-//===-- ScheduleDAG.cpp - Implement a trivial DAG scheduler ---------------===//
+//===---- ScheduleDAG.cpp - Implement the ScheduleDAG class ---------------===//
//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Chris Lattner and is distributed under the
+// This file was developed by James M. Laskey and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
-// This implements a simple code linearizer for DAGs. This is not a very good
-// way to emit code, but gets working code quickly.
+// This implements a simple two pass scheduler. The first pass attempts to push
+// backward any lengthy instructions and critical paths. The second pass packs
+// instructions into semi-optimal time slots.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "sched"
+#include "llvm/CodeGen/ScheduleDAG.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/SelectionDAGISel.h"
-#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SSARegMap.h"
+#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MathExtras.h"
+#include <iostream>
using namespace llvm;
-#ifndef _NDEBUG
-static cl::opt<bool>
-ViewDAGs("view-sched-dags", cl::Hidden,
- cl::desc("Pop up a window to show sched dags as they are processed"));
-#else
-static const bool ViewDAGS = 0;
-#endif
-namespace {
- class SimpleSched {
- SelectionDAG &DAG;
- MachineBasicBlock *BB;
- const TargetMachine &TM;
- const TargetInstrInfo &TII;
- const MRegisterInfo &MRI;
- SSARegMap *RegMap;
+/// BuildSchedUnits - Build SUnits from the selection dag that we are input.
+/// This SUnit graph is similar to the SelectionDAG, but represents flagged
+/// together nodes with a single SUnit.
+void ScheduleDAG::BuildSchedUnits() {
+ // Reserve entries in the vector for each of the SUnits we are creating. This
+ // ensure that reallocation of the vector won't happen, so SUnit*'s won't get
+ // invalidated.
+ SUnits.reserve(std::distance(DAG.allnodes_begin(), DAG.allnodes_end()));
+
+ const InstrItineraryData &InstrItins = TM.getInstrItineraryData();
+
+ for (SelectionDAG::allnodes_iterator NI = DAG.allnodes_begin(),
+ E = DAG.allnodes_end(); NI != E; ++NI) {
+ if (isPassiveNode(NI)) // Leaf node, e.g. a TargetImmediate.
+ continue;
+
+ // If this node has already been processed, stop now.
+ if (SUnitMap[NI]) continue;
- std::map<SDNode *, unsigned> EmittedOps;
- public:
- SimpleSched(SelectionDAG &D, MachineBasicBlock *bb)
- : DAG(D), BB(bb), TM(D.getTarget()), TII(*TM.getInstrInfo()),
- MRI(*TM.getRegisterInfo()), RegMap(BB->getParent()->getSSARegMap()) {
- assert(&TII && "Target doesn't provide instr info?");
- assert(&MRI && "Target doesn't provide register info?");
+ SUnit *NodeSUnit = NewSUnit(NI);
+
+ // See if anything is flagged to this node, if so, add them to flagged
+ // nodes. Nodes can have at most one flag input and one flag output. Flags
+ // are required the be the last operand and result of a node.
+
+ // Scan up, adding flagged preds to FlaggedNodes.
+ SDNode *N = NI;
+ if (N->getNumOperands() &&
+ N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Flag) {
+ do {
+ N = N->getOperand(N->getNumOperands()-1).Val;
+ NodeSUnit->FlaggedNodes.push_back(N);
+ SUnitMap[N] = NodeSUnit;
+ } while (N->getNumOperands() &&
+ N->getOperand(N->getNumOperands()-1).getValueType()== MVT::Flag);
+ std::reverse(NodeSUnit->FlaggedNodes.begin(),
+ NodeSUnit->FlaggedNodes.end());
}
- void Run() {
- Emit(DAG.getRoot());
+ // Scan down, adding this node and any flagged succs to FlaggedNodes if they
+ // have a user of the flag operand.
+ N = NI;
+ while (N->getValueType(N->getNumValues()-1) == MVT::Flag) {
+ SDOperand FlagVal(N, N->getNumValues()-1);
+
+ // There are either zero or one users of the Flag result.
