord* + +-- --------------------------------------------------------------------- +-- +-- Assignments +-- +-- Generating assignments is what we're all about, here +-- +pprAssign :: DynFlags -> 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 dflags r1 (CmmRegOff r2 off) + | isPtrReg r1 && isPtrReg r2 && (off `rem` wORD_SIZE dflags == 0) + = hcat [ pprAsPtrReg r1, equals, pprAsPtrReg r2, op, int off', semi ] + where + off1 = off `shiftR` wordShift dflags + + (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 _ r1 r2 + | isFixedPtrReg r1 = mkAssign (mkP_ <> pprExpr1 r2) + | Just ty <- strangeRegType r1 = mkAssign (parens ty <> pprExpr1 r2) + | otherwise = mkAssign (pprExpr r2) + where mkAssign x = if r1 == CmmGlobal BaseReg + then text "ASSIGN_BaseReg" <> parens x <> semi + else pprReg r1 <> text " = " <> 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 (text "struct CostCentreStack_ *") +strangeRegType (CmmGlobal CurrentTSO) = Just (text "struct StgTSO_ *") +strangeRegType (CmmGlobal CurrentNursery) = Just (text "struct bdescr_ *") +strangeRegType (CmmGlobal BaseReg) = Just (text "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 <> text ".p" +pprAsPtrReg other_reg = pprReg other_reg + +pprGlobalReg :: GlobalReg -> SDoc +pprGlobalReg gr = case gr of + VanillaReg n _ -> char 'R' <> int n <> text ".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 -> text "Sp" + SpLim -> text "SpLim" + Hp -> text "Hp" + HpLim -> text "HpLim" + CCCS -> text "CCCS" + CurrentTSO -> text "CurrentTSO" + CurrentNursery -> text "CurrentNursery" + HpAlloc -> text "HpAlloc" + BaseReg -> text "BaseReg" + EagerBlackholeInfo -> text "stg_EAGER_BLACKHOLE_info" + GCEnter1 -> text "stg_gc_enter_1" + GCFun -> text "stg_gc_fun" + other -> panic $ "pprGlobalReg: Unsupported register: " ++ show other + +pprLocalReg :: LocalReg -> SDoc +pprLocalReg (LocalReg uniq _) = char '_' <> ppr uniq + +-- ----------------------------------------------------------------------------- +-- Foreign Calls + +pprCall :: SDoc -> CCallConv -> [Hinted CmmFormal] -> [Hinted CmmActual] -> SDoc +pprCall 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 [(one,hint)] rhs + = pprLocalReg one <> text " = " + <> pprUnHint hint (localRegType one) <> rhs + ppr_assign _other _rhs = panic "pprCall: multiple results" + + pprArg (expr, AddrHint) + = cCast (text "void *") expr + -- see comment by machRepHintCType below + pprArg (expr, SignedHint) + = sdocWithDynFlags $ \dflags -> + cCast (machRep_S_CType $ typeWidth $ cmmExprType dflags expr) expr + pprArg (expr, _other) + = pprExpr 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 PrimCallConv = False +is_cishCC JavaScriptCallConv = False + +-- --------------------------------------------------------------------- +-- Find and print local and external declarations for a list of +-- Cmm statements. +-- +pprTempAndExternDecls :: [CmmBlock] -> (SDoc{-temps-}, SDoc{-externs-}) +pprTempAndExternDecls stmts + = (pprUFM (getUniqSet temps) (vcat . map pprTempDecl), + vcat (map pprExternDecl (Map.keys lbls))) + where (temps, lbls) = runTE (mapM_ te_BB stmts) + +pprDataExterns :: [CmmStatic] -> SDoc +pprDataExterns statics + = vcat (map pprExternDecl (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 :: CLabel -> SDoc +pprExternDecl 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, ppr lbl, text ");" + -- occasionally useful to see label type + -- , text "/* ", pprDebugCLabel lbl, text " */" + ] + where + label_type lbl | isBytesLabel lbl = text "B_" + | isForeignLabel lbl && isCFunctionLabel lbl + = text "FF_" + | isCFunctionLabel lbl = text "F_" + | isStaticClosureLabel lbl = text "C_" + -- generic .rodata labels + | isSomeRODataLabel lbl = text "RO_" + -- generic .data labels (common case) + | otherwise = text "RW_" + + 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 = sdocWithDynFlags $ \dflags -> + text "extern __attribute__((stdcall)) void " <> ppr lbl + <> parens (commafy (replicate (sz `quot` wORD_SIZE