diff --git a/llvm/include/llvm/Support/KnownBits.h b/llvm/include/llvm/Support/KnownBits.h
--- a/llvm/include/llvm/Support/KnownBits.h
+++ b/llvm/include/llvm/Support/KnownBits.h
@@ -293,9 +293,48 @@
     return KnownBits(~C, C);
   }
 
+  /// Returns the greatest lower bound of this (aka LHS) and RHS, i.e. the
+  /// information that is known to be true for both LHS and RHS.
+  ///
+  /// When an operation is known to return one of its operands, this can be used
+  /// to combine information about the known bits of the operands to get the
+  /// information that must be true about the result.
+  void meet(const KnownBits &RHS) {
+    Zero &= RHS.Zero;
+    One &= RHS.One;
+  }
+  static KnownBits meet(KnownBits LHS, const KnownBits &RHS) {
+    LHS.meet(RHS);
+    return LHS;
+  }
+  static KnownBits meet(const KnownBits &LHS, KnownBits &&RHS) {
+    RHS.meet(LHS);
+    return std::move(RHS);
+  }
+
+  /// Returns the least upper bound of this (aka LHS) and RHS, i.e. the
+  /// information that is known to be true for either LHS or RHS or both.
+  ///
+  /// This can be used to combine different sources of information about the
+  /// known bits of a single value, e.g. information about the low bits and the
+  /// high bits of the result of a multiplication.
+  void join(const KnownBits &RHS) {
+    Zero |= RHS.Zero;
+    One |= RHS.One;
+  }
+  static KnownBits join(KnownBits LHS, const KnownBits &RHS) {
+    LHS.join(RHS);
+    return LHS;
+  }
+  static KnownBits join(const KnownBits &LHS, KnownBits &&RHS) {
+    RHS.join(LHS);
+    return std::move(RHS);
+  }
+
   /// Compute known bits common to LHS and RHS.
+  LLVM_DEPRECATED("use meet instead", "meet")
   static KnownBits commonBits(const KnownBits &LHS, const KnownBits &RHS) {
-    return KnownBits(LHS.Zero & RHS.Zero, LHS.One & RHS.One);
+    return meet(LHS, RHS);
   }
 
   /// Return true if LHS and RHS have no common bits set.
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -668,8 +668,7 @@
     if (match(Cmp, m_c_ICmp(Pred, m_V, m_Value(A)))) {
       KnownBits RHSKnown =
           computeKnownBits(A, Depth + 1, QueryNoAC).anyextOrTrunc(BitWidth);
-      Known.Zero |= RHSKnown.Zero;
-      Known.One |= RHSKnown.One;
+      Known.join(RHSKnown);
       // assume(v & b = a)
     } else if (match(Cmp,
                      m_c_ICmp(Pred, m_c_And(m_V, m_Value(B)), m_Value(A)))) {
@@ -758,9 +757,8 @@
       // For those bits in RHS that are known, we can propagate them to known
       // bits in V shifted to the right by C.
       RHSKnown.Zero.lshrInPlace(C);
-      Known.Zero |= RHSKnown.Zero;
       RHSKnown.One.lshrInPlace(C);
-      Known.One |= RHSKnown.One;
+      Known.join(RHSKnown);
       // assume(~(v << c) = a)
     } else if (match(Cmp, m_c_ICmp(Pred, m_Not(m_Shl(m_V, m_ConstantInt(C))),
                                    m_Value(A))) &&
@@ -1053,8 +1051,7 @@
         continue;
     }
 
-    Known = KnownBits::commonBits(
-        Known, KF(Known2, KnownBits::makeConstant(APInt(32, ShiftAmt))));
+    Known.meet(KF(Known2, KnownBits::makeConstant(APInt(32, ShiftAmt))));
   }
 
