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|
{-# OPTIONS -w #-}
-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and fix
-- any warnings in the module. See
-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
-- for details
-----------------------------------------------------------------------------
--
-- 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.
--
-- ToDo: save/restore volatile registers around calls.
module PprC (
writeCs,
pprStringInCStyle
) where
#include "HsVersions.h"
-- Cmm stuff
import BlockId
import Cmm
import PprCmm () -- Instances only
import CLabel
import ForeignCall
import ClosureInfo
-- Utils
import DynFlags
import Unique
import UniqSet
import FiniteMap
import UniqFM
import FastString
import Outputable
import Constants
-- The rest
import Data.List
import Data.Bits
import Data.Char
import System.IO
import Data.Word
import Data.Array.ST
import Control.Monad.ST
#if x86_64_TARGET_ARCH
import StaticFlags ( opt_Unregisterised )
#endif
#if defined(alpha_TARGET_ARCH) || defined(mips_TARGET_ARCH) || defined(mipsel_TARGET_ARCH) || defined(arm_TARGET_ARCH)
#define BEWARE_LOAD_STORE_ALIGNMENT
#endif
-- --------------------------------------------------------------------------
-- Top level
pprCs :: DynFlags -> [RawCmm] -> SDoc
pprCs dflags cmms
= pprCode CStyle (vcat $ map (\c -> split_marker $$ pprC c) cmms)
where
split_marker
| dopt Opt_SplitObjs dflags = ptext (sLit "__STG_SPLIT_MARKER")
| otherwise = empty
writeCs :: DynFlags -> Handle -> [RawCmm] -> IO ()
writeCs dflags handle cmms
= printForC handle (pprCs dflags cmms)
-- --------------------------------------------------------------------------
-- Now do some real work
--
-- for fun, we could call cmmToCmm over the tops...
--
pprC :: RawCmm -> SDoc
pprC (Cmm tops) = vcat $ intersperse (text "") $ map pprTop tops
--
-- top level procs
--
pprTop :: RawCmmTop -> SDoc
pprTop (CmmProc info clbl _params (ListGraph blocks)) =
(if not (null info)
then pprDataExterns info $$
pprWordArray (entryLblToInfoLbl clbl) info
else empty) $$
(case blocks of
[] -> empty
-- the first block doesn't get a label:
(BasicBlock _ stmts : rest) -> vcat [
text "",
extern_decls,
(if (externallyVisibleCLabel clbl)
then mkFN_ else mkIF_) (pprCLabel clbl) <+> lbrace,
nest 8 temp_decls,
nest 8 mkFB_,
nest 8 (vcat (map pprStmt stmts)) $$
vcat (map pprBBlock rest),
nest 8 mkFE_,
rbrace ]
)
where
(temp_decls, extern_decls) = pprTempAndExternDecls blocks
-- Chunks of static data.
-- We only handle (a) arrays of word-sized things and (b) strings.
pprTop (CmmData _section _ds@[CmmDataLabel lbl, CmmString str]) =
hcat [
pprLocalness lbl, ptext (sLit "char "), pprCLabel lbl,
ptext (sLit "[] = "), pprStringInCStyle str, semi
]
pprTop (CmmData _section _ds@[CmmDataLabel lbl, CmmUninitialised size]) =
hcat [
pprLocalness lbl, ptext (sLit "char "), pprCLabel lbl,
brackets (int size), semi
]
pprTop top@(CmmData _section (CmmDataLabel lbl : lits)) =
pprDataExterns lits $$
pprWordArray lbl lits
-- Floating info table for safe a foreign call.
pprTop top@(CmmData _section d@(_ : _))
| CmmDataLabel lbl : lits <- reverse d =
let lits' = reverse lits
in pprDataExterns lits' $$
pprWordArray lbl lits'
-- these shouldn't appear?
pprTop (CmmData _ _) = panic "PprC.pprTop: can't handle this data"
-- --------------------------------------------------------------------------
-- BasicBlocks are self-contained entities: they always end in a jump.
