diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 8a09838873a..013fbb0b004 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -11629,8 +11629,8 @@ SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0,
 
 /// Given an ISD::SDIV node expressing a divide by constant, return
 /// a DAG expression to select that will generate the same value by multiplying
-/// by a magic number.  See:
-/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
+/// by a magic number.
+/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
 SDValue DAGCombiner::BuildSDIV(SDNode *N) {
   ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
   if (!C)
@@ -11670,8 +11670,8 @@ SDValue DAGCombiner::BuildSDIVPow2(SDNode *N) {
 
 /// Given an ISD::UDIV node expressing a divide by constant, return a DAG
 /// expression that will generate the same value by multiplying by a magic
-/// number. See:
-/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
+/// number.
+/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
 SDValue DAGCombiner::BuildUDIV(SDNode *N) {
   ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
   if (!C)
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index ed3f770afec..dd932ebd80e 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2786,7 +2786,7 @@ SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op,
     // x = x | (x >>32); // for 64-bit input
     // return popcount(~x);
     //
-    // but see also: http://www.hackersdelight.org/HDcode/nlz.cc
+    // Ref: "Hacker's Delight" by Henry Warren
     EVT VT = Op.getValueType();
     EVT ShVT = TLI.getShiftAmountTy(VT);
     unsigned len = VT.getSizeInBits();
@@ -2805,7 +2805,7 @@ SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op,
     // for now, we use: { return popcount(~x & (x - 1)); }
     // unless the target has ctlz but not ctpop, in which case we use:
     // { return 32 - nlz(~x & (x-1)); }
-    // see also http://www.hackersdelight.org/HDcode/ntz.cc
+    // Ref: "Hacker's Delight" by Henry Warren
     EVT VT = Op.getValueType();
     SDValue Tmp3 = DAG.getNode(ISD::AND, dl, VT,
                                DAG.getNOT(dl, Op, VT),
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 1bd3d2988d7..ee667124084 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2643,8 +2643,8 @@ SDValue TargetLowering::BuildExactSDIV(SDValue Op1, SDValue Op2, SDLoc dl,
 
 /// \brief Given an ISD::SDIV node expressing a divide by constant,
 /// return a DAG expression to select that will generate the same value by
-/// multiplying by a magic number.  See:
-/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
+/// multiplying by a magic number.
+/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
 SDValue TargetLowering::BuildSDIV(SDNode *N, const APInt &Divisor,
                                   SelectionDAG &DAG, bool IsAfterLegalization,
                                   std::vector<SDNode *> *Created) const {
@@ -2702,8 +2702,8 @@ SDValue TargetLowering::BuildSDIV(SDNode *N, const APInt &Divisor,
 
 /// \brief Given an ISD::UDIV node expressing a divide by constant,
 /// return a DAG expression to select that will generate the same value by
-/// multiplying by a magic number.  See:
-/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
+/// multiplying by a magic number.
+/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
 SDValue TargetLowering::BuildUDIV(SDNode *N, const APInt &Divisor,
                                   SelectionDAG &DAG, bool IsAfterLegalization,
                                   std::vector<SDNode *> *Created) const {