   // If the known bits conflict, the result is poison. Return a 0 and hope the
@@ -1242,7 +1239,7 @@
     computeKnownBits(I->getOperand(1), Known2, Depth + 1, Q);
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
 
     if (SPF == SPF_ABS) {
       // RHS from matchSelectPattern returns the negation part of abs pattern.
@@ -1680,7 +1677,7 @@
           }
         }
 
-        Known = KnownBits::commonBits(Known, Known2);
+        Known.meet(Known2);
         // If all bits have been ruled out, there's no need to check
         // more operands.
         if (Known.isUnknown())
@@ -1699,8 +1696,7 @@
       computeKnownBitsFromRangeMetadata(*MD, Known);
     if (const Value *RV = cast<CallBase>(I)->getReturnedArgOperand()) {
       computeKnownBits(RV, Known2, Depth + 1, Q);
-      Known.Zero |= Known2.Zero;
-      Known.One |= Known2.One;
+      Known.join(Known2);
     }
     if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
       switch (II->getIntrinsicID()) {
@@ -1872,7 +1868,7 @@
     if (!!DemandedRHS) {
       const Value *RHS = Shuf->getOperand(1);
       computeKnownBits(RHS, DemandedRHS, Known2, Depth + 1, Q);
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
     }
     break;
   }
@@ -1905,7 +1901,7 @@
     DemandedVecElts.clearBit(EltIdx);
     if (!!DemandedVecElts) {
       computeKnownBits(Vec, DemandedVecElts, Known2, Depth + 1, Q);
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
     }
     break;
   }
diff --git a/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp b/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
--- a/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
@@ -115,7 +115,7 @@
   computeKnownBitsImpl(Src0, Known2, DemandedElts, Depth);
 
   // Only known if known in both the LHS and RHS.
-  Known = KnownBits::commonBits(Known, Known2);
+  Known.meet(Known2);
 }
 
 // Bitfield extract is computed as (Src >> Offset) & Mask, where Mask is
@@ -191,7 +191,7 @@
                            Depth + 1);
 
       // Known bits are the values that are shared by every demanded element.
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
 
       // If we don't know any bits, early out.
       if (Known.isUnknown())
@@ -235,7 +235,7 @@
         // For COPYs we don't do anything, don't increase the depth.
         computeKnownBitsImpl(SrcReg, Known2, DemandedElts,
                              Depth + (Opcode != TargetOpcode::COPY));
-        Known = KnownBits::commonBits(Known, Known2);
+        Known.meet(Known2);
         // If we reach a point where we don't know anything
         // just stop looking through the operands.
         if (Known.One == 0 && Known.Zero == 0)
diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -505,7 +505,7 @@
       return;
     }
     DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, SrcLOI->NumSignBits);
-    DestLOI.Known = KnownBits::commonBits(DestLOI.Known, SrcLOI->Known);
+    DestLOI.Known.meet(SrcLOI->Known);
   }
 }
 
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3051,7 +3051,7 @@
       }
 
       // Known bits are the values that are shared by every demanded element.
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
 
