aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/llvm/CodeGen/ScheduleDAG.h15
-rw-r--r--lib/CodeGen/PostRASchedulerList.cpp483
-rw-r--r--lib/CodeGen/ScheduleDAG.cpp5
-rw-r--r--lib/CodeGen/ScheduleDAGInstrs.cpp160
-rw-r--r--lib/CodeGen/ScheduleDAGInstrs.h91
-rw-r--r--lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp35
-rw-r--r--lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp28
-rw-r--r--lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp64
8 files changed, 524 insertions, 357 deletions
diff --git a/include/llvm/CodeGen/ScheduleDAG.h b/include/llvm/CodeGen/ScheduleDAG.h
index c62c3af232..786a5f4073 100644
--- a/include/llvm/CodeGen/ScheduleDAG.h
+++ b/include/llvm/CodeGen/ScheduleDAG.h
@@ -282,6 +282,16 @@ namespace llvm {
isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0),
CopyDstRC(NULL), CopySrcRC(NULL) {}
+ /// SUnit - Construct a placeholder SUnit.
+ SUnit()
+ : Node(0), Instr(0), OrigNode(0), NodeNum(~0u), NodeQueueId(0),
+ Latency(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0), NumSuccsLeft(0),
+ isTwoAddress(false), isCommutable(false), hasPhysRegDefs(false),
+ isPending(false), isAvailable(false), isScheduled(false),
+ isScheduleHigh(false), isCloned(false),
+ isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0),
+ CopyDstRC(NULL), CopySrcRC(NULL) {}
+
/// setNode - Assign the representative SDNode for this SUnit.
/// This may be used during pre-regalloc scheduling.
void setNode(SDNode *N) {
@@ -430,6 +440,8 @@ namespace llvm {
std::vector<SUnit*> Sequence; // The schedule. Null SUnit*'s
// represent noop instructions.
std::vector<SUnit> SUnits; // The scheduling units.
+ SUnit EntrySU; // Special node for the region entry.
+ SUnit ExitSU; // Special node for the region exit.
explicit ScheduleDAG(MachineFunction &mf);
@@ -446,6 +458,9 @@ namespace llvm {
MachineBasicBlock::iterator Begin,
MachineBasicBlock::iterator End);
+ /// EmitSchedule - Insert MachineInstrs into the MachineBasicBlock
+ /// according to the order specified in Sequence.
+ ///
virtual MachineBasicBlock *EmitSchedule() = 0;
void dumpSchedule() const;
diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp
index 94b6be19fb..617b4ac1ec 100644
--- a/lib/CodeGen/PostRASchedulerList.cpp
+++ b/lib/CodeGen/PostRASchedulerList.cpp
@@ -94,6 +94,25 @@ namespace {
/// HazardRec - The hazard recognizer to use.
ScheduleHazardRecognizer *HazardRec;
+ /// Classes - For live regs that are only used in one register class in a
+ /// live range, the register class. If the register is not live, the
+ /// corresponding value is null. If the register is live but used in
+ /// multiple register classes, the corresponding value is -1 casted to a
+ /// pointer.
+ const TargetRegisterClass *
+ Classes[TargetRegisterInfo::FirstVirtualRegister];
+
+ /// RegRegs - Map registers to all their references within a live range.
+ std::multimap<unsigned, MachineOperand *> RegRefs;
+
+ /// The index of the most recent kill (proceding bottom-up), or ~0u if
+ /// the register is not live.
+ unsigned KillIndices[TargetRegisterInfo::FirstVirtualRegister];
+
+ /// The index of the most recent complete def (proceding bottom up), or ~0u
+ /// if the register is live.
+ unsigned DefIndices[TargetRegisterInfo::FirstVirtualRegister];
+
public:
SchedulePostRATDList(MachineFunction &MF,
const MachineLoopInfo &MLI,
@@ -107,10 +126,29 @@ namespace {
delete HazardRec;
}
+ /// StartBlock - Initialize register live-range state for scheduling in
+ /// this block.
+ ///
+ void StartBlock(MachineBasicBlock *BB);
+
+ /// Schedule - Schedule the instruction range using list scheduling.
+ ///
void Schedule();
+ /// Observe - Update liveness information to account for the current
+ /// instruction, which will not be scheduled.
