(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 Id ( mkWildId )
-import Literal ( Literal(..), isLitLitLit, mkMachInt, mkMachWord
+import Id ( mkWildId, isPrimOpId_maybe )
+import Literal ( Literal(..), mkMachInt, mkMachWord
, literalType
, word2IntLit, int2WordLit
- , intToInt8Lit, intToInt16Lit, intToInt32Lit
- , wordToWord8Lit, wordToWord16Lit, wordToWord32Lit
+ , narrow8IntLit, narrow16IntLit, narrow32IntLit
+ , narrow8WordLit, narrow16WordLit, narrow32WordLit
, char2IntLit, int2CharLit
, float2IntLit, int2FloatLit, double2IntLit, int2DoubleLit
- , addr2IntLit, int2AddrLit, float2DoubleLit, double2FloatLit
+ , float2DoubleLit, double2FloatLit
)
import PrimOp ( PrimOp(..), primOpOcc )
-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 PrelNames ( unpackCStringFoldrName, unpackCStringFoldrIdKey, hasKey )
+import TysWiredIn ( boolTy, trueDataConId, falseDataConId )
+import TyCon ( tyConDataCons_maybe, isEnumerationTyCon, isNewTyCon )
+import DataCon ( dataConTag, dataConTyCon, dataConWorkId, fIRST_TAG )
+import CoreUtils ( cheapEqExpr, exprIsConApp_maybe )
+import Type ( tyConAppTyCon, coreEqType )
+import OccName ( occNameFS )
+import PrelNames ( unpackCStringFoldrName, unpackCStringFoldrIdKey, hasKey,
+ eqStringName, unpackCStringIdKey )
+import Maybes ( orElse )
import Name ( Name )
-import Bits ( Bits(..) )
+import Outputable
+import FastString
+import StaticFlags ( opt_SimplExcessPrecision )
+
+import DATA_BITS ( Bits(..) )
#if __GLASGOW_HASKELL__ >= 500
-import Word ( Word )
+import DATA_WORD ( Word )
#else
-import Word ( Word64 )
+import DATA_WORD ( Word64 )
#endif
-import Outputable
-import CmdLineOpts ( opt_SimplExcessPrecision )
\end{code}
\begin{code}
-primOpRule :: PrimOp -> Maybe CoreRule
-primOpRule op = fmap BuiltinRule (primop_rule op)
+primOpRules :: PrimOp -> Name -> [CoreRule]
+primOpRules op op_name = primop_rule op
where
- op_name = _PK_ (occNameUserString (primOpOcc op))
- op_name_case = op_name _APPEND_ SLIT("->case")
+ 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 }]
-- ToDo: something for integer-shift ops?
-- NotOp
- primop_rule SeqOp = Just seqRule
- primop_rule TagToEnumOp = Just tagToEnumRule
- primop_rule DataToTagOp = Just dataToTagRule
+ primop_rule TagToEnumOp = one_rule tagToEnumRule
+ primop_rule DataToTagOp = one_rule dataToTagRule
-- Int operations
- primop_rule IntAddOp = Just (twoLits (intOp2 (+) op_name))
- primop_rule IntSubOp = Just (twoLits (intOp2 (-) op_name))
- primop_rule IntMulOp = Just (twoLits (intOp2 (*) op_name))
- primop_rule IntQuotOp = Just (twoLits (intOp2Z quot op_name))
- primop_rule IntRemOp = Just (twoLits (intOp2Z rem op_name))
- primop_rule IntNegOp = Just (oneLit (negOp op_name))
+ 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 = Just (twoLits (wordOp2 (+) op_name))
- primop_rule WordSubOp = Just (twoLits (wordOp2 (-) op_name))
- primop_rule WordMulOp = Just (twoLits (wordOp2 (*) op_name))
+ 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 = Just (twoLits (wordOp2Z quot op_name))
- primop_rule WordRemOp = Just (twoLits (wordOp2Z rem op_name))
+ primop_rule WordQuotOp = one_rule (twoLits (wordOp2Z quot))
+ primop_rule WordRemOp = one_rule (twoLits (wordOp2Z rem))
#if __GLASGOW_HASKELL__ >= 407
- primop_rule AndOp = Just (twoLits (wordBitOp2 (.&.) op_name))
- primop_rule OrOp = Just (twoLits (wordBitOp2 (.|.) op_name))
- primop_rule XorOp = Just (twoLits (wordBitOp2 xor op_name))
+ 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 = Just (oneLit (litCoerce word2IntLit op_name))
- primop_rule Int2WordOp = Just (oneLit (litCoerce int2WordLit op_name))
