%
\section[ConFold]{Constant Folder}
+Conceptually, constant folding should be parameterized with the kind
+of target machine to get identical behaviour during compilation time
+and runtime. We cheat a little bit here...
+
ToDo:
check boundaries before folding, e.g. we can fold the Float addition
(i1 + i2) only if it results in a valid Float.
\begin{code}
-module PrelRules ( primOpRule, builtinRules ) where
+
+{-# OPTIONS -optc-DNON_POSIX_SOURCE #-}
+
+module PrelRules ( primOpRules, builtinRules ) where
#include "HsVersions.h"
import CoreSyn
-import Rules ( ProtoCoreRule(..) )
-import Id ( getIdUnfolding )
-import Const ( mkMachInt, mkMachWord, Literal(..), Con(..) )
+import Id ( mkWildId )
+import Literal ( Literal(..), isLitLitLit, mkMachInt, mkMachWord
+ , literalType
+ , word2IntLit, int2WordLit
+ , narrow8IntLit, narrow16IntLit, narrow32IntLit
+ , narrow8WordLit, narrow16WordLit, narrow32WordLit
+ , char2IntLit, int2CharLit
+ , float2IntLit, int2FloatLit, double2IntLit, int2DoubleLit
+ , nullAddrLit, float2DoubleLit, double2FloatLit
+ )
import PrimOp ( PrimOp(..), primOpOcc )
-import TysWiredIn ( trueDataCon, falseDataCon )
-import TyCon ( tyConDataCons, isEnumerationTyCon, isNewTyCon )
-import DataCon ( dataConTag, dataConTyCon, fIRST_TAG )
-import CoreUnfold ( maybeUnfoldingTemplate )
-import CoreUtils ( exprIsValue, cheapEqExpr )
-import Type ( splitTyConApp_maybe )
+import TysWiredIn ( trueDataConId, falseDataConId )
+import TyCon ( tyConDataConsIfAvailable, isEnumerationTyCon, isNewTyCon )
+import DataCon ( dataConTag, dataConTyCon, dataConId, fIRST_TAG )
+import CoreUtils ( exprIsValue, cheapEqExpr, exprIsConApp_maybe )
+import Type ( tyConAppTyCon, eqType )
import OccName ( occNameUserString)
-import ThinAir ( unpackCStringFoldrId )
-import Maybes ( maybeToBool )
-import Char ( ord, chr )
-import Outputable
-
-#if __GLASGOW_HASKELL__ >= 404
-import GlaExts ( fromInt )
+import PrelNames ( unpackCStringFoldrName, unpackCStringFoldrIdKey, hasKey,
+ eqStringName, unpackCStringListIdKey )
+import Name ( Name )
+import Bits ( Bits(..) )
+#if __GLASGOW_HASKELL__ >= 500
+import Word ( Word )
+#else
+import Word ( Word64 )
#endif
+import Outputable
+import CmdLineOpts ( opt_SimplExcessPrecision )
\end{code}
-
\begin{code}
-primOpRule :: PrimOp -> CoreRule
-primOpRule op
- = BuiltinRule (primop_rule op)
+primOpRules :: PrimOp -> [CoreRule]
+primOpRules op = primop_rule op
where
op_name = _PK_ (occNameUserString (primOpOcc op))
- op_name_case = op_name _APPEND_ SLIT("case")
+ op_name_case = op_name _APPEND_ SLIT("->case")
+
+ -- A useful shorthand
+ one_rule rule_fn = [BuiltinRule op_name rule_fn]
-- ToDo: something for integer-shift ops?
-- NotOp
- -- Int2WordOp -- SIGH: these two cause trouble in unfoldery
- -- Int2AddrOp -- as we can't distinguish unsigned literals in interfaces (ToDo?)
