From: Eli Friedman <eli.friedman@gmail.com>
Date: Mon, 5 Mar 2012 23:22:40 +0000 (+0000)
Subject: A few more cases of missing masking in ComputeMaskedBits; found by inspection.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=923bb4117a13eac03a6ff630a108829ab767d519;p=oota-llvm.git

A few more cases of missing masking in ComputeMaskedBits; found by inspection.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152070 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index b35e2074acb..745e5fe99cc 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -723,17 +723,17 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask,
         // If this call is undefined for 0, the result will be less than 2^n.
         if (II->getArgOperand(1) == ConstantInt::getTrue(II->getContext()))
           LowBits -= 1;
-        KnownZero = APInt::getHighBitsSet(BitWidth, BitWidth - LowBits);
+        KnownZero = Mask & APInt::getHighBitsSet(BitWidth, BitWidth - LowBits);
         break;
       }
       case Intrinsic::ctpop: {
         unsigned LowBits = Log2_32(BitWidth)+1;
-        KnownZero = APInt::getHighBitsSet(BitWidth, BitWidth - LowBits);
+        KnownZero = Mask & APInt::getHighBitsSet(BitWidth, BitWidth - LowBits);
         break;
       }
       case Intrinsic::x86_sse42_crc32_64_8:
       case Intrinsic::x86_sse42_crc32_64_64:
-        KnownZero = APInt::getHighBitsSet(64, 32);
+        KnownZero = Mask & APInt::getHighBitsSet(64, 32);
         break;
       }
     }