(i1 + i2) only if it results in a valid Float.
\begin{code}
-
{-# OPTIONS -optc-DNON_POSIX_SOURCE #-}
module PrelRules ( primOpRules, builtinRules ) where
#include "HsVersions.h"
import CoreSyn
-import Id ( mkWildId, idUnfolding )
-import Literal ( Literal(..), mkMachInt, mkMachWord
- , literalType
- , word2IntLit, int2WordLit
- , narrow8IntLit, narrow16IntLit, narrow32IntLit
- , narrow8WordLit, narrow16WordLit, narrow32WordLit
- , char2IntLit, int2CharLit
- , float2IntLit, int2FloatLit, double2IntLit, int2DoubleLit
- , float2DoubleLit, double2FloatLit
- )
-import PrimOp ( PrimOp(..), primOpOcc, tagToEnumKey )
-import TysWiredIn ( boolTy, trueDataConId, falseDataConId )
+import MkCore
+import Id
+import Literal
+import PrimOp ( PrimOp(..), tagToEnumKey )
+import TysWiredIn
import TyCon ( tyConDataCons_maybe, isEnumerationTyCon, isNewTyCon )
import DataCon ( dataConTag, dataConTyCon, dataConWorkId, fIRST_TAG )
-import CoreUtils ( cheapEqExpr, exprIsConApp_maybe )
-import Type ( tyConAppTyCon, coreEqType )
+import CoreUtils ( cheapEqExpr )
+import CoreUnfold ( exprIsConApp_maybe )
+import Type
import OccName ( occNameFS )
-import PrelNames ( unpackCStringFoldrName, unpackCStringFoldrIdKey, hasKey,
- eqStringName, unpackCStringIdKey, inlineIdName )
+import PrelNames
import Maybes ( orElse )
-import Name ( Name )
+import Name ( Name, nameOccName )
import Outputable
import FastString
import StaticFlags ( opt_SimplExcessPrecision )
+import Constants
-import Data.Bits ( Bits(..) )
-#if __GLASGOW_HASKELL__ >= 500
+import Data.Bits as Bits
import Data.Word ( Word )
-#else
-import Data.Word ( Word64 )
-#endif
\end{code}
primOpRules :: PrimOp -> Name -> [CoreRule]
primOpRules op op_name = primop_rule op
where
- rule_name = occNameFS (primOpOcc op)
- rule_name_case = rule_name `appendFS` FSLIT("->case")
-
-- A useful shorthand
- one_rule rule_fn = [BuiltinRule { ru_name = rule_name,
- ru_fn = op_name,
- ru_try = rule_fn }]
- case_rule rule_fn = [BuiltinRule { ru_name = rule_name_case,
- ru_fn = op_name,
- ru_try = rule_fn }]
+ one_lit = oneLit op_name
+ two_lits = twoLits op_name
+ relop cmp = two_lits (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.
-- ToDo: something for integer-shift ops?
-- NotOp
- primop_rule TagToEnumOp = one_rule tagToEnumRule
- primop_rule DataToTagOp = one_rule dataToTagRule
+ primop_rule TagToEnumOp = mkBasicRule op_name 2 tagToEnumRule
+ primop_rule DataToTagOp = mkBasicRule op_name 2 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)
+ primop_rule IntAddOp = two_lits (intOp2 (+))
+ primop_rule IntSubOp = two_lits (intOp2 (-))
+ primop_rule IntMulOp = two_lits (intOp2 (*))
+ primop_rule IntQuotOp = two_lits (intOp2Z quot)
+ primop_rule IntRemOp = two_lits (intOp2Z rem)
+ primop_rule IntNegOp = one_lit negOp
+ primop_rule ISllOp = two_lits (intShiftOp2 Bits.shiftL)
+ primop_rule ISraOp = two_lits (intShiftOp2 Bits.shiftR)
+ primop_rule ISrlOp = two_lits (intShiftOp2 shiftRightLogical)
-- 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
+ primop_rule WordAddOp = two_lits (wordOp2 (+))
+ primop_rule WordSubOp = two_lits (wordOp2 (-))
+ primop_rule WordMulOp = two_lits (wordOp2 (*))
+ primop_rule WordQuotOp = two_lits (wordOp2Z quot)
+ primop_rule WordRemOp = two_lits (wordOp2Z rem)
+ primop_rule AndOp = two_lits (wordBitOp2 (.&.))
