#ifndef SCHEDULEDAGINSTRS_H
#define SCHEDULEDAGINSTRS_H
+#include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/ScheduleDAG.h"
+#include "llvm/Support/Compiler.h"
#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/ADT/SmallSet.h"
+#include <map>
namespace llvm {
class MachineLoopInfo;
class MachineDominatorTree;
- class ScheduleDAGInstrs : public ScheduleDAG {
+ /// LoopDependencies - This class analyzes loop-oriented register
+ /// dependencies, which are used to guide scheduling decisions.
+ /// For example, loop induction variable increments should be
+ /// scheduled as soon as possible after the variable's last use.
+ ///
+ class LLVM_LIBRARY_VISIBILITY 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) {}
+
+ /// VisitLoop - Clear out any previous state and analyze the given loop.
+ ///
+ void VisitLoop(const MachineLoop *Loop) {
+ assert(Deps.empty() && "stale loop dependencies");
+
+ 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) {
+ const MachineInstr *MI = I;
+ if (MI->isDebugValue())
+ continue;
+ 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)));
+ }
+ ++Count; // Not every iteration due to dbg_value above.
+ }
+
+ 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 - A ScheduleDAG subclass for scheduling lists of
+ /// MachineInstrs.
+ class LLVM_LIBRARY_VISIBILITY ScheduleDAGInstrs : public ScheduleDAG {
+ const MachineLoopInfo &MLI;
+ const MachineDominatorTree &MDT;
+ const MachineFrameInfo *MFI;
+ const InstrItineraryData *InstrItins;
+
/// Defs, Uses - Remember where defs and uses of each physical register
/// are as we iterate upward through the instructions. This is allocated
/// here instead of inside BuildSchedGraph to avoid the need for it to be
/// initialized and destructed for each block.
- std::vector<SUnit *> Defs[TargetRegisterInfo::FirstVirtualRegister];
- std::vector<SUnit *> Uses[TargetRegisterInfo::FirstVirtualRegister];
+ std::vector<std::vector<SUnit *> > Defs;
+ std::vector<std::vector<SUnit *> > Uses;
/// PendingLoads - Remember where unknown loads are after the most recent
/// unknown store, as we iterate. As with Defs and Uses, this is here
/// to minimize construction/destruction.
std::vector<SUnit *> PendingLoads;
+ /// LoopRegs - Track which registers are used for loop-carried dependencies.
+ ///
+ LoopDependencies LoopRegs;
+
+ /// LoopLiveInRegs - Track which regs are live into a loop, to help guide
+ /// back-edge-aware scheduling.
+ ///
+ SmallSet<unsigned, 8> LoopLiveInRegs;
+
+ protected:
+
+ /// DbgValues - Remember instruction that preceeds DBG_VALUE.
+ typedef std::vector<std::pair<MachineInstr *, MachineInstr *> >
+ DbgValueVector;
+ DbgValueVector DbgValues;
+ MachineInstr *FirstDbgValue;
+
public:
+ MachineBasicBlock::iterator Begin; // The beginning of the range to
+ // be scheduled. The range extends
+ // to InsertPos.
+ unsigned InsertPosIndex; // The index in BB of InsertPos.
+
explicit ScheduleDAGInstrs(MachineFunction &mf,
const MachineLoopInfo &mli,
const MachineDominatorTree &mdt);
return &SUnits.back();
}
+ /// Run - perform scheduling.
+ ///
+ void Run(MachineBasicBlock *bb,
+ MachineBasicBlock::iterator begin,
+ MachineBasicBlock::iterator end,
+ unsigned endindex);
+
/// BuildSchedGraph - Build SUnits from the MachineBasicBlock that we are
/// input.
- virtual void BuildSchedGraph();
+ virtual void BuildSchedGraph(AliasAnalysis *AA);
+
+ /// AddSchedBarrierDeps - Add dependencies from instructions in the current
+ /// list of instructions being scheduled to scheduling barrier. We want to
+ /// make sure instructions which define registers that are either used by
+ /// the terminator or are live-out are properly scheduled. This is
+ /// especially important when the definition latency of the return value(s)
+ /// are too high to be hidden by the branch or when the liveout registers
+ /// used by instructions in the fallthrough block.
+ void AddSchedBarrierDeps();
/// ComputeLatency - Compute node latency.
///
virtual void ComputeLatency(SUnit *SU);
+ /// ComputeOperandLatency - Override dependence edge latency using
+ /// operand use/def information
+ ///
+ virtual void ComputeOperandLatency(SUnit *Def, SUnit *Use,
+ SDep& dep) const;
+
virtual MachineBasicBlock *EmitSchedule();
+ /// StartBlock - Prepare to perform scheduling in the given block.
+ ///
+ virtual void StartBlock(MachineBasicBlock *BB);
+
/// Schedule - Order nodes according to selected style, filling
/// in the Sequence member.
///
virtual void Schedule() = 0;
+ /// FinishBlock - Clean up after scheduling in the given block.
+ ///
+ virtual void FinishBlock();
+
virtual void dumpNode(const SUnit *SU) const;
virtual std::string getGraphNodeLabel(const SUnit *SU) const;