+ ///
+ void Observe(MachineInstr *MI);
+
+ /// FinishBlock - Clean up register live-range state.
+ ///
+ void FinishBlock();
+
private:
+ void PrescanInstruction(MachineInstr *MI);
+ void ScanInstruction(MachineInstr *MI, unsigned Count);
void ReleaseSucc(SUnit *SU, SDep *SuccEdge);
+ void ReleaseSuccessors(SUnit *SU);
void ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle);
void ListScheduleTopDown();
bool BreakAntiDependencies();
@@ -173,6 +211,19 @@ namespace {
};
}
+/// isSchedulingBoundary - Test if the given instruction should be
+/// considered a scheduling boundary. This primarily includes labels
+/// and terminators.
+///
+static bool isSchedulingBoundary(const MachineInstr *MI,
+ const MachineFunction &MF) {
+ // Terminators and labels can't be scheduled around.
+ if (MI->getDesc().isTerminator() || MI->isLabel())
+ return true;
+
+ return false;
+}
+
bool PostRAScheduler::runOnMachineFunction(MachineFunction &Fn) {
DOUT << "PostRAScheduler\n";
@@ -187,26 +238,111 @@ bool PostRAScheduler::runOnMachineFunction(MachineFunction &Fn) {
// Loop over all of the basic blocks
for (MachineFunction::iterator MBB = Fn.begin(), MBBe = Fn.end();
MBB != MBBe; ++MBB) {
+ // Initialize register live-range state for scheduling in this block.
+ Scheduler.StartBlock(MBB);
+
// Schedule each sequence of instructions not interrupted by a label
// or anything else that effectively needs to shut down scheduling.
- MachineBasicBlock::iterator Current = MBB->end(), Top = MBB->begin();
- for (MachineBasicBlock::iterator I = Current; I != Top; ) {
- MachineInstr *MI = --I;
- if (MI->getDesc().isTerminator() || MI->isLabel()) {
- Scheduler.Run(0, MBB, next(I), Current);
- Scheduler.EmitSchedule();
- Current = I;
+ MachineBasicBlock::iterator Current = MBB->end();
+ for (MachineBasicBlock::iterator I = Current; I != MBB->begin(); ) {
+ MachineInstr *MI = prior(I);
+ if (isSchedulingBoundary(MI, Fn)) {
+ if (I != Current) {
+ Scheduler.Run(0, MBB, I, Current);
+ Scheduler.EmitSchedule();
+ }
+ Scheduler.Observe(MI);
+ Current = MI;
}
+ I = MI;
}
-
- Scheduler.Run(0, MBB, Top, Current);
+ Scheduler.Run(0, MBB, MBB->begin(), Current);
Scheduler.EmitSchedule();
+
+ // Clean up register live-range state.
+ Scheduler.FinishBlock();
}
return true;
}
-/// Schedule - Schedule the DAG using list scheduling.
+/// StartBlock - Initialize register live-range state for scheduling in
+/// this block.
+///
+void SchedulePostRATDList::StartBlock(MachineBasicBlock *BB) {
+ // Call the superclass.
+ ScheduleDAGInstrs::StartBlock(BB);
+
+ // Clear out the register class data.
+ std::fill(Classes, array_endof(Classes),
+ static_cast<const TargetRegisterClass *>(0));
+
+ // Initialize the indices to indicate that no registers are live.
+ std::fill(KillIndices, array_endof(KillIndices), ~0u);
+ std::fill(DefIndices, array_endof(DefIndices), BB->size());
+
+ // Determine the live-out physregs for this block.
+ if (!BB->empty() && BB->back().getDesc().isReturn())
+ // In a return block, examine the function live-out regs.
+ for (MachineRegisterInfo::liveout_iterator I = MRI.liveout_begin(),
+ E = MRI.liveout_end(); I != E; ++I) {
+ unsigned Reg = *I;
+ Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ KillIndices[Reg] = BB->size();
+ DefIndices[Reg] = ~0u;
+ // Repeat, for all aliases.
+ for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
+ unsigned AliasReg = *Alias;
+ Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ KillIndices[AliasReg] = BB->size();
+ DefIndices[AliasReg] = ~0u;
+ }
+ }
+ else
+ // In a non-return block, examine the live-in regs of all successors.
