commit 41429e3f1e4d72ee4f7d4df786b5b0c87405f5b0
author Chris Lattner <sabre@nondot.org> Thu Feb 17 02:23:02 2011 +0000
committer Chris Lattner <sabre@nondot.org> Thu Feb 17 02:23:02 2011 +0000
tree b84c775e728c3187f9450e611f2b6115eef0a6ef
parent 3e468e1efafe905b34f51517f7211ae62cbff480

preserve NUW/NSW when transforming add x,x


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125711 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/InstCombine/InstCombineAddSub.cpp

diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 4ff005e..89cc540 100644
--- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -147,8 +147,13 @@
     return BinaryOperator::CreateXor(LHS, RHS);
 
   // X + X --> X << 1
-  if (LHS == RHS && I.getType()->isIntegerTy())
-    return BinaryOperator::CreateShl(LHS, ConstantInt::get(I.getType(), 1));
+  if (LHS == RHS && I.getType()->isIntegerTy()) {
+    BinaryOperator *New =
+      BinaryOperator::CreateShl(LHS, ConstantInt::get(I.getType(), 1));
+    New->setHasNoSignedWrap(I.hasNoSignedWrap());
+    New->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
+    return New;
+  }
 
   // -A + B  -->  B - A
   // -A + -B  -->  -(A + B)