       // If we don't know any bits, early out.
       if (Known.isUnknown())
@@ -3074,7 +3074,7 @@
     if (!!DemandedLHS) {
       SDValue LHS = Op.getOperand(0);
       Known2 = computeKnownBits(LHS, DemandedLHS, Depth + 1);
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
     }
     // If we don't know any bits, early out.
     if (Known.isUnknown())
@@ -3082,7 +3082,7 @@
     if (!!DemandedRHS) {
       SDValue RHS = Op.getOperand(1);
       Known2 = computeKnownBits(RHS, DemandedRHS, Depth + 1);
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
     }
     break;
   }
@@ -3100,7 +3100,7 @@
       if (!!DemandedSub) {
         SDValue Sub = Op.getOperand(i);
         Known2 = computeKnownBits(Sub, DemandedSub, Depth + 1);
-        Known = KnownBits::commonBits(Known, Known2);
+        Known.meet(Known2);
       }
       // If we don't know any bits, early out.
       if (Known.isUnknown())
@@ -3130,7 +3130,7 @@
     }
     if (!!DemandedSrcElts) {
       Known2 = computeKnownBits(Src, DemandedSrcElts, Depth + 1);
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
     }
     break;
   }
@@ -3220,8 +3220,7 @@
         if (DemandedElts[i]) {
           unsigned Shifts = IsLE ? i : NumElts - 1 - i;
           unsigned Offset = (Shifts % SubScale) * BitWidth;
-          Known = KnownBits::commonBits(Known,
-                                        Known2.extractBits(BitWidth, Offset));
+          Known.meet(Known2.extractBits(BitWidth, Offset));
           // If we don't know any bits, early out.
           if (Known.isUnknown())
             break;
@@ -3319,7 +3318,7 @@
     Known2 = computeKnownBits(Op.getOperand(1), DemandedElts, Depth+1);
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   case ISD::SELECT_CC:
     Known = computeKnownBits(Op.getOperand(3), DemandedElts, Depth+1);
@@ -3329,7 +3328,7 @@
     Known2 = computeKnownBits(Op.getOperand(2), DemandedElts, Depth+1);
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   case ISD::SMULO:
   case ISD::UMULO:
@@ -3409,8 +3408,7 @@
         Known2.One.lshrInPlace(Amt);
         Known2.Zero.lshrInPlace(Amt);
       }
-      Known.One |= Known2.One;
-      Known.Zero |= Known2.Zero;
+      Known.join(Known2);
     }
     break;
   case ISD::SHL_PARTS:
@@ -3780,11 +3778,11 @@
     Known.Zero.setAllBits();
     if (DemandedVal) {
       Known2 = computeKnownBits(InVal, Depth + 1);
-      Known = KnownBits::commonBits(Known, Known2.zextOrTrunc(BitWidth));
+      Known.meet(Known2.zextOrTrunc(BitWidth));
     }
     if (!!DemandedVecElts) {
       Known2 = computeKnownBits(InVec, DemandedVecElts, Depth + 1);
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
     }
     break;
   }
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1195,7 +1195,7 @@
       return true;
 
     if (!!DemandedVecElts)
-      Known = KnownBits::commonBits(Known, KnownVec);
+      Known.meet(KnownVec);
 
     return false;
   }
@@ -1223,9 +1223,9 @@
     Known.Zero.setAllBits();
     Known.One.setAllBits();
     if (!!DemandedSubElts)
-      Known = KnownBits::commonBits(Known, KnownSub);
+      Known.meet(KnownSub);
     if (!!DemandedSrcElts)
-      Known = KnownBits::commonBits(Known, KnownSrc);
+      Known.meet(KnownSrc);
 
     // Attempt to avoid multi-use src if we don't need anything from it.
     if (!DemandedBits.isAllOnes() || !DemandedSubElts.isAllOnes() ||
@@ -1287,7 +1287,7 @@
         return true;
       // Known bits are shared by every demanded subvector element.
       if (!!DemandedSubElts)
-        Known = KnownBits::commonBits(Known, Known2);
+        Known.meet(Known2);
     }
     break;
   }
@@ -1311,13 +1311,13 @@
         if (SimplifyDemandedBits(Op0, DemandedBits, DemandedLHS, Known2, TLO,
                                  Depth + 1))
           return true;
-        Known = KnownBits::commonBits(Known, Known2);
+        Known.meet(Known2);
       }
       if (!!DemandedRHS) {
         if (SimplifyDemandedBits(Op1, DemandedBits, DemandedRHS, Known2, TLO,
                                  Depth + 1))
           return true;
-        Known = KnownBits::commonBits(Known, Known2);
+        Known.meet(Known2);
       }
 
