Eliminate the ISel priority queue, which used the topological order for a
priority function. Instead, just iterate over the AllNodes list, which is
already in topological order. This eliminates a fair amount of bookkeeping,
and speeds up the isel phase by about 15% on many testcases.
The impact on most targets is that AddToISelQueue calls can be simply removed.
In the x86 target, there are two additional notable changes.
The rule-bending AND+SHIFT optimization in MatchAddress that creates new
pre-isel nodes during isel is now a little more verbose, but more robust.
Instead of either creating an invalid DAG or creating an invalid topological
sort, as it has historically done, it can now just insert the new nodes into
the node list at a position where they will be consistent with the topological
ordering.
Also, the address-matching code has logic that checked to see if a node was
"already selected". However, when a node is selected, it has all its uses
taken away via ReplaceAllUsesWith or equivalent, so it won't recieve any
further visits from MatchAddress. This code is now removed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58748 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 7ba6218..137944a 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -777,9 +777,6 @@
return true;
}
- int id = N.getNode()->getNodeId();
- bool AlreadySelected = isSelected(id); // Already selected, not yet replaced.
-
switch (N.getOpcode()) {
default: break;
case ISD::Constant: {
@@ -794,7 +791,6 @@
case X86ISD::Wrapper: {
DOUT << "Wrapper: 64bit " << is64Bit;
DOUT << " AM "; DEBUG(AM.dump()); DOUT << "\n";
- DOUT << "AlreadySelected " << AlreadySelected << "\n";
// Under X86-64 non-small code model, GV (and friends) are 64-bits.
// Also, base and index reg must be 0 in order to use rip as base.
if (is64Bit && (TM.getCodeModel() != CodeModel::Small ||
@@ -805,7 +801,7 @@
// If value is available in a register both base and index components have
// been picked, we can't fit the result available in the register in the
// addressing mode. Duplicate GlobalAddress or ConstantPool as displacement.
- if (!AlreadySelected || (AM.Base.Reg.getNode() && AM.IndexReg.getNode())) {
+ {
SDValue N0 = N.getOperand(0);
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(N0)) {
if (!is64Bit || isInt32(AM.Disp + G->getOffset())) {
@@ -846,8 +842,7 @@
break;
case ISD::SHL:
- if (AlreadySelected || AM.IndexReg.getNode() != 0
- || AM.Scale != 1 || AM.isRIPRel)
+ if (AM.IndexReg.getNode() != 0 || AM.Scale != 1 || AM.isRIPRel)
break;
if (ConstantSDNode
@@ -885,8 +880,7 @@
// FALL THROUGH
case ISD::MUL:
// X*[3,5,9] -> X+X*[2,4,8]
- if (!AlreadySelected &&
- AM.BaseType == X86ISelAddressMode::RegBase &&
+ if (AM.BaseType == X86ISelAddressMode::RegBase &&
AM.Base.Reg.getNode() == 0 &&
AM.IndexReg.getNode() == 0 &&
!AM.isRIPRel) {
@@ -924,7 +918,7 @@
break;
case ISD::ADD:
- if (!AlreadySelected) {
+ {
X86ISelAddressMode Backup = AM;
if (!MatchAddress(N.getNode()->getOperand(0), AM, false, Depth+1) &&
!MatchAddress(N.getNode()->getOperand(1), AM, false, Depth+1))
@@ -939,8 +933,6 @@
case ISD::OR:
// Handle "X | C" as "X + C" iff X is known to have C bits clear.
- if (AlreadySelected) break;
-
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
X86ISelAddressMode Backup = AM;
// Start with the LHS as an addr mode.
@@ -961,10 +953,9 @@
case ISD::AND: {
// Handle "(x << C1) & C2" as "(X & (C2>>C1)) << C1" if safe and if this
// allows us to fold the shift into this addressing mode.
- if (AlreadySelected) break;
SDValue Shift = N.getOperand(0);
if (Shift.getOpcode() != ISD::SHL) break;
-
+
// Scale must not be used already.
if (AM.IndexReg.getNode() != 0 || AM.Scale != 1) break;
@@ -987,14 +978,34 @@
break;
// Get the new AND mask, this folds to a constant.