+ primop_rule OrOp = two_lits (wordBitOp2 (.|.))
+ primop_rule XorOp = two_lits (wordBitOp2 xor)
+ primop_rule SllOp = two_lits (wordShiftOp2 Bits.shiftL)
+ primop_rule SrlOp = two_lits (wordShiftOp2 shiftRightLogical)
-- 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))
+ primop_rule Word2IntOp = one_lit (litCoerce word2IntLit)
+ primop_rule Int2WordOp = one_lit (litCoerce int2WordLit)
+ primop_rule Narrow8IntOp = one_lit (litCoerce narrow8IntLit)
+ primop_rule Narrow16IntOp = one_lit (litCoerce narrow16IntLit)
+ primop_rule Narrow32IntOp = one_lit (litCoerce narrow32IntLit)
+ primop_rule Narrow8WordOp = one_lit (litCoerce narrow8WordLit)
+ primop_rule Narrow16WordOp = one_lit (litCoerce narrow16WordLit)
+ primop_rule Narrow32WordOp = one_lit (litCoerce narrow32WordLit)
+ primop_rule OrdOp = one_lit (litCoerce char2IntLit)
+ primop_rule ChrOp = one_lit (predLitCoerce litFitsInChar int2CharLit)
+ primop_rule Float2IntOp = one_lit (litCoerce float2IntLit)
+ primop_rule Int2FloatOp = one_lit (litCoerce int2FloatLit)
+ primop_rule Double2IntOp = one_lit (litCoerce double2IntLit)
+ primop_rule Int2DoubleOp = one_lit (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))
+ primop_rule Float2DoubleOp = one_lit (litCoerce float2DoubleLit)
+ primop_rule Double2FloatOp = one_lit (litCoerce double2FloatLit)
-- Float
- 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)
+ primop_rule FloatAddOp = two_lits (floatOp2 (+))
+ primop_rule FloatSubOp = two_lits (floatOp2 (-))
+ primop_rule FloatMulOp = two_lits (floatOp2 (*))
+ primop_rule FloatDivOp = two_lits (floatOp2Z (/))
+ primop_rule FloatNegOp = one_lit negOp
-- Double
- 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)
+ primop_rule DoubleAddOp = two_lits (doubleOp2 (+))
+ primop_rule DoubleSubOp = two_lits (doubleOp2 (-))
+ primop_rule DoubleMulOp = two_lits (doubleOp2 (*))
+ primop_rule DoubleDivOp = two_lits (doubleOp2Z (/))
+ primop_rule DoubleNegOp = one_lit negOp
-- Relational operators
- primop_rule IntEqOp = one_rule (relop (==)) ++ case_rule (litEq True)
- primop_rule IntNeOp = one_rule (relop (/=)) ++ case_rule (litEq False)
- primop_rule CharEqOp = one_rule (relop (==)) ++ case_rule (litEq True)
- primop_rule CharNeOp = one_rule (relop (/=)) ++ case_rule (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.
