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[PowerPC] Remove dead code from PPCDAGToDAGISel::SelectSETCC 

The subroutine getCRIdxForSetCC has a parameter "Other" and comment:

  If this returns with Other != -1, then the returned comparison
  is an or of two simpler comparisons.

However for at least the last five years this routine has never
returned a value of Other != -1; these cases are now handled
differently to begin with.

This patch removes the parameter and the code in SelectSETCC that
attempted to handle the Other != -1 case.

llvm-svn: 185541
This commit is contained in:
Ulrich Weigand 2013-07-03 15:13:30 +00:00
parent 31ee5866de
commit 47e9328afe
1 changed files with 5 additions and 23 deletions
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28
llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
View File

@ -594,12 +594,8 @@ static PPC::Predicate getPredicateForSetCC(ISD::CondCode CC) {
/// getCRIdxForSetCC - Return the index of the condition register field
/// associated with the SetCC condition, and whether or not the field is
/// treated as inverted. That is, lt = 0; ge = 0 inverted.
///
/// If this returns with Other != -1, then the returned comparison is an or of
/// two simpler comparisons. In this case, Invert is guaranteed to be false.
static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool &Invert, int &Other) {
static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool &Invert) {
Invert = false;
Other = -1;
switch (CC) {
default: llvm_unreachable("Unknown condition!");
case ISD::SETOLT:
@ -847,8 +843,7 @@ SDNode *PPCDAGToDAGISel::SelectSETCC(SDNode *N) {
}
bool Inv;
int OtherCondIdx;
unsigned Idx = getCRIdxForSetCC(CC, Inv, OtherCondIdx);
unsigned Idx = getCRIdxForSetCC(CC, Inv);
SDValue CCReg = SelectCC(LHS, RHS, CC, dl);
SDValue IntCR;
@ -859,7 +854,7 @@ SDNode *PPCDAGToDAGISel::SelectSETCC(SDNode *N) {
CCReg = CurDAG->getCopyToReg(CurDAG->getEntryNode(), dl, CR7Reg, CCReg,
InFlag).getValue(1);
if (PPCSubTarget.hasMFOCRF() && OtherCondIdx == -1)
if (PPCSubTarget.hasMFOCRF())
IntCR = SDValue(CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32, CR7Reg,
CCReg), 0);
else
@ -868,26 +863,13 @@ SDNode *PPCDAGToDAGISel::SelectSETCC(SDNode *N) {
SDValue Ops[] = { IntCR, getI32Imm((32-(3-Idx)) & 31),
getI32Imm(31), getI32Imm(31) };
if (OtherCondIdx == -1 && !Inv)
if (!Inv)
return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops, 4);
// Get the specified bit.
SDValue Tmp =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
if (Inv) {
assert(OtherCondIdx == -1 && "Can't have split plus negation");
return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1));
}
// Otherwise, we have to turn an operation like SETONE -> SETOLT | SETOGT.
// We already got the bit for the first part of the comparison (e.g. SETULE).
// Get the other bit of the comparison.
Ops[1] = getI32Imm((32-(3-OtherCondIdx)) & 31);
SDValue OtherCond =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
return CurDAG->SelectNodeTo(N, PPC::OR, MVT::i32, Tmp, OtherCond);
return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1));
}