+ for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
+ SE = BB->succ_end(); SI != SE; ++SI)
+ for (MachineBasicBlock::livein_iterator I = (*SI)->livein_begin(),
+ E = (*SI)->livein_end(); I != E; ++I) {
+ unsigned Reg = *I;
+ Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ KillIndices[Reg] = BB->size();
+ DefIndices[Reg] = ~0u;
+ // Repeat, for all aliases.
+ for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
+ unsigned AliasReg = *Alias;
+ Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ KillIndices[AliasReg] = BB->size();
+ DefIndices[AliasReg] = ~0u;
+ }
+ }
+
+ // Consider callee-saved registers as live-out, since we're running after
+ // prologue/epilogue insertion so there's no way to add additional
+ // saved registers.
+ //
+ // TODO: If the callee saves and restores these, then we can potentially
+ // use them between the save and the restore. To do that, we could scan
+ // the exit blocks to see which of these registers are defined.
+ // Alternatively, callee-saved registers that aren't saved and restored
+ // could be marked live-in in every block.
+ for (const unsigned *I = TRI->getCalleeSavedRegs(); *I; ++I) {
+ unsigned Reg = *I;
+ Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ KillIndices[Reg] = BB->size();
+ DefIndices[Reg] = ~0u;
+ // Repeat, for all aliases.
+ for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
+ unsigned AliasReg = *Alias;
+ Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ KillIndices[AliasReg] = BB->size();
+ DefIndices[AliasReg] = ~0u;
+ }
+ }
+}
+
+/// Schedule - Schedule the instruction range using list scheduling.
+///
void SchedulePostRATDList::Schedule() {
DOUT << "********** List Scheduling **********\n";
@@ -222,6 +358,8 @@ void SchedulePostRATDList::Schedule() {
// that register, and add new anti-dependence and output-dependence
// edges based on the next live range of the register.
SUnits.clear();
+ EntrySU = SUnit();
+ ExitSU = SUnit();
BuildSchedGraph();
}
}
@@ -233,6 +371,23 @@ void SchedulePostRATDList::Schedule() {
AvailableQueue.releaseState();
}
+/// Observe - Update liveness information to account for the current
+/// instruction, which will not be scheduled.
+///
+void SchedulePostRATDList::Observe(MachineInstr *MI) {
+ PrescanInstruction(MI);
+ ScanInstruction(MI, 0);
+}
+
+/// FinishBlock - Clean up register live-range state.
+///
+void SchedulePostRATDList::FinishBlock() {
+ RegRefs.clear();
+
+ // Call the superclass.
+ ScheduleDAGInstrs::FinishBlock();
+}
+
/// getInstrOperandRegClass - Return register class of the operand of an
/// instruction of the specified TargetInstrDesc.
static const TargetRegisterClass*
@@ -267,6 +422,111 @@ static SDep *CriticalPathStep(SUnit *SU) {
return Next;
}
+void SchedulePostRATDList::PrescanInstruction(MachineInstr *MI) {
+ // Scan the register operands for this instruction and update
+ // Classes and RegRefs.
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg()) continue;
+ unsigned Reg = MO.getReg();
+ if (Reg == 0) continue;
+ const TargetRegisterClass *NewRC =
+ getInstrOperandRegClass(TRI, MI->getDesc(), i);
+
+ // For now, only allow the register to be changed if its register
+ // class is consistent across all uses.
+ if (!Classes[Reg] && NewRC)
+ Classes[Reg] = NewRC;
+ else if (!NewRC || Classes[Reg] != NewRC)
+ Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
+
+ // Now check for aliases.
+ for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
+ // If an alias of the reg is used during the live range, give up.
+ // Note that this allows us to skip checking if AntiDepReg
+ // overlaps with any of the aliases, among other things.
+ unsigned AliasReg = *Alias;
+ if (Classes[AliasReg]) {
+ Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ }
+ }
+
+ // If we're still willing to consider this register, note the reference.
+ if (Classes[Reg] != reinterpret_cast<TargetRegisterClass *>(-1))
+ RegRefs.insert(std::make_pair(Reg, &MO));
+ }
+}
+
+void SchedulePostRATDList::ScanInstruction(MachineInstr *MI,
+ unsigned Count) {
+ // Update liveness.
+ // Proceding upwards, registers that are defed but not used in this
+ // instruction are now dead.
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg()) continue;
+ unsigned Reg = MO.getReg();
+ if (Reg == 0) continue;
+ if (!MO.isDef()) continue;
+ // Ignore two-addr defs.