-
- primop_rule SeqOp = seqRule
- primop_rule TagToEnumOp = tagToEnumRule
- primop_rule DataToTagOp = dataToTagRule
-
- -- Addr operations
- primop_rule Addr2IntOp = oneLit (addr2IntOp op_name)
-
- -- Char operations
- primop_rule OrdOp = oneLit (chrOp op_name)
-
- -- Int/Word operations
- primop_rule IntAddOp = twoLits (intOp2 (+) op_name)
- primop_rule IntSubOp = twoLits (intOp2 (-) op_name)
- primop_rule IntMulOp = twoLits (intOp2 (*) op_name)
- primop_rule IntQuotOp = twoLits (intOp2Z quot op_name)
- primop_rule IntRemOp = twoLits (intOp2Z rem op_name)
- primop_rule IntNegOp = oneLit (negOp op_name)
-
- primop_rule ChrOp = oneLit (intCoerce (mkCharVal . chr) op_name)
- primop_rule Int2FloatOp = oneLit (intCoerce mkFloatVal op_name)
- primop_rule Int2DoubleOp = oneLit (intCoerce mkDoubleVal op_name)
- primop_rule Word2IntOp = oneLit (intCoerce mkIntVal op_name)
- primop_rule Int2WordOp = oneLit (intCoerce mkWordVal op_name)
+
+ primop_rule AddrNullOp = one_rule nullAddrRule
+ primop_rule SeqOp = one_rule seqRule
+ primop_rule TagToEnumOp = one_rule tagToEnumRule
+ primop_rule DataToTagOp = one_rule dataToTagRule
+
+ -- Int operations
+ primop_rule IntAddOp = one_rule (twoLits (intOp2 (+)))
+ primop_rule IntSubOp = one_rule (twoLits (intOp2 (-)))
+ primop_rule IntMulOp = one_rule (twoLits (intOp2 (*)))
+ primop_rule IntQuotOp = one_rule (twoLits (intOp2Z quot))
+ primop_rule IntRemOp = one_rule (twoLits (intOp2Z rem))
+ primop_rule IntNegOp = one_rule (oneLit negOp)
+
+ -- Word operations
+#if __GLASGOW_HASKELL__ >= 500
+ primop_rule WordAddOp = one_rule (twoLits (wordOp2 (+)))
+ primop_rule WordSubOp = one_rule (twoLits (wordOp2 (-)))
+ primop_rule WordMulOp = one_rule (twoLits (wordOp2 (*)))
+#endif
+ primop_rule WordQuotOp = one_rule (twoLits (wordOp2Z quot))
+ primop_rule WordRemOp = one_rule (twoLits (wordOp2Z rem))
+#if __GLASGOW_HASKELL__ >= 407
+ primop_rule AndOp = one_rule (twoLits (wordBitOp2 (.&.)))
+ primop_rule OrOp = one_rule (twoLits (wordBitOp2 (.|.)))
+ primop_rule XorOp = one_rule (twoLits (wordBitOp2 xor))
+#endif
+
+ -- coercions
+ primop_rule Word2IntOp = one_rule (oneLit (litCoerce word2IntLit))
+ primop_rule Int2WordOp = one_rule (oneLit (litCoerce int2WordLit))
+ primop_rule Narrow8IntOp = one_rule (oneLit (litCoerce narrow8IntLit))
+ primop_rule Narrow16IntOp = one_rule (oneLit (litCoerce narrow16IntLit))
+ primop_rule Narrow32IntOp = one_rule (oneLit (litCoerce narrow32IntLit))
+ primop_rule Narrow8WordOp = one_rule (oneLit (litCoerce narrow8WordLit))
+ primop_rule Narrow16WordOp = one_rule (oneLit (litCoerce narrow16WordLit))
+ primop_rule Narrow32WordOp = one_rule (oneLit (litCoerce narrow32WordLit))
+ primop_rule OrdOp = one_rule (oneLit (litCoerce char2IntLit))
+ primop_rule ChrOp = one_rule (oneLit (litCoerce int2CharLit))
+ primop_rule Float2IntOp = one_rule (oneLit (litCoerce float2IntLit))
+ primop_rule Int2FloatOp = one_rule (oneLit (litCoerce int2FloatLit))
+ primop_rule Double2IntOp = one_rule (oneLit (litCoerce double2IntLit))
+ primop_rule Int2DoubleOp = one_rule (oneLit (litCoerce int2DoubleLit))
+ -- SUP: Not sure what the standard says about precision in the following 2 cases
+ primop_rule Float2DoubleOp = one_rule (oneLit (litCoerce float2DoubleLit))
+ primop_rule Double2FloatOp = one_rule (oneLit (litCoerce double2FloatLit))
