commit 05c1d372b770f812930915663e4fd8e315234808
author Dan Gohman <gohman@apple.com> Mon Apr 27 01:41:10 2009 +0000
committer Dan Gohman <gohman@apple.com> Mon Apr 27 01:41:10 2009 +0000
tree 2668511caca279fd4e61f7dc4c6429e53184fdb8
parent 6019e07b3b06d6c21d805424688a3df503773bc0

Handle ands with ~0 correctly too. This fixes PR4052.

llvm-svn: 70176

llvm/lib/Analysis/ScalarEvolution.cpp

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 495290d..a9521bb 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -1756,6 +1756,8 @@
     if (ConstantInt *CI = dyn_cast<ConstantInt>(U->getOperand(1))) {
       if (CI->isNullValue())
         return getSCEV(U->getOperand(1));
+      if (CI->isAllOnesValue())
+        return getSCEV(U->getOperand(0));
       const APInt &A = CI->getValue();
       unsigned Ones = A.countTrailingOnes();
       if (APIntOps::isMask(Ones, A))