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[SystemZ] Split up PerformDAGCombine. [NFC] 

This function is already a bit too long, and I'm about to make it worse.

llvm-svn: 274191
This commit is contained in:
Marcin Koscielnicki 2016-06-30 00:08:54 +00:00
parent 3a94477625
commit 68747ac78e
2 changed files with 184 additions and 143 deletions
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320
llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
View File

@ -4842,154 +4842,199 @@ SDValue SystemZTargetLowering::combineTruncateExtract(
return SDValue();
}
SDValue SystemZTargetLowering::PerformDAGCombine(SDNode *N,
DAGCombinerInfo &DCI) const {
SDValue SystemZTargetLowering::combineSIGN_EXTEND(
SDNode *N, DAGCombinerInfo &DCI) const {
// Convert (sext (ashr (shl X, C1), C2)) to
// (ashr (shl (anyext X), C1'), C2')), since wider shifts are as
// cheap as narrower ones.
SelectionDAG &DAG = DCI.DAG;
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
if (N0.hasOneUse() && N0.getOpcode() == ISD::SRA) {
auto *SraAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1));
SDValue Inner = N0.getOperand(0);
if (SraAmt && Inner.hasOneUse() && Inner.getOpcode() == ISD::SHL) {
if (auto *ShlAmt = dyn_cast<ConstantSDNode>(Inner.getOperand(1))) {
unsigned Extra = (VT.getSizeInBits() -
N0.getValueType().getSizeInBits());
unsigned NewShlAmt = ShlAmt->getZExtValue() + Extra;
unsigned NewSraAmt = SraAmt->getZExtValue() + Extra;
EVT ShiftVT = N0.getOperand(1).getValueType();
SDValue Ext = DAG.getNode(ISD::ANY_EXTEND, SDLoc(Inner), VT,
Inner.getOperand(0));
SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(Inner), VT, Ext,
DAG.getConstant(NewShlAmt, SDLoc(Inner),
ShiftVT));
return DAG.getNode(ISD::SRA, SDLoc(N0), VT, Shl,
DAG.getConstant(NewSraAmt, SDLoc(N0), ShiftVT));
}
}
}
return SDValue();
}
SDValue SystemZTargetLowering::combineMERGE(
SDNode *N, DAGCombinerInfo &DCI) const {
SelectionDAG &DAG = DCI.DAG;
unsigned Opcode = N->getOpcode();
if (Opcode == ISD::SIGN_EXTEND) {
// Convert (sext (ashr (shl X, C1), C2)) to
// (ashr (shl (anyext X), C1'), C2')), since wider shifts are as
// cheap as narrower ones.
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
if (N0.hasOneUse() && N0.getOpcode() == ISD::SRA) {
auto *SraAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1));
SDValue Inner = N0.getOperand(0);
if (SraAmt && Inner.hasOneUse() && Inner.getOpcode() == ISD::SHL) {
if (auto *ShlAmt = dyn_cast<ConstantSDNode>(Inner.getOperand(1))) {
unsigned Extra = (VT.getSizeInBits() -
N0.getValueType().getSizeInBits());
unsigned NewShlAmt = ShlAmt->getZExtValue() + Extra;
unsigned NewSraAmt = SraAmt->getZExtValue() + Extra;
EVT ShiftVT = N0.getOperand(1).getValueType();
SDValue Ext = DAG.getNode(ISD::ANY_EXTEND, SDLoc(Inner), VT,
Inner.getOperand(0));
SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(Inner), VT, Ext,
DAG.getConstant(NewShlAmt, SDLoc(Inner),
ShiftVT));
return DAG.getNode(ISD::SRA, SDLoc(N0), VT, Shl,
DAG.getConstant(NewSraAmt, SDLoc(N0), ShiftVT));
}
}
}
}
if (Opcode == SystemZISD::MERGE_HIGH ||
Opcode == SystemZISD::MERGE_LOW) {
SDValue Op0 = N->getOperand(0);
SDValue Op1 = N->getOperand(1);
if (Op0.getOpcode() == ISD::BITCAST)
Op0 = Op0.getOperand(0);
if (Op0.getOpcode() == SystemZISD::BYTE_MASK &&
cast<ConstantSDNode>(Op0.getOperand(0))->getZExtValue() == 0) {
// (z_merge_* 0, 0) -> 0. This is mostly useful for using VLLEZF
// for v4f32.
if (Op1 == N->getOperand(0))
return Op1;
// (z_merge_? 0, X) -> (z_unpackl_? 0, X).
EVT VT = Op1.getValueType();
unsigned ElemBytes = VT.getVectorElementType().getStoreSize();
if (ElemBytes <= 4) {
Opcode = (Opcode == SystemZISD::MERGE_HIGH ?
