Add the "ppc specific" setcc-equivalent select_cc cases

Prefer 'neg X' to 'subfic 0, X' since it does not set XER[CA]


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23000 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nate Begeman 2005-08-24 04:59:21 +00:00
parent cebd433d8d
commit 4b46fc094d

View File

@ -1052,9 +1052,6 @@ unsigned ISel::SelectExpr(SDOperand N, bool Recording) {
case MVT::i8:
BuildMI(BB, PPC::EXTSB, 1, Result).addReg(Tmp1);
break;
case MVT::i1:
BuildMI(BB, PPC::SUBFIC, 2, Result).addReg(Tmp1).addSImm(0);
break;
}
return Result;
@ -1325,7 +1322,10 @@ unsigned ISel::SelectExpr(SDOperand N, bool Recording) {
if (isIntImmediate(N.getOperand(0), Tmp1) && isInt16(Tmp1)) {
Tmp1 = Lo16(Tmp1);
Tmp2 = SelectExpr(N.getOperand(1));
BuildMI(BB, PPC::SUBFIC, 2, Result).addReg(Tmp2).addSImm(Tmp1);
if (0 == Tmp1)
BuildMI(BB, PPC::NEG, 1, Result).addReg(Tmp2);
else
BuildMI(BB, PPC::SUBFIC, 2, Result).addReg(Tmp2).addSImm(Tmp1);
return Result;
}
if (SelectIntImmediateExpr(N, Result, PPC::ADDIS, PPC::ADDI, true, true))
@ -1662,6 +1662,27 @@ unsigned ISel::SelectExpr(SDOperand N, bool Recording) {
assert(0 && "Should never get here");
}
// handle the setcc cases here. select_cc lhs, 0, 1, 0, cc
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N.getOperand(2));
ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N.getOperand(3));
if (N1C && N2C && N3C && N1C->isNullValue() && N3C->isNullValue() &&
N2C->getValue() == 1ULL && (CC == ISD::SETNE || CC == ISD::SETEQ)) {
Tmp1 = SelectExpr(Node->getOperand(0));
Tmp2 = MakeIntReg();
if (CC == ISD::SETNE) {
BuildMI(BB, PPC::ADDIC, 2, Tmp2).addReg(Tmp1).addSImm(-1);
BuildMI(BB, PPC::SUBFE, 2, Result).addReg(Tmp2).addReg(Tmp1);
} else {
Tmp3 = MakeIntReg();
BuildMI(BB, PPC::NEG, 2, Tmp2).addReg(Tmp1);
BuildMI(BB, PPC::ANDC, 2, Tmp3).addReg(Tmp2).addReg(Tmp1);
BuildMI(BB, PPC::RLWINM, 4, Result).addReg(Tmp3).addImm(1).addImm(31)
.addImm(31);
}
return Result;
}
// If the False value only has one use, we can generate better code by
// selecting it in the fallthrough basic block rather than here, which
// increases register pressure.