       // Attempt to avoid multi-use ops if we don't need anything from them.
@@ -1619,7 +1619,7 @@
       return true;
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   case ISD::VSELECT:
     if (SimplifyDemandedBits(Op.getOperand(2), DemandedBits, DemandedElts,
@@ -1632,7 +1632,7 @@
     assert(!Known2.hasConflict() && "Bits known to be one AND zero?");
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   case ISD::SELECT_CC:
     if (SimplifyDemandedBits(Op.getOperand(3), DemandedBits, Known, TLO,
@@ -1649,7 +1649,7 @@
       return true;
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   case ISD::SETCC: {
     SDValue Op0 = Op.getOperand(0);
@@ -1997,8 +1997,7 @@
       Known2.Zero <<= (IsFSHL ? Amt : (BitWidth - Amt));
       Known.One.lshrInPlace(IsFSHL ? (BitWidth - Amt) : Amt);
       Known.Zero.lshrInPlace(IsFSHL ? (BitWidth - Amt) : Amt);
-      Known.One |= Known2.One;
-      Known.Zero |= Known2.Zero;
+      Known.join(Known2);
 
       // Attempt to avoid multi-use ops if we don't need anything from them.
       if (!Demanded0.isAllOnes() || !Demanded1.isAllOnes() ||
diff --git a/llvm/lib/Support/KnownBits.cpp b/llvm/lib/Support/KnownBits.cpp
--- a/llvm/lib/Support/KnownBits.cpp
+++ b/llvm/lib/Support/KnownBits.cpp
@@ -129,7 +129,7 @@
   // are common to these two values are also known in the result.
   KnownBits L = LHS.makeGE(RHS.getMinValue());
   KnownBits R = RHS.makeGE(LHS.getMinValue());
-  return KnownBits::commonBits(L, R);
+  return KnownBits::meet(L, R);
 }
 
 KnownBits KnownBits::umin(const KnownBits &LHS, const KnownBits &RHS) {
@@ -208,7 +208,7 @@
       KnownBits SpecificShift;
       SpecificShift.Zero = LHS.Zero << ShiftAmt;
       SpecificShift.One = LHS.One << ShiftAmt;
-      Known = KnownBits::commonBits(Known, SpecificShift);
+      Known.meet(SpecificShift);
       if (Known.isUnknown())
         break;
     }
@@ -261,7 +261,7 @@
       KnownBits SpecificShift = LHS;
       SpecificShift.Zero.lshrInPlace(ShiftAmt);
       SpecificShift.One.lshrInPlace(ShiftAmt);
-      Known = KnownBits::commonBits(Known, SpecificShift);
+      Known.meet(SpecificShift);
       if (Known.isUnknown())
         break;
     }
@@ -319,7 +319,7 @@
       KnownBits SpecificShift = LHS;
       SpecificShift.Zero.ashrInPlace(ShiftAmt);
       SpecificShift.One.ashrInPlace(ShiftAmt);
-      Known = KnownBits::commonBits(Known, SpecificShift);
+      Known.meet(SpecificShift);
       if (Known.isUnknown())
         break;
     }
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -2061,7 +2061,7 @@
     KnownBits Known2;
     Known = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
     Known2 = DAG.computeKnownBits(Op->getOperand(1), Depth + 1);
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   }
   case AArch64ISD::BICi: {
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -20010,7 +20010,7 @@
       return;
 
     KnownBits KnownRHS = DAG.computeKnownBits(Op.getOperand(1), Depth+1);
-    Known = KnownBits::commonBits(Known, KnownRHS);
+    Known.meet(KnownRHS);
     return;
   }
   case ISD::INTRINSIC_W_CHAIN: {
@@ -20092,7 +20092,7 @@
       KnownOp1 = KnownBits::mul(
           KnownOp1, KnownBits::makeConstant(APInt(32, -1)));
 