+ if (MI->isRegReDefinedByTwoAddr(i)) continue;
+
+ DefIndices[Reg] = Count;
+ KillIndices[Reg] = ~0u;
+ Classes[Reg] = 0;
+ RegRefs.erase(Reg);
+ // Repeat, for all subregs.
+ for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
+ *Subreg; ++Subreg) {
+ unsigned SubregReg = *Subreg;
+ DefIndices[SubregReg] = Count;
+ KillIndices[SubregReg] = ~0u;
+ Classes[SubregReg] = 0;
+ RegRefs.erase(SubregReg);
+ }
+ // Conservatively mark super-registers as unusable.
+ for (const unsigned *Super = TRI->getSuperRegisters(Reg);
+ *Super; ++Super) {
+ unsigned SuperReg = *Super;
+ Classes[SuperReg] = reinterpret_cast<TargetRegisterClass *>(-1);
+ }
+ }
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (!MO.isReg()) continue;
+ unsigned Reg = MO.getReg();
+ if (Reg == 0) continue;
+ if (!MO.isUse()) continue;
+
+ const TargetRegisterClass *NewRC =
+ getInstrOperandRegClass(TRI, MI->getDesc(), i);
+
+ // For now, only allow the register to be changed if its register
+ // class is consistent across all uses.
+ if (!Classes[Reg] && NewRC)
+ Classes[Reg] = NewRC;
+ else if (!NewRC || Classes[Reg] != NewRC)
+ Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
+
+ RegRefs.insert(std::make_pair(Reg, &MO));
+
+ // It wasn't previously live but now it is, this is a kill.
+ if (KillIndices[Reg] == ~0u) {
+ KillIndices[Reg] = Count;
+ DefIndices[Reg] = ~0u;
+ }
+ // Repeat, for all aliases.
+ for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
+ unsigned AliasReg = *Alias;
+ if (KillIndices[AliasReg] == ~0u) {
+ KillIndices[AliasReg] = Count;
+ DefIndices[AliasReg] = ~0u;
+ }
+ }
+ }
+}
+
/// BreakAntiDependencies - Identifiy anti-dependencies along the critical path
/// of the ScheduleDAG and break them by renaming registers.
///
@@ -291,84 +551,6 @@ bool SchedulePostRATDList::BreakAntiDependencies() {
SUnit *CriticalPathSU = Max;
MachineInstr *CriticalPathMI = CriticalPathSU->getInstr();
- // For live regs that are only used in one register class in a live range,
- // the register class. If the register is not live, the corresponding value
- // is null. If the register is live but used in multiple register classes,
- // the corresponding value is -1 casted to a pointer.
- const TargetRegisterClass *
- Classes[TargetRegisterInfo::FirstVirtualRegister] = {};
-
- // Map registers to all their references within a live range.
- std::multimap<unsigned, MachineOperand *> RegRefs;
-
- // The index of the most recent kill (proceding bottom-up), or ~0u if
- // the register is not live.
- unsigned KillIndices[TargetRegisterInfo::FirstVirtualRegister];
- std::fill(KillIndices, array_endof(KillIndices), ~0u);
- // The index of the most recent complete def (proceding bottom up), or ~0u if
- // the register is live.
- unsigned DefIndices[TargetRegisterInfo::FirstVirtualRegister];
- std::fill(DefIndices, array_endof(DefIndices), BB->size());
-
- // Determine the live-out physregs for this block.
- if (BB->back().getDesc().isReturn())
- // In a return block, examine the function live-out regs.
- for (MachineRegisterInfo::liveout_iterator I = MRI.liveout_begin(),
- E = MRI.liveout_end(); I != E; ++I) {
- unsigned Reg = *I;
- Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
- KillIndices[Reg] = BB->size();
- DefIndices[Reg] = ~0u;
- // Repeat, for all aliases.
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
- unsigned AliasReg = *Alias;
- Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
- KillIndices[AliasReg] = BB->size();
- DefIndices[AliasReg] = ~0u;
- }
- }
- else
- // In a non-return block, examine the live-in regs of all successors.