+ bool HasFlagUse = false;
+ for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
+ UI != E; ++UI)
+ if (FlagVal.isOperand(*UI)) {
+ HasFlagUse = true;
+ NodeSUnit->FlaggedNodes.push_back(N);
+ SUnitMap[N] = NodeSUnit;
+ N = *UI;
+ break;
+ }
+ if (!HasFlagUse) break;
}
- private:
- unsigned Emit(SDOperand Op);
- };
+ // Now all flagged nodes are in FlaggedNodes and N is the bottom-most node.
+ // Update the SUnit
+ NodeSUnit->Node = N;
+ SUnitMap[N] = NodeSUnit;
+
+ // Compute the latency for the node. We use the sum of the latencies for
+ // all nodes flagged together into this SUnit.
+ if (InstrItins.isEmpty()) {
+ // No latency information.
+ NodeSUnit->Latency = 1;
+ } else {
+ NodeSUnit->Latency = 0;
+ if (N->isTargetOpcode()) {
+ unsigned SchedClass = TII->getSchedClass(N->getTargetOpcode());
+ InstrStage *S = InstrItins.begin(SchedClass);
+ InstrStage *E = InstrItins.end(SchedClass);
+ for (; S != E; ++S)
+ NodeSUnit->Latency += S->Cycles;
+ }
+ for (unsigned i = 0, e = NodeSUnit->FlaggedNodes.size(); i != e; ++i) {
+ SDNode *FNode = NodeSUnit->FlaggedNodes[i];
+ if (FNode->isTargetOpcode()) {
+ unsigned SchedClass = TII->getSchedClass(FNode->getTargetOpcode());
+ InstrStage *S = InstrItins.begin(SchedClass);
+ InstrStage *E = InstrItins.end(SchedClass);
+ for (; S != E; ++S)
+ NodeSUnit->Latency += S->Cycles;
+ }
+ }
+ }
+ }
+
+ // Pass 2: add the preds, succs, etc.
+ for (unsigned su = 0, e = SUnits.size(); su != e; ++su) {
+ SUnit *SU = &SUnits[su];
+ SDNode *MainNode = SU->Node;
+
+ if (MainNode->isTargetOpcode()) {
+ unsigned Opc = MainNode->getTargetOpcode();
+ if (TII->isTwoAddrInstr(Opc))
+ SU->isTwoAddress = true;
+ if (TII->isCommutableInstr(Opc))
+ SU->isCommutable = true;
+ }
+
+ // Find all predecessors and successors of the group.
+ // Temporarily add N to make code simpler.
+ SU->FlaggedNodes.push_back(MainNode);
+
+ for (unsigned n = 0, e = SU->FlaggedNodes.size(); n != e; ++n) {
+ SDNode *N = SU->FlaggedNodes[n];
+
+ for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
+ SDNode *OpN = N->getOperand(i).Val;
+ if (isPassiveNode(OpN)) continue; // Not scheduled.
+ SUnit *OpSU = SUnitMap[OpN];
+ assert(OpSU && "Node has no SUnit!");
+ if (OpSU == SU) continue; // In the same group.
+
+ MVT::ValueType OpVT = N->getOperand(i).getValueType();
+ assert(OpVT != MVT::Flag && "Flagged nodes should be in same sunit!");
+ bool isChain = OpVT == MVT::Other;
+
+ if (SU->addPred(OpSU, isChain)) {
+ if (!isChain) {
+ SU->NumPreds++;
+ SU->NumPredsLeft++;
+ } else {
+ SU->NumChainPredsLeft++;
+ }
+ }
+ if (OpSU->addSucc(SU, isChain)) {
+ if (!isChain) {
+ OpSU->NumSuccs++;
+ OpSU->NumSuccsLeft++;
+ } else {
+ OpSU->NumChainSuccsLeft++;
+ }
+ }
+ }
+ }
+
+ // Remove MainNode from FlaggedNodes again.