+ primop_rule IntEqOp = relop (==) ++ litEq op_name True
+ primop_rule IntNeOp = relop (/=) ++ litEq op_name False
+ primop_rule CharEqOp = relop (==) ++ litEq op_name True
+ primop_rule CharNeOp = relop (/=) ++ litEq op_name False
+
+ primop_rule IntGtOp = relop (>)
+ primop_rule IntGeOp = relop (>=)
+ primop_rule IntLeOp = relop (<=)
+ primop_rule IntLtOp = relop (<)
+
+ primop_rule CharGtOp = relop (>)
+ primop_rule CharGeOp = relop (>=)
+ primop_rule CharLeOp = relop (<=)
+ primop_rule CharLtOp = relop (<)
+
+ primop_rule FloatGtOp = relop (>)
+ primop_rule FloatGeOp = relop (>=)
+ primop_rule FloatLeOp = relop (<=)
+ primop_rule FloatLtOp = relop (<)
+ primop_rule FloatEqOp = relop (==)
+ primop_rule FloatNeOp = relop (/=)
+
+ primop_rule DoubleGtOp = relop (>)
+ primop_rule DoubleGeOp = relop (>=)
+ primop_rule DoubleLeOp = relop (<=)
+ primop_rule DoubleLtOp = relop (<)
+ primop_rule DoubleEqOp = relop (==)
+ primop_rule DoubleNeOp = relop (/=)
+
+ primop_rule WordGtOp = relop (>)
+ primop_rule WordGeOp = relop (>=)
+ primop_rule WordLeOp = relop (<=)
+ primop_rule WordLtOp = relop (<)
+ primop_rule WordEqOp = relop (==)
+ primop_rule WordNeOp = relop (/=)
+
+ primop_rule _ = []
+
+
\end{code}
%************************************************************************
litCoerce :: (Literal -> Literal) -> Literal -> Maybe CoreExpr
litCoerce fn lit = Just (Lit (fn lit))
+predLitCoerce :: (Literal -> Bool) -> (Literal -> Literal) -> Literal -> Maybe CoreExpr
+predLitCoerce p fn lit
+ | p lit = Just (Lit (fn lit))
+ | otherwise = Nothing
+
--------------------------
cmpOp :: (Ordering -> Bool) -> Literal -> Literal -> Maybe CoreExpr
cmpOp cmp l1 l2
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
+ go _ _ = Nothing
--------------------------
-negOp (MachFloat 0.0) = Nothing -- can't represent -0.0 as a Rational
-negOp (MachFloat f) = Just (mkFloatVal (-f))
+negOp :: Literal -> Maybe CoreExpr -- Negate
+negOp (MachFloat 0.0) = Nothing -- can't represent -0.0 as a Rational
+negOp (MachFloat f) = Just (mkFloatVal (-f))
negOp (MachDouble 0.0) = Nothing
negOp (MachDouble d) = Just (mkDoubleVal (-d))
negOp (MachInt i) = intResult (-i)
-negOp l = Nothing
+negOp _ = Nothing
--------------------------
+intOp2 :: (Integer->Integer->Integer) -> Literal -> Literal -> Maybe CoreExpr
intOp2 op (MachInt i1) (MachInt i2) = intResult (i1 `op` i2)
-intOp2 op l1 l2 = Nothing -- Could find LitLit
+intOp2 _ _ _ = Nothing -- Could find LitLit
+intOp2Z :: (Integer->Integer->Integer) -> Literal -> Literal -> Maybe CoreExpr
+-- Like intOp2, but Nothing if i2=0
intOp2Z op (MachInt i1) (MachInt i2)
- | i2 /= 0 = Just (mkIntVal (i1 `op` i2))
-intOp2Z op l1 l2 = Nothing -- LitLit or zero dividend
+ | i2 /= 0 = intResult (i1 `op` i2)
+intOp2Z _ _ _ = Nothing -- LitLit or zero dividend
+
+intShiftOp2 :: (Integer->Int->Integer) -> Literal -> Literal -> Maybe CoreExpr
+ -- Shifts take an Int; hence second arg of op is Int
