#include "HsVersions.h"
import CoreSyn
-import Id ( mkWildId, isPrimOpId_maybe )
+import Id ( mkWildId, idUnfolding )
import Literal ( Literal(..), mkMachInt, mkMachWord
, literalType
, word2IntLit, int2WordLit
, float2IntLit, int2FloatLit, double2IntLit, int2DoubleLit
, float2DoubleLit, double2FloatLit
)
-import PrimOp ( PrimOp(..), primOpOcc )
+import PrimOp ( PrimOp(..), tagToEnumKey )
import TysWiredIn ( boolTy, trueDataConId, falseDataConId )
import TyCon ( tyConDataCons_maybe, isEnumerationTyCon, isNewTyCon )
import DataCon ( dataConTag, dataConTyCon, dataConWorkId, fIRST_TAG )
import Type ( tyConAppTyCon, coreEqType )
import OccName ( occNameFS )
import PrelNames ( unpackCStringFoldrName, unpackCStringFoldrIdKey, hasKey,
- eqStringName, unpackCStringIdKey )
+ eqStringName, unpackCStringIdKey, inlineIdName )
import Maybes ( orElse )
-import Name ( Name )
+import Name ( Name, nameOccName )
import Outputable
import FastString
import StaticFlags ( opt_SimplExcessPrecision )
-import DATA_BITS ( Bits(..) )
+import Data.Bits ( Bits(..) )
#if __GLASGOW_HASKELL__ >= 500
-import DATA_WORD ( Word )
+import Data.Word ( Word )
#else
-import DATA_WORD ( Word64 )
+import Data.Word ( Word64 )
#endif
\end{code}
+Note [Constant folding]
+~~~~~~~~~~~~~~~~~~~~~~~
+primOpRules generates the rewrite rules for each primop
+These rules do what is often called "constant folding"
+E.g. the rules for +# might say
+ 4 +# 5 = 9
+Well, of course you'd need a lot of rules if you did it
+like that, so we use a BuiltinRule instead, so that we
+can match in any two literal values. So the rule is really
+more like
+ (Lit 4) +# (Lit y) = Lit (x+#y)
+where the (+#) on the rhs is done at compile time
+
+That is why these rules are built in here. Other rules
+which don't need to be built in are in GHC.Base. For
+example:
+ x +# 0 = x
+
+
\begin{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
-- 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 (*)))
+ primop_rule WordAddOp = two_lits (wordOp2 (+))
+ primop_rule WordSubOp = two_lits (wordOp2 (-))
+ primop_rule WordMulOp = two_lits (wordOp2 (*))
#endif
- primop_rule WordQuotOp = one_rule (twoLits (wordOp2Z quot))
- primop_rule WordRemOp = one_rule (twoLits (wordOp2Z rem))
+ primop_rule WordQuotOp = two_lits (wordOp2Z quot)
+ primop_rule WordRemOp = two_lits (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))
+ primop_rule AndOp = two_lits (wordBitOp2 (.&.))
+ primop_rule OrOp = two_lits (wordBitOp2 (.|.))
+ primop_rule XorOp = two_lits (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))
+ 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 (litCoerce 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 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 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}
%************************************************************************
-- 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 other = Nothing
+
+ do_lit_eq lit expr
+ = Just (Case expr (mkWildId (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
%************************************************************************
\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 -> ([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 = Var trueDataConId
falseVal = Var falseDataConId
mkIntVal i = Lit (mkMachInt i)
\begin{code}
dataToTagRule [Type ty1, Var tag_to_enum `App` Type ty2 `App` tag]
- | Just TagToEnumOp <- isPrimOpId_maybe tag_to_enum
+ | tag_to_enum `hasKey` tagToEnumKey
, ty1 `coreEqType` ty2
= Just tag -- dataToTag (tagToEnum x) ==> x
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("AppendLitString") unpackCStringFoldrName 4 match_append_lit,
+ BuiltinRule FSLIT("EqString") eqStringName 2 match_eq_string,
+ BuiltinRule FSLIT("Inline") inlineIdName 1 match_inline
]
+---------------------------------------------------
-- The rule is this:
-- unpackFoldrCString# "foo" c (unpackFoldrCString# "baz" c n) = unpackFoldrCString# "foobaz" c n
match_append_lit other = Nothing
+---------------------------------------------------
-- The rule is this:
-- eqString (unpackCString# (Lit s1)) (unpackCString# (Lit s2) = s1==s2
= Just (if s1 == s2 then trueVal else falseVal)
match_eq_string other = Nothing
+
+
+---------------------------------------------------
+-- The rule is this:
+-- inline (f a b c) = <f's unfolding> a b c
+-- (if f has an unfolding)
+match_inline (e:_)
+ | (Var f, args1) <- collectArgs e,
+ Just unf <- maybeUnfoldingTemplate (idUnfolding f)
+ = Just (mkApps unf args1)
+
+match_inline other = Nothing
\end{code}