+ SU->FlaggedNodes.pop_back();
+ }
+
+ return;
+}
+
+static void CalculateDepths(SUnit &SU, unsigned Depth) {
+ if (SU.Depth == 0 || Depth > SU.Depth) {
+ SU.Depth = Depth;
+ for (SUnit::succ_iterator I = SU.Succs.begin(), E = SU.Succs.end();
+ I != E; ++I)
+ CalculateDepths(*I->first, Depth+1);
+ }
}
-unsigned SimpleSched::Emit(SDOperand Op) {
- // Check to see if we have already emitted this. If so, return the value
- // already emitted. Note that if a node has a single use it cannot be
- // revisited, so don't bother putting it in the map.
- unsigned *OpSlot;
- if (Op.Val->hasOneUse()) {
- OpSlot = 0; // No reuse possible.
+void ScheduleDAG::CalculateDepths() {
+ SUnit *Entry = SUnitMap[DAG.getEntryNode().Val];
+ ::CalculateDepths(*Entry, 0U);
+ for (unsigned i = 0, e = SUnits.size(); i != e; ++i)
+ if (SUnits[i].Preds.size() == 0 && &SUnits[i] != Entry) {
+ ::CalculateDepths(SUnits[i], 0U);
+ }
+}
+
+static void CalculateHeights(SUnit &SU, unsigned Height) {
+ if (SU.Height == 0 || Height > SU.Height) {
+ SU.Height = Height;
+ for (SUnit::pred_iterator I = SU.Preds.begin(), E = SU.Preds.end();
+ I != E; ++I)
+ CalculateHeights(*I->first, Height+1);
+ }
+}
+void ScheduleDAG::CalculateHeights() {
+ SUnit *Root = SUnitMap[DAG.getRoot().Val];
+ ::CalculateHeights(*Root, 0U);
+}
+
+/// CountResults - The results of target nodes have register or immediate
+/// operands first, then an optional chain, and optional flag operands (which do
+/// not go into the machine instrs.)
+static unsigned CountResults(SDNode *Node) {
+ unsigned N = Node->getNumValues();
+ while (N && Node->getValueType(N - 1) == MVT::Flag)
+ --N;
+ if (N && Node->getValueType(N - 1) == MVT::Other)
+ --N; // Skip over chain result.
+ return N;
+}
+
+/// CountOperands The inputs to target nodes have any actual inputs first,
+/// followed by an optional chain operand, then flag operands. Compute the
+/// number of actual operands that will go into the machine instr.
+static unsigned CountOperands(SDNode *Node) {
+ unsigned N = Node->getNumOperands();
+ while (N && Node->getOperand(N - 1).getValueType() == MVT::Flag)
+ --N;
+ if (N && Node->getOperand(N - 1).getValueType() == MVT::Other)
+ --N; // Ignore chain if it exists.
+ return N;
+}
+
+static const TargetRegisterClass *getInstrOperandRegClass(
+ const MRegisterInfo *MRI,
+ const TargetInstrInfo *TII,
+ const TargetInstrDescriptor *II,
+ unsigned Op) {
+ if (Op >= II->numOperands) {
+ assert((II->Flags & M_VARIABLE_OPS)&& "Invalid operand # of instruction");
+ return NULL;
+ }
+ const TargetOperandInfo &toi = II->OpInfo[Op];
+ return (toi.Flags & M_LOOK_UP_PTR_REG_CLASS)
+ ? TII->getPointerRegClass() : MRI->getRegClass(toi.RegClass);
+}
+
+static unsigned CreateVirtualRegisters(const MRegisterInfo *MRI,
+ MachineInstr *MI,
+ unsigned NumResults,
+ SSARegMap *RegMap,
+ const TargetInstrInfo *TII,
+ const TargetInstrDescriptor &II) {
+ // Create the result registers for this node and add the result regs to
+ // the machine instruction.
+ unsigned ResultReg =
+ RegMap->createVirtualRegister(getInstrOperandRegClass(MRI, TII, &II, 0));
+ MI->addRegOperand(ResultReg, MachineOperand::Def);
+ for (unsigned i = 1; i != NumResults; ++i) {
+ const TargetRegisterClass *RC = getInstrOperandRegClass(MRI, TII, &II, i);
+ assert(RC && "Isn't a register operand!");
+ MI->addRegOperand(RegMap->createVirtualRegister(RC), MachineOperand::Def);
+ }
+ return ResultReg;
+}
+
+/// getVR - Return the virtual register corresponding to the specified result
+/// of the specified node.
