From: simonpj@microsoft.com <unknown>
Date: Tue, 3 Nov 2009 15:48:11 +0000 (+0000)
Subject: Comment only
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=eeef817a869bdbfa8820608be081f133dad71071;p=ghc-hetmet.git

Comment only
---

diff --git a/compiler/deSugar/DsExpr.lhs b/compiler/deSugar/DsExpr.lhs
index 11fddf5..d8bd7cd 100644
--- a/compiler/deSugar/DsExpr.lhs
+++ b/compiler/deSugar/DsExpr.lhs
@@ -656,6 +656,7 @@ dsExplicitList elt_ty xs
        ; let (dynamic_prefix, static_suffix) = spanTail is_static xs'
        ; if opt_SimpleListLiterals 	       		-- -fsimple-list-literals
          || not (dopt Opt_EnableRewriteRules dflags)	-- Rewrite rules off
+	    	-- Don't generate a build if there are no rules to eliminate it!
          || null dynamic_prefix   -- Avoid build (\c n. foldr c n xs)!
          then return $ mkListExpr elt_ty xs'
          else mkBuildExpr elt_ty (mkSplitExplicitList dynamic_prefix static_suffix) }