- primop_rule IntToInt8Op = Just (oneLit (litCoerce intToInt8Lit op_name))
- primop_rule IntToInt16Op = Just (oneLit (litCoerce intToInt16Lit op_name))
- primop_rule IntToInt32Op = Just (oneLit (litCoerce intToInt32Lit op_name))
- primop_rule WordToWord8Op = Just (oneLit (litCoerce wordToWord8Lit op_name))
- primop_rule WordToWord16Op = Just (oneLit (litCoerce wordToWord16Lit op_name))
- primop_rule WordToWord32Op = Just (oneLit (litCoerce wordToWord32Lit op_name))
- primop_rule OrdOp = Just (oneLit (litCoerce char2IntLit op_name))
- primop_rule ChrOp = Just (oneLit (litCoerce int2CharLit op_name))
- primop_rule Float2IntOp = Just (oneLit (litCoerce float2IntLit op_name))
- primop_rule Int2FloatOp = Just (oneLit (litCoerce int2FloatLit op_name))
- primop_rule Double2IntOp = Just (oneLit (litCoerce double2IntLit op_name))
- primop_rule Int2DoubleOp = Just (oneLit (litCoerce int2DoubleLit op_name))
- primop_rule Addr2IntOp = Just (oneLit (litCoerce addr2IntLit op_name))
- primop_rule Int2AddrOp = Just (oneLit (litCoerce int2AddrLit op_name))
+ 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 = Just (oneLit (litCoerce float2DoubleLit op_name))
- primop_rule Double2FloatOp = Just (oneLit (litCoerce double2FloatLit op_name))
+ primop_rule Float2DoubleOp = one_rule (oneLit (litCoerce float2DoubleLit))
+ primop_rule Double2FloatOp = one_rule (oneLit (litCoerce double2FloatLit))
-- Float
- primop_rule FloatAddOp = Just (twoLits (floatOp2 (+) op_name))
- primop_rule FloatSubOp = Just (twoLits (floatOp2 (-) op_name))
- primop_rule FloatMulOp = Just (twoLits (floatOp2 (*) op_name))
- primop_rule FloatDivOp = Just (twoLits (floatOp2Z (/) op_name))
- primop_rule FloatNegOp = Just (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 = Just (twoLits (doubleOp2 (+) op_name))
- primop_rule DoubleSubOp = Just (twoLits (doubleOp2 (-) op_name))
- primop_rule DoubleMulOp = Just (twoLits (doubleOp2 (*) op_name))
- primop_rule DoubleDivOp = Just (twoLits (doubleOp2Z (/) op_name))
- primop_rule DoubleNegOp = Just (oneLit (negOp 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 = Just (relop (==) `or_rule` litEq True op_name_case)
- primop_rule IntNeOp = Just (relop (/=) `or_rule` litEq False op_name_case)
- primop_rule CharEqOp = Just (relop (==) `or_rule` litEq True op_name_case)
- primop_rule CharNeOp = Just (relop (/=) `or_rule` litEq False op_name_case)
-
- primop_rule IntGtOp = Just (relop (>))
- primop_rule IntGeOp = Just (relop (>=))
- primop_rule IntLeOp = Just (relop (<=))
- primop_rule IntLtOp = Just (relop (<))
-
- primop_rule CharGtOp = Just (relop (>))
- primop_rule CharGeOp = Just (relop (>=))
- primop_rule CharLeOp = Just (relop (<=))
- primop_rule CharLtOp = Just (relop (<))
-
- primop_rule FloatGtOp = Just (relop (>))
- primop_rule FloatGeOp = Just (relop (>=))
- primop_rule FloatLeOp = Just (relop (<=))
- primop_rule FloatLtOp = Just (relop (<))
- primop_rule FloatEqOp = Just (relop (==))
- primop_rule FloatNeOp = Just (relop (/=))
-
- primop_rule DoubleGtOp = Just (relop (>))
- primop_rule DoubleGeOp = Just (relop (>=))
- primop_rule DoubleLeOp = Just (relop (<=))
- primop_rule DoubleLtOp = Just (relop (<))
- primop_rule DoubleEqOp = Just (relop (==))
- primop_rule DoubleNeOp = Just (relop (/=))
-
- primop_rule WordGtOp = Just (relop (>))
- primop_rule WordGeOp = Just (relop (>=))
- primop_rule WordLeOp = Just (relop (<=))
- primop_rule WordLtOp = Just (relop (<))
- primop_rule WordEqOp = Just (relop (==))
- primop_rule WordNeOp = Just (relop (/=))
-
- primop_rule other = Nothing
-
-
- relop cmp = twoLits (cmpOp (\ord -> ord `cmp` EQ) op_name)
+ 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.
