diff options
Diffstat (limited to 'compiler/GHC/Cmm/Expr.hs')
| -rw-r--r-- | compiler/GHC/Cmm/Expr.hs | 473 |
1 files changed, 203 insertions, 270 deletions
diff --git a/compiler/GHC/Cmm/Expr.hs b/compiler/GHC/Cmm/Expr.hs index f910e65f04..ccc94a8b92 100644 --- a/compiler/GHC/Cmm/Expr.hs +++ b/compiler/GHC/Cmm/Expr.hs @@ -10,6 +10,7 @@ module GHC.Cmm.Expr , CmmReg(..), cmmRegType, cmmRegWidth , CmmLit(..), cmmLitType , AlignmentSpec(..) + -- TODO: Remove: , LocalReg(..), localRegType , GlobalReg(..), isArgReg, globalRegType , spReg, hpReg, spLimReg, hpLimReg, nodeReg @@ -26,6 +27,11 @@ module GHC.Cmm.Expr , plusRegSet, minusRegSet, timesRegSet, sizeRegSet, nullRegSet , regSetToList + , isTrivialCmmExpr + , hasNoGlobalRegs + , isLit + , isComparisonExpr + , Area(..) , module GHC.Cmm.MachOp , module GHC.Cmm.Type @@ -39,12 +45,16 @@ import GHC.Cmm.BlockId import GHC.Cmm.CLabel import GHC.Cmm.MachOp import GHC.Cmm.Type +import GHC.Cmm.Reg +import GHC.Utils.Trace (pprTrace) import GHC.Utils.Panic (panic) import GHC.Utils.Outputable import GHC.Types.Unique +import Data.Maybe import Data.Set (Set) import qualified Data.Set as Set +import Numeric ( fromRat ) import GHC.Types.Basic (Alignment, mkAlignment, alignmentOf) @@ -78,14 +88,12 @@ instance Eq CmmExpr where -- Equality ignores the types CmmStackSlot a1 i1 == CmmStackSlot a2 i2 = a1==a2 && i1==i2 _e1 == _e2 = False +instance OutputableP Platform CmmExpr where + pdoc = pprExpr + data AlignmentSpec = NaturallyAligned | Unaligned deriving (Eq, Ord, Show) -data CmmReg - = CmmLocal {-# UNPACK #-} !LocalReg - | CmmGlobal GlobalReg - deriving( Eq, Ord, Show ) - -- | A stack area is either the stack slot where a variable is spilled -- or the stack space where function arguments and results are passed. data Area @@ -94,6 +102,14 @@ data Area -- See Note [Continuation BlockIds] in GHC.Cmm.Node. deriving (Eq, Ord, Show) +instance Outputable Area where + ppr e = pprArea e + +pprArea :: Area -> SDoc +pprArea Old = text "old" +pprArea (Young id) = hcat [ text "young<", ppr id, text ">" ] + + {- Note [Old Area] ~~~~~~~~~~~~~~~~~~ There is a single call area 'Old', allocated at the extreme old @@ -217,6 +233,9 @@ data CmmLit -- of bytes used deriving (Eq, Show) +instance OutputableP Platform CmmLit where + pdoc = pprLit + instance Outputable CmmLit where ppr (CmmInt n w) = text "CmmInt" <+> ppr n <+> ppr w ppr (CmmFloat n w) = text "CmmFloat" <+> text (show n) <+> ppr w @@ -276,38 +295,34 @@ maybeInvertCmmExpr (CmmMachOp op args) = do op' <- maybeInvertComparison op return (CmmMachOp op' args) maybeInvertCmmExpr _ = Nothing ------------------------------------------------------------------------------ --- Local registers ------------------------------------------------------------------------------ - -data LocalReg - = LocalReg {-# UNPACK #-} !Unique !CmmType - -- ^ Parameters: - -- 1. Identifier - -- 2. Type - deriving Show - -instance Eq LocalReg where - (LocalReg u1 _) == (LocalReg u2 _) = u1 == u2 +--------------------------------------------------- +-- CmmExpr predicates +--------------------------------------------------- --- This is non-deterministic but we do not currently support deterministic --- code-generation. See Note [Unique Determinism and code generation] --- See Note [No Ord for Unique] -instance Ord LocalReg where - compare (LocalReg u1 _) (LocalReg u2 _) = nonDetCmpUnique u1 u2 +isTrivialCmmExpr :: CmmExpr -> Bool +isTrivialCmmExpr (CmmLoad _ _ _) = False +isTrivialCmmExpr (CmmMachOp _ _) = False +isTrivialCmmExpr (CmmLit _) = True +isTrivialCmmExpr (CmmReg _) = True +isTrivialCmmExpr (CmmRegOff _ _) = True +isTrivialCmmExpr (CmmStackSlot _ _) = panic "isTrivialCmmExpr CmmStackSlot" -instance