-- Float
- primop_rule FloatAddOp = twoLits (floatOp2 (+) op_name)
- primop_rule FloatSubOp = twoLits (floatOp2 (-) op_name)
- primop_rule FloatMulOp = twoLits (floatOp2 (*) op_name)
- primop_rule FloatDivOp = twoLits (floatOp2Z (/) op_name)
- primop_rule FloatNegOp = oneLit (negOp op_name)
+ primop_rule FloatAddOp = one_rule (twoLits (floatOp2 (+)))
+ primop_rule FloatSubOp = one_rule (twoLits (floatOp2 (-)))
+ primop_rule FloatMulOp = one_rule (twoLits (floatOp2 (*)))
+ primop_rule FloatDivOp = one_rule (twoLits (floatOp2Z (/)))
+ primop_rule FloatNegOp = one_rule (oneLit negOp)
-- Double
- primop_rule DoubleAddOp = twoLits (doubleOp2 (+) op_name)
- primop_rule DoubleSubOp = twoLits (doubleOp2 (-) op_name)
- primop_rule DoubleMulOp = twoLits (doubleOp2 (*) op_name)
- primop_rule DoubleDivOp = twoLits (doubleOp2Z (/) op_name)
+ primop_rule DoubleAddOp = one_rule (twoLits (doubleOp2 (+)))
+ primop_rule DoubleSubOp = one_rule (twoLits (doubleOp2 (-)))
+ primop_rule DoubleMulOp = one_rule (twoLits (doubleOp2 (*)))
+ primop_rule DoubleDivOp = one_rule (twoLits (doubleOp2Z (/)))
+ primop_rule DoubleNegOp = one_rule (oneLit negOp)
-- Relational operators
- primop_rule IntEqOp = relop (==) op_name `or_rule` litVar True op_name_case
- primop_rule IntNeOp = relop (/=) op_name `or_rule` litVar False op_name_case
- primop_rule CharEqOp = relop (==) op_name `or_rule` litVar True op_name_case
- primop_rule CharNeOp = relop (/=) op_name `or_rule` litVar False op_name_case
-
- primop_rule IntGtOp = relop (>) op_name
- primop_rule IntGeOp = relop (>=) op_name
- primop_rule IntLeOp = relop (<=) op_name
- primop_rule IntLtOp = relop (<) op_name
-
- primop_rule CharGtOp = relop (>) op_name
- primop_rule CharGeOp = relop (>=) op_name
- primop_rule CharLeOp = relop (<=) op_name
- primop_rule CharLtOp = relop (<) op_name
-
- primop_rule FloatGtOp = relop (>) op_name
- primop_rule FloatGeOp = relop (>=) op_name
- primop_rule FloatLeOp = relop (<=) op_name
- primop_rule FloatLtOp = relop (<) op_name
- primop_rule FloatEqOp = relop (==) op_name
- primop_rule FloatNeOp = relop (/=) op_name
-
- primop_rule DoubleGtOp = relop (>) op_name
- primop_rule DoubleGeOp = relop (>=) op_name
- primop_rule DoubleLeOp = relop (<=) op_name
- primop_rule DoubleLtOp = relop (<) op_name
- primop_rule DoubleEqOp = relop (==) op_name
- primop_rule DoubleNeOp = relop (/=) op_name
-
- primop_rule WordGtOp = relop (>) op_name
- primop_rule WordGeOp = relop (>=) op_name
- primop_rule WordLeOp = relop (<=) op_name
- primop_rule WordLtOp = relop (<) op_name
- primop_rule WordEqOp = relop (==) op_name
- primop_rule WordNeOp = relop (/=) op_name
-
- primop_rule other = \args -> Nothing
+ primop_rule IntEqOp = [BuiltinRule op_name (relop (==)), BuiltinRule op_name_case (litEq True)]
+ primop_rule IntNeOp = [BuiltinRule op_name (relop (/=)), BuiltinRule op_name_case (litEq False)]
+ primop_rule CharEqOp = [BuiltinRule op_name (relop (==)), BuiltinRule op_name_case (litEq True)]
+ primop_rule CharNeOp = [BuiltinRule op_name (relop (/=)), BuiltinRule op_name_case (litEq False)]
+
+ primop_rule IntGtOp = one_rule (relop (>))
+ primop_rule IntGeOp = one_rule (relop (>=))
+ primop_rule IntLeOp = one_rule (relop (<=))
+ primop_rule IntLtOp = one_rule (relop (<))
+
+ primop_rule CharGtOp = one_rule (relop (>))
