commit c7ebba1e4c07dc61f8aee843c4f2afba0ef7b79e
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 be03175da682845c2982d401fa3dcb63b48d190b
parent 276793921c7f7caf2edfb2e3a4406d322c019e1c

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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70176 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/ScalarEvolution.cpp

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 495290d..a9521bb 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/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))