//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CODEGEN_SPILLER_H
-#define LLVM_CODEGEN_SPILLER_H
-
-#include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/IndexedMap.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/Streams.h"
-#include "llvm/Function.h"
-#include "llvm/CodeGen/LiveIntervalAnalysis.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/SmallSet.h"
-#include "VirtRegMap.h"
-#include <map>
+#ifndef LLVM_LIB_CODEGEN_SPILLER_H
+#define LLVM_LIB_CODEGEN_SPILLER_H
namespace llvm {
-
- /// Spiller interface: Implementations of this interface assign spilled
- /// virtual registers to stack slots, rewriting the code.
- struct Spiller {
- virtual ~Spiller();
- virtual bool runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM,
- LiveIntervals* LIs) = 0;
- };
-
- /// createSpiller - Create an return a spiller object, as specified on the
- /// command line.
- Spiller* createSpiller();
-
- // ************************************************************************ //
-
- // Simple Spiller Implementation
- struct VISIBILITY_HIDDEN SimpleSpiller : public Spiller {
- bool runOnMachineFunction(MachineFunction& mf, VirtRegMap &VRM,
- LiveIntervals* LIs);
- };
-
- // ************************************************************************ //
-
- /// AvailableSpills - As the local spiller is scanning and rewriting an MBB
- /// from top down, keep track of which spills slots or remat are available in
- /// each register.
- ///
- /// Note that not all physregs are created equal here. In particular, some
- /// physregs are reloads that we are allowed to clobber or ignore at any time.
- /// Other physregs are values that the register allocated program is using
- /// that we cannot CHANGE, but we can read if we like. We keep track of this
- /// on a per-stack-slot / remat id basis as the low bit in the value of the
- /// SpillSlotsAvailable entries. The predicate 'canClobberPhysReg()' checks
- /// this bit and addAvailable sets it if.
- class VISIBILITY_HIDDEN AvailableSpills {
- const TargetRegisterInfo *TRI;
- const TargetInstrInfo *TII;
-
- // SpillSlotsOrReMatsAvailable - This map keeps track of all of the spilled
- // or remat'ed virtual register values that are still available, due to
- // being loaded or stored to, but not invalidated yet.
- std::map<int, unsigned> SpillSlotsOrReMatsAvailable;
-
- // PhysRegsAvailable - This is the inverse of SpillSlotsOrReMatsAvailable,
- // indicating which stack slot values are currently held by a physreg. This
- // is used to invalidate entries in SpillSlotsOrReMatsAvailable when a
- // physreg is modified.
- std::multimap<unsigned, int> PhysRegsAvailable;
-
- void disallowClobberPhysRegOnly(unsigned PhysReg);
-
- void ClobberPhysRegOnly(unsigned PhysReg);
- public:
- AvailableSpills(const TargetRegisterInfo *tri, const TargetInstrInfo *tii)
- : TRI(tri), TII(tii) {
- }
-
- /// clear - Reset the state.
- void clear() {
- SpillSlotsOrReMatsAvailable.clear();
- PhysRegsAvailable.clear();
- }
-
- const TargetRegisterInfo *getRegInfo() const { return TRI; }
-
- /// getSpillSlotOrReMatPhysReg - If the specified stack slot or remat is
- /// available in a physical register, return that PhysReg, otherwise
- /// return 0.
- unsigned getSpillSlotOrReMatPhysReg(int Slot) const {
- std::map<int, unsigned>::const_iterator I =
- SpillSlotsOrReMatsAvailable.find(Slot);
- if (I != SpillSlotsOrReMatsAvailable.end()) {
- return I->second >> 1; // Remove the CanClobber bit.
- }
- return 0;
- }
-
- /// addAvailable - Mark that the specified stack slot / remat is available
- /// in the specified physreg. If CanClobber is true, the physreg can be
- /// modified at any time without changing the semantics of the program.
- void addAvailable(int SlotOrReMat, unsigned Reg, bool CanClobber = true) {
- // If this stack slot is thought to be available in some other physreg,
- // remove its record.
- ModifyStackSlotOrReMat(SlotOrReMat);
-
- PhysRegsAvailable.insert(std::make_pair(Reg, SlotOrReMat));
- SpillSlotsOrReMatsAvailable[SlotOrReMat]= (Reg << 1) |
- (unsigned)CanClobber;
-
- if (SlotOrReMat > VirtRegMap::MAX_STACK_SLOT)
- DOUT << "Remembering RM#" << SlotOrReMat-VirtRegMap::MAX_STACK_SLOT-1;
- else
- DOUT << "Remembering SS#" << SlotOrReMat;
- DOUT << " in physreg " << TRI->getName(Reg) << "\n";
- }
-
- /// canClobberPhysRegForSS - Return true if the spiller is allowed to change
- /// the value of the specified stackslot register if it desires. The
- /// specified stack slot must be available in a physreg for this query to
- /// make sense.
- bool canClobberPhysRegForSS(int SlotOrReMat) const {
- assert(SpillSlotsOrReMatsAvailable.count(SlotOrReMat) &&
- "Value not available!");
- return SpillSlotsOrReMatsAvailable.find(SlotOrReMat)->second & 1;
- }
- /// canClobberPhysReg - Return true if the spiller is allowed to clobber the
- /// physical register where values for some stack slot(s) might be
- /// available.