+ primop_rule CharGeOp = one_rule (relop (>=))
+ primop_rule CharLeOp = one_rule (relop (<=))
+ primop_rule CharLtOp = one_rule (relop (<))
+
+ primop_rule FloatGtOp = one_rule (relop (>))
+ primop_rule FloatGeOp = one_rule (relop (>=))
+ primop_rule FloatLeOp = one_rule (relop (<=))
+ primop_rule FloatLtOp = one_rule (relop (<))
+ primop_rule FloatEqOp = one_rule (relop (==))
+ primop_rule FloatNeOp = one_rule (relop (/=))
+
+ primop_rule DoubleGtOp = one_rule (relop (>))
+ primop_rule DoubleGeOp = one_rule (relop (>=))
+ primop_rule DoubleLeOp = one_rule (relop (<=))
+ primop_rule DoubleLtOp = one_rule (relop (<))
+ primop_rule DoubleEqOp = one_rule (relop (==))
+ primop_rule DoubleNeOp = one_rule (relop (/=))
+
+ primop_rule WordGtOp = one_rule (relop (>))
+ primop_rule WordGeOp = one_rule (relop (>=))
+ primop_rule WordLeOp = one_rule (relop (<=))
+ primop_rule WordLtOp = one_rule (relop (<))
+ primop_rule WordEqOp = one_rule (relop (==))
+ primop_rule WordNeOp = one_rule (relop (/=))
+
+ primop_rule other = []
+
+
+ relop cmp = twoLits (cmpOp (\ord -> ord `cmp` EQ))
+ -- Cunning. cmpOp compares the values to give an Ordering.
+ -- It applies its argument to that ordering value to turn
+ -- the ordering into a boolean value. (`cmp` EQ) is just the job.
\end{code}
%************************************************************************
%* *
%************************************************************************
+ IMPORTANT NOTE
+
+In all these operations we might find a LitLit as an operand; that's
+why we have the catch-all Nothing case.
+
\begin{code}
--------------------------
-intCoerce :: Num a => (a -> CoreExpr) -> RuleName -> Literal -> Maybe (RuleName, CoreExpr)
-intCoerce fn name (MachInt i _) = Just (name, fn (fromInteger i))
+litCoerce :: (Literal -> Literal) -> Literal -> Maybe CoreExpr
+litCoerce fn lit | isLitLitLit lit = Nothing
+ | otherwise = Just (Lit (fn lit))
--------------------------
-relop cmp name = twoLits (\l1 l2 -> Just (name, if l1 `cmp` l2 then trueVal else falseVal))
+cmpOp :: (Ordering -> Bool) -> Literal -> Literal -> Maybe CoreExpr
+cmpOp cmp l1 l2
+ = go l1 l2
+ where
+ done res | cmp res = Just trueVal
+ | otherwise = Just falseVal
+
+ -- These compares are at different types
+ go (MachChar i1) (MachChar i2) = done (i1 `compare` i2)
+ go (MachInt i1) (MachInt i2) = done (i1 `compare` i2)
+ go (MachInt64 i1) (MachInt64 i2) = done (i1 `compare` i2)
+ go (MachWord i1) (MachWord i2) = done (i1 `compare` i2)
+ go (MachWord64 i1) (MachWord64 i2) = done (i1 `compare` i2)
+ go (MachFloat i1) (MachFloat i2) = done (i1 `compare` i2)
+ go (MachDouble i1) (MachDouble i2) = done (i1 `compare` i2)
+ go l1 l2 = Nothing
--------------------------
-negOp name (MachFloat f) = Just (name, mkFloatVal (-f))
-negOp name (MachDouble d) = Just (name, mkDoubleVal (-d))
-negOp name (MachInt i _) = Just (name, mkIntVal (-i))
-chrOp name (MachChar c) = Just (name, mkIntVal (fromInt (ord c)))
-
-addr2IntOp name (MachAddr i) = Just (name, mkIntVal i)
+negOp (MachFloat f) = Just (mkFloatVal (-f))
+negOp (MachDouble d) = Just (mkDoubleVal (-d))
+negOp (MachInt i) = intResult (-i)
+negOp l = Nothing
--------------------------
-intOp2 op name l1@(MachInt i1 s1) l2@(MachInt i2 s2)
- | (result > fromInt maxInt) || (result < fromInt minInt)
- -- Better tell the user that we've overflowed...
