Optimize FSEL a bit for fneg arguments. This fixes the recently added test

case so that we emit

_test_fneg_sel:
.LBB_test_fneg_sel_0:   ;
        fsel f1, f1, f3, f2
        blr

instead of:

_test_fneg_sel:
.LBB_test_fneg_sel_0:   ;
        fneg f0, f1
        fneg f0, f0
        fsel f1, f0, f3, f2
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21177 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nate Begeman 2005-04-09 09:33:07 +00:00
parent 9a98a77446
commit af4ab1b103

View File

@ -999,7 +999,6 @@ unsigned ISel::SelectExprFP(SDOperand N, unsigned Result)
SetCC->getCondition() != ISD::SETEQ &&
SetCC->getCondition() != ISD::SETNE) {
MVT::ValueType VT = SetCC->getOperand(0).getValueType();
Tmp1 = SelectExpr(SetCC->getOperand(0)); // Val to compare against
unsigned TV = SelectExpr(N.getOperand(1)); // Use if TRUE
unsigned FV = SelectExpr(N.getOperand(2)); // Use if FALSE
@ -1009,29 +1008,31 @@ unsigned ISel::SelectExprFP(SDOperand N, unsigned Result)
default: assert(0 && "Invalid FSEL condition"); abort();
case ISD::SETULT:
case ISD::SETLT:
BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp1).addReg(FV).addReg(TV);
return Result;
std::swap(TV, FV); // fsel is natively setge, swap operands for setlt
case ISD::SETUGE:
case ISD::SETGE:
Tmp1 = SelectExpr(SetCC->getOperand(0)); // Val to compare against
BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp1).addReg(TV).addReg(FV);
return Result;
case ISD::SETUGT:
case ISD::SETGT: {
Tmp2 = MakeReg(VT);
BuildMI(BB, PPC::FNEG, 1, Tmp2).addReg(Tmp1);
BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp2).addReg(FV).addReg(TV);
return Result;
}
case ISD::SETGT:
std::swap(TV, FV); // fsel is natively setge, swap operands for setlt
case ISD::SETULE:
case ISD::SETLE: {
Tmp2 = MakeReg(VT);
BuildMI(BB, PPC::FNEG, 1, Tmp2).addReg(Tmp1);
if (SetCC->getOperand(0).getOpcode() == ISD::FNEG) {
Tmp2 = SelectExpr(SetCC->getOperand(0).getOperand(0));
} else {
Tmp2 = MakeReg(VT);
Tmp1 = SelectExpr(SetCC->getOperand(0)); // Val to compare against
BuildMI(BB, PPC::FNEG, 1, Tmp2).addReg(Tmp1);
}
BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp2).addReg(TV).addReg(FV);
return Result;
}
}
} else {
Opc = (MVT::f64 == VT) ? PPC::FSUB : PPC::FSUBS;
Tmp1 = SelectExpr(SetCC->getOperand(0)); // Val to compare against
Tmp2 = SelectExpr(SetCC->getOperand(1));
Tmp3 = MakeReg(VT);
switch(SetCC->getCondition()) {