- for (MachineBasicBlock::succ_iterator SI = BB->succ_begin(),
- SE = BB->succ_end(); SI != SE; ++SI)
- for (MachineBasicBlock::livein_iterator I = (*SI)->livein_begin(),
- E = (*SI)->livein_end(); I != E; ++I) {
- unsigned Reg = *I;
- Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
- KillIndices[Reg] = BB->size();
- DefIndices[Reg] = ~0u;
- // Repeat, for all aliases.
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
- unsigned AliasReg = *Alias;
- Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
- KillIndices[AliasReg] = BB->size();
- DefIndices[AliasReg] = ~0u;
- }
- }
-
- // Consider callee-saved registers as live-out, since we're running after
- // prologue/epilogue insertion so there's no way to add additional
- // saved registers.
- //
- // TODO: If the callee saves and restores these, then we can potentially
- // use them between the save and the restore. To do that, we could scan
- // the exit blocks to see which of these registers are defined.
- // Alternatively, callee-saved registers that aren't saved and restored
- // could be marked live-in in every block.
- for (const unsigned *I = TRI->getCalleeSavedRegs(); *I; ++I) {
- unsigned Reg = *I;
- Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
- KillIndices[Reg] = BB->size();
- DefIndices[Reg] = ~0u;
- // Repeat, for all aliases.
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
- unsigned AliasReg = *Alias;
- Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
- KillIndices[AliasReg] = BB->size();
- DefIndices[AliasReg] = ~0u;
- }
- }
-
// Consider this pattern:
// A = ...
// ... = A
@@ -481,43 +663,19 @@ bool SchedulePostRATDList::BreakAntiDependencies() {
}
}
- // Scan the register operands for this instruction and update
- // Classes and RegRefs.
+ PrescanInstruction(MI);
+
+ // If this instruction has a use of AntiDepReg, breaking it
+ // is invalid.
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg()) continue;
unsigned Reg = MO.getReg();
if (Reg == 0) continue;
- const TargetRegisterClass *NewRC =
- getInstrOperandRegClass(TRI, MI->getDesc(), i);
-
- // If this instruction has a use of AntiDepReg, breaking it
- // is invalid.
- if (MO.isUse() && AntiDepReg == Reg)
+ if (MO.isUse() && AntiDepReg == Reg) {
AntiDepReg = 0;
-
- // For now, only allow the register to be changed if its register
- // class is consistent across all uses.
- if (!Classes[Reg] && NewRC)
- Classes[Reg] = NewRC;
- else if (!NewRC || Classes[Reg] != NewRC)
- Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
-
- // Now check for aliases.
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
- // If an alias of the reg is used during the live range, give up.
- // Note that this allows us to skip checking if AntiDepReg
- // overlaps with any of the aliases, among other things.
- unsigned AliasReg = *Alias;
- if (Classes[AliasReg]) {
- Classes[AliasReg] = reinterpret_cast<TargetRegisterClass *>(-1);
- Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
- }
+ break;
}
-
- // If we're still willing to consider this register, note the reference.
- if (Classes[Reg] != reinterpret_cast<TargetRegisterClass *>(-1))
- RegRefs.insert(std::make_pair(Reg, &MO));
}
// Determine AntiDepReg's register class, if it is live and is
@@ -584,71 +742,7 @@ bool SchedulePostRATDList::BreakAntiDependencies() {
}
}
- // Update liveness.
- // Proceding upwards, registers that are defed but not used in this
- // instruction are now dead.
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (!MO.isReg()) continue;
- unsigned Reg = MO.getReg();
- if (Reg == 0) continue;
- if (!MO.isDef()) continue;
- // Ignore two-addr defs.
- if (MI->isRegReDefinedByTwoAddr(i)) continue;
-
- DefIndices[Reg] = Count;
- KillIndices[Reg] = ~0u;
- Classes[Reg] = 0;
- RegRefs.erase(Reg);
- // Repeat, for all subregs.
- for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
- *Subreg; ++Subreg) {
- unsigned SubregReg = *Subreg;
- DefIndices[SubregReg] = Count;
- KillIndices[SubregReg] = ~0u;
- Classes[SubregReg] = 0;
- RegRefs.erase(SubregReg);
- }
- // Conservatively mark super-registers as unusable.