+static unsigned getVR(SDOperand Op, std::map<SDNode*, unsigned> &VRBaseMap) {
+ std::map<SDNode*, unsigned>::iterator I = VRBaseMap.find(Op.Val);
+ assert(I != VRBaseMap.end() && "Node emitted out of order - late");
+ return I->second + Op.ResNo;
+}
+
+
+/// AddOperand - Add the specified operand to the specified machine instr. II
+/// specifies the instruction information for the node, and IIOpNum is the
+/// operand number (in the II) that we are adding. IIOpNum and II are used for
+/// assertions only.
+void ScheduleDAG::AddOperand(MachineInstr *MI, SDOperand Op,
+ unsigned IIOpNum,
+ const TargetInstrDescriptor *II,
+ std::map<SDNode*, unsigned> &VRBaseMap) {
+ if (Op.isTargetOpcode()) {
+ // Note that this case is redundant with the final else block, but we
+ // include it because it is the most common and it makes the logic
+ // simpler here.
+ assert(Op.getValueType() != MVT::Other &&
+ Op.getValueType() != MVT::Flag &&
+ "Chain and flag operands should occur at end of operand list!");
+
+ // Get/emit the operand.
+ unsigned VReg = getVR(Op, VRBaseMap);
+ MI->addRegOperand(VReg, MachineOperand::Use);
+
+ // Verify that it is right.
+ assert(MRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
+ if (II) {
+ const TargetRegisterClass *RC =
+ getInstrOperandRegClass(MRI, TII, II, IIOpNum);
+ assert(RC && "Don't have operand info for this instruction!");
+ assert(RegMap->getRegClass(VReg) == RC &&
+ "Register class of operand and regclass of use don't agree!");
+ }
+ } else if (ConstantSDNode *C =
+ dyn_cast<ConstantSDNode>(Op)) {
+ MI->addImmOperand(C->getValue());
+ } else if (RegisterSDNode*R =
+ dyn_cast<RegisterSDNode>(Op)) {
+ MI->addRegOperand(R->getReg(), MachineOperand::Use);
+ } else if (GlobalAddressSDNode *TGA =
+ dyn_cast<GlobalAddressSDNode>(Op)) {
+ MI->addGlobalAddressOperand(TGA->getGlobal(), TGA->getOffset());
+ } else if (BasicBlockSDNode *BB =
+ dyn_cast<BasicBlockSDNode>(Op)) {
+ MI->addMachineBasicBlockOperand(BB->getBasicBlock());
+ } else if (FrameIndexSDNode *FI =
+ dyn_cast<FrameIndexSDNode>(Op)) {
+ MI->addFrameIndexOperand(FI->getIndex());
+ } else if (JumpTableSDNode *JT =
+ dyn_cast<JumpTableSDNode>(Op)) {
+ MI->addJumpTableIndexOperand(JT->getIndex());
+ } else if (ConstantPoolSDNode *CP =
+ dyn_cast<ConstantPoolSDNode>(Op)) {
+ int Offset = CP->getOffset();
+ unsigned Align = CP->getAlignment();
+ // MachineConstantPool wants an explicit alignment.
+ if (Align == 0) {
+ if (CP->get()->getType() == Type::DoubleTy)
+ Align = 3; // always 8-byte align doubles.
+ else {
+ Align = TM.getTargetData()
+ ->getTypeAlignmentShift(CP->get()->getType());
+ if (Align == 0) {
+ // Alignment of packed types. FIXME!
+ Align = TM.getTargetData()->getTypeSize(CP->get()->getType());
+ Align = Log2_64(Align);
+ }
+ }
+ }
+
+ unsigned Idx = ConstPool->getConstantPoolIndex(CP->get(), Align);
+ MI->addConstantPoolIndexOperand(Idx, Offset);
+ } else if (ExternalSymbolSDNode *ES =
+ dyn_cast<ExternalSymbolSDNode>(Op)) {
+ MI->addExternalSymbolOperand(ES->getSymbol());
} else {
- std::map<SDNode *, unsigned>::iterator OpI = EmittedOps.lower_bound(Op.Val);
- if (OpI != EmittedOps.end() && OpI->first == Op.Val)
- return OpI->second + Op.ResNo;
- OpSlot = &EmittedOps.insert(OpI, std::make_pair(Op.Val, 0))->second;
+ assert(Op.getValueType() != MVT::Other &&
+ Op.getValueType() != MVT::Flag &&
+ "Chain and flag operands should occur at end of operand list!");
+ unsigned VReg = getVR(Op, VRBaseMap);
+ MI->addRegOperand(VReg, MachineOperand::Use);
+
+ // Verify that it is right.