+intShiftOp2 op (MachInt i1) (MachInt i2) = intResult (i1 `op` fromInteger i2)
+intShiftOp2 _ _ _ = Nothing
+
+shiftRightLogical :: Integer -> Int -> Integer
+-- Shift right, putting zeros in rather than sign-propagating as Bits.shiftR would do
+-- Do this by converting to Word and back. Obviously this won't work for big
+-- values, but its ok as we use it here
+shiftRightLogical x n = fromIntegral (fromInteger x `shiftR` n :: Word)
+
--------------------------
-#if __GLASGOW_HASKELL__ >= 500
+wordOp2 :: (Integer->Integer->Integer) -> Literal -> Literal -> Maybe CoreExpr
wordOp2 op (MachWord w1) (MachWord w2)
= wordResult (w1 `op` w2)
-wordOp2 op l1 l2 = Nothing -- Could find LitLit
-#endif
+wordOp2 _ _ _ = Nothing -- Could find LitLit
+wordOp2Z :: (Integer->Integer->Integer) -> Literal -> Literal -> Maybe CoreExpr
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
+ | w2 /= 0 = wordResult (w1 `op` w2)
+wordOp2Z _ _ _ = Nothing -- LitLit or zero dividend
+
+wordBitOp2 :: (Integer->Integer->Integer) -> Literal -> Literal
+ -> Maybe CoreExpr
+wordBitOp2 op (MachWord w1) (MachWord w2)
+ = wordResult (w1 `op` w2)
+wordBitOp2 _ _ _ = Nothing -- Could find LitLit
+
+wordShiftOp2 :: (Integer->Int->Integer) -> Literal -> Literal -> Maybe CoreExpr
+ -- Shifts take an Int; hence second arg of op is Int
+wordShiftOp2 op (MachWord x) (MachInt n)
+ = wordResult (x `op` fromInteger n)
+ -- Do the shift at type Integer
+wordShiftOp2 _ _ _ = Nothing
--------------------------
+floatOp2 :: (Rational -> Rational -> Rational) -> Literal -> Literal
+ -> Maybe (Expr CoreBndr)
floatOp2 op (MachFloat f1) (MachFloat f2)
= Just (mkFloatVal (f1 `op` f2))
-floatOp2 op l1 l2 = Nothing
+floatOp2 _ _ _ = Nothing
+floatOp2Z :: (Rational -> Rational -> Rational) -> Literal -> Literal
+ -> Maybe (Expr CoreBndr)
floatOp2Z op (MachFloat f1) (MachFloat f2)
- | f2 /= 0 = Just (mkFloatVal (f1 `op` f2))
-floatOp2Z op l1 l2 = Nothing
+ | (f1 /= 0 || f2 > 0) -- see Note [negative zero]
+ && f2 /= 0 -- avoid NaN and Infinity/-Infinity
+ = Just (mkFloatVal (f1 `op` f2))
+floatOp2Z _ _ _ = Nothing
--------------------------
+doubleOp2 :: (Rational -> Rational -> Rational) -> Literal -> Literal
+ -> Maybe (Expr CoreBndr)
doubleOp2 op (MachDouble f1) (MachDouble f2)
= Just (mkDoubleVal (f1 `op` f2))
-doubleOp2 op l1 l2 = Nothing
+doubleOp2 _ _ _ = Nothing
+doubleOp2Z :: (Rational -> Rational -> Rational) -> Literal -> Literal
+ -> Maybe (Expr CoreBndr)
doubleOp2Z op (MachDouble f1) (MachDouble f2)
- | f2 /= 0 = Just (mkDoubleVal (f1 `op` f2))
-doubleOp2Z op l1 l2 = Nothing
+ | (f1 /= 0 || f2 > 0) -- see Note [negative zero]
+ && f2 /= 0 -- avoid NaN and Infinity/-Infinity
+ = Just (mkDoubleVal (f1 `op` f2))
+ -- Note [negative zero] Avoid (0 / -d), otherwise 0/(-1) reduces to
+ -- zero, but we might want to preserve the negative zero here which
+ -- is representable in Float/Double but not in (normalised)
+ -- Rational. (#3676) Perhaps we should generate (0 :% (-1)) instead?