%* *
%************************************************************************
- IMPORTANT NOTE
-
-In all these operations we might find a LitLit as an operand; that's
-why we have the catch-all Nothing case.
+ToDo: the reason these all return Nothing is because there used to be
+the possibility of an argument being a litlit. Litlits are now gone,
+so this could be cleaned up.
\begin{code}
--------------------------
-litCoerce :: (Literal -> Literal) -> RuleName -> Literal -> Maybe (RuleName, CoreExpr)
-litCoerce fn name lit | isLitLitLit lit = Nothing
- | otherwise = Just (name, Lit (fn lit))
+litCoerce :: (Literal -> Literal) -> Literal -> Maybe CoreExpr
+litCoerce fn lit = Just (Lit (fn lit))
--------------------------
-cmpOp :: (Ordering -> Bool) -> FAST_STRING -> Literal -> Literal -> Maybe (RuleName, CoreExpr)
-cmpOp cmp name l1 l2
+cmpOp :: (Ordering -> Bool) -> Literal -> Literal -> Maybe CoreExpr
+cmpOp cmp l1 l2
= go l1 l2
where
- done res | cmp res = Just (name, trueVal)
- | otherwise = Just (name, falseVal)
+ done res | cmp res = Just trueVal
+ | otherwise = Just falseVal
-- These compares are at different types
go (MachChar i1) (MachChar i2) = done (i1 `compare` i2)
--------------------------
-negOp name (MachFloat f) = Just (name, mkFloatVal (-f))
-negOp name (MachDouble d) = Just (name, mkDoubleVal (-d))
-negOp name (MachInt i) = intResult name (-i)
-negOp name l = Nothing
+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
--------------------------
-intOp2 op name (MachInt i1) (MachInt i2)
- = intResult name (i1 `op` i2)
-intOp2 op name l1 l2 = Nothing -- Could find LitLit
+intOp2 op (MachInt i1) (MachInt i2) = intResult (i1 `op` i2)
+intOp2 op l1 l2 = Nothing -- Could find LitLit
-intOp2Z op name (MachInt i1) (MachInt i2)
- | i2 /= 0 = Just (name, mkIntVal (i1 `op` i2))
-intOp2Z op name l1 l2 = Nothing -- LitLit or zero dividend
+intOp2Z op (MachInt i1) (MachInt i2)
+ | i2 /= 0 = Just (mkIntVal (i1 `op` i2))
+intOp2Z op l1 l2 = Nothing -- LitLit or zero dividend
--------------------------
#if __GLASGOW_HASKELL__ >= 500
-wordOp2 op name (MachWord w1) (MachWord w2)
- = wordResult name (w1 `op` w2)
-wordOp2 op name l1 l2 = Nothing -- Could find LitLit
+wordOp2 op (MachWord w1) (MachWord w2)
+ = wordResult (w1 `op` w2)
+wordOp2 op l1 l2 = Nothing -- Could find LitLit
#endif
-wordOp2Z op name (MachWord w1) (MachWord w2)
- | w2 /= 0 = Just (name, mkWordVal (w1 `op` w2))
-wordOp2Z op name l1 l2 = Nothing -- LitLit or zero dividend
+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 name l1@(MachWord w1) l2@(MachWord w2)
- = Just (name, mkWordVal (w1 `op` w2))
+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 name l1@(MachWord w1) l2@(MachWord w2)
- = Just (name, mkWordVal ((fromIntegral::Word64->Integer) (fromIntegral w1 `op` fromIntegral w2)))
+wordBitOp2 op l1@(MachWord w1) l2@(MachWord w2)
+ = Just (mkWordVal ((fromIntegral::Word64->Integer) (fromIntegral w1 `op` fromIntegral w2)))
#endif
-wordBitOp2 op name l1 l2 = Nothing -- Could find LitLit
+wordBitOp2 op l1 l2 = Nothing -- Could find LitLit
--------------------------
-floatOp2 op name (MachFloat f1) (MachFloat f2)
- = Just (name, mkFloatVal (f1 `op` f2))
-floatOp2 op name l1 l2 = Nothing
+floatOp2 op (MachFloat f1) (MachFloat f2)
+ = Just (mkFloatVal (f1 `op` f2))