+ assert(MRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
+ if (II) {
+ const TargetRegisterClass *RC =
+ getInstrOperandRegClass(MRI, TII, II, IIOpNum);
+ assert(RC && "Don't have operand info for this instruction!");
+ assert(RegMap->getRegClass(VReg) == RC &&
+ "Register class of operand and regclass of use don't agree!");
+ }
}
- unsigned ResultReg = 0;
- if (Op.isTargetOpcode()) {
- unsigned Opc = Op.getTargetOpcode();
- const TargetInstrDescriptor &II = TII.get(Opc);
-
- // Target nodes have any register or immediate operands before any chain
- // nodes. Check that the DAG matches the TD files's expectation of #
- // operands.
- unsigned NumResults = Op.Val->getNumValues();
- if (NumResults && Op.getOperand(NumResults-1).getValueType() == MVT::Other)
- --NumResults;
-#ifndef _NDEBUG
- unsigned Operands = Op.getNumOperands();
- if (Operands && Op.getOperand(Operands-1).getValueType() == MVT::Other)
- --Operands;
- assert(unsigned(II.numOperands) == Operands+NumResults &&
+}
+
+
+/// EmitNode - Generate machine code for an node and needed dependencies.
+///
+void ScheduleDAG::EmitNode(SDNode *Node,
+ std::map<SDNode*, unsigned> &VRBaseMap) {
+ unsigned VRBase = 0; // First virtual register for node
+
+ // If machine instruction
+ if (Node->isTargetOpcode()) {
+ unsigned Opc = Node->getTargetOpcode();
+ const TargetInstrDescriptor &II = TII->get(Opc);
+
+ unsigned NumResults = CountResults(Node);
+ unsigned NodeOperands = CountOperands(Node);
+ unsigned NumMIOperands = NodeOperands + NumResults;
+#ifndef NDEBUG
+ assert((unsigned(II.numOperands) == NumMIOperands ||
+ (II.Flags & M_VARIABLE_OPS)) &&
"#operands for dag node doesn't match .td file!");
#endif
// Create the new machine instruction.
- MachineInstr *MI = new MachineInstr(Opc, II.numOperands, true, true);
+ MachineInstr *MI = new MachineInstr(Opc, NumMIOperands);
// Add result register values for things that are defined by this
// instruction.
- if (NumResults) {
- // Create the result registers for this node and add the result regs to
- // the machine instruction.
- const TargetOperandInfo *OpInfo = II.OpInfo;
- ResultReg = RegMap->createVirtualRegister(OpInfo[0].RegClass);
- MI->addRegOperand(ResultReg, MachineOperand::Def);
- for (unsigned i = 1; i != NumResults; ++i) {
- assert(OpInfo[i].RegClass && "Isn't a register operand!");
- MI->addRegOperand(RegMap->createVirtualRegister(OpInfo[0].RegClass),
- MachineOperand::Def);
+
+ // If the node is only used by a CopyToReg and the dest reg is a vreg, use
+ // the CopyToReg'd destination register instead of creating a new vreg.
+ if (NumResults == 1) {
+ for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
+ UI != E; ++UI) {
+ SDNode *Use = *UI;
+ if (Use->getOpcode() == ISD::CopyToReg &&
+ Use->getOperand(2).Val == Node) {
+ unsigned Reg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
+ if (MRegisterInfo::isVirtualRegister(Reg)) {
+ VRBase = Reg;
+ MI->addRegOperand(Reg, MachineOperand::Def);
+ break;
+ }
+ }
}
}
- // Emit all of the operands of this instruction, adding them to the
+ // Otherwise, create new virtual registers.