SystemZISD::UNPACKL_HIGH : SystemZISD::UNPACKL_LOW);
EVT InVT = VT.changeVectorElementTypeToInteger();
EVT OutVT = MVT::getVectorVT(MVT::getIntegerVT(ElemBytes * 16),
SystemZ::VectorBytes / ElemBytes / 2);
if (VT != InVT) {
Op1 = DAG.getNode(ISD::BITCAST, SDLoc(N), InVT, Op1);
DCI.AddToWorklist(Op1.getNode());
}
SDValue Op = DAG.getNode(Opcode, SDLoc(N), OutVT, Op1);
DCI.AddToWorklist(Op.getNode());
return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Op);
SDValue Op0 = N->getOperand(0);
SDValue Op1 = N->getOperand(1);
if (Op0.getOpcode() == ISD::BITCAST)
Op0 = Op0.getOperand(0);
if (Op0.getOpcode() == SystemZISD::BYTE_MASK &&
cast<ConstantSDNode>(Op0.getOperand(0))->getZExtValue() == 0) {
// (z_merge_* 0, 0) -> 0. This is mostly useful for using VLLEZF
// for v4f32.
if (Op1 == N->getOperand(0))
return Op1;
// (z_merge_? 0, X) -> (z_unpackl_? 0, X).
EVT VT = Op1.getValueType();
unsigned ElemBytes = VT.getVectorElementType().getStoreSize();
if (ElemBytes <= 4) {
Opcode = (Opcode == SystemZISD::MERGE_HIGH ?
SystemZISD::UNPACKL_HIGH : SystemZISD::UNPACKL_LOW);
EVT InVT = VT.changeVectorElementTypeToInteger();
EVT OutVT = MVT::getVectorVT(MVT::getIntegerVT(ElemBytes * 16),
SystemZ::VectorBytes / ElemBytes / 2);
if (VT != InVT) {
Op1 = DAG.getNode(ISD::BITCAST, SDLoc(N), InVT, Op1);
DCI.AddToWorklist(Op1.getNode());
}
SDValue Op = DAG.getNode(Opcode, SDLoc(N), OutVT, Op1);
DCI.AddToWorklist(Op.getNode());
return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Op);
}
}
return SDValue();
}
SDValue SystemZTargetLowering::combineSTORE(
SDNode *N, DAGCombinerInfo &DCI) const {
SelectionDAG &DAG = DCI.DAG;
auto *SN = cast<StoreSDNode>(N);
auto &Op1 = N->getOperand(1);
EVT MemVT = SN->getMemoryVT();
// If we have (truncstoreiN (extract_vector_elt X, Y), Z) then it is better
// for the extraction to be done on a vMiN value, so that we can use VSTE.
// If X has wider elements then convert it to:
// (truncstoreiN (extract_vector_elt (bitcast X), Y2), Z).
if (Opcode == ISD::STORE) {
auto *SN = cast<StoreSDNode>(N);
EVT MemVT = SN->getMemoryVT();
if (MemVT.isInteger()) {
if (SDValue Value =
combineTruncateExtract(SDLoc(N), MemVT, SN->getValue(), DCI)) {
DCI.AddToWorklist(Value.getNode());
if (MemVT.isInteger()) {
if (SDValue Value =
combineTruncateExtract(SDLoc(N), MemVT, SN->getValue(), DCI)) {
DCI.AddToWorklist(Value.getNode());
// Rewrite the store with the new form of stored value.
return DAG.getTruncStore(SN->getChain(), SDLoc(SN), Value,
SN->getBasePtr(), SN->getMemoryVT(),
SN->getMemOperand());
}
// Rewrite the store with the new form of stored value.
return DAG.getTruncStore(SN->getChain(), SDLoc(SN), Value,
SN->getBasePtr(), SN->getMemoryVT(),
SN->getMemOperand());
}
}
// Combine STORE (BSWAP) into STRVH/STRV/STRVG
// See comment in combineBSWAP about volatile accesses.
if (!SN->isVolatile() &&
Op1.getOpcode() == ISD::BSWAP &&
Op1.getNode()->hasOneUse() &&
(Op1.getValueType() == MVT::i16 ||
Op1.getValueType() == MVT::i32 ||
Op1.getValueType() == MVT::i64)) {
SDValue BSwapOp = Op1.getOperand(0);
if (BSwapOp.getValueType() == MVT::i16)
BSwapOp = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), MVT::i32, BSwapOp);
SDValue Ops[] = {
N->getOperand(0), BSwapOp, N->getOperand(2),
DAG.getValueType(Op1.getValueType())
};
return
DAG.getMemIntrinsicNode(SystemZISD::STRV, SDLoc(N), DAG.getVTList(MVT::Other),
Ops, MemVT, SN->getMemOperand());
}
return SDValue();
}
SDValue SystemZTargetLowering::combineEXTRACT_VECTOR_ELT(
SDNode *N, DAGCombinerInfo &DCI) const {
// Try to simplify a vector extraction.
