From 53af2d13e763c2d6e8ea1baf29644d954edb999d Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 11 Jan 2010 22:49:40 +0000
Subject: [PATCH] reenable the piece that turns trunc(zext(x)) -> x even if
 zext has multiple uses, codegen has no apparent problem with the trunc
 version of this, because it turns into a simple subreg idiom

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93202 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/InstCombine/InstCombineCasts.cpp | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index b5da3e615be..e018b351082 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -327,9 +327,7 @@ static bool CanEvaluateTruncated(Value *V, const Type *Ty) {
   
   // If this is an extension from the dest type, we can eliminate it, even if it
   // has multiple uses.
-  // FIXME: This is currently disabled until codegen can handle this without
-  // pessimizing code, PR5997.
-  if (0 && (isa<ZExtInst>(I) || isa<SExtInst>(I)) && 
+  if ((isa<ZExtInst>(I) || isa<SExtInst>(I)) && 
       I->getOperand(0)->getType() == Ty)
     return true;