+ if (NumResults && VRBase == 0)
+ VRBase = CreateVirtualRegisters(MRI, MI, NumResults, RegMap, TII, II);
+
+ // Emit all of the actual operands of this instruction, adding them to the
// instruction as appropriate.
- for (unsigned i = 0, e = Op.getNumOperands(); i != e; ++i) {
- if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(i))) {
- MI->addZeroExtImm64Operand(C->getValue());
- } else if (RegisterSDNode*R =dyn_cast<RegisterSDNode>(Op.getOperand(i))) {
- MI->addRegOperand(R->getReg(), MachineOperand::Use);
- } else {
- unsigned R = Emit(Op.getOperand(i));
- // Add an operand, unless this corresponds to a chain node.
- if (Op.getOperand(i).getValueType() != MVT::Other)
- MI->addRegOperand(R, MachineOperand::Use);
+ for (unsigned i = 0; i != NodeOperands; ++i)
+ AddOperand(MI, Node->getOperand(i), i+NumResults, &II, VRBaseMap);
+
+ // Commute node if it has been determined to be profitable.
+ if (CommuteSet.count(Node)) {
+ MachineInstr *NewMI = TII->commuteInstruction(MI);
+ if (NewMI == 0)
+ DEBUG(std::cerr << "Sched: COMMUTING FAILED!\n");
+ else {
+ DEBUG(std::cerr << "Sched: COMMUTED TO: " << *NewMI);
+ if (MI != NewMI) {
+ delete MI;
+ MI = NewMI;
+ }
}
}
// Now that we have emitted all operands, emit this instruction itself.
- BB->insert(BB->end(), MI);
+ if ((II.Flags & M_USES_CUSTOM_DAG_SCHED_INSERTION) == 0) {
+ BB->insert(BB->end(), MI);
+ } else {
+ // Insert this instruction into the end of the basic block, potentially
+ // taking some custom action.
+ BB = DAG.getTargetLoweringInfo().InsertAtEndOfBasicBlock(MI, BB);
+ }
} else {
- switch (Op.getOpcode()) {
+ switch (Node->getOpcode()) {
default:
- Op.Val->dump();
+#ifndef NDEBUG
+ Node->dump();
+#endif
assert(0 && "This target-independent node should have been selected!");
- case ISD::EntryToken: break;
+ case ISD::EntryToken: // fall thru
case ISD::TokenFactor:
- for (unsigned i = 0, e = Op.getNumOperands(); i != e; ++i)
- Emit(Op.getOperand(i));
break;
case ISD::CopyToReg: {
- Emit(Op.getOperand(0)); // Emit the chain.
- unsigned Val = Emit(Op.getOperand(2));
- MRI.copyRegToReg(*BB, BB->end(),
- cast<RegisterSDNode>(Op.getOperand(1))->getReg(), Val,
- RegMap->getRegClass(Val));
+ unsigned InReg = getVR(Node->getOperand(2), VRBaseMap);
+ unsigned DestReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
+ if (InReg != DestReg) // Coalesced away the copy?
+ MRI->copyRegToReg(*BB, BB->end(), DestReg, InReg,
+ RegMap->getRegClass(InReg));
break;
}
case ISD::CopyFromReg: {
- Emit(Op.getOperand(0)); // Emit the chain.
- unsigned SrcReg = cast<RegisterSDNode>(Op.getOperand(1))->getReg();
-
- // Figure out the register class to create for the destreg.
- const TargetRegisterClass *TRC;
+ unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
if (MRegisterInfo::isVirtualRegister(SrcReg)) {
- TRC = RegMap->getRegClass(SrcReg);
+ VRBase = SrcReg; // Just use the input register directly!
+ break;
+ }
+
+ // If the node is only used by a CopyToReg and the dest reg is a vreg, use
+ // the CopyToReg'd destination register instead of creating a new vreg.
+ for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
+ UI != E; ++UI) {
+ SDNode *Use = *UI;
+ if (Use->getOpcode() == ISD::CopyToReg &&
+ Use->getOperand(2).Val == Node) {
+ unsigned DestReg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
+ if (MRegisterInfo::isVirtualRegister(DestReg)) {
+ VRBase = DestReg;
+ break;
+ }
+ }
+ }
+
+ // Figure out the register class to create for the destreg.