- for (const unsigned *Super = TRI->getSuperRegisters(Reg);
- *Super; ++Super) {
- unsigned SuperReg = *Super;
- Classes[SuperReg] = reinterpret_cast<TargetRegisterClass *>(-1);
- }
- }
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (!MO.isReg()) continue;
- unsigned Reg = MO.getReg();
- if (Reg == 0) continue;
- if (!MO.isUse()) continue;
-
- const TargetRegisterClass *NewRC =
- getInstrOperandRegClass(TRI, MI->getDesc(), i);
-
- // For now, only allow the register to be changed if its register
- // class is consistent across all uses.
- if (!Classes[Reg] && NewRC)
- Classes[Reg] = NewRC;
- else if (!NewRC || Classes[Reg] != NewRC)
- Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
-
- RegRefs.insert(std::make_pair(Reg, &MO));
-
- // It wasn't previously live but now it is, this is a kill.
- if (KillIndices[Reg] == ~0u) {
- KillIndices[Reg] = Count;
- DefIndices[Reg] = ~0u;
- }
- // Repeat, for all aliases.
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
- unsigned AliasReg = *Alias;
- if (KillIndices[AliasReg] == ~0u) {
- KillIndices[AliasReg] = Count;
- DefIndices[AliasReg] = ~0u;
- }
- }
- }
+ ScanInstruction(MI, Count);
}
assert(Count == ~0u && "Count mismatch!");
@@ -679,9 +773,17 @@ void SchedulePostRATDList::ReleaseSucc(SUnit *SU, SDep *SuccEdge) {
// their latencies.
SuccSU->setDepthToAtLeast(SU->getDepth() + SuccEdge->getLatency());
- if (SuccSU->NumPredsLeft == 0) {
+ // If all the node's predecessors are scheduled, this node is ready
+ // to be scheduled. Ignore the special ExitSU node.
+ if (SuccSU->NumPredsLeft == 0 && SuccSU != &ExitSU)
PendingQueue.push_back(SuccSU);
- }
+}
+
+/// ReleaseSuccessors - Call ReleaseSucc on each of SU's successors.
+void SchedulePostRATDList::ReleaseSuccessors(SUnit *SU) {
+ for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
+ I != E; ++I)
+ ReleaseSucc(SU, &*I);
}
/// ScheduleNodeTopDown - Add the node to the schedule. Decrement the pending
@@ -695,11 +797,7 @@ void SchedulePostRATDList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
assert(CurCycle >= SU->getDepth() && "Node scheduled above its depth!");
SU->setDepthToAtLeast(CurCycle);
- // Top down: release successors.
- for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
- I != E; ++I)
- ReleaseSucc(SU, &*I);
-
+ ReleaseSuccessors(SU);
SU->isScheduled = true;
AvailableQueue.ScheduledNode(SU);
}
@@ -709,6 +807,9 @@ void SchedulePostRATDList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
void SchedulePostRATDList::ListScheduleTopDown() {
unsigned CurCycle = 0;
+ // Release any successors of the special Entry node.
+ ReleaseSuccessors(&EntrySU);
+
// All leaves to Available queue.
for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
// It is available if it has no predecessors.
@@ -717,7 +818,7 @@ void SchedulePostRATDList::ListScheduleTopDown() {
SUnits[i].isAvailable = true;
}
}
-
+
// While Available queue is not empty, grab the node with the highest
// priority. If it is not ready put it back. Schedule the node.
