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Turn expanded shift operations into (e.g.) SHL_PARTS if the target supports it. 

llvm-svn: 21002
This commit is contained in:
Chris Lattner 2005-04-02 03:38:53 +00:00
parent 5b7bb56ef8
commit 2e5872c671
1 changed files with 39 additions and 9 deletions
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48
llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
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@ -125,8 +125,8 @@ private:
SDOperand Source);
bool ExpandShift(unsigned Opc, SDOperand Op, SDOperand Amt,
SDOperand &Lo, SDOperand &Hi);
void ExpandAddSub(bool isAdd, SDOperand Op, SDOperand Amt,
SDOperand &Lo, SDOperand &Hi);
void ExpandByParts(unsigned NodeOp, SDOperand Op, SDOperand Amt,
SDOperand &Lo, SDOperand &Hi);
SDOperand getIntPtrConstant(uint64_t Val) {
return DAG.getConstant(Val, TLI.getPointerTy());
@ -1288,8 +1288,9 @@ SDOperand SelectionDAGLegalize::PromoteOp(SDOperand Op) {
/// ExpandAddSub - Find a clever way to expand this add operation into
/// subcomponents.
void SelectionDAGLegalize::ExpandAddSub(bool isAdd, SDOperand LHS,SDOperand RHS,
SDOperand &Lo, SDOperand &Hi) {
void SelectionDAGLegalize::
ExpandByParts(unsigned NodeOp, SDOperand LHS, SDOperand RHS,
SDOperand &Lo, SDOperand &Hi) {
// Expand the subcomponents.
SDOperand LHSL, LHSH, RHSL, RHSH;
ExpandOp(LHS, LHSL, LHSH);
@ -1297,13 +1298,12 @@ void SelectionDAGLegalize::ExpandAddSub(bool isAdd, SDOperand LHS,SDOperand RHS,
// Convert this add to the appropriate ADDC pair. The low part has no carry
// in.
unsigned Opc = isAdd ? ISD::ADD_PARTS : ISD::SUB_PARTS;
std::vector<SDOperand> Ops;
Ops.push_back(LHSL);
Ops.push_back(LHSH);
Ops.push_back(RHSL);
Ops.push_back(RHSH);
Lo = DAG.getNode(Opc, LHSL.getValueType(), Ops);
Lo = DAG.getNode(NodeOp, LHSL.getValueType(), Ops);
Hi = Lo.getValue(1);
}
@ -1313,6 +1313,10 @@ void SelectionDAGLegalize::ExpandAddSub(bool isAdd, SDOperand LHS,SDOperand RHS,
/// low-parts expanded into Lo and Hi.
bool SelectionDAGLegalize::ExpandShift(unsigned Opc, SDOperand Op,SDOperand Amt,
SDOperand &Lo, SDOperand &Hi) {
// FIXME: This code is buggy, disable it for now. Note that we should at
// least handle the case when Amt is an immediate here.
return false;
assert((Opc == ISD::SHL || Opc == ISD::SRA || Opc == ISD::SRL) &&
"This is not a shift!");
MVT::ValueType NVT = TLI.getTypeToTransformTo(Op.getValueType());
@ -1746,6 +1750,14 @@ void SelectionDAGLegalize::ExpandOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi){
// If we can emit an efficient shift operation, do so now.
if (ExpandShift(ISD::SHL, Node->getOperand(0), Node->getOperand(1), Lo, Hi))
break;
// If this target supports SHL_PARTS, use it.
if (TLI.getOperationAction(ISD::SHL_PARTS, NVT) == TargetLowering::Legal) {
ExpandByParts(ISD::SHL_PARTS, Node->getOperand(0), Node->getOperand(1),
Lo, Hi);
break;
}
// Otherwise, emit a libcall.
Lo = ExpandLibCall("__ashldi3", Node, Hi);
break;
@ -1754,6 +1766,14 @@ void SelectionDAGLegalize::ExpandOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi){
// If we can emit an efficient shift operation, do so now.
if (ExpandShift(ISD::SRA, Node->getOperand(0), Node->getOperand(1), Lo, Hi))
break;
// If this target supports SRA_PARTS, use it.
if (TLI.getOperationAction(ISD::SRA_PARTS, NVT) == TargetLowering::Legal) {
ExpandByParts(ISD::SRA_PARTS, Node->getOperand(0), Node->getOperand(1),
Lo, Hi);
break;
}
// Otherwise, emit a libcall.
Lo = ExpandLibCall("__ashrdi3", Node, Hi);
break;
@ -1761,15 +1781,25 @@ void SelectionDAGLegalize::ExpandOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi){
// If we can emit an efficient shift operation, do so now.
if (ExpandShift(ISD::SRL, Node->getOperand(0), Node->getOperand(1), Lo, Hi))
break;
// If this target supports SRL_PARTS, use it.
if (TLI.getOperationAction(ISD::SRL_PARTS, NVT) == TargetLowering::Legal) {
ExpandByParts(ISD::SRL_PARTS, Node->getOperand(0), Node->getOperand(1),
Lo, Hi);
break;
}
// Otherwise, emit a libcall.
Lo = ExpandLibCall("__lshrdi3", Node, Hi);
break;
case ISD::ADD:
ExpandAddSub(true, Node->getOperand(0), Node->getOperand(1), Lo, Hi);
case ISD::ADD:
ExpandByParts(ISD::ADD_PARTS, Node->getOperand(0), Node->getOperand(1),
Lo, Hi);
break;
case ISD::SUB:
ExpandAddSub(false, Node->getOperand(0), Node->getOperand(1), Lo, Hi);
ExpandByParts(ISD::SUB_PARTS, Node->getOperand(0), Node->getOperand(1),
Lo, Hi);
break;
case ISD::MUL: Lo = ExpandLibCall("__muldi3" , Node, Hi); break;
case ISD::SDIV: Lo = ExpandLibCall("__divdi3" , Node, Hi); break;