From: simonpj@microsoft.com <unknown>
Date: Thu, 10 Aug 2006 14:13:40 +0000 (+0000)
Subject: Do not call preInlineUnconditionally in simplNonRecX
X-Git-Tag: Before_FC_branch_merge~235
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=3df4d7ee5a9ba08583a7671b224f213e8ee4482b

Do not call preInlineUnconditionally in simplNonRecX

This looks to me like a long-standing bug. simplNonRecX was calling
preInlineUnconditionally, even though it was given an already-simplified
expression.  Exponential behaviour beckons.
---

diff --git a/compiler/simplCore/Simplify.lhs b/compiler/simplCore/Simplify.lhs
index d8f9506..4a71774 100644
--- a/compiler/simplCore/Simplify.lhs
+++ b/compiler/simplCore/Simplify.lhs
@@ -364,6 +364,7 @@ simplNonRecX env bndr new_rhs thing_inside
     let body' = wrapFloats floats body in 
     returnSmpl (emptyFloats env, Case new_rhs bndr' (exprType body') [(DEFAULT, [], body')])
 
+{- No, no, no!  Do not try preInlineUnconditionally 
   | preInlineUnconditionally env NotTopLevel bndr new_rhs
   	-- This happens; for example, the case_bndr during case of
 	-- known constructor:  case (a,b) of x { (p,q) -> ... }
@@ -374,6 +375,7 @@ simplNonRecX env bndr new_rhs thing_inside
 	-- e.g.  case (f x, g y) of (a,b) -> ....
 	-- If a,b occur once we can avoid constructing the let binding for them.
   = thing_inside (extendIdSubst env bndr (DoneEx new_rhs))
+-}
 
   | otherwise
   = simplBinder env bndr	`thenSmpl` \ (env, bndr') ->