+doubleOp2Z _ _ _ = Nothing
--------------------------
-- m -> e2
-- (modulo the usual precautions to avoid duplicating e1)
-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_eq is_eq lit expr
- = Just (Case expr (mkWildId (literalType lit)) boolTy
- [(DEFAULT, [], val_if_neq),
- (LitAlt lit, [], val_if_eq)])
+litEq :: Name
+ -> Bool -- True <=> equality, False <=> inequality
+ -> [CoreRule]
+litEq op_name is_eq
+ = [BuiltinRule { ru_name = occNameFS (nameOccName op_name)
+ `appendFS` (fsLit "->case"),
+ ru_fn = op_name,
+ ru_nargs = 2, ru_try = rule_fn }]
where
+ rule_fn _ [Lit lit, expr] = do_lit_eq lit expr
+ rule_fn _ [expr, Lit lit] = do_lit_eq lit expr
+ rule_fn _ _ = Nothing
+
+ do_lit_eq lit expr
+ = Just (mkWildCase expr (literalType lit) boolTy
+ [(DEFAULT, [], val_if_neq),
+ (LitAlt lit, [], val_if_eq)])
val_if_eq | is_eq = trueVal
- | otherwise = falseVal
+ | otherwise = falseVal
val_if_neq | is_eq = falseVal
| otherwise = trueVal
-- 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... :-(
+-- *target* Int/Word range.
intResult :: Integer -> Maybe CoreExpr
intResult result
- = Just (mkIntVal (toInteger (fromInteger result :: Int)))
+ = Just (mkIntVal (toInteger (fromInteger result :: TargetInt)))
-#if __GLASGOW_HASKELL__ >= 500
wordResult :: Integer -> Maybe CoreExpr
wordResult result
- = Just (mkWordVal (toInteger (fromInteger result :: Word)))
-#endif
+ = Just (mkWordVal (toInteger (fromInteger result :: TargetWord)))
\end{code}
%************************************************************************
\begin{code}
-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
+mkBasicRule :: Name -> Int
+ -> (IdUnfoldingFun -> [CoreExpr] -> Maybe CoreExpr)
+ -> [CoreRule]
+-- Gives the Rule the same name as the primop itself
+mkBasicRule op_name n_args rule_fn
+ = [BuiltinRule { ru_name = occNameFS (nameOccName op_name),
+ ru_fn = op_name,
+ ru_nargs = n_args, ru_try = rule_fn }]
+
+oneLit :: Name -> (Literal -> Maybe CoreExpr)
+ -> [CoreRule]
+oneLit op_name test
+ = mkBasicRule op_name 1 rule_fn
+ where
+ rule_fn _ [Lit l1] = test (convFloating l1)
+ rule_fn _ _ = Nothing
-oneLit :: (Literal -> Maybe CoreExpr) -> RuleFun
-oneLit rule [Lit l1] = rule (convFloating l1)
-oneLit rule _ = Nothing
+twoLits :: Name -> (Literal -> Literal -> Maybe CoreExpr)
+ -> [CoreRule]
+twoLits op_name test
+ = mkBasicRule op_name 2 rule_fn
+ where
+ rule_fn _ [Lit l1, Lit l2] = test (convFloating l1) (convFloating l2)
+ rule_fn _ _ = Nothing
-- When excess precision is not requested, cut down the precision of the
-- Rational value to that of Float/Double. We confuse host architecture
MachDouble (toRational ((fromRational d) :: Double))
convFloating l = l
-
+trueVal, falseVal :: Expr CoreBndr
trueVal = Var trueDataConId
falseVal = Var falseDataConId
+mkIntVal :: Integer -> Expr CoreBndr
mkIntVal i = Lit (mkMachInt i)
+mkWordVal :: Integer -> Expr CoreBndr
mkWordVal w = Lit (mkMachWord w)
+mkFloatVal :: Rational -> Expr CoreBndr
mkFloatVal f = Lit (convFloating (MachFloat f))
+mkDoubleVal :: Rational -> Expr CoreBndr
mkDoubleVal d = Lit (convFloating (MachDouble d))
\end{code}
%* *
%************************************************************************
+Note [tagToEnum#]
+~~~~~~~~~~~~~~~~~
+Nasty check to ensure that tagToEnum# is applied to a type that is an
+enumeration TyCon. Unification may refine the type later, but this
+check won't see that, alas. It's crude but it works.