- -- ..not that it stops us from actually folding!
- = pprTrace "Warning:" (text "Integer overflow in expression: " <>
- ppr name <+> ppr l1 <+> ppr l2) $
- Just (name, mkIntVal result)
-
- | otherwise
- = ASSERT( s1 && s2 ) -- Both should be signed
- Just (name, mkIntVal result)
- where
- result = i1 `op` i2
-
-intOp2Z op name (MachInt i1 s1) (MachInt i2 s2)
- | i2 == 0 = Nothing -- Don't do it if the dividend < 0
- | otherwise = Just (name, mkIntVal (i1 `op` i2))
+intOp2 op (MachInt i1) (MachInt i2) = intResult (i1 `op` i2)
+intOp2 op l1 l2 = Nothing -- Could find LitLit
+intOp2Z op (MachInt i1) (MachInt i2)
+ | i2 /= 0 = Just (mkIntVal (i1 `op` i2))
+intOp2Z op l1 l2 = Nothing -- LitLit or zero dividend
--------------------------
-floatOp2 op name (MachFloat f1) (MachFloat f2)
- = Just (name, mkFloatVal (f1 `op` f2))
+#if __GLASGOW_HASKELL__ >= 500
+wordOp2 op (MachWord w1) (MachWord w2)
+ = wordResult (w1 `op` w2)
+wordOp2 op l1 l2 = Nothing -- Could find LitLit
+#endif
-floatOp2Z op name (MachFloat f1) (MachFloat f2)
- | f1 /= 0 = Just (name, mkFloatVal (f1 `op` f2))
- | otherwise = Nothing
+wordOp2Z op (MachWord w1) (MachWord w2)
+ | w2 /= 0 = Just (mkWordVal (w1 `op` w2))
+wordOp2Z op l1 l2 = Nothing -- LitLit or zero dividend
+
+#if __GLASGOW_HASKELL__ >= 500
+wordBitOp2 op l1@(MachWord w1) l2@(MachWord w2)
+ = Just (mkWordVal (w1 `op` w2))
+#else
+-- Integer is not an instance of Bits, so we operate on Word64
+wordBitOp2 op l1@(MachWord w1) l2@(MachWord w2)
+ = Just (mkWordVal ((fromIntegral::Word64->Integer) (fromIntegral w1 `op` fromIntegral w2)))
+#endif
+wordBitOp2 op l1 l2 = Nothing -- Could find LitLit
+
+--------------------------
+floatOp2 op (MachFloat f1) (MachFloat f2)
+ = Just (mkFloatVal (f1 `op` f2))
+floatOp2 op l1 l2 = Nothing
+floatOp2Z op (MachFloat f1) (MachFloat f2)
+ | f2 /= 0 = Just (mkFloatVal (f1 `op` f2))
+floatOp2Z op l1 l2 = Nothing
--------------------------
-doubleOp2 op name (MachDouble f1) (MachDouble f2)
- = Just (name, mkDoubleVal (f1 `op` f2))
+doubleOp2 op (MachDouble f1) (MachDouble f2)
+ = Just (mkDoubleVal (f1 `op` f2))
+doubleOp2 op l1 l2 = Nothing
-doubleOp2Z op name (MachDouble f1) (MachDouble f2)
- | f1 /= 0 = Just (name, mkDoubleVal (f1 `op` f2))
- | otherwise = Nothing
+doubleOp2Z op (MachDouble f1) (MachDouble f2)
+ | f2 /= 0 = Just (mkDoubleVal (f1 `op` f2))
+doubleOp2Z op l1 l2 = Nothing
--------------------------
-- m -> e2
-- (modulo the usual precautions to avoid duplicating e1)
-litVar :: Bool -- True <=> equality, False <=> inequality
- -> RuleName
- -> RuleFun
-litVar is_eq name [Con (Literal lit) _, Var var] = do_lit_var is_eq name lit var
-litVar is_eq name [Var var, Con (Literal lit) _] = do_lit_var is_eq name lit var
-litVar is_eq name other = Nothing
+litEq :: Bool -- True <=> equality, False <=> inequality
+ -> RuleFun
+litEq is_eq [Lit lit, expr] = do_lit_eq is_eq lit expr
+litEq is_eq [expr, Lit lit] = do_lit_eq is_eq lit expr
+litEq is_eq other = Nothing
-do_lit_var is_eq name lit var
- = Just (name, Case (Var var) var [(Literal lit, [], val_if_eq),
