From 86c0e232b7ce1fe640d474c7dcb57f1e19253c7c Mon Sep 17 00:00:00 2001
From: Shuxin Yang <shuxin.llvm@gmail.com>
Date: Tue, 4 Dec 2012 03:28:32 +0000
Subject: rdar://12329730 (2nd part, revised)

The type of shirt-right (logical or arithemetic) should remain unchanged
when transforming  "X << C1 >> C2" into "X << (C1-C2)"

llvm-svn: 169209
---
 llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp')

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index c65076e..c832ca5 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -876,7 +876,8 @@ Value *InstCombiner::SimplifyShrShlDemandedBits(Instruction *Shr,
       New->setHasNoUnsignedWrap(Orig->hasNoUnsignedWrap());
     } else {
       Constant *Amt = ConstantInt::get(VarX->getType(), ShrAmt - ShlAmt);
-      New = BinaryOperator::CreateLShr(VarX, Amt);
+      New = isLshr ? BinaryOperator::CreateLShr(VarX, Amt) :
+                     BinaryOperator::CreateAShr(VarX, Amt);
     }
 
     return InsertNewInstWith(New, *Shl);
-- 
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