--
-- Like nativeGen/AsmCodeGen, we could probably reorder blocks to turn
-- as many jumps as possible into fall throughs.
--
pprBBlock :: CmmBasicBlock -> SDoc
pprBBlock (BasicBlock lbl stmts) =
if null stmts then
pprTrace "pprC.pprBBlock: curious empty code block for"
(pprBlockId lbl) empty
else
nest 4 (pprBlockId lbl <> colon) $$
nest 8 (vcat (map pprStmt stmts))
-- --------------------------------------------------------------------------
-- Info tables. Just arrays of words.
-- See codeGen/ClosureInfo, and nativeGen/PprMach
pprWordArray :: CLabel -> [CmmStatic] -> SDoc
pprWordArray lbl ds
= hcat [ pprLocalness lbl, ptext (sLit "StgWord")
, space, pprCLabel lbl, ptext (sLit "[] = {") ]
$$ nest 8 (commafy (pprStatics ds))
$$ ptext (sLit "};")
--
-- has to be static, if it isn't globally visible
--
pprLocalness :: CLabel -> SDoc
pprLocalness lbl | not $ externallyVisibleCLabel lbl = ptext (sLit "static ")
| otherwise = empty
-- --------------------------------------------------------------------------
-- Statements.
--
pprStmt :: CmmStmt -> SDoc
pprStmt stmt = case stmt of
CmmNop -> empty
CmmComment s -> (hang (ptext (sLit "/*")) 3 (ftext s)) $$ ptext (sLit "*/")
CmmAssign dest src -> pprAssign 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 dest <> comma <> pprExpr src) <> semi
| otherwise
-> hsep [ pprExpr (CmmLoad dest rep), equals, pprExpr src <> semi ]
where
rep = cmmExprType src
CmmCall (CmmCallee fn cconv) results args safety ret ->
maybe_proto $$
pprCall ppr_fn cconv results args safety
where
cast_fn = parens (cCast (pprCFunType (char '*') cconv results args) fn)
real_fun_proto lbl = char ';' <>
pprCFunType (pprCLabel lbl) cconv results args <>
noreturn_attr <> semi
data_proto lbl = ptext (sLit ";EI_(") <>
pprCLabel lbl <> char ')' <> semi
noreturn_attr = case ret of
CmmNeverReturns -> text "__attribute__ ((noreturn))"
CmmMayReturn -> empty
-- See wiki:Commentary/Compiler/Backends/PprC#Prototypes
(maybe_proto, ppr_fn) =
case fn of
CmmLit (CmmLabel lbl)
| StdCallConv <- cconv -> (real_fun_proto lbl, pprCLabel lbl)
-- 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 -> (real_fun_proto lbl, pprCLabel lbl)
| not (isMathFun lbl) -> (data_proto lbl, cast_fn)
-- we declare all other called functions as
-- data labels, and then cast them to the
-- right type when calling. This is because
-- the label might already have a declaration
-- as a data label in the same file,
-- e.g. Foreign.Marshal.Alloc declares 'free'
-- as both a data label and a function label.
_ ->
(empty {- no proto -}, cast_fn)
-- for a dynamic call, no declaration is necessary.