+floatOp2 op l1 l2 = Nothing
-floatOp2Z op name (MachFloat f1) (MachFloat f2)
- | f2 /= 0 = Just (name, mkFloatVal (f1 `op` f2))
-floatOp2Z op name 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 name l1 l2 = Nothing
+doubleOp2 op (MachDouble f1) (MachDouble f2)
+ = Just (mkDoubleVal (f1 `op` f2))
+doubleOp2 op l1 l2 = Nothing
-doubleOp2Z op name (MachDouble f1) (MachDouble f2)
- | f2 /= 0 = Just (name, mkDoubleVal (f1 `op` f2))
-doubleOp2Z op name l1 l2 = Nothing
+doubleOp2Z op (MachDouble f1) (MachDouble f2)
+ | f2 /= 0 = Just (mkDoubleVal (f1 `op` f2))
+doubleOp2Z op l1 l2 = Nothing
--------------------------
-- (modulo the usual precautions to avoid duplicating e1)
litEq :: Bool -- True <=> equality, False <=> inequality
- -> RuleName
- -> RuleFun
-litEq is_eq name [Lit lit, expr] = do_lit_eq is_eq name lit expr
-litEq is_eq name [expr, Lit lit] = do_lit_eq is_eq name lit expr
-litEq is_eq name other = Nothing
-
-do_lit_eq is_eq name lit expr
- = Just (name, Case expr (mkWildId (literalType lit))
- [(DEFAULT, [], val_if_neq),
- (LitAlt lit, [], val_if_eq)])
+ -> 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)])
where
val_if_eq | is_eq = trueVal
| otherwise = falseVal
-- ((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 :: RuleName -> Integer -> Maybe (RuleName, CoreExpr)
-intResult name result
- = Just (name, mkIntVal (toInteger (fromInteger result :: Int)))
+intResult :: Integer -> Maybe CoreExpr
+intResult result
+ = Just (mkIntVal (toInteger (fromInteger result :: Int)))
#if __GLASGOW_HASKELL__ >= 500
-wordResult :: RuleName -> Integer -> Maybe (RuleName, CoreExpr)
-wordResult name result
- = Just (name, mkWordVal (toInteger (fromInteger result :: Word)))
+wordResult :: Integer -> Maybe CoreExpr
+wordResult result
+ = Just (mkWordVal (toInteger (fromInteger result :: Word)))
#endif
\end{code}
%************************************************************************
\begin{code}
-type RuleFun = [CoreExpr] -> Maybe (RuleName, CoreExpr)
+type RuleFun = [CoreExpr] -> Maybe CoreExpr
-or_rule :: RuleFun -> RuleFun -> RuleFun
-or_rule r1 r2 args = maybe (r2 args) Just (r1 args) -- i.e.: r1 args `mplus` r2 args
-
-twoLits :: (Literal -> Literal -> Maybe (RuleName, CoreExpr)) -> RuleFun
+twoLits :: (Literal -> Literal -> Maybe CoreExpr) -> RuleFun
twoLits rule [Lit l1, Lit l2] = rule (convFloating l1) (convFloating l2)
twoLits rule _ = Nothing
-oneLit :: (Literal -> Maybe (RuleName, CoreExpr)) -> RuleFun
+oneLit :: (Literal -> Maybe CoreExpr) -> RuleFun
oneLit rule [Lit l1] = rule (convFloating l1)
oneLit rule _ = Nothing
%* *
%************************************************************************
-In the parallel world, we use _seq_ to control the order in which
-certain expressions will be evaluated. Operationally, the expression
-``_seq_ a b'' evaluates a and then evaluates b. We have an inlining
-for _seq_ which translates _seq_ to:
-
- _seq_ = /\ a b -> \ x::a y::b -> case seq# x of { 0# -> parError#; _ -> y }
-
-Now, we know that the seq# primitive will never return 0#, but we
-don't let the simplifier know that. We also use a special error
-value, parError#, which is *not* a bottoming Id, so as far as the
-simplifier is concerned, we have to evaluate seq# a before we know
-whether or not y will be evaluated.