Uniquable LocalReg where - getUnique (LocalReg uniq _) = uniq +hasNoGlobalRegs :: CmmExpr -> Bool +hasNoGlobalRegs (CmmLoad e _ _) = hasNoGlobalRegs e +hasNoGlobalRegs (CmmMachOp _ es) = all hasNoGlobalRegs es +hasNoGlobalRegs (CmmLit _) = True +hasNoGlobalRegs (CmmReg (CmmLocal _)) = True +hasNoGlobalRegs (CmmRegOff (CmmLocal _) _) = True +hasNoGlobalRegs _ = False -cmmRegType :: Platform -> CmmReg -> CmmType -cmmRegType _ (CmmLocal reg) = localRegType reg -cmmRegType platform (CmmGlobal reg) = globalRegType platform reg +isLit :: CmmExpr -> Bool +isLit (CmmLit _) = True +isLit _ = False -cmmRegWidth :: Platform -> CmmReg -> Width -cmmRegWidth platform = typeWidth . cmmRegType platform +isComparisonExpr :: CmmExpr -> Bool +isComparisonExpr (CmmMachOp op _) = isComparisonMachOp op +isComparisonExpr _ = False -localRegType :: LocalReg -> CmmType -localRegType (LocalReg _ rep) = rep ----------------------------------------------------------------------------- -- Register-use information for expressions and other types @@ -404,241 +419,159 @@ instance DefinerOfRegs r a => DefinerOfRegs r [a] where foldRegsDefd platform f set as = foldl' (foldRegsDefd platform f) set as {-# INLINABLE foldRegsDefd #-} ------------------------------------------------------------------------------ --- Global STG registers ------------------------------------------------------------------------------ - -data VGcPtr = VGcPtr | VNonGcPtr deriving( Eq, Show ) - ------------------------------------------------------------------------------ --- Global STG registers ------------------------------------------------------------------------------ -{- -Note [Overlapping global registers] -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -The backend might not faithfully implement the abstraction of the STG -machine with independent registers for different values of type -GlobalReg. Specifically, certain pairs of registers (r1, r2) may -overlap in the sense that a store to r1 invalidates the value in r2, -and vice versa. - -Currently this occurs only on the x86_64 architecture where FloatReg n -and DoubleReg n are assigned the same microarchitectural register, in -order to allow functions to receive more Float# or Double# arguments -in registers (as opposed to on the stack). - -There are no specific rules about which registers might overlap with -which other registers, but presumably it's safe to assume that nothing -will overlap with special registers like Sp or BaseReg. - -Use GHC.Cmm.Utils.regsOverlap to determine whether two GlobalRegs overlap -on a particular platform. The instance Eq GlobalReg is syntactic -equality of STG registers and does not take overlap into -account. However it is still used in UserOfRegs/DefinerOfRegs and -there are likely still bugs there, beware! --} - -data GlobalReg - -- Argument and return registers - = VanillaReg -- pointers, unboxed ints and chars - {-# UNPACK #-} !Int -- its number - VGcPtr - - | FloatReg -- single-precision floating-point registers - {-# UNPACK #-} !Int -- its number - - | DoubleReg -- double-precision floating-point registers - {-# UNPACK #-} !Int -- its number - - | LongReg -- long int registers (64-bit, really) - {-# UNPACK #-} !Int -- its number - - | XmmReg -- 128-bit SIMD vector register - {-# UNPACK #-} !Int -- its number - - | YmmReg -- 256-bit SIMD vector register - {-# UNPACK #-} !Int -- its number - - | ZmmReg -- 512-bit SIMD vector register - {-# UNPACK #-} !Int -- its number - - -- STG registers - | Sp -- Stack ptr; points to last occupied stack location. - | SpLim -- Stack limit - | Hp -- Heap ptr; points to last occupied heap location. - | HpLim -- Heap limit register - | CCCS -- Current cost-centre stack - | CurrentTSO -- pointer to current thread's TSO - | CurrentNursery -- pointer to allocation area - | HpAlloc -- allocation count for heap check failure - - -- We keep the address of some commonly-called - -- functions in the register table, to keep code - -- size down: - | EagerBlackholeInfo -- stg_EAGER_BLACKHOLE_info - | GCEnter1 -- stg_gc_enter_1 - | GCFun -- stg_gc_fun - - -- Base offset for the register table, used for accessing registers - -- which do not have real registers assigned to them. This register - -- will only appear after we have expanded GlobalReg into memory accesses - -- (where necessary) in the native code generator. - | BaseReg - - -- The register used by the platform for the C stack pointer. This is - -- a break in the STG abstraction used exclusively to setup stack unwinding - -- information. - | MachSp - - -- The is a dummy register used to indicate to the stack unwinder where - -- a routine would return to. - | UnwindReturnReg - - -- Base Register for PIC (position-independent code) calculations - -- Only used inside the native code generator. It's exact meaning differs - -- from platform to platform (see module PositionIndependentCode). - | PicBaseReg - - deriving( Show ) - -instance Eq GlobalReg where - VanillaReg i _ == VanillaReg j _ = i==j -- Ignore type when seeking clashes - FloatReg i == FloatReg j = i==j - DoubleReg i == DoubleReg j = i==j - LongReg i == LongReg j = i==j - -- NOTE: XMM, YMM, ZMM registers actually are the same registers - -- at least with respect to store at YMM i and then read from XMM i - -- and similarly for ZMM etc. - XmmReg i == XmmReg j = i==j - YmmReg i == YmmReg j = i==j - ZmmReg i == ZmmReg j = i==j - Sp == Sp = True - SpLim == SpLim = True - Hp == Hp = True - HpLim == HpLim = True - CCCS == CCCS = True - CurrentTSO == CurrentTSO = True - CurrentNursery == CurrentNursery = True - HpAlloc == HpAlloc = True - EagerBlackholeInfo == EagerBlackholeInfo = True - GCEnter1 == GCEnter1 = True - GCFun == GCFun = True - BaseReg == BaseReg = True - MachSp == MachSp = True - UnwindReturnReg == UnwindReturnReg = True - PicBaseReg == PicBaseReg = True - _r1 == _r2 = False - --- NOTE: this Ord instance affects the tuple layout in GHCi, see --- Note [GHCi tuple layout] -instance Ord GlobalReg where - compare (VanillaReg i _) (VanillaReg j _) = compare i j - -- Ignore type when seeking clashes - compare (FloatReg i) (FloatReg j) = compare i j - compare (DoubleReg i) (DoubleReg j) = compare i j - compare (LongReg i) (LongReg j) = compare i j - compare (XmmReg i) (XmmReg j) = compare i j - compare (YmmReg i) (YmmReg j) = compare i j - compare (ZmmReg i) (ZmmReg j) = compare i j - compare Sp Sp = EQ - compare SpLim SpLim = EQ - compare Hp Hp = EQ - compare HpLim HpLim = EQ - compare CCCS CCCS = EQ - compare CurrentTSO CurrentTSO = EQ - compare CurrentNursery CurrentNursery = EQ - compare HpAlloc HpAlloc = EQ - compare EagerBlackholeInfo EagerBlackholeInfo = EQ - compare GCEnter1 GCEnter1 = EQ - compare GCFun GCFun = EQ - compare BaseReg BaseReg = EQ - compare MachSp MachSp = EQ - compare UnwindReturnReg UnwindReturnReg = EQ - compare PicBaseReg PicBaseReg = EQ - compare (VanillaReg _ _) _ = LT - compare _ (VanillaReg _ _) = GT - compare (FloatReg _) _ = LT - compare _ (FloatReg _) = GT - compare (DoubleReg _) _ = LT - compare _ (DoubleReg _) = GT - compare (LongReg _) _ = LT - compare _ (LongReg _) = GT - compare (XmmReg _) _ = LT - compare _ (XmmReg _) = GT - compare (YmmReg _) _ = LT - compare _ (YmmReg _) = GT - compare (ZmmReg _) _ = LT - compare _ (ZmmReg _) = GT - compare Sp _ = LT - compare _ Sp = GT - compare SpLim _ = LT - compare _ SpLim = GT - compare Hp _ = LT - compare _ Hp = GT - compare