#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterClassInfo.h"
/// AA - AliasAnalysis for making memory reference queries.
AliasAnalysis *AA;
- /// LiveRegs - true if the register is live.
- BitVector LiveRegs;
-
/// The schedule. Null SUnit*'s represent noop instructions.
std::vector<SUnit*> Sequence;
///
void finishBlock();
- /// FixupKills - Fix register kill flags that have been made
- /// invalid due to scheduling
- ///
- void FixupKills(MachineBasicBlock *MBB);
-
private:
void ReleaseSucc(SUnit *SU, SDep *SuccEdge);
void ReleaseSuccessors(SUnit *SU);
void ListScheduleTopDown();
void StartBlockForKills(MachineBasicBlock *BB);
- // ToggleKillFlag - Toggle a register operand kill flag. Other
- // adjustments may be made to the instruction if necessary. Return
- // true if the operand has been deleted, false if not.
- bool ToggleKillFlag(MachineInstr *MI, MachineOperand &MO);
-
void dumpSchedule() const;
void emitNoop(unsigned CurCycle);
};
AliasAnalysis *AA, const RegisterClassInfo &RCI,
TargetSubtargetInfo::AntiDepBreakMode AntiDepMode,
SmallVectorImpl<const TargetRegisterClass*> &CriticalPathRCs)
- : ScheduleDAGInstrs(MF, MLI, MDT, /*IsPostRA=*/true), AA(AA),
- LiveRegs(TRI->getNumRegs()), EndIndex(0)
-{
+ : ScheduleDAGInstrs(MF, MLI, MDT, /*IsPostRA=*/true), AA(AA), EndIndex(0) {
+
const TargetMachine &TM = MF.getTarget();
const InstrItineraryData *InstrItins = TM.getInstrItineraryData();
HazardRec =
Scheduler.finishBlock();
// Update register kills
- Scheduler.FixupKills(MBB);
+ Scheduler.fixupKills(MBB);
}
return true;
ScheduleDAGInstrs::finishBlock();
}
-/// StartBlockForKills - Initialize register live-range state for updating kills
-///
-void SchedulePostRATDList::StartBlockForKills(MachineBasicBlock *BB) {
- // Start with no live registers.
- LiveRegs.reset();
-
- // 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;
- // Repeat, for reg and all subregs.
- for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- LiveRegs.set(*SubRegs);
- }
- }
-}
-
-bool SchedulePostRATDList::ToggleKillFlag(MachineInstr *MI,
- MachineOperand &MO) {
- // Setting kill flag...
- if (!MO.isKill()) {
- MO.setIsKill(true);
- return false;
- }
-
- // If MO itself is live, clear the kill flag...
- if (LiveRegs.test(MO.getReg())) {
- MO.setIsKill(false);
- return false;
- }
-
- // If any subreg of MO is live, then create an imp-def for that
- // subreg and keep MO marked as killed.
- MO.setIsKill(false);
- bool AllDead = true;
- const unsigned SuperReg = MO.getReg();
- MachineInstrBuilder MIB(MF, MI);
- for (MCSubRegIterator SubRegs(SuperReg, TRI); SubRegs.isValid(); ++SubRegs) {
- if (LiveRegs.test(*SubRegs)) {
- MIB.addReg(*SubRegs, RegState::ImplicitDefine);
- AllDead = false;
- }
- }
-
- if(AllDead)
- MO.setIsKill(true);
- return false;
-}
-
-/// FixupKills - Fix the register kill flags, they may have been made
-/// incorrect by instruction reordering.
-///
-void SchedulePostRATDList::FixupKills(MachineBasicBlock *MBB) {
- DEBUG(dbgs() << "Fixup kills for BB#" << MBB->getNumber() << '\n');
-
- BitVector killedRegs(TRI->getNumRegs());
-
- StartBlockForKills(MBB);
-
- // Examine block from end to start...
- unsigned Count = MBB->size();
- for (MachineBasicBlock::iterator I = MBB->end(), E = MBB->begin();
- I != E; --Count) {
- MachineInstr *MI = --I;
- if (MI->isDebugValue())
- continue;
-
- // Update liveness. Registers that are defed but not used in this
- // instruction are now dead. Mark register and all subregs as they
- // are completely defined.
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (MO.isRegMask())
- LiveRegs.clearBitsNotInMask(MO.getRegMask());
- if (!MO.isReg()) continue;
- unsigned Reg = MO.getReg();
- if (Reg == 0) continue;
- if (!MO.isDef()) continue;
- // Ignore two-addr defs.
- if (MI->isRegTiedToUseOperand(i)) continue;
-
- // Repeat for reg and all subregs.
- for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- LiveRegs.reset(*SubRegs);
- }
-
- // Examine all used registers and set/clear kill flag. When a
- // register is used multiple times we only set the kill flag on
- // the first use. Don't set kill flags on undef operands.
- killedRegs.reset();
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (!MO.isReg() || !MO.isUse() || MO.isUndef()) continue;
- unsigned Reg = MO.getReg();
- if ((Reg == 0) || MRI.isReserved(Reg)) continue;
-
- bool kill = false;
- if (!killedRegs.test(Reg)) {
- kill = true;
- // A register is not killed if any subregs are live...
- for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
- if (LiveRegs.test(*SubRegs)) {
- kill = false;
- break;
- }
- }
-
- // If subreg is not live, then register is killed if it became
- // live in this instruction
- if (kill)
- kill = !LiveRegs.test(Reg);
- }
-
- if (MO.isKill() != kill) {
- DEBUG(dbgs() << "Fixing " << MO << " in ");
- // Warning: ToggleKillFlag may invalidate MO.
- ToggleKillFlag(MI, MO);
- DEBUG(MI->dump());
- }
-
- killedRegs.set(Reg);
- }
-
- // Mark any used register (that is not using undef) and subregs as
- // now live...
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MI->getOperand(i);
- if (!MO.isReg() || !MO.isUse() || MO.isUndef()) continue;
- unsigned Reg = MO.getReg();
- if ((Reg == 0) || MRI.isReserved(Reg)) continue;
-
- for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
- SubRegs.isValid(); ++SubRegs)
- LiveRegs.set(*SubRegs);
- }
- }
-}
-
//===----------------------------------------------------------------------===//
// Top-Down Scheduling
//===----------------------------------------------------------------------===//
projects / oota-llvm.git / blobdiff