CmmCall (CmmPrim op) results args safety _ret ->
pprCall ppr_fn CCallConv results args safety
where
ppr_fn = pprCallishMachOp_for_C op
CmmBranch ident -> pprBranch ident
CmmCondBranch expr ident -> pprCondBranch expr ident
CmmJump lbl _params -> mkJMP_(pprExpr lbl) <> semi
CmmSwitch arg ids -> pprSwitch arg ids
pprCFunType :: SDoc -> CCallConv -> HintedCmmFormals -> HintedCmmActuals -> SDoc
pprCFunType ppr_fn cconv ress args
= res_type ress <+>
parens (text (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
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 :: CmmExpr -> BlockId -> SDoc
pprCondBranch expr ident
= hsep [ ptext (sLit "if") , parens(pprExpr 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 :: CmmExpr -> [ Maybe BlockId ] -> SDoc
pprSwitch 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 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 ]
-- ---------------------------------------------------------------------
-- 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 -> pprLoad 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 mop args
pprLoad :: CmmExpr -> CmmType -> SDoc
pprLoad e ty
| width == W64, wordWidth /= W64
= (if isFloatType ty then ptext (sLit "PK_DBL")
else ptext (sLit "PK_Word64"))
<> parens (mkP_ <> pprExpr1 e)
| otherwise
= case e of
CmmReg r | isPtrReg r && width == wordWidth && not (isFloatType ty)
-> char '*' <> pprAsPtrReg r
CmmRegOff r 0 | isPtrReg r && width == wordWidth && not (isFloatType ty)
-> char '*' <> pprAsPtrReg r
CmmRegOff r off | isPtrReg r && width == wordWidth
, off `rem` wORD_SIZE == 0 && not (isFloatType ty)
-- ToDo: check that the offset is a word multiple?
-- (For tagging to work, I had to avoid unaligned loads. --ARY)
-> pprAsPtrReg r <> brackets (ppr (off `shiftR` wordShift))
_other -> cLoad e ty
where
width = typeWidth ty
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
= ptext (sLit "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' 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 (machRep_S_CType (typeWidth (cmmExprType e))) e
| needsFCasts mop = cCast (machRep_F_CType (typeWidth (cmmExprType 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 = ptext (sLit "-INFINITY")
| isInfinite d = ptext (sLit "INFINITY")
| isNaN d = ptext (sLit "NAN")
| otherwise = text (show d)
-- these constants come from <math.h>
-- see #1861
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 clbl2 i
-- WARNING:
-- * the lit must occur in the info table clbl2
-- * clbl1 must be an SRT, a slow entry point or a large bitmap
-- The Mangler is expected to convert any reference to an SRT,
-- a slow entry point or a large bitmap
-- from an info table to an offset.
-> mkW_ <> pprCLabelAddr clbl1 <> char '+' <> int i
pprCLabelAddr lbl = char '&' <> pprCLabel 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 :: [CmmStatic] -> [SDoc]
pprStatics [] = []
pprStatics (CmmStaticLit (CmmFloat f W32) : rest)
-- floats are padded to a word, see #1852
| wORD_SIZE == 8, CmmStaticLit (CmmInt 0 W32) : rest' <- rest
= pprLit1 (floatToWord f) : pprStatics rest'
| wORD_SIZE == 4
= pprLit1 (floatToWord f) : pprStatics rest
| otherwise
= pprPanic "pprStatics: float" (vcat (map (\(CmmStaticLit l) -> ppr (cmmLitType l)) rest))
pprStatics (CmmStaticLit (CmmFloat f W64) : rest)
= map pprLit1 (doubleToWords f) ++ pprStatics rest
pprStatics (CmmStaticLit (CmmInt i W64) : rest)
| wordWidth == W32
#ifdef WORDS_BIGENDIAN
= pprStatics (CmmStaticLit (CmmInt q W32) :
CmmStaticLit (CmmInt r W32) : rest)
#else
= pprStatics (CmmStaticLit (CmmInt r W32) :
CmmStaticLit (CmmInt q W32) : rest)
#endif
where r = i .&. 0xffffffff
q = i `shiftR` 32
pprStatics (CmmStaticLit (CmmInt i w) : rest)
| w /= wordWidth
= panic "pprStatics: cannot emit a non-word-sized static literal"
pprStatics (CmmStaticLit lit : rest)
= pprLit1 lit : pprStatics rest
pprStatics (other : rest)
= pprPanic "pprWord" (pprStatic other)
pprStatic :: CmmStatic -> SDoc
pprStatic s = case s of
CmmStaticLit lit -> nest 4 (pprLit lit)
CmmAlign i -> nest 4 (ptext (sLit "/* align */") <+> int i)
CmmDataLabel clbl -> pprCLabel clbl <> colon
CmmUninitialised i -> nest 4 (mkC_ <> brackets (int i))
-- these should be inlined, like the old .hc
CmmString s' -> nest 4 (mkW_ <> parens(pprStringInCStyle s'))
-- ---------------------------------------------------------------------------
-- Block Ids
pprBlockId :: BlockId -> SDoc
pprBlockId b = char '_' <> ppr (getUnique b)
-- --------------------------------------------------------------------------
-- Print a MachOp in a way suitable for emitting via C.