std::vector<SUnit*> NotReady;
diff --git a/lib/CodeGen/ScheduleDAG.cpp b/lib/CodeGen/ScheduleDAG.cpp
index 718f591902..f9b9408354 100644
--- a/lib/CodeGen/ScheduleDAG.cpp
+++ b/lib/CodeGen/ScheduleDAG.cpp
@@ -28,7 +28,8 @@ ScheduleDAG::ScheduleDAG(MachineFunction &mf)
TRI(TM.getRegisterInfo()),
TLI(TM.getTargetLowering()),
MF(mf), MRI(mf.getRegInfo()),
- ConstPool(MF.getConstantPool()) {
+ ConstPool(MF.getConstantPool()),
+ EntrySU(), ExitSU() {
}
ScheduleDAG::~ScheduleDAG() {}
@@ -58,6 +59,8 @@ void ScheduleDAG::Run(SelectionDAG *dag, MachineBasicBlock *bb,
BB = bb;
Begin = begin;
End = end;
+ EntrySU = SUnit();
+ ExitSU = SUnit();
Schedule();
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index eee398ea16..dac29f1161 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -15,86 +15,22 @@
#define DEBUG_TYPE "sched-instrs"
#include "ScheduleDAGInstrs.h"
#include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtarget.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/SmallSet.h"
-#include <map>
using namespace llvm;
-namespace {
- class VISIBILITY_HIDDEN LoopDependencies {
- const MachineLoopInfo &MLI;
- const MachineDominatorTree &MDT;
-
- public:
- typedef std::map<unsigned, std::pair<const MachineOperand *, unsigned> >
- LoopDeps;
- LoopDeps Deps;
-
- LoopDependencies(const MachineLoopInfo &mli,
- const MachineDominatorTree &mdt) :
- MLI(mli), MDT(mdt) {}
-
- void VisitLoop(const MachineLoop *Loop) {
- Deps.clear();
- MachineBasicBlock *Header = Loop->getHeader();
- SmallSet<unsigned, 8> LoopLiveIns;
- for (MachineBasicBlock::livein_iterator LI = Header->livein_begin(),
- LE = Header->livein_end(); LI != LE; ++LI)
- LoopLiveIns.insert(*LI);
-
- const MachineDomTreeNode *Node = MDT.getNode(Header);
- const MachineBasicBlock *MBB = Node->getBlock();
- assert(Loop->contains(MBB) &&
- "Loop does not contain header!");
- VisitRegion(Node, MBB, Loop, LoopLiveIns);
- }
-
- private:
- void VisitRegion(const MachineDomTreeNode *Node,
- const MachineBasicBlock *MBB,
- const MachineLoop *Loop,
- const SmallSet<unsigned, 8> &LoopLiveIns) {
- unsigned Count = 0;
- for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
- I != E; ++I, ++Count) {
- const MachineInstr *MI = I;
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- const MachineOperand &MO = MI->getOperand(i);
- if (!MO.isReg() || !MO.isUse())
- continue;
- unsigned MOReg = MO.getReg();
- if (LoopLiveIns.count(MOReg))
- Deps.insert(std::make_pair(MOReg, std::make_pair(&MO, Count)));
- }
- }
-
- const std::vector<MachineDomTreeNode*> &Children = Node->getChildren();
- for (std::vector<MachineDomTreeNode*>::const_iterator I =
- Children.begin(), E = Children.end(); I != E; ++I) {
- const MachineDomTreeNode *ChildNode = *I;
- MachineBasicBlock *ChildBlock = ChildNode->getBlock();
- if (Loop->contains(ChildBlock))
- VisitRegion(ChildNode, ChildBlock, Loop, LoopLiveIns);
- }
- }
- };
-}
-
ScheduleDAGInstrs::ScheduleDAGInstrs(MachineFunction &mf,
const MachineLoopInfo &mli,
const MachineDominatorTree &mdt)
- : ScheduleDAG(mf), MLI(mli), MDT(mdt) {}
+ : ScheduleDAG(mf), MLI(mli), MDT(mdt), LoopRegs(MLI, MDT) {}
/// getOpcode - If this is an Instruction or a ConstantExpr, return the
/// opcode value. Otherwise return UserOp1.
@@ -172,7 +108,20 @@ static const Value *getUnderlyingObjectForInstr(const MachineInstr *MI) {
return V;
}
+void ScheduleDAGInstrs::StartBlock(MachineBasicBlock *BB) {
+ if (MachineLoop *ML = MLI.getLoopFor(BB))
+ if (BB == ML->getLoopLatch()) {
+ MachineBasicBlock *Header = ML->getHeader();
+ for (MachineBasicBlock::livein_iterator I = Header->livein_begin(),
+ E = Header->livein_end(); I != E; ++I)
+ LoopLiveInRegs.insert(*I);
+ LoopRegs.VisitLoop(ML);
+ }
+}
+
void ScheduleDAGInstrs::BuildSchedGraph() {
+ // We'll be allocating one SUnit for each instruction, plus one for
+ // the region exit node.
SUnits.reserve(BB->size());
// We build scheduling units by walking a block's instruction list from bottom
@@ -189,30 +138,6 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
std::map<const Value *, SUnit *> MemDefs;
std::map<const Value *, std::vector<SUnit *> > MemUses;
- // If we have an SUnit which is representing a terminator instruction, we
- // can use it as a place-holder successor for inter-block dependencies.
