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Pattern match min/max nodes when we have sse. This implements 

CodeGen/X86/scalar_sse_minmax.ll

llvm-svn: 30719
This commit is contained in:
Chris Lattner 2006-10-04 06:57:07 +00:00
parent 1e21d3a5ae
commit 9259b1efb6
1 changed files with 66 additions and 0 deletions
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66
llvm/lib/Target/X86/X86ISelLowering.cpp
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@ -386,6 +386,7 @@ X86TargetLowering::X86TargetLowering(TargetMachine &TM)
// We have target-specific dag combine patterns for the following nodes:
setTargetDAGCombine(ISD::VECTOR_SHUFFLE);
setTargetDAGCombine(ISD::SELECT);
computeRegisterProperties();
@ -5355,6 +5356,69 @@ static SDOperand PerformShuffleCombine(SDNode *N, SelectionDAG &DAG,
}
}
/// PerformSELECTCombine - Do target-specific dag combines on SELECT nodes.
static SDOperand PerformSELECTCombine(SDNode *N, SelectionDAG &DAG,
const X86Subtarget *Subtarget) {
SDOperand Cond = N->getOperand(0);
// If we have SSE[12] support, try to form min/max nodes.
if (Subtarget->hasSSE2() &&
(N->getValueType(0) == MVT::f32 || N->getValueType(0) == MVT::f64)) {
if (Cond.getOpcode() == ISD::SETCC) {
// Get the LHS/RHS of the select.
SDOperand LHS = N->getOperand(1);
SDOperand RHS = N->getOperand(2);
ISD::CondCode CC = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
unsigned IntNo = 0;
if (LHS == Cond.getOperand(0) && RHS == Cond.getOperand(1)) {
// (X olt Y) ? X : Y -> min
if (CC == ISD::SETOLT || CC == ISD::SETLT)
IntNo = LHS.getValueType() == MVT::f32 ? Intrinsic::x86_sse_min_ss :
Intrinsic::x86_sse2_min_sd;
// (X uge Y) ? X : Y -> max
if (CC == ISD::SETUGE || CC == ISD::SETGE)
IntNo = LHS.getValueType() == MVT::f32 ? Intrinsic::x86_sse_max_ss :
Intrinsic::x86_sse2_max_sd;
// TODO: Handle more cases if unsafe math!
} else if (LHS == Cond.getOperand(1) && RHS == Cond.getOperand(0)) {
// (X uge Y) ? Y : X -> min
if (CC == ISD::SETUGE || CC == ISD::SETGE)
IntNo = LHS.getValueType() == MVT::f32 ? Intrinsic::x86_sse_min_ss :
Intrinsic::x86_sse2_min_sd;
// (X olt Y) ? Y : X -> max
if (CC == ISD::SETOLT || CC == ISD::SETLT)
IntNo = LHS.getValueType() == MVT::f32 ? Intrinsic::x86_sse_max_ss :
Intrinsic::x86_sse2_max_sd;
// TODO: Handle more cases if unsafe math!
}
// minss/maxss take a v4f32 operand.
if (IntNo) {
if (LHS.getValueType() == MVT::f32) {
LHS = DAG.getNode(ISD::SCALAR_TO_VECTOR, MVT::v4f32, LHS);
RHS = DAG.getNode(ISD::SCALAR_TO_VECTOR, MVT::v4f32, RHS);
} else {
LHS = DAG.getNode(ISD::SCALAR_TO_VECTOR, MVT::v2f64, LHS);
RHS = DAG.getNode(ISD::SCALAR_TO_VECTOR, MVT::v2f64, RHS);
}
MVT::ValueType PtrTy = Subtarget->is64Bit() ? MVT::i64 : MVT::i32;
SDOperand IntNoN = DAG.getConstant(IntNo, PtrTy);
SDOperand Val = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, LHS.getValueType(),
IntNoN, LHS, RHS);
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, N->getValueType(0), Val,
DAG.getConstant(0, PtrTy));
}
}
}
return SDOperand();
}
SDOperand X86TargetLowering::PerformDAGCombine(SDNode *N,
DAGCombinerInfo &DCI) const {
TargetMachine &TM = getTargetMachine();
@ -5363,6 +5427,8 @@ SDOperand X86TargetLowering::PerformDAGCombine(SDNode *N,
default: break;
case ISD::VECTOR_SHUFFLE:
return PerformShuffleCombine(N, DAG, Subtarget);
case ISD::SELECT:
return PerformSELECTCombine(N, DAG, Subtarget);
}
return SDOperand();