+ SDValue X = Shift.getOperand(0);
SDValue NewANDMask = CurDAG->getNode(ISD::SRL, N.getValueType(),
SDValue(C2, 0), SDValue(C1, 0));
- SDValue NewAND = CurDAG->getNode(ISD::AND, N.getValueType(),
- Shift.getOperand(0), NewANDMask);
+ SDValue NewAND = CurDAG->getNode(ISD::AND, N.getValueType(), X, NewANDMask);
SDValue NewSHIFT = CurDAG->getNode(ISD::SHL, N.getValueType(),
NewAND, SDValue(C1, 0));
- NewAND.getNode()->setNodeId(Shift.getNode()->getNodeId());
- NewSHIFT.getNode()->setNodeId(N.getNode()->getNodeId());
+
+ // Insert the new nodes into the topological ordering.
+ if (C1->getNodeId() > X.getNode()->getNodeId()) {
+ CurDAG->RepositionNode(X.getNode(), C1);
+ C1->setNodeId(X.getNode()->getNodeId());
+ }
+ if (NewANDMask.getNode()->getNodeId() == -1 ||
+ NewANDMask.getNode()->getNodeId() > X.getNode()->getNodeId()) {
+ CurDAG->RepositionNode(X.getNode(), NewANDMask.getNode());
+ NewANDMask.getNode()->setNodeId(X.getNode()->getNodeId());
+ }
+ if (NewAND.getNode()->getNodeId() == -1 ||
+ NewAND.getNode()->getNodeId() > Shift.getNode()->getNodeId()) {
+ CurDAG->RepositionNode(Shift.getNode(), NewAND.getNode());
+ NewAND.getNode()->setNodeId(Shift.getNode()->getNodeId());
+ }
+ if (NewSHIFT.getNode()->getNodeId() == -1 ||
+ NewSHIFT.getNode()->getNodeId() > N.getNode()->getNodeId()) {
+ CurDAG->RepositionNode(N.getNode(), NewSHIFT.getNode());
+ NewSHIFT.getNode()->setNodeId(N.getNode()->getNodeId());
+ }
+
CurDAG->ReplaceAllUsesWith(N, NewSHIFT);
AM.Scale = 1 << ShiftCst;
@@ -1212,14 +1223,6 @@
if (!SelectAddr(In1, In1, Tmp0, Tmp1, Tmp2, Tmp3))
return NULL;
SDValue LSI = Node->getOperand(4); // MemOperand
- AddToISelQueue(Tmp0);
- AddToISelQueue(Tmp1);
- AddToISelQueue(Tmp2);
- AddToISelQueue(Tmp3);
- AddToISelQueue(In2L);
- AddToISelQueue(In2H);
- // For now, don't select the MemOperand object, we don't know how.
- AddToISelQueue(Chain);
const SDValue Ops[] = { Tmp0, Tmp1, Tmp2, Tmp3, In2L, In2H, LSI, Chain };
return CurDAG->getTargetNode(Opc, MVT::i32, MVT::i32, MVT::Other, Ops, 8);
}
@@ -1308,16 +1311,10 @@
std::swap(N0, N1);
}
- AddToISelQueue(N0);
SDValue InFlag = CurDAG->getCopyToReg(CurDAG->getEntryNode(), LoReg,
N0, SDValue()).getValue(1);
if (foldedLoad) {
- AddToISelQueue(N1.getOperand(0));
- AddToISelQueue(Tmp0);
- AddToISelQueue(Tmp1);
- AddToISelQueue(Tmp2);
- AddToISelQueue(Tmp3);
SDValue Ops[] = { Tmp0, Tmp1, Tmp2, Tmp3, N1.getOperand(0), InFlag };
SDNode *CNode =
CurDAG->getTargetNode(MOpc, MVT::Other, MVT::Flag, Ops, 6);
@@ -1325,7 +1322,6 @@
// Update the chain.
