/// 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)
/// 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)
// 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();
// 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),
/// \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 {
/// \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 {