[KnownBits] Add wrapper methods for setting and clear all bits in the underlying APInts in KnownBits.

This adds routines for reseting KnownBits to unknown, making the value all zeros or all ones. It also adds methods for querying if the value is zero, all ones or unknown.

Differential Revision: https://reviews.llvm.org/D32637

llvm-svn: 302262

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/Lint.cpp b/llvm/lib/Analysis/Lint.cpp
index 59813824644..471ccb62970 100644
--- a/llvm/lib/Analysis/Lint.cpp
+++ b/llvm/lib/Analysis/Lint.cpp
@@ -537,7 +537,7 @@ static bool isZero(Value *V, const DataLayout &DL, DominatorTree *DT,
     unsigned BitWidth = V->getType()->getIntegerBitWidth();
     KnownBits Known(BitWidth);
     computeKnownBits(V, Known, DL, 0, AC, dyn_cast<Instruction>(V), DT);
-    return Known.Zero.isAllOnesValue();
+    return Known.isZero();
   }
 
   // Per-component check doesn't work with zeroinitializer
@@ -558,7 +558,7 @@ static bool isZero(Value *V, const DataLayout &DL, DominatorTree *DT,
 
     KnownBits Known(BitWidth);
     computeKnownBits(Elem, Known, DL);
-    if (Known.Zero.isAllOnesValue())
+    if (Known.isZero())
       return true;
   }