ReplaceUses(N1.getValue(1), SDValue(CNode, 0));
} else {
- AddToISelQueue(N1);
InFlag =
SDValue(CurDAG->getTargetNode(Opc, MVT::Flag, N1, InFlag), 0);
}
@@ -1436,18 +1432,12 @@
SDValue Tmp0, Tmp1, Tmp2, Tmp3, Move, Chain;
if (TryFoldLoad(N, N0, Tmp0, Tmp1, Tmp2, Tmp3)) {
SDValue Ops[] = { Tmp0, Tmp1, Tmp2, Tmp3, N0.getOperand(0) };
- AddToISelQueue(N0.getOperand(0));
- AddToISelQueue(Tmp0);
- AddToISelQueue(Tmp1);
- AddToISelQueue(Tmp2);
- AddToISelQueue(Tmp3);
Move =
SDValue(CurDAG->getTargetNode(X86::MOVZX16rm8, MVT::i16, MVT::Other,
Ops, 5), 0);
Chain = Move.getValue(1);
ReplaceUses(N0.getValue(1), Chain);
} else {
- AddToISelQueue(N0);
Move =
SDValue(CurDAG->getTargetNode(X86::MOVZX16rr8, MVT::i16, N0), 0);
Chain = CurDAG->getEntryNode();
@@ -1455,7 +1445,6 @@
Chain = CurDAG->getCopyToReg(Chain, X86::AX, Move, SDValue());
InFlag = Chain.getValue(1);
} else {
- AddToISelQueue(N0);
InFlag =
CurDAG->getCopyToReg(CurDAG->getEntryNode(),
LoReg, N0, SDValue()).getValue(1);
@@ -1472,11 +1461,6 @@
}
if (foldedLoad) {
- AddToISelQueue(N1.getOperand(0));
- AddToISelQueue(Tmp0);
- AddToISelQueue(Tmp1);
- AddToISelQueue(Tmp2);
- AddToISelQueue(Tmp3);
SDValue Ops[] = { Tmp0, Tmp1, Tmp2, Tmp3, N1.getOperand(0), InFlag };
SDNode *CNode =
CurDAG->getTargetNode(MOpc, MVT::Other, MVT::Flag, Ops, 6);
@@ -1484,7 +1468,6 @@
// Update the chain.
ReplaceUses(N1.getValue(1), SDValue(CNode, 0));
} else {
- AddToISelQueue(N1);
InFlag =
SDValue(CurDAG->getTargetNode(Opc, MVT::Flag, N1, InFlag), 0);
}
@@ -1540,7 +1523,6 @@
MVT SVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
if (SVT == MVT::i8 && !Subtarget->is64Bit()) {
SDValue N0 = Node->getOperand(0);
- AddToISelQueue(N0);
SDValue TruncOp = SDValue(getTruncateTo8Bit(N0), 0);
unsigned Opc = 0;
@@ -1573,7 +1555,6 @@
case ISD::TRUNCATE: {
if (NVT == MVT::i8 && !Subtarget->is64Bit()) {
SDValue Input = Node->getOperand(0);
- AddToISelQueue(Node->getOperand(0));
SDNode *ResNode = getTruncateTo8Bit(Input);
#ifndef NDEBUG
@@ -1605,7 +1586,6 @@
cast<GlobalAddressSDNode>(N2.getOperand(0))->getGlobal();
SDValue Tmp1 = CurDAG->getTargetFrameIndex(FI, TLI.getPointerTy());
SDValue Tmp2 = CurDAG->getTargetGlobalAddress(GV, TLI.getPointerTy());
- AddToISelQueue(Chain);
SDValue Ops[] = { Tmp1, Tmp2, Chain };
return CurDAG->getTargetNode(TargetInstrInfo::DECLARE,
MVT::Other, Ops, 3);
@@ -1647,10 +1627,6 @@
OutOps.push_back(Op1);
OutOps.push_back(Op2);
OutOps.push_back(Op3);
- AddToISelQueue(Op0);
- AddToISelQueue(Op1);
- AddToISelQueue(Op2);
- AddToISelQueue(Op3);
return false;
}