[project @ 2003-02-20 13:00:24 by simonpj]

Eliminate bogus string-literal duplication

diff --git a/ghc/compiler/basicTypes/Literal.lhs b/ghc/compiler/basicTypes/Literal.lhs
index f2d09f3..b8e28d8 100644 (file)
--- a/ghc/compiler/basicTypes/Literal.lhs
+++ b/ghc/compiler/basicTypes/Literal.lhs
@@ -8,7 +8,8 @@ module Literal
        ( Literal(..)           -- Exported to ParseIface
        , mkMachInt, mkMachWord
        , mkMachInt64, mkMachWord64
-       , isLitLitLit, maybeLitLit, litSize, litIsDupable,
+       , isLitLitLit, maybeLitLit, litSize
+       , litIsDupable, litIsTrivial
        , literalType, literalPrimRep
        , hashLiteral
 
@@ -282,9 +283,17 @@ isLitLitLit _                   = False
 maybeLitLit (MachLitLit s t) = Just (s,t)
 maybeLitLit _               = Nothing
 
+litIsTrivial :: Literal -> Bool
+-- True if there is absolutely no penalty to duplicating the literal
+--     c.f. CoreUtils.exprIsTrivial
+-- False principally of strings
+litIsTrivial (MachStr _) = False
+litIsTrivial other      = True
+
 litIsDupable :: Literal -> Bool
-       -- True if code space does not go bad if we duplicate this literal
-       -- False principally of strings
+-- True if code space does not go bad if we duplicate this literal
+--     c.f. CoreUtils.exprIsDupable
+-- Currently we treat it just like litIsTrivial
 litIsDupable (MachStr _) = False
 litIsDupable other      = True
 

diff --git a/ghc/compiler/coreSyn/CoreUtils.lhs b/ghc/compiler/coreSyn/CoreUtils.lhs
index 9de9bf1..537f85b 100644 (file)
--- a/ghc/compiler/coreSyn/CoreUtils.lhs
+++ b/ghc/compiler/coreSyn/CoreUtils.lhs
@@ -45,7 +45,7 @@ import PprCore                ( pprCoreExpr )
 import Var             ( Var, isId, isTyVar )
 import VarEnv
 import Name            ( hashName )
-import Literal         ( hashLiteral, literalType, litIsDupable, isZeroLit )
+import Literal         ( hashLiteral, literalType, litIsDupable, litIsTrivial, isZeroLit )
 import DataCon         ( DataCon, dataConRepArity, dataConArgTys, isExistentialDataCon, dataConTyCon )
 import PrimOp          ( PrimOp(..), primOpOkForSpeculation, primOpIsCheap )
 import Id              ( Id, idType, globalIdDetails, idNewStrictness, 
@@ -326,7 +326,7 @@ saturating them.
 \begin{code}
 exprIsTrivial (Var v)     = True       -- See notes above
 exprIsTrivial (Type _)    = True
-exprIsTrivial (Lit lit)    = True
+exprIsTrivial (Lit lit)    = litIsTrivial lit
 exprIsTrivial (App e arg)  = not (isRuntimeArg arg) && exprIsTrivial e
 exprIsTrivial (Note _ e)   = exprIsTrivial e
 exprIsTrivial (Lam b body) = not (isRuntimeVar b) && exprIsTrivial body