+ const TargetRegisterClass *TRC = 0;
+ if (VRBase) {
+ TRC = RegMap->getRegClass(VRBase);
} else {
- // FIXME: we don't know what register class to generate this for. Do
- // a brute force search and pick the first match. :(
- for (MRegisterInfo::regclass_iterator I = MRI.regclass_begin(),
- E = MRI.regclass_end(); I != E; ++I)
- if ((*I)->contains(SrcReg)) {
+
+ // Pick the register class of the right type that contains this physreg.
+ for (MRegisterInfo::regclass_iterator I = MRI->regclass_begin(),
+ E = MRI->regclass_end(); I != E; ++I)
+ if ((*I)->hasType(Node->getValueType(0)) &&
+ (*I)->contains(SrcReg)) {
TRC = *I;
break;
}
assert(TRC && "Couldn't find register class for reg copy!");
+
+ // Create the reg, emit the copy.
+ VRBase = RegMap->createVirtualRegister(TRC);
}
+ MRI->copyRegToReg(*BB, BB->end(), VRBase, SrcReg, TRC);
+ break;
+ }
+ case ISD::INLINEASM: {
+ unsigned NumOps = Node->getNumOperands();
+ if (Node->getOperand(NumOps-1).getValueType() == MVT::Flag)
+ --NumOps; // Ignore the flag operand.
+
+ // Create the inline asm machine instruction.
+ MachineInstr *MI =
+ new MachineInstr(BB, TargetInstrInfo::INLINEASM, (NumOps-2)/2+1);
+
+ // Add the asm string as an external symbol operand.
+ const char *AsmStr =
+ cast<ExternalSymbolSDNode>(Node->getOperand(1))->getSymbol();
+ MI->addExternalSymbolOperand(AsmStr);
- // Create the reg, emit the copy.
- ResultReg = RegMap->createVirtualRegister(TRC);
- MRI.copyRegToReg(*BB, BB->end(), ResultReg, SrcReg, TRC);
+ // Add all of the operand registers to the instruction.
+ for (unsigned i = 2; i != NumOps;) {
+ unsigned Flags = cast<ConstantSDNode>(Node->getOperand(i))->getValue();
+ unsigned NumVals = Flags >> 3;
+
+ MI->addImmOperand(Flags);
+ ++i; // Skip the ID value.
+
+ switch (Flags & 7) {
+ default: assert(0 && "Bad flags!");
+ case 1: // Use of register.
+ for (; NumVals; --NumVals, ++i) {
+ unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
+ MI->addRegOperand(Reg, MachineOperand::Use);
+ }
+ break;
+ case 2: // Def of register.
+ for (; NumVals; --NumVals, ++i) {
+ unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
+ MI->addRegOperand(Reg, MachineOperand::Def);
+ }
+ break;
+ case 3: { // Immediate.
+ assert(NumVals == 1 && "Unknown immediate value!");
+ uint64_t Val = cast<ConstantSDNode>(Node->getOperand(i))->getValue();
+ MI->addImmOperand(Val);
+ ++i;
+ break;
+ }
+ case 4: // Addressing mode.
+ // The addressing mode has been selected, just add all of the
+ // operands to the machine instruction.
+ for (; NumVals; --NumVals, ++i)
+ AddOperand(MI, Node->getOperand(i), 0, 0, VRBaseMap);
+ break;
+ }
+ }
break;
}
}
}
+
+ assert(!VRBaseMap.count(Node) && "Node emitted out of order - early");
+ VRBaseMap[Node] = VRBase;
+}
+
+void ScheduleDAG::EmitNoop() {
+ TII->insertNoop(*BB, BB->end());
+}
+
+/// EmitSchedule - Emit the machine code in scheduled order.
+void ScheduleDAG::EmitSchedule() {
+ // If this is the first basic block in the function, and if it has live ins
+ // that need to be copied into vregs, emit the copies into the top of the
+ // block before emitting the code for the block.