dflags) (machRep_U_CType (wordWidth dflags)))) + <> semi + +type TEState = (UniqSet LocalReg, Map CLabel ()) +newtype TE a = TE { unTE :: TEState -> (a, TEState) } deriving (Functor) + +instance Applicative TE where + pure a = TE $ \s -> (a, s) + (<*>) = ap + +instance Monad TE where + TE m >>= k = TE $ \s -> case m s of (a, s') -> unTE (k 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 :: CmmBlock -> TE () +te_BB block = mapM_ te_Stmt (blockToList mid) >> te_Stmt last + where (_, mid, last) = blockSplit block + +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 :: CmmNode e x -> 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 (CmmUnsafeForeignCall target rs es) + = do te_Target target + mapM_ te_temp rs + mapM_ te_Expr es +te_Stmt (CmmCondBranch e _ _ _) = te_Expr e +te_Stmt (CmmSwitch e _) = te_Expr e +te_Stmt (CmmCall { cml_target = e }) = te_Expr e +te_Stmt _ = return () + +te_Target :: ForeignTarget -> TE () +te_Target (ForeignTarget e _) = te_Expr e +te_Target (PrimTarget{}) = 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 :: SDoc -> CmmExpr -> SDoc +cCast ty expr = parens ty <> pprExpr1 expr + +cLoad :: CmmExpr -> CmmType -> SDoc +cLoad expr rep + = sdocWithPlatform $ \platform -> + if bewareLoadStoreAlignment (platformArch platform) + then let decl = machRepCType rep <+> text "x" <> semi + struct = text "struct" <+> braces (decl) + packed_attr = text "__attribute__((packed))" + cast = parens (struct <+> packed_attr <> char '*') + in parens (cast <+> pprExpr1 expr) <> text "->x" + else char '*' <> parens (cCast (machRepPtrCType rep) expr) + where -- On these platforms, unaligned loads are known to cause problems + bewareLoadStoreAlignment ArchAlpha = True + bewareLoadStoreAlignment ArchMipseb = True + bewareLoadStoreAlignment ArchMipsel = True + bewareLoadStoreAlignment (ArchARM {}) = True + bewareLoadStoreAlignment ArchARM64 = True + bewareLoadStoreAlignment ArchSPARC = True + bewareLoadStoreAlignment ArchSPARC64 = True + -- Pessimistically assume that they will also cause problems + -- on unknown arches + bewareLoadStoreAlignment ArchUnknown = True + bewareLoadStoreAlignment _ = False + +isCmmWordType :: DynFlags -> CmmType -> Bool +-- True of GcPtrReg/NonGcReg of native word size +isCmmWordType dflags ty = not (isFloatType ty) + && typeWidth ty == wordWidth dflags + +-- 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 = text "void *" +machRepHintCType rep SignedHint = machRep_S_CType (typeWidth rep) +machRepHintCType rep _other = machRepCType rep + +machRepPtrCType :: CmmType -> SDoc +machRepPtrCType r + = sdocWithDynFlags $ \dflags -> + if isCmmWordType dflags r then text "P_" + else 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 = text "StgFloat" -- ToDo: correct? +machRep_F_CType W64 = text "StgDouble" +machRep_F_CType _ = panic "machRep_F_CType" + +machRep_U_CType :: Width -> SDoc +machRep_U_CType w + = sdocWithDynFlags $ \dflags -> + case w of + _ | w == wordWidth dflags -> text "W_" + W8 -> text "StgWord8" + W16 -> text "StgWord16" + W32 -> text "StgWord32" + W64 -> text "StgWord64" + _ -> panic "machRep_U_CType" + +machRep_S_CType :: Width -> SDoc +machRep_S_CType w + = sdocWithDynFlags $ \dflags -> + case w of + _ | w == wordWidth dflags -> text "I_" + W8 -> text "StgInt8" + W16 -> text "StgInt16" + W32 -> text "StgInt32" + W64 -> text "StgInt64" + _ -> panic "machRep_S_CType" + + +-- --------------------------------------------------------------------- +-- print strings as valid C strings + +pprStringInCStyle :: ByteString -> SDoc +pprStringInCStyle s = doubleQuotes (text (concatMap charToC (BS.unpack 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. +-- +-- Consider a concrete C example: +-- double d = 2.5e-10; +-- float f = 2.5e-10f; +-- +-- int * i2 = &d; printf ("i2: %08X %08X\n", i2[0], i2[1]); +-- long long * l = &d; printf (" l: %016llX\n", l[0]); +-- int * i = &f; printf (" i: %08X\n", i[0]); +-- Result on 64-bit LE (x86_64): +-- i2: E826D695 3DF12E0B +-- l: 3DF12E0BE826D695 +-- i: 2F89705F +-- Result on 32-bit BE (m68k): +-- i2: 3DF12E0B E826D695 +-- l: 3DF12E0BE826D695 +-- i: 2F89705F +-- +-- The trick here is to notice that binary representation does not +-- change much: only Word32 values get swapped on LE hosts / targets. + +-- This is a hack to turn the floating point numbers into ints that we +-- can safely initialise to static locations. + +castFloatToWord32Array :: STUArray s Int Float -> ST s (STUArray s Int Word32) +castFloatToWord32Array = U.castSTUArray + +castDoubleToWord64Array :: STUArray s Int Double -> ST s (STUArray s Int Word64) +castDoubleToWord64Array = U.castSTUArray + +floatToWord :: DynFlags -> Rational -> CmmLit +floatToWord dflags r + = runST (do + arr <- newArray_ ((0::Int),0) + writeArray arr 0 (fromRational r) + arr' <- castFloatToWord32Array arr + w32 <- readArray arr' 0 + return (CmmInt (toInteger w32 `shiftL` wo) (wordWidth dflags)) + ) + where wo | wordWidth dflags == W64 + , wORDS_BIGENDIAN dflags = 32 + | otherwise = 0 + +floatPairToWord :: DynFlags -> Rational -> Rational -> CmmLit +floatPairToWord dflags r1 r2 + = runST (do + arr <- newArray_ ((0::Int),1) + writeArray arr 0 (fromRational r1) + writeArray arr 1 (fromRational r2) + arr' <- castFloatToWord32Array arr + w32_1 <- readArray arr' 0 + w32_2 <- readArray arr' 1 + return (pprWord32Pair w32_1 w32_2) + ) + where pprWord32Pair w32_1 w32_2 + | wORDS_BIGENDIAN dflags = + CmmInt ((shiftL i1 32) .|. i2) W64 + | otherwise = + CmmInt ((shiftL i2 32) .|. i1) W64 + where i1 = toInteger w32_1 + i2 = toInteger w32_2 + +doubleToWords :: DynFlags -> Rational -> [CmmLit] +doubleToWords dflags r + = runST (do + arr <- newArray_ ((0::Int),1) + writeArray arr 0 (fromRational r) + arr' <- castDoubleToWord64Array arr + w64 <- readArray arr' 0 + return (pprWord64 w64) + ) + where targetWidth = wordWidth dflags + targetBE = wORDS_BIGENDIAN dflags + pprWord64 w64 + | targetWidth == W64 = + [ CmmInt (toInteger w64) targetWidth ] + | targetWidth == W32 = + [ CmmInt (toInteger targetW1) targetWidth + , CmmInt (toInteger targetW2) targetWidth + ] + | otherwise = panic "doubleToWords.pprWord64" + where (targetW1, targetW2) + | targetBE = (wHi, wLo) + | otherwise = (wLo, wHi) + wHi = w64 `shiftR` 32 + wLo = w64 .&. 0xFFFFffff + +-- --------------------------------------------------------------------------- +-- Utils + +wordShift :: DynFlags -> Int +wordShift dflags = widthInLog (wordWidth dflags) + +commafy :: [SDoc] -> SDoc +commafy xs = hsep $ punctuate comma xs + +-- Print in C hex format: 0x13fa +pprHexVal :: Integer -> Width -> SDoc +pprHexVal w rep + | w < 0 = parens (char '-' <> + text "0x" <> intToDoc (-w) <> repsuffix rep) + | otherwise = text "0x" <> intToDoc 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. + + repsuffix W64 = sdocWithDynFlags $ \dflags -> + if cINT_SIZE dflags == 8 then char 'U' + else if cLONG_SIZE dflags == 8 then text "UL" + else if cLONG_LONG_SIZE dflags == 8 then text "ULL" + else panic "pprHexVal: Can't find a 64-bit type" + repsuffix _ = char 'U' + + intToDoc :: Integer -> SDoc + intToDoc i = case truncInt i of + 0 -> char '0' + v -> go v + + -- We need to truncate value as Cmm backend does not drop + -- redundant bits to ease handling of negative values. + -- Thus the following Cmm code on 64-bit arch, like amd64: + -- CInt v; + -- v = {something}; + -- if (v == %lobits32(-1)) { ... + -- leads to the following C code: + -- StgWord64 v = (StgWord32)({something}); + -- if (v == 0xFFFFffffFFFFffffU) { ... + -- Such code is incorrect as it promotes both operands to StgWord64 + -- and the whole condition is always false. + truncInt :: Integer -> Integer + truncInt i = + case rep of + W8 -> i `rem` (2^(8 :: Int)) + W16 -> i `rem` (2^(16 :: Int)) + W32 -> i `rem` (2^(32 :: Int)) + W64 -> i `rem` (2^(64 :: Int)) + _ -> panic ("pprHexVal/truncInt: C backend can't encode " + ++ show rep ++ " literals") + + 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')) |