if (Opcode == ISD::EXTRACT_VECTOR_ELT) {
if (auto *IndexN = dyn_cast<ConstantSDNode>(N->getOperand(1))) {
SDValue Op0 = N->getOperand(0);
EVT VecVT = Op0.getValueType();
return combineExtract(SDLoc(N), N->getValueType(0), VecVT, Op0,
IndexN->getZExtValue(), DCI, false);
}
if (auto *IndexN = dyn_cast<ConstantSDNode>(N->getOperand(1))) {
SDValue Op0 = N->getOperand(0);
EVT VecVT = Op0.getValueType();
return combineExtract(SDLoc(N), N->getValueType(0), VecVT, Op0,
IndexN->getZExtValue(), DCI, false);
}
return SDValue();
}
SDValue SystemZTargetLowering::combineJOIN_DWORDS(
SDNode *N, DAGCombinerInfo &DCI) const {
SelectionDAG &DAG = DCI.DAG;
// (join_dwords X, X) == (replicate X)
if (Opcode == SystemZISD::JOIN_DWORDS &&
N->getOperand(0) == N->getOperand(1))
if (N->getOperand(0) == N->getOperand(1))
return DAG.getNode(SystemZISD::REPLICATE, SDLoc(N), N->getValueType(0),
N->getOperand(0));
return SDValue();
}
SDValue SystemZTargetLowering::combineFP_ROUND(
SDNode *N, DAGCombinerInfo &DCI) const {
// (fround (extract_vector_elt X 0))
// (fround (extract_vector_elt X 1)) ->
// (extract_vector_elt (VROUND X) 0)
// (extract_vector_elt (VROUND X) 1)
//
// This is a special case since the target doesn't really support v2f32s.
if (Opcode == ISD::FP_ROUND) {
SDValue Op0 = N->getOperand(0);
if (N->getValueType(0) == MVT::f32 &&
Op0.hasOneUse() &&
Op0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
Op0.getOperand(0).getValueType() == MVT::v2f64 &&
Op0.getOperand(1).getOpcode() == ISD::Constant &&
cast<ConstantSDNode>(Op0.getOperand(1))->getZExtValue() == 0) {
SDValue Vec = Op0.getOperand(0);
for (auto *U : Vec->uses()) {
if (U != Op0.getNode() &&
U->hasOneUse() &&
U->getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
U->getOperand(0) == Vec &&
U->getOperand(1).getOpcode() == ISD::Constant &&
cast<ConstantSDNode>(U->getOperand(1))->getZExtValue() == 1) {
SDValue OtherRound = SDValue(*U->use_begin(), 0);
if (OtherRound.getOpcode() == ISD::FP_ROUND &&
OtherRound.getOperand(0) == SDValue(U, 0) &&
OtherRound.getValueType() == MVT::f32) {
SDValue VRound = DAG.getNode(SystemZISD::VROUND, SDLoc(N),
MVT::v4f32, Vec);
DCI.AddToWorklist(VRound.getNode());
SDValue Extract1 =
DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(U), MVT::f32,
VRound, DAG.getConstant(2, SDLoc(U), MVT::i32));
DCI.AddToWorklist(Extract1.getNode());
DAG.ReplaceAllUsesOfValueWith(OtherRound, Extract1);
SDValue Extract0 =
DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(Op0), MVT::f32,
VRound, DAG.getConstant(0, SDLoc(Op0), MVT::i32));
return Extract0;
}
SelectionDAG &DAG = DCI.DAG;
SDValue Op0 = N->getOperand(0);
if (N->getValueType(0) == MVT::f32 &&
Op0.hasOneUse() &&
Op0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
Op0.getOperand(0).getValueType() == MVT::v2f64 &&
Op0.getOperand(1).getOpcode() == ISD::Constant &&
cast<ConstantSDNode>(Op0.getOperand(1))->getZExtValue() == 0) {
SDValue Vec = Op0.getOperand(0);
for (auto *U : Vec->uses()) {
if (U != Op0.getNode() &&
U->hasOneUse() &&
U->getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
U->getOperand(0) == Vec &&
U->getOperand(1).getOpcode() == ISD::Constant &&
cast<ConstantSDNode>(U->getOperand(1))->getZExtValue() == 1) {
SDValue OtherRound = SDValue(*U->use_begin(), 0);
if (OtherRound.getOpcode() == ISD::FP_ROUND &&
OtherRound.getOperand(0) == SDValue(U, 0) &&
OtherRound.getValueType() == MVT::f32) {
SDValue VRound = DAG.getNode(SystemZISD::VROUND, SDLoc(N),
MVT::v4f32, Vec);
DCI.AddToWorklist(VRound.getNode());
SDValue Extract1 =
DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(U), MVT::f32,
VRound, DAG.getConstant(2, SDLoc(U), MVT::i32));
DCI.AddToWorklist(Extract1.getNode());
DAG.ReplaceAllUsesOfValueWith(OtherRound, Extract1);
SDValue Extract0 =
DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(Op0), MVT::f32,
VRound, DAG.getConstant(0, SDLoc(Op0), MVT::i32));
return Extract0;
}
}
}
}
return SDValue();
}
SDValue SystemZTargetLowering::combineBSWAP(
SDNode *N, DAGCombinerInfo &DCI) const {
SelectionDAG &DAG = DCI.DAG;
// Combine BSWAP (LOAD) into LRVH/LRV/LRVG
// These loads are allowed to access memory multiple times, and so we must check
// that the loads are not volatile before performing the combine.