- SUnit *Terminator = 0;
-
- // Terminators can perform control transfers, we we need to make sure that
- // all the work of the block is done before the terminator. Labels can
- // mark points of interest for various types of meta-data (eg. EH data),
- // and we need to make sure nothing is scheduled around them.
- SUnit *SchedulingBarrier = 0;
-
- LoopDependencies LoopRegs(MLI, MDT);
-
- // Track which regs are live into a loop, to help guide back-edge-aware
- // scheduling.
- SmallSet<unsigned, 8> LoopLiveInRegs;
- if (MachineLoop *ML = MLI.getLoopFor(BB))
- if (BB == ML->getLoopLatch()) {
- MachineBasicBlock *Header = ML->getHeader();
- for (MachineBasicBlock::livein_iterator I = Header->livein_begin(),
- E = Header->livein_end(); I != E; ++I)
- LoopLiveInRegs.insert(*I);
- LoopRegs.VisitLoop(ML);
- }
-
// Check to see if the scheduler cares about latencies.
bool UnitLatencies = ForceUnitLatencies();
@@ -220,10 +145,14 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
unsigned SpecialAddressLatency =
TM.getSubtarget<TargetSubtarget>().getSpecialAddressLatency();
+ // Walk the list of instructions, from bottom moving up.
for (MachineBasicBlock::iterator MII = End, MIE = Begin;
MII != MIE; --MII) {
MachineInstr *MI = prior(MII);
const TargetInstrDesc &TID = MI->getDesc();
+ assert(!TID.isTerminator() && !MI->isLabel() &&
+ "Cannot schedule terminators or labels!");
+ // Create the SUnit for this MI.
SUnit *SU = NewSUnit(MI);
// Assign the Latency field of SU using target-provided information.
@@ -298,8 +227,7 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
// If a def is going to wrap back around to the top of the loop,
// backschedule it.
- // TODO: Blocks in loops without terminators can benefit too.
- if (!UnitLatencies && Terminator && DefList.empty()) {
+ if (!UnitLatencies && DefList.empty()) {
LoopDependencies::LoopDeps::iterator I = LoopRegs.Deps.find(Reg);
if (I != LoopRegs.Deps.end()) {
const MachineOperand *UseMO = I->second.first;
@@ -323,10 +251,10 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
// scheduling region.
Latency -= std::min(Latency, Count);
// Add the artifical edge.
- Terminator->addPred(SDep(SU, SDep::Order, Latency,
- /*Reg=*/0, /*isNormalMemory=*/false,
- /*isMustAlias=*/false,
- /*isArtificial=*/true));
+ ExitSU.addPred(SDep(SU, SDep::Order, Latency,
+ /*Reg=*/0, /*isNormalMemory=*/false,
+ /*isMustAlias=*/false,
+ /*isArtificial=*/true));
} else if (SpecialAddressLatency > 0 &&
UseTID.OpInfo[UseMOIdx].isLookupPtrRegClass()) {
// The entire loop body is within the current scheduling region
@@ -355,7 +283,7 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
// after stack slots are lowered to actual addresses.
// TODO: Use an AliasAnalysis and do real alias-analysis queries, and
// produce more precise dependence information.
- if (TID.isCall() || TID.isTerminator() || TID.hasUnmodeledSideEffects()) {
+ if (TID.isCall() || TID.hasUnmodeledSideEffects()) {
new_chain:
// This is the conservative case. Add dependencies on all memory
// references.
@@ -379,7 +307,7 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
// See if it is known to just have a single memory reference.
MachineInstr *ChainMI = Chain->getInstr();
const TargetInstrDesc &ChainTID = ChainMI->getDesc();
- if (!ChainTID.isCall() && !ChainTID.isTerminator() &&
+ if (!ChainTID.isCall() &&
!ChainTID.hasUnmodeledSideEffects() &&
ChainMI->hasOneMemOperand() &&
!ChainMI->memoperands_begin()->isVolatile() &&
@@ -452,28 +380,6 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
PendingLoads.push_back(SU);
}
}
-
- // Add chain edges from terminators and labels to ensure that no
- // instructions are scheduled past them.
- if (SchedulingBarrier && SU->Succs.empty())
- SchedulingBarrier->addPred(SDep(SU, SDep::Order, SU->Latency));
- // If we encounter a mid-block label, we need to go back and add
- // dependencies on SUnits we've