+ MachineFunction &MF = DAG.getMachineFunction();
+ if (&MF.front() == BB && MF.livein_begin() != MF.livein_end()) {
+ for (MachineFunction::livein_iterator LI = MF.livein_begin(),
+ E = MF.livein_end(); LI != E; ++LI)
+ if (LI->second)
+ MRI->copyRegToReg(*MF.begin(), MF.begin()->end(), LI->second,
+ LI->first, RegMap->getRegClass(LI->second));
+ }
- if (OpSlot) *OpSlot = ResultReg;
- return ResultReg+Op.ResNo;
+
+ // Finally, emit the code for all of the scheduled instructions.
+ std::map<SDNode*, unsigned> VRBaseMap;
+ for (unsigned i = 0, e = Sequence.size(); i != e; i++) {
+ if (SUnit *SU = Sequence[i]) {
+ for (unsigned j = 0, ee = SU->FlaggedNodes.size(); j != ee; j++)
+ EmitNode(SU->FlaggedNodes[j], VRBaseMap);
+ EmitNode(SU->Node, VRBaseMap);
+ } else {
+ // Null SUnit* is a noop.
+ EmitNoop();
+ }
+ }
+}
+
+/// dump - dump the schedule.
+void ScheduleDAG::dumpSchedule() const {
+ for (unsigned i = 0, e = Sequence.size(); i != e; i++) {
+ if (SUnit *SU = Sequence[i])
+ SU->dump(&DAG);
+ else
+ std::cerr << "**** NOOP ****\n";
+ }
+}
+
+
+/// Run - perform scheduling.
+///
+MachineBasicBlock *ScheduleDAG::Run() {
+ TII = TM.getInstrInfo();
+ MRI = TM.getRegisterInfo();
+ RegMap = BB->getParent()->getSSARegMap();
+ ConstPool = BB->getParent()->getConstantPool();
+
+ Schedule();
+ return BB;
+}
+
+/// SUnit - Scheduling unit. It's an wrapper around either a single SDNode or
+/// a group of nodes flagged together.
+void SUnit::dump(const SelectionDAG *G) const {
+ std::cerr << "SU(" << NodeNum << "): ";
+ Node->dump(G);
+ std::cerr << "\n";
+ if (FlaggedNodes.size() != 0) {
+ for (unsigned i = 0, e = FlaggedNodes.size(); i != e; i++) {
+ std::cerr << " ";
+ FlaggedNodes[i]->dump(G);
+ std::cerr << "\n";
+ }
+ }
}
+void SUnit::dumpAll(const SelectionDAG *G) const {
+ dump(G);
-/// Pick a safe ordering and emit instructions for each target node in the
-/// graph.
-void SelectionDAGISel::ScheduleAndEmitDAG(SelectionDAG &SD) {
- if (ViewDAGs) SD.viewGraph();
- SimpleSched(SD, BB).Run();
+ std::cerr << " # preds left : " << NumPredsLeft << "\n";
+ std::cerr << " # succs left : " << NumSuccsLeft << "\n";
+ std::cerr << " # chain preds left : " << NumChainPredsLeft << "\n";
+ std::cerr << " # chain succs left : " << NumChainSuccsLeft << "\n";
+ std::cerr << " Latency : " << Latency << "\n";
+ std::cerr << " Depth : " << Depth << "\n";
+ std::cerr << " Height : " << Height << "\n";
+
+ if (Preds.size() != 0) {
+ std::cerr << " Predecessors:\n";
+ for (SUnit::const_succ_iterator I = Preds.begin(), E = Preds.end();
+ I != E; ++I) {
+ if (I->second)
+ std::cerr << " ch #";
+ else
+ std::cerr << " val #";
+ std::cerr << I->first << "\n";
+ }
+ }
+ if (Succs.size() != 0) {
+ std::cerr << " Successors:\n";
+ for (SUnit::const_succ_iterator I = Succs.begin(), E = Succs.end();
+ I != E; ++I) {
+ if (I->second)
+ std::cerr << " ch #";
+ else
+ std::cerr << " val #";
+ std::cerr << I->first << "\n";
+ }
+ }
+ std::cerr << "\n";
}
projects / oota-llvm.git / blobdiff