- (DEFAULT, [], val_if_neq)])
+do_lit_eq is_eq lit expr
+ = Just (Case expr (mkWildId (literalType lit))
+ [(DEFAULT, [], val_if_neq),
+ (LitAlt lit, [], val_if_eq)])
where
val_if_eq | is_eq = trueVal
| otherwise = falseVal
val_if_neq | is_eq = falseVal
| otherwise = trueVal
+
+-- Note that we *don't* warn the user about overflow. It's not done at
+-- runtime either, and compilation of completely harmless things like
+-- ((124076834 :: Word32) + (2147483647 :: Word32))
+-- would yield a warning. Instead we simply squash the value into the
+-- Int range, but not in a way suitable for cross-compiling... :-(
+intResult :: Integer -> Maybe CoreExpr
+intResult result
+ = Just (mkIntVal (toInteger (fromInteger result :: Int)))
+
+#if __GLASGOW_HASKELL__ >= 500
+wordResult :: Integer -> Maybe CoreExpr
+wordResult result
+ = Just (mkWordVal (toInteger (fromInteger result :: Word)))
+#endif
\end{code}
%************************************************************************
\begin{code}
-type RuleFun = [CoreExpr] -> Maybe (RuleName, CoreExpr)
-
-or_rule :: RuleFun -> RuleFun -> RuleFun
-or_rule r1 r2 args = case r1 args of
- Just stuff -> Just stuff
- Nothing -> r2 args
-
-twoLits :: (Literal -> Literal -> Maybe (RuleName, CoreExpr)) -> RuleFun
-twoLits rule [Con (Literal l1) _, Con (Literal l2) _] = rule l1 l2
-twoLits rule other = Nothing
-
-oneLit :: (Literal -> Maybe (RuleName, CoreExpr)) -> RuleFun
-oneLit rule [Con (Literal l1) _] = rule l1
-oneLit rule other = Nothing
-
+type RuleFun = [CoreExpr] -> Maybe CoreExpr
+
+twoLits :: (Literal -> Literal -> Maybe CoreExpr) -> RuleFun
+twoLits rule [Lit l1, Lit l2] = rule (convFloating l1) (convFloating l2)
+twoLits rule _ = Nothing
+
+oneLit :: (Literal -> Maybe CoreExpr) -> RuleFun
+oneLit rule [Lit l1] = rule (convFloating l1)
+oneLit rule _ = Nothing
+
+-- When excess precision is not requested, cut down the precision of the
+-- Rational value to that of Float/Double. We confuse host architecture
+-- and target architecture here, but it's convenient (and wrong :-).
+convFloating :: Literal -> Literal
+convFloating (MachFloat f) | not opt_SimplExcessPrecision =
+ MachFloat (toRational ((fromRational f) :: Float ))
+convFloating (MachDouble d) | not opt_SimplExcessPrecision =
+ MachDouble (toRational ((fromRational d) :: Double))
+convFloating l = l
+
+
+trueVal = Var trueDataConId
+falseVal = Var falseDataConId
+mkIntVal i = Lit (mkMachInt i)
+mkWordVal w = Lit (mkMachWord w)
+mkFloatVal f = Lit (convFloating (MachFloat f))
+mkDoubleVal d = Lit (convFloating (MachDouble d))
+\end{code}
-trueVal = Con (DataCon trueDataCon) []
-falseVal = Con (DataCon falseDataCon) []
-mkIntVal i = Con (Literal (mkMachInt i)) []
-mkCharVal c = Con (Literal (MachChar c)) []
-mkWordVal w = Con (Literal (mkMachWord w)) []
-mkFloatVal f = Con (Literal (MachFloat f)) []
-mkDoubleVal d = Con (Literal (MachDouble d)) []
+\begin{code}
+nullAddrRule _ = Just(Lit nullAddrLit)
\end{code}
The second case must never be floated outside of the first!