--
pprMachOp_for_C :: MachOp -> SDoc
pprMachOp_for_C mop = case mop of
-- Integer operations
MO_Add _ -> char '+'
MO_Sub _ -> char '-'
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)
-- TEMPORARY: the old code didn't check this case, so let's leave it out
-- to facilitate comparisons against the old output code.
--MO_FF_Conv from to | from == to -> empty
MO_FF_Conv _from to -> parens (machRep_F_CType to)
MO_SF_Conv _from to -> parens (machRep_F_CType to)
MO_FS_Conv _from to -> parens (machRep_S_CType to)
_ -> pprTrace "offending mop" (ptext $ sLit $ show mop) $
panic "PprC.pprMachOp_for_C: unknown machop"
signedOp :: MachOp -> Bool -- Argument type(s) are signed ints
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")
-- ---------------------------------------------------------------------
-- 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_,mkPP_,mkI_,mkA_,mkD_,mkF_,mkB_,mkL_,mkLI_,mkLW_ :: SDoc
mkC_ = ptext (sLit "(C_)") -- StgChar
mkW_ = ptext (sLit "(W_)") -- StgWord
mkP_ = ptext (sLit "(P_)") -- StgWord*
mkPP_ = ptext (sLit "(PP_)") -- P_*
mkI_ = ptext (sLit "(I_)") -- StgInt
mkA_ = ptext (sLit "(A_)") -- StgAddr
mkD_ = ptext (sLit "(D_)") -- const StgWord*
mkF_ = ptext (sLit "(F_)") -- StgFunPtr
mkB_ = ptext (sLit "(B_)") -- StgByteArray
mkL_ = ptext (sLit "(L_)") -- StgClosurePtr
mkLI_ = ptext (sLit "(LI_)") -- StgInt64
mkLW_ = ptext (sLit "(LW_)") -- StgWord64
-- ---------------------------------------------------------------------
--
-- Assignments
--
-- Generating assignments is what we're all about, here
--
pprAssign :: CmmReg -> CmmExpr -> SDoc
-- dest is a reg, rhs is a reg
pprAssign r1 (CmmReg r2)
| 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 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 ptext (sLit "ASSIGN_BaseReg") <> parens x <> semi
else pprReg r1 <> ptext (sLit " = ") <> x <> semi
-- ---------------------------------------------------------------------
-- Registers
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 n VGcPtr)) = True -- if we print via pprAsPtrReg
isPtrReg (CmmGlobal (VanillaReg n 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 CurrentTSO = True
isStrangeTypeGlobal CurrentNursery = True
isStrangeTypeGlobal BaseReg = True
isStrangeTypeGlobal r = isFixedPtrGlobalReg r
strangeRegType :: CmmReg -> Maybe SDoc
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")
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")
pprLocalReg :: LocalReg -> SDoc
pprLocalReg (LocalReg uniq _) = char '_' <> ppr uniq
-- -----------------------------------------------------------------------------
-- Foreign Calls
pprCall :: SDoc -> CCallConv -> HintedCmmFormals -> HintedCmmActuals -> CmmSafety
-> SDoc
pprCall ppr_fn cconv results args _
| not (is_cish cconv)
= panic "pprCall: unknown calling convention"
| otherwise
=
#if x86_64_TARGET_ARCH
-- HACK around gcc optimisations.
