[commit: ghc] supercompiler: Change lookupIdSubst to rename global variables if a mapping is available (5a51410)

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : supercompiler

http://hackage.haskell.org/trac/ghc/changeset/5a5141018ec6d0629fc1aa0373941abd2683772b

>---------------------------------------------------------------

commit 5a5141018ec6d0629fc1aa0373941abd2683772b
Author: Max Bolingbroke <[email protected]>
Date:   Tue Mar 20 15:27:25 2012 +0000

    Change lookupIdSubst to rename global variables if a mapping is available

>---------------------------------------------------------------

 compiler/coreSyn/CoreSubst.lhs |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/compiler/coreSyn/CoreSubst.lhs b/compiler/coreSyn/CoreSubst.lhs
index 16173fb..96f0a2b 100644
--- a/compiler/coreSyn/CoreSubst.lhs
+++ b/compiler/coreSyn/CoreSubst.lhs
@@ -265,12 +265,11 @@ extendSubstList subst ((var,rhs):prs) = extendSubstList (extendSubst subst var r
 -- | Find the substitution for an 'Id' in the 'Subst'
 lookupIdSubst :: SDoc -> Subst -> Id -> CoreExpr
 lookupIdSubst doc (Subst in_scope ids _ _) v
-  | not (isLocalId v) = Var v
   | Just e  <- lookupVarEnv ids       v = e
   | Just v' <- lookupInScope in_scope v = Var v'
 	-- Vital! See Note [Extending the Subst]
-  | otherwise = WARN( True, ptext (sLit "CoreSubst.lookupIdSubst") <+> doc <+> ppr v 
-                            $$ ppr in_scope) 
+  | otherwise = WARN( isLocalId v, ptext (sLit "CoreSubst.lookupIdSubst") <+> doc <+> ppr v 
+                                   $$ ppr in_scope) 
 		Var v
 
 -- | Find the substitution for a 'TyVar' in the 'Subst'