commit ab6ceab8a65e26667a437a4ace7fe93a3772c6ff
author David Majnemer <david.majnemer@gmail.com> Tue Jul 09 18:11:10 2013 +0000
committer David Majnemer <david.majnemer@gmail.com> Tue Jul 09 18:11:10 2013 +0000
tree abed41e4b29796b9ab0694e5f35dd30cd0ffc9c6
parent 29b741942807bc4c0441d98f1330b70446794b88

ValueTracking: Fix bugs in isKnownToBeAPowerOfTwo

(add nsw x, (and x, y)) isn't a power of two if x is zero, it's zero
(add nsw x, (xor x, y)) isn't a power of two if y has bits set that aren't set in x


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185954 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/ValueTracking.cpp

diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index b3693b3..1b20a25 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -861,16 +861,14 @@
         // Adding a power of two to the same power of two is a power of two or
         // zero.
         if (BinaryOperator *XBO = dyn_cast<BinaryOperator>(X))
-          if (XBO->getOpcode() == Instruction::And ||
-              XBO->getOpcode() == Instruction::Xor)
+          if (XBO->getOpcode() == Instruction::And)
             if (XBO->getOperand(0) == Y || XBO->getOperand(1) == Y)
-              if (isKnownToBeAPowerOfTwo(Y, /*OrZero*/true, Depth))
+              if (isKnownToBeAPowerOfTwo(Y, OrZero, Depth))
                 return true;
         if (BinaryOperator *YBO = dyn_cast<BinaryOperator>(Y))
-          if (YBO->getOpcode() == Instruction::And ||
-              YBO->getOpcode() == Instruction::Xor)
+          if (YBO->getOpcode() == Instruction::And)
             if (YBO->getOperand(0) == X || YBO->getOperand(1) == X)
-              if (isKnownToBeAPowerOfTwo(X, /*OrZero*/true, Depth))
+              if (isKnownToBeAPowerOfTwo(X, OrZero, Depth))
                 return true;
       }