+
+Here's are two cases that should fail
+ f :: forall a. a
+ f = tagToEnum# 0 -- Can't do tagToEnum# at a type variable
+
+ g :: Int
+ g = tagToEnum# 0 -- Int is not an enumeration
+
+We used to make this check in the type inference engine, but it's quite
+ugly to do so, because the delayed constraint solving means that we don't
+really know what's going on until the end. It's very much a corner case
+because we don't expect the user to call tagToEnum# at all; we merely
+generate calls in derived instances of Enum. So we compromise: a
+rewrite rule rewrites a bad instance of tagToEnum# to an error call,
+and emits a warning.
+
\begin{code}
-tagToEnumRule [Type ty, Lit (MachInt i)]
+tagToEnumRule :: IdUnfoldingFun -> [Expr CoreBndr] -> Maybe (Expr CoreBndr)
+tagToEnumRule _ [Type ty, _]
+ | not (is_enum_ty ty) -- See Note [tagToEnum#]
+ = WARN( True, ptext (sLit "tagToEnum# on non-enumeration type") <+> ppr ty )
+ Just (mkRuntimeErrorApp rUNTIME_ERROR_ID ty "tagToEnum# on non-enumeration type")
+ where
+ is_enum_ty ty = case splitTyConApp_maybe ty of
+ Just (tc, _) -> isEnumerationTyCon tc
+ Nothing -> False
+
+tagToEnumRule _ [Type ty, Lit (MachInt i)]
= ASSERT( isEnumerationTyCon tycon )
case filter correct_tag (tyConDataCons_maybe tycon `orElse` []) of
-
-
[] -> Nothing -- Abstract type
(dc:rest) -> ASSERT( null rest )
Just (Var (dataConWorkId dc))
tag = fromInteger i
tycon = tyConAppTyCon ty
-tagToEnumRule other = Nothing
+tagToEnumRule _ _ = Nothing
\end{code}
+
For dataToTag#, we can reduce if either
(a) the argument is a constructor
(b) the argument is a variable whose unfolding is a known constructor
\begin{code}
-dataToTagRule [Type ty1, Var tag_to_enum `App` Type ty2 `App` tag]
+dataToTagRule :: IdUnfoldingFun -> [Expr CoreBndr] -> Maybe (Arg CoreBndr)
+dataToTagRule _ [Type ty1, Var tag_to_enum `App` Type ty2 `App` tag]
| tag_to_enum `hasKey` tagToEnumKey
, ty1 `coreEqType` ty2
= Just tag -- dataToTag (tagToEnum x) ==> x
-dataToTagRule [_, val_arg]
- | Just (dc,_) <- exprIsConApp_maybe val_arg
+dataToTagRule id_unf [_, val_arg]
+ | Just (dc,_,_) <- exprIsConApp_maybe id_unf val_arg
= ASSERT( not (isNewTyCon (dataConTyCon dc)) )
Just (mkIntVal (toInteger (dataConTag dc - fIRST_TAG)))
-dataToTagRule other = Nothing
+dataToTagRule _ _ = Nothing
\end{code}
%************************************************************************
%* *
%************************************************************************
+Note [Scoping for Builtin rules]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+When compiling a (base-package) module that defines one of the
+functions mentioned in the RHS of a built-in rule, there's a danger
+that we'll see
+
+ f = ...(eq String x)....
+
+ ....and lower down...
+
+ eqString = ...
+
+Then a rewrite would give
+
+ f = ...(eqString x)...
+ ....and lower down...
+ eqString = ...
+
+and lo, eqString is not in scope. This only really matters when we get to code
+generation. With -O we do a GlomBinds step that does a new SCC analysis on the whole
+set of bindings, which sorts out the dependency. Without -O we don't do any rule
+rewriting so again we are fine.