-    Known = KnownBits::commonBits(KnownOp0, KnownOp1);
+    Known = KnownBits::meet(KnownOp0, KnownOp1);
     break;
   }
   }
diff --git a/llvm/lib/Target/Lanai/LanaiISelLowering.cpp b/llvm/lib/Target/Lanai/LanaiISelLowering.cpp
--- a/llvm/lib/Target/Lanai/LanaiISelLowering.cpp
+++ b/llvm/lib/Target/Lanai/LanaiISelLowering.cpp
@@ -1499,7 +1499,7 @@
     KnownBits Known2;
     Known = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
     Known2 = DAG.computeKnownBits(Op->getOperand(1), Depth + 1);
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   }
 }
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -12442,7 +12442,7 @@
     KnownBits Known2 = DAG.computeKnownBits(Op.getOperand(3), Depth + 1);
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   }
   case RISCVISD::REMUW: {
diff --git a/llvm/lib/Target/Sparc/SparcISelLowering.cpp b/llvm/lib/Target/Sparc/SparcISelLowering.cpp
--- a/llvm/lib/Target/Sparc/SparcISelLowering.cpp
+++ b/llvm/lib/Target/Sparc/SparcISelLowering.cpp
@@ -2031,7 +2031,7 @@
     Known2 = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   }
 }
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -7273,7 +7273,7 @@
       DAG.computeKnownBits(Op.getOperand(OpNo), Src0DemE, Depth + 1);
   KnownBits RHSKnown =
       DAG.computeKnownBits(Op.getOperand(OpNo + 1), Src1DemE, Depth + 1);
-  Known = KnownBits::commonBits(LHSKnown, RHSKnown);
+  Known = KnownBits::meet(LHSKnown, RHSKnown);
 }
 
 void
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -38733,11 +38733,11 @@
     KnownBits Known2;
     if (!!DemandedLHS) {
       Known2 = DAG.computeKnownBits(Op.getOperand(0), DemandedLHS, Depth + 1);
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
     }
     if (!!DemandedRHS) {
       Known2 = DAG.computeKnownBits(Op.getOperand(1), DemandedRHS, Depth + 1);
-      Known = KnownBits::commonBits(Known, Known2);
+      Known.meet(Known2);
     }
 
     if (Known.countMinLeadingZeros() < BitWidth)
@@ -38824,7 +38824,7 @@
     KnownBits Known2 = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(Known, Known2);
+    Known.meet(Known2);
     break;
   }
   case X86ISD::BEXTR:
@@ -38934,7 +38934,7 @@
           break;
         }
         KnownBits Known2 = KnownBits::makeConstant(EltBits[I]);
-        Known = KnownBits::commonBits(Known, Known2);
+        Known.meet(Known2);
       }
       return;
     }
@@ -38985,7 +38985,7 @@
             continue;
           KnownBits Known2 =
               DAG.computeKnownBits(Ops[i], DemandedOps[i], Depth + 1);
-          Known = KnownBits::commonBits(Known, Known2);
+          Known.meet(Known2);
         }
       }
     }
@@ -43929,7 +43929,7 @@
         return true;
 
       KnownScl = KnownScl.trunc(VecVT.getScalarSizeInBits());
-      Known = KnownBits::commonBits(KnownVec, KnownScl);
+      Known = KnownBits::meet(KnownVec, KnownScl);
       return false;
     }
     break;
@@ -54801,8 +54801,8 @@
   if (VT.isVector() && OpVT.isVector() && OpVT.isInteger()) {
     bool CanMakeSigned = false;
     if (ISD::isUnsignedIntSetCC(CC)) {
-      KnownBits CmpKnown = KnownBits::commonBits(DAG.computeKnownBits(LHS),
-                                                 DAG.computeKnownBits(RHS));
+      KnownBits CmpKnown = KnownBits::meet(DAG.computeKnownBits(LHS),
+                                           DAG.computeKnownBits(RHS));
       // If we know LHS/RHS share the same sign bit at each element we can
       // make this signed.
       // NOTE: `computeKnownBits` on a vector type aggregates common bits
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -384,7 +384,7 @@
       return I;
 
     // Only known if known in both the LHS and RHS.
-    Known = KnownBits::commonBits(LHSKnown, RHSKnown);
+    Known = KnownBits::meet(LHSKnown, RHSKnown);
     break;
   }
   case Instruction::Trunc: {