HpLim _ = LT - compare _ HpLim = GT - compare CCCS _ = LT - compare _ CCCS = GT - compare CurrentTSO _ = LT - compare _ CurrentTSO = GT - compare CurrentNursery _ = LT - compare _ CurrentNursery = GT - compare HpAlloc _ = LT - compare _ HpAlloc = GT - compare GCEnter1 _ = LT - compare _ GCEnter1 = GT - compare GCFun _ = LT - compare _ GCFun = GT - compare BaseReg _ = LT - compare _ BaseReg = GT - compare MachSp _ = LT - compare _ MachSp = GT - compare UnwindReturnReg _ = LT - compare _ UnwindReturnReg = GT - compare EagerBlackholeInfo _ = LT - compare _ EagerBlackholeInfo = GT - --- convenient aliases -baseReg, spReg, hpReg, spLimReg, hpLimReg, nodeReg, - currentTSOReg, currentNurseryReg, hpAllocReg, cccsReg :: CmmReg -baseReg = CmmGlobal BaseReg -spReg = CmmGlobal Sp -hpReg = CmmGlobal Hp -hpLimReg = CmmGlobal HpLim -spLimReg = CmmGlobal SpLim -nodeReg = CmmGlobal node -currentTSOReg = CmmGlobal CurrentTSO -currentNurseryReg = CmmGlobal CurrentNursery -hpAllocReg = CmmGlobal HpAlloc -cccsReg = CmmGlobal CCCS - -node :: GlobalReg -node = VanillaReg 1 VGcPtr - -globalRegType :: Platform -> GlobalReg -> CmmType -globalRegType platform = \case - (VanillaReg _ VGcPtr) -> gcWord platform - (VanillaReg _ VNonGcPtr) -> bWord platform - (FloatReg _) -> cmmFloat W32 - (DoubleReg _) -> cmmFloat W64 - (LongReg _) -> cmmBits W64 - -- TODO: improve the internal model of SIMD/vectorized registers - -- the right design SHOULd improve handling of float and double code too. - -- see remarks in "NOTE [SIMD Design for the future]"" in GHC.StgToCmm.Prim - (XmmReg _) -> cmmVec 4 (cmmBits W32) - (YmmReg _) -> cmmVec 8 (cmmBits W32) - (ZmmReg _) -> cmmVec 16 (cmmBits W32) - - Hp -> gcWord platform -- The initialiser for all - -- dynamically allocated closures - _ -> bWord platform - -isArgReg :: GlobalReg -> Bool -isArgReg (VanillaReg {}) = True -isArgReg (FloatReg {}) = True -isArgReg (DoubleReg {}) = True -isArgReg (LongReg {}) = True -isArgReg (XmmReg {}) = True -isArgReg (YmmReg {}) = True -isArgReg (ZmmReg {}) = True -isArgReg _ = False +-- -------------------------------------------------------------------------- +-- Pretty-printing expressions +-- -------------------------------------------------------------------------- + +pprExpr :: Platform -> CmmExpr -> SDoc +pprExpr platform e + = case e of + CmmRegOff reg i -> + pprExpr platform (CmmMachOp (MO_Add rep) + [CmmReg reg, CmmLit (CmmInt (fromIntegral i) rep)]) + where rep = typeWidth (cmmRegType platform reg) + CmmLit lit -> pprLit platform lit + _other -> pprExpr1 platform e + +-- Here's the precedence table from GHC.Cmm.Parser: +-- %nonassoc '>=' '>' '<=' '<' '!=' '==' +-- %left '|' +-- %left '^' +-- %left '&' +-- %left '>>' '<<' +-- %left '-' '+' +-- %left '/' '*' '%' +-- %right '~' + +-- We just cope with the common operators for now, the rest will get +-- a default conservative behaviour. + +-- %nonassoc '>=' '>' '<=' '<' '!=' '==' +pprExpr1, pprExpr7, pprExpr8 :: Platform -> CmmExpr -> SDoc +pprExpr1 platform (CmmMachOp op [x,y]) + | Just doc <- infixMachOp1 op + = pprExpr7 platform x <+> doc <+> pprExpr7 platform y +pprExpr1 platform e = pprExpr7 platform e + +infixMachOp1, infixMachOp7, infixMachOp8 :: MachOp -> Maybe SDoc + +infixMachOp1 (MO_Eq _) = Just (text "==") +infixMachOp1 (MO_Ne _) = Just (text "!