+
+(This whole thing doesn't show up for non-built-in rules because their dependencies
+are explicit.)
+
+
\begin{code}
builtinRules :: [CoreRule]
-- Rules for non-primops that can't be expressed using a RULE pragma
builtinRules
- = [ BuiltinRule FSLIT("AppendLitString") unpackCStringFoldrName match_append_lit,
- BuiltinRule FSLIT("EqString") eqStringName match_eq_string,
- BuiltinRule FSLIT("Inline") inlineIdName match_inline
+ = [ BuiltinRule { ru_name = fsLit "AppendLitString", ru_fn = unpackCStringFoldrName,
+ ru_nargs = 4, ru_try = match_append_lit },
+ BuiltinRule { ru_name = fsLit "EqString", ru_fn = eqStringName,
+ ru_nargs = 2, ru_try = match_eq_string },
+ BuiltinRule { ru_name = fsLit "Inline", ru_fn = inlineIdName,
+ ru_nargs = 2, ru_try = match_inline }
]
---------------------------------------------------
-- The rule is this:
--- unpackFoldrCString# "foo" c (unpackFoldrCString# "baz" c n) = unpackFoldrCString# "foobaz" c n
-
-match_append_lit [Type ty1,
- Lit (MachStr s1),
- c1,
- Var unpk `App` Type ty2
- `App` Lit (MachStr s2)
- `App` c2
- `App` n
- ]
+-- unpackFoldrCString# "foo" c (unpackFoldrCString# "baz" c n)
+-- = unpackFoldrCString# "foobaz" c n
+
+match_append_lit :: IdUnfoldingFun -> [Expr CoreBndr] -> Maybe (Expr CoreBndr)
+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 `coreEqType` ty2 )
`App` c1
`App` n)
-match_append_lit other = Nothing
+match_append_lit _ _ = Nothing
---------------------------------------------------
-- The rule is this:
-- eqString (unpackCString# (Lit s1)) (unpackCString# (Lit s2) = s1==s2
-match_eq_string [Var unpk1 `App` Lit (MachStr s1),
- Var unpk2 `App` Lit (MachStr s2)]
+match_eq_string :: IdUnfoldingFun -> [Expr CoreBndr] -> Maybe (Expr CoreBndr)
+match_eq_string _ [Var unpk1 `App` Lit (MachStr s1),
+ Var unpk2 `App` Lit (MachStr s2)]
| unpk1 `hasKey` unpackCStringIdKey,
unpk2 `hasKey` unpackCStringIdKey
= Just (if s1 == s2 then trueVal else falseVal)
-match_eq_string other = Nothing
+match_eq_string _ _ = Nothing
---------------------------------------------------
-- The rule is this:
--- inline (f a b c) = <f's unfolding> a b c
--- (if f has an unfolding)
-match_inline (e:args2)
+-- inline f_ty (f a b c) = <f's unfolding> a b c
+-- (if f has an unfolding, EVEN if it's a loop breaker)
+--
+-- It's important to allow the argument to 'inline' to have args itself
+-- (a) because its more forgiving to allow the programmer to write
+-- inline f a b c
+-- or inline (f a b c)
+-- (b) because a polymorphic f wll get a type argument that the
+-- programmer can't avoid
+--
+-- Also, don't forget about 'inline's type argument!
+match_inline :: IdUnfoldingFun -> [Expr CoreBndr] -> Maybe (Expr CoreBndr)
+match_inline _ (Type _ : e : _)
| (Var f, args1) <- collectArgs e,
- Just unf <- maybeUnfoldingTemplate (idUnfolding f)
- = Just (mkApps (mkApps unf args1) args2)
+ Just unf <- maybeUnfoldingTemplate (realIdUnfolding f)
+ -- Ignore the IdUnfoldingFun here!
+ = Just (mkApps unf args1)
+
+match_inline _ _ = Nothing
+\end{code}
-match_inline other = Nothing
-\end{code}
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