-
-If we didn't have the extra case, then after inlining the compiler might
-see:
- f p q = case seq# p of { _ -> p+q }
-
-If it sees that, it can see that f is strict in q, and hence it might
-evaluate q before p! The "0# ->" case prevents this happening.
-By having the parError# branch we make sure that anything in the
-other branch stays there!
-
-This is fine, but we'd like to get rid of the extraneous code. Hence,
-we *do* let the simplifier know that seq# is strict in its argument.
-As a result, we hope that `a' will be evaluated before seq# is called.
-At this point, we have a very special and magical simpification which
-says that ``seq# a'' can be immediately simplified to `1#' if we
-know that `a' is already evaluated.
-
-NB: If we ever do case-floating, we have an extra worry:
-
- case a of
- a' -> let b' = case seq# a of { True -> b; False -> parError# }
- in case b' of ...
-
- =>
-
- case a of
- a' -> let b' = case True of { True -> b; False -> parError# }
- in case b' of ...
-
- =>
-
- case a of
- a' -> let b' = b
- in case b' of ...
-
- =>
-
- case a of
- a' -> case b of ...
-
-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 other = Nothing
-\end{code}
-
-
\begin{code}
tagToEnumRule [Type ty, Lit (MachInt i)]
= ASSERT( isEnumerationTyCon tycon )
- case filter correct_tag (tyConDataConsIfAvailable tycon) of
+ case filter correct_tag (tyConDataCons_maybe tycon `orElse` []) of
[] -> Nothing -- Abstract type
(dc:rest) -> ASSERT( null rest )
- Just (SLIT("TagToEnum"), Var (dataConId dc))
+ Just (Var (dataConWorkId dc))
where
correct_tag dc = (dataConTag dc - fIRST_TAG) == tag
tag = fromInteger i
(b) the argument is a variable whose unfolding is a known constructor
\begin{code}
-dataToTagRule [_, val_arg]
- = case exprIsConApp_maybe val_arg of
- Just (dc,_) -> ASSERT( not (isNewTyCon (dataConTyCon dc)) )
- Just (SLIT("DataToTag"),
- mkIntVal (toInteger (dataConTag dc - fIRST_TAG)))
+dataToTagRule [Type ty1, Var tag_to_enum `App` Type ty2 `App` tag]
+ | Just TagToEnumOp <- isPrimOpId_maybe tag_to_enum
+ , ty1 `coreEqType` ty2
+ = Just tag -- dataToTag (tagToEnum x) ==> x
- other -> Nothing
+dataToTagRule [_, val_arg]
+ | Just (dc,_) <- exprIsConApp_maybe val_arg
+ = ASSERT( not (isNewTyCon (dataConTyCon dc)) )
+ Just (mkIntVal (toInteger (dataConTag dc - fIRST_TAG)))
dataToTagRule other = Nothing
\end{code}
%************************************************************************
\begin{code}
-builtinRules :: [(Name, CoreRule)]
+builtinRules :: [CoreRule]
-- Rules for non-primops that can't be expressed using a RULE pragma
builtinRules
- = [ (unpackCStringFoldrName, BuiltinRule match_append_lit_str)
+ = [ BuiltinRule FSLIT("AppendLitString") unpackCStringFoldrName match_append_lit,
+ BuiltinRule FSLIT("EqString") eqStringName match_eq_string
]
-- The rule is this:
-- unpackFoldrCString# "foo" c (unpackFoldrCString# "baz" c n) = unpackFoldrCString# "foobaz" c n
-match_append_lit_str [Type ty1,
- Lit (MachStr s1),
- c1,
- Var unpk `App` Type ty2
- `App` Lit (MachStr s2)
- `App` c2
- `App` n
- ]
+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 `eqType` ty2 )
- Just (SLIT("AppendLitString"),
- Var unpk `App` Type ty1
- `App` Lit (MachStr (s1 _APPEND_ s2))
+ = ASSERT( ty1 `coreEqType` ty2 )
+ Just (Var unpk `App` Type ty1
+ `App` Lit (MachStr (s1 `appendFS` s2))
`App` c1
`App` n)
-match_append_lit_str other = Nothing
+match_append_lit other = 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)]
+ | unpk1 `hasKey` unpackCStringIdKey,
+ unpk2 `hasKey` unpackCStringIdKey
+ = Just (if s1 == s2 then trueVal else falseVal)
+
+match_eq_string other = Nothing
\end{code}
projects / ghc-hetmet.git / blobdiff