=") +infixMachOp1 (MO_Shl _) = Just (text "<<") +infixMachOp1 (MO_U_Shr _) = Just (text ">>") +infixMachOp1 (MO_U_Ge _) = Just (text ">=") +infixMachOp1 (MO_U_Le _) = Just (text "<=") +infixMachOp1 (MO_U_Gt _) = Just (char '>') +infixMachOp1 (MO_U_Lt _) = Just (char '<') +infixMachOp1 _ = Nothing + +-- %left '-' '+' +pprExpr7 platform (CmmMachOp (MO_Add rep1) [x, CmmLit (CmmInt i rep2)]) | i < 0 + = pprExpr7 platform (CmmMachOp (MO_Sub rep1) [x, CmmLit (CmmInt (negate i) rep2)]) +pprExpr7 platform (CmmMachOp op [x,y]) + | Just doc <- infixMachOp7 op + = pprExpr7 platform x <+> doc <+> pprExpr8 platform y +pprExpr7 platform e = pprExpr8 platform e + +infixMachOp7 (MO_Add _) = Just (char '+') +infixMachOp7 (MO_Sub _) = Just (char '-') +infixMachOp7 _ = Nothing + +-- %left '/' '*' '%' +pprExpr8 platform (CmmMachOp op [x,y]) + | Just doc <- infixMachOp8 op + = pprExpr8 platform x <+> doc <+> pprExpr9 platform y +pprExpr8 platform e = pprExpr9 platform e + +infixMachOp8 (MO_U_Quot _) = Just (char '/') +infixMachOp8 (MO_Mul _) = Just (char '*') +infixMachOp8 (MO_U_Rem _) = Just (char '%') +infixMachOp8 _ = Nothing + +pprExpr9 :: Platform -> CmmExpr -> SDoc +pprExpr9 platform e = + case e of + CmmLit lit -> pprLit1 platform lit + CmmLoad expr rep align + -> let align_mark = + case align of + NaturallyAligned -> empty + Unaligned -> text "^" + in ppr rep <> align_mark <> brackets (pdoc platform expr) + CmmReg reg -> ppr reg + CmmRegOff reg off -> parens (ppr reg <+> char '+' <+> int off) + CmmStackSlot a off -> parens (ppr a <+> char '+' <+> int off) + CmmMachOp mop args -> genMachOp platform mop args + +genMachOp :: Platform -> MachOp -> [CmmExpr] -> SDoc +genMachOp platform mop args + | Just doc <- infixMachOp mop = case args of + -- dyadic + [x,y] -> pprExpr9 platform x <+> doc <+> pprExpr9 platform y + + -- unary + [x] -> doc <> pprExpr9 platform x + + _ -> pprTrace "GHC.Cmm.Expr.genMachOp: machop with strange number of args" + (pprMachOp mop <+> + parens (hcat $ punctuate comma (map (pprExpr platform) args))) + empty + + | isJust (infixMachOp1 mop) + || isJust (infixMachOp7 mop) + || isJust (infixMachOp8 mop) = parens (pprExpr platform (CmmMachOp mop args)) + + | otherwise = char '%' <> ppr_op <> parens (commafy (map (pprExpr platform) args)) + where ppr_op = text (map (\c -> if c == ' ' then '_' else c) + (show mop)) + -- replace spaces in (show mop) with underscores, + +-- +-- Unsigned ops on the word size of the machine get nice symbols. +-- All else get dumped in their ugly format. +-- +infixMachOp :: MachOp -> Maybe SDoc +infixMachOp mop + = case mop of + MO_And _ -> Just $ char '&' + MO_Or _ -> Just $ char '|' + MO_Xor _ -> Just $ char '^' + MO_Not _ -> Just $ char '~' + MO_S_Neg _ -> Just $ char '-' -- there is no unsigned neg :) + _ -> Nothing + +-- -------------------------------------------------------------------------- +-- Pretty-printing literals +-- +-- To minimise line noise we adopt the convention that if the literal +-- has the natural machine word size, we do not append the type +-- -------------------------------------------------------------------------- + +pprLit :: Platform -> CmmLit -> SDoc +pprLit platform lit = case lit of + CmmInt i rep -> + hcat [ (if i < 0 then parens else id)(integer i) + , ppUnless (rep == wordWidth platform) $ + space <> dcolon <+> ppr rep ] + + CmmFloat f rep -> hsep [ double (fromRat f), dcolon, ppr rep ] + CmmVec lits -> char '<' <> commafy (map (pprLit platform) lits) <> char '>' + CmmLabel clbl -> pdoc platform clbl + CmmLabelOff clbl i -> pdoc platform clbl <> ppr_offset i + CmmLabelDiffOff clbl1 clbl2 i _ -> pdoc platform clbl1 <> char '-' + <> pdoc platform clbl2 <> ppr_offset i + CmmBlock id -> ppr id + CmmHighStackMark -> text "<highSp>" + +pprLit1 :: Platform -> CmmLit -> SDoc +pprLit1 platform lit@(CmmLabelOff {}) = parens (pprLit platform lit) +pprLit1 platform lit = pprLit platform lit + +ppr_offset :: Int -> SDoc +ppr_offset i + | i==0 = empty + | i>=0 = char '+' <> int i + | otherwise = char '-' <> int (-i) + +commafy :: [SDoc] -> SDoc +commafy xs = fsep $ punctuate comma xs |