-- x86_64 needs a __DISCARD__() here, to create a barrier between
-- putting the arguments into temporaries and passing the arguments
-- to the callee, because the argument expressions may refer to
-- machine registers that are also used for passing arguments in the
-- C calling convention.
(if (not opt_Unregisterised)
then ptext (sLit "__DISCARD__();")
else empty) $$
#endif
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 (ptext (sLit "void *")) expr
-- see comment by machRepHintCType below
pprArg (CmmHinted expr SignedHint)
= cCast (machRep_S_CType $ typeWidth $ cmmExprType expr) expr
pprArg (CmmHinted expr _other)
= pprExpr expr
pprUnHint AddrHint rep = parens (machRepCType rep)
pprUnHint SignedHint rep = parens (machRepCType rep)
pprUnHint _ _ = empty
pprGlobalRegName :: GlobalReg -> SDoc
pprGlobalRegName gr = case gr of
VanillaReg n _ -> char 'R' <> int n -- without the .w suffix
_ -> pprGlobalReg gr
-- Currently we only have these two calling conventions, but this might
-- change in the future...
is_cish CCallConv = True
is_cish StdCallConv = True
-- ---------------------------------------------------------------------
-- Find and print local and external declarations for a list of
-- Cmm statements.
--
pprTempAndExternDecls :: [CmmBasicBlock] -> (SDoc{-temps-}, SDoc{-externs-})
pprTempAndExternDecls stmts
= (vcat (map pprTempDecl (uniqSetToList temps)),
vcat (map (pprExternDecl False{-ToDo-}) (keysFM lbls)))
where (temps, lbls) = runTE (mapM_ te_BB stmts)
pprDataExterns :: [CmmStatic] -> SDoc
pprDataExterns statics
= vcat (map (pprExternDecl False{-ToDo-}) (keysFM lbls))
where (_, lbls) = runTE (mapM_ te_Static statics)
pprTempDecl :: LocalReg -> SDoc
pprTempDecl l@(LocalReg _ rep)
= hcat [ machRepCType rep, space, pprLocalReg l, semi ]
pprExternDecl :: Bool -> CLabel -> SDoc
pprExternDecl in_srt lbl
-- do not print anything for "known external" things
| not (needsCDecl lbl) = empty
| Just sz <- foreignLabelStdcallInfo lbl = stdcall_decl sz
| otherwise =
hcat [ visibility, label_type lbl,
lparen, pprCLabel 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 lbl
<> parens (commafy (replicate (sz `quot` wORD_SIZE) (machRep_U_CType wordWidth)))
<> semi
type TEState = (UniqSet LocalReg, FiniteMap 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, addToFM lbls lbl ()))
te_temp :: LocalReg -> TE ()
te_temp r = TE $ \(temps,lbls) -> ((), (addOneToUniqSet temps r, lbls))
runTE :: TE () -> TEState
runTE (TE m) = snd (m (emptyUniqSet, emptyFM))
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 l2 _) = 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_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
#ifdef BEWARE_LOAD_STORE_ALIGNMENT
cLoad expr rep =
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 expr) <> ptext (sLit "->x")
#else
cLoad expr rep = char '*' <> parens (cCast (machRepPtrCType rep) expr)
#endif
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 rep 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))
charToC :: Word8 -> String
charToC w =
case chr (fromIntegral w) of
'\"' -> "\\\""
'\'' -> "\\\'"
'\\' -> "\\\\"
c | c >= ' ' && c <= '~' -> [c]
| otherwise -> ['\\',
chr (ord '0' + ord c `div` 64),
chr (ord '0' + ord c `div` 8 `mod` 8),
chr (ord '0' + ord c `mod` 8)]
-- ---------------------------------------------------------------------------
-- Initialising static objects with floating-point numbers. We can't
-- just emit the floating point number, because C will cast it to an int
-- by rounding it. We want the actual bit-representation of the float.
-- This is a hack to turn the floating point numbers into ints that we
-- can safely initialise to static locations.
big_doubles
| 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'))
|