if (Opcode == ISD::BSWAP &&
ISD::isNON_EXTLoad(N->getOperand(0).getNode()) &&
N->getOperand(0).hasOneUse() &&
(N->getValueType(0) == MVT::i16 || N->getValueType(0) == MVT::i32 ||
N->getValueType(0) == MVT::i64) &&
!cast<LoadSDNode>(N->getOperand(0))->isVolatile()) {
if (ISD::isNON_EXTLoad(N->getOperand(0).getNode()) &&
N->getOperand(0).hasOneUse() &&
(N->getValueType(0) == MVT::i16 || N->getValueType(0) == MVT::i32 ||
N->getValueType(0) == MVT::i64) &&
!cast<LoadSDNode>(N->getOperand(0))->isVolatile()) {
SDValue Load = N->getOperand(0);
LoadSDNode *LD = cast<LoadSDNode>(Load);
@ -5021,33 +5066,22 @@ SDValue SystemZTargetLowering::PerformDAGCombine(SDNode *N,
// Return N so it doesn't get rechecked!
return SDValue(N, 0);
}
return SDValue();
}
// Combine STORE (BSWAP) into STRVH/STRV/STRVG
// See comment above about volatile accesses.
if (Opcode == ISD::STORE &&
!cast<StoreSDNode>(N)->isVolatile() &&
N->getOperand(1).getOpcode() == ISD::BSWAP &&
N->getOperand(1).getNode()->hasOneUse() &&
(N->getOperand(1).getValueType() == MVT::i16 ||
N->getOperand(1).getValueType() == MVT::i32 ||
N->getOperand(1).getValueType() == MVT::i64)) {
SDValue BSwapOp = N->getOperand(1).getOperand(0);
if (BSwapOp.getValueType() == MVT::i16)
BSwapOp = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), MVT::i32, BSwapOp);
SDValue Ops[] = {
N->getOperand(0), BSwapOp, N->getOperand(2),
DAG.getValueType(N->getOperand(1).getValueType())
};
return
DAG.getMemIntrinsicNode(SystemZISD::STRV, SDLoc(N), DAG.getVTList(MVT::Other),
Ops, cast<StoreSDNode>(N)->getMemoryVT(),
cast<StoreSDNode>(N)->getMemOperand());
}
SDValue SystemZTargetLowering::PerformDAGCombine(SDNode *N,
DAGCombinerInfo &DCI) const {
switch(N->getOpcode()) {
default: break;
case ISD::SIGN_EXTEND: return combineSIGN_EXTEND(N, DCI);
case SystemZISD::MERGE_HIGH:
case SystemZISD::MERGE_LOW: return combineMERGE(N, DCI);
case ISD::STORE: return combineSTORE(N, DCI);
case ISD::EXTRACT_VECTOR_ELT: return combineEXTRACT_VECTOR_ELT(N, DCI);
case SystemZISD::JOIN_DWORDS: return combineJOIN_DWORDS(N, DCI);
case ISD::FP_ROUND: return combineFP_ROUND(N, DCI);
case ISD::BSWAP: return combineBSWAP(N, DCI);
}
return SDValue();
}

7
llvm/lib/Target/SystemZ/SystemZISelLowering.h
View File

@ -545,6 +545,13 @@ private:
bool Force) const;
SDValue combineTruncateExtract(const SDLoc &DL, EVT TruncVT, SDValue Op,
DAGCombinerInfo &DCI) const;
SDValue combineSIGN_EXTEND(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue combineMERGE(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue combineSTORE(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue combineEXTRACT_VECTOR_ELT(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue combineJOIN_DWORDS(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue combineFP_ROUND(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue combineBSWAP(SDNode *N, DAGCombinerInfo &DCI) const;
// If the last instruction before MBBI in MBB was some form of COMPARE,
// try to replace it with a COMPARE AND BRANCH just before MBBI.