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Use rep/stosl; and Count 0x3; rep/stosb for memset with 4 byte aligned dest. 

and variable value.
Similarly for memcpy.

llvm-svn: 26603
This commit is contained in:
Evan Cheng 2006-03-07 23:29:39 +00:00
parent 207291fd1a
commit adc7093fc1
1 changed files with 72 additions and 12 deletions
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76
llvm/lib/Target/X86/X86ISelLowering.cpp
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@ -1711,7 +1711,7 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
// If not DWORD aligned, call memset if size is less than the threshold.
// It knows how to align to the right boundary first.
if ((Align & 3) != 0 ||
!(I && I->getValue() >= Subtarget->getMinRepStrSizeThreshold())) {
(I && I->getValue() < Subtarget->getMinRepStrSizeThreshold())) {
MVT::ValueType IntPtr = getPointerTy();
const Type *IntPtrTy = getTargetData().getIntPtrType();
std::vector<std::pair<SDOperand, const Type*> > Args;
@ -1730,6 +1730,7 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
SDOperand Count;
ConstantSDNode *ValC = dyn_cast<ConstantSDNode>(Op.getOperand(2));
unsigned BytesLeft = 0;
bool TwoRepStos = false;
if (ValC) {
unsigned ValReg;
unsigned Val = ValC->getValue() & 255;
@ -1745,8 +1746,14 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
break;
case 0: // DWORD aligned
AVT = MVT::i32;
if (I) {
Count = DAG.getConstant(I->getValue() / 4, MVT::i32);
BytesLeft = I->getValue() % 4;
} else {
Count = DAG.getNode(ISD::SRL, MVT::i32, Op.getOperand(3),
DAG.getConstant(2, MVT::i8));
TwoRepStos = true;
}
Val = (Val << 8) | Val;
Val = (Val << 16) | Val;
ValReg = X86::EAX;
@ -1772,10 +1779,33 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
InFlag = Chain.getValue(1);
Chain = DAG.getCopyToReg(Chain, X86::EDI, Op.getOperand(1), InFlag);
InFlag = Chain.getValue(1);
Chain = DAG.getNode(X86ISD::REP_STOS, MVT::Other, Chain,
DAG.getValueType(AVT), InFlag);
if (BytesLeft) {
std::vector<MVT::ValueType> Tys;
Tys.push_back(MVT::Other);
Tys.push_back(MVT::Flag);
std::vector<SDOperand> Ops;
Ops.push_back(Chain);
Ops.push_back(DAG.getValueType(AVT));
Ops.push_back(InFlag);
Chain = DAG.getNode(X86ISD::REP_STOS, Tys, Ops);
if (TwoRepStos) {
InFlag = Chain.getValue(1);
Count = Op.getOperand(3);
MVT::ValueType CVT = Count.getValueType();
SDOperand Left = DAG.getNode(ISD::AND, CVT, Count,
DAG.getConstant(3, CVT));
Chain = DAG.getCopyToReg(Chain, X86::ECX, Left, InFlag);
InFlag = Chain.getValue(1);
Tys.clear();
Tys.push_back(MVT::Other);
Tys.push_back(MVT::Flag);
Ops.clear();
Ops.push_back(Chain);
Ops.push_back(DAG.getValueType(MVT::i8));
Ops.push_back(InFlag);
Chain = DAG.getNode(X86ISD::REP_STOS, Tys, Ops);
} else if (BytesLeft) {
// Issue stores for the last 1 - 3 bytes.
SDOperand Value;
unsigned Val = ValC->getValue() & 255;
@ -1813,7 +1843,7 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
// If not DWORD aligned, call memcpy if size is less than the threshold.
// It knows how to align to the right boundary first.
if ((Align & 3) != 0 ||
!(I && I->getValue() >= Subtarget->getMinRepStrSizeThreshold())) {
(I && I->getValue() < Subtarget->getMinRepStrSizeThreshold())) {
MVT::ValueType IntPtr = getPointerTy();
const Type *IntPtrTy = getTargetData().getIntPtrType();
std::vector<std::pair<SDOperand, const Type*> > Args;
@ -1829,6 +1859,7 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
MVT::ValueType AVT;
SDOperand Count;
unsigned BytesLeft = 0;
bool TwoRepMovs = false;
switch (Align & 3) {
case 2: // WORD aligned
AVT = MVT::i16;
@ -1837,8 +1868,14 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
break;
case 0: // DWORD aligned
AVT = MVT::i32;
if (I) {
Count = DAG.getConstant(I->getValue() / 4, MVT::i32);
BytesLeft = I->getValue() % 4;
} else {
Count = DAG.getNode(ISD::SRL, MVT::i32, Op.getOperand(3),
DAG.getConstant(2, MVT::i8));
TwoRepMovs = true;
}
break;
default: // Byte aligned
AVT = MVT::i8;
@ -1853,10 +1890,33 @@ SDOperand X86TargetLowering::LowerOperation(SDOperand Op, SelectionDAG &DAG) {
InFlag = Chain.getValue(1);
Chain = DAG.getCopyToReg(Chain, X86::ESI, Op.getOperand(2), InFlag);
InFlag = Chain.getValue(1);
Chain = DAG.getNode(X86ISD::REP_MOVS, MVT::Other, Chain,
DAG.getValueType(AVT), InFlag);
if (BytesLeft) {
std::vector<MVT::ValueType> Tys;
Tys.push_back(MVT::Other);
Tys.push_back(MVT::Flag);
std::vector<SDOperand> Ops;
Ops.push_back(Chain);
Ops.push_back(DAG.getValueType(AVT));
Ops.push_back(InFlag);
Chain = DAG.getNode(X86ISD::REP_MOVS, Tys, Ops);
if (TwoRepMovs) {
InFlag = Chain.getValue(1);
Count = Op.getOperand(3);
MVT::ValueType CVT = Count.getValueType();
SDOperand Left = DAG.getNode(ISD::AND, CVT, Count,
DAG.getConstant(3, CVT));
Chain = DAG.getCopyToReg(Chain, X86::ECX, Left, InFlag);
InFlag = Chain.getValue(1);
Tys.clear();
Tys.push_back(MVT::Other);
Tys.push_back(MVT::Flag);
Ops.clear();
Ops.push_back(Chain);
Ops.push_back(DAG.getValueType(MVT::i8));
Ops.push_back(InFlag);
Chain = DAG.getNode(X86ISD::REP_MOVS, Tys, Ops);
} else if (BytesLeft) {
// Issue loads and stores for the last 1 - 3 bytes.
unsigned Offset = I->getValue() - BytesLeft;
SDOperand DstAddr = Op.getOperand(1);