\begin{code}
-seqRule [Type ty, arg] | exprIsValue arg = Just (SLIT("Seq"), mkIntVal 1)
+seqRule [Type ty, arg] | exprIsValue arg = Just (mkIntVal 1)
seqRule other = Nothing
\end{code}
\begin{code}
-tagToEnumRule [Type ty, Con (Literal (MachInt i _)) _]
+tagToEnumRule [Type ty, Lit (MachInt i)]
= ASSERT( isEnumerationTyCon tycon )
- Just (SLIT("TagToEnum"), Con (DataCon dc) [])
+ case filter correct_tag (tyConDataConsIfAvailable tycon) of
+
+
+ [] -> Nothing -- Abstract type
+ (dc:rest) -> ASSERT( null rest )
+ Just (Var (dataConId dc))
where
- tag = fromInteger i
- constrs = tyConDataCons tycon
- (dc:_) = [ dc | dc <- constrs, tag == dataConTag dc - fIRST_TAG ]
- (Just (tycon,_)) = splitTyConApp_maybe ty
+ correct_tag dc = (dataConTag dc - fIRST_TAG) == tag
+ tag = fromInteger i
+ tycon = tyConAppTyCon ty
tagToEnumRule other = Nothing
\end{code}
\begin{code}
dataToTagRule [_, val_arg]
- = case val_arg of
- Con (DataCon dc) _ -> yes dc
- Var x -> case maybeUnfoldingTemplate (getIdUnfolding x) of
- Just (Con (DataCon dc) _) -> yes dc
- other -> Nothing
- other -> Nothing
- where
- yes dc = ASSERT( not (isNewTyCon (dataConTyCon dc)) )
- Just (SLIT("DataToTag"),
- mkIntVal (toInteger (dataConTag dc - fIRST_TAG)))
+ = case exprIsConApp_maybe val_arg of
+ Just (dc,_) -> ASSERT( not (isNewTyCon (dataConTyCon dc)) )
+ Just (mkIntVal (toInteger (dataConTag dc - fIRST_TAG)))
+
+ other -> Nothing
dataToTagRule other = Nothing
\end{code}
%************************************************************************
\begin{code}
-builtinRules :: [ProtoCoreRule]
+builtinRules :: [(Name, CoreRule)]
+-- Rules for non-primops that can't be expressed using a RULE pragma
builtinRules
- = [ ProtoCoreRule False unpackCStringFoldrId
- (BuiltinRule match_append_lit_str)
+ = [ (unpackCStringFoldrName, BuiltinRule SLIT("AppendLitString") match_append_lit),
+ (eqStringName, BuiltinRule SLIT("EqString") match_eq_string)
]
--- unpack "foo" c (unpack "baz" c n) = unpack "foobaz" c n
+-- The rule is this:
+-- unpackFoldrCString# "foo" c (unpackFoldrCString# "baz" c n) = unpackFoldrCString# "foobaz" c n
-match_append_lit_str [Type ty1,
- Con (Literal (MachStr s1)) [],
- c1,
- Var unpk `App` Type ty2
- `App` Con (Literal (MachStr s2)) []
- `App` c2
- `App` n
- ]
- | unpk == unpackCStringFoldrId &&
+match_append_lit [Type ty1,
+ Lit (MachStr s1),
+ c1,
+ Var unpk `App` Type ty2
+ `App` Lit (MachStr s2)
+ `App` c2
+ `App` n
+ ]
+ | unpk `hasKey` unpackCStringFoldrIdKey &&
c1 `cheapEqExpr` c2
- = ASSERT( ty1 == ty2 )
- Just (SLIT("AppendLitString"),
- Var unpk `App` Type ty1
- `App` Con (Literal (MachStr (s1 _APPEND_ s2))) []
+ = ASSERT( ty1 `eqType` ty2 )
+ Just (Var unpk `App` Type ty1
+ `App` Lit (MachStr (s1 _APPEND_ s2))
`App` c1
`App` n)
-match_append_lit_str other = Nothing
+match_append_lit other = Nothing
+
+-- The rule is this:
+-- eqString (unpackCStringList# (Lit s1)) (unpackCStringList# (Lit s2) = s1==s2
+
+match_eq_string [Var unpk1 `App` Lit (MachStr s1),
+ Var unpk2 `App` Lit (MachStr s2)]
+ | unpk1 `hasKey` unpackCStringListIdKey,
+ unpk2 `hasKey` unpackCStringListIdKey
+ = Just (if s1 == s2 then trueVal else falseVal)
+
+match_eq_string other = Nothing
\end{code}
projects / ghc-hetmet.git / blobdiff