- bool canClobberPhysReg(unsigned PhysReg) const {
- std::multimap<unsigned, int>::const_iterator I =
- PhysRegsAvailable.lower_bound(PhysReg);
- while (I != PhysRegsAvailable.end() && I->first == PhysReg) {
- int SlotOrReMat = I->second;
- I++;
- if (!canClobberPhysRegForSS(SlotOrReMat))
- return false;
- }
- return true;
- }
+ class LiveRangeEdit;
+ class MachineFunction;
+ class MachineFunctionPass;
+ class VirtRegMap;
- /// disallowClobberPhysReg - Unset the CanClobber bit of the specified
- /// stackslot register. The register is still available but is no longer
- /// allowed to be modifed.
- void disallowClobberPhysReg(unsigned PhysReg);
-
- /// ClobberPhysReg - This is called when the specified physreg changes
- /// value. We use this to invalidate any info about stuff that lives in
- /// it and any of its aliases.
- void ClobberPhysReg(unsigned PhysReg);
-
- /// ModifyStackSlotOrReMat - This method is called when the value in a stack
- /// slot changes. This removes information about which register the
- /// previous value for this slot lives in (as the previous value is dead
- /// now).
- void ModifyStackSlotOrReMat(int SlotOrReMat);
-
- /// AddAvailableRegsToLiveIn - Availability information is being kept coming
- /// into the specified MBB. Add available physical registers as potential
- /// live-in's. If they are reused in the MBB, they will be added to the
- /// live-in set to make register scavenger and post-allocation scheduler.
- void AddAvailableRegsToLiveIn(MachineBasicBlock &MBB, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps);
- };
-
- // ************************************************************************ //
-
- // ReusedOp - For each reused operand, we keep track of a bit of information,
- // in case we need to rollback upon processing a new operand. See comments
- // below.
- struct ReusedOp {
- // The MachineInstr operand that reused an available value.
- unsigned Operand;
-
- // StackSlotOrReMat - The spill slot or remat id of the value being reused.
- unsigned StackSlotOrReMat;
-
- // PhysRegReused - The physical register the value was available in.
- unsigned PhysRegReused;
-
- // AssignedPhysReg - The physreg that was assigned for use by the reload.
- unsigned AssignedPhysReg;
-
- // VirtReg - The virtual register itself.
- unsigned VirtReg;
-
- ReusedOp(unsigned o, unsigned ss, unsigned prr, unsigned apr,
- unsigned vreg)
- : Operand(o), StackSlotOrReMat(ss), PhysRegReused(prr),
- AssignedPhysReg(apr), VirtReg(vreg) {}
- };
-
- /// ReuseInfo - This maintains a collection of ReuseOp's for each operand that
- /// is reused instead of reloaded.
- class VISIBILITY_HIDDEN ReuseInfo {
- MachineInstr &MI;
- std::vector<ReusedOp> Reuses;
- BitVector PhysRegsClobbered;
+ /// Spiller interface.
+ ///
+ /// Implementations are utility classes which insert spill or remat code on
+ /// demand.
+ class Spiller {
+ virtual void anchor();
public:
- ReuseInfo(MachineInstr &mi, const TargetRegisterInfo *tri) : MI(mi) {
- PhysRegsClobbered.resize(tri->getNumRegs());
- }
-
- bool hasReuses() const {
- return !Reuses.empty();
- }
-
- /// addReuse - If we choose to reuse a virtual register that is already
- /// available instead of reloading it, remember that we did so.
- void addReuse(unsigned OpNo, unsigned StackSlotOrReMat,
- unsigned PhysRegReused, unsigned AssignedPhysReg,
- unsigned VirtReg) {
- // If the reload is to the assigned register anyway, no undo will be
- // required.
- if (PhysRegReused == AssignedPhysReg) return;
-
- // Otherwise, remember this.
- Reuses.push_back(ReusedOp(OpNo, StackSlotOrReMat, PhysRegReused,
- AssignedPhysReg, VirtReg));
- }
+ virtual ~Spiller() = 0;
- void markClobbered(unsigned PhysReg) {
- PhysRegsClobbered.set(PhysReg);
- }
+ /// spill - Spill the LRE.getParent() live interval.
+ virtual void spill(LiveRangeEdit &LRE) = 0;
- bool isClobbered(unsigned PhysReg) const {
- return PhysRegsClobbered.test(PhysReg);
- }
-
- /// GetRegForReload - We are about to emit a reload into PhysReg. If there
- /// is some other operand that is using the specified register, either pick
- /// a new register to use, or evict the previous reload and use this reg.
- unsigned GetRegForReload(unsigned PhysReg, MachineInstr *MI,
- AvailableSpills &Spills,
- std::vector<MachineInstr*> &MaybeDeadStores,
- SmallSet<unsigned, 8> &Rejected,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
-
- /// GetRegForReload - Helper for the above GetRegForReload(). Add a
- /// 'Rejected' set to remember which registers have been considered and
- /// rejected for the reload. This avoids infinite looping in case like
- /// this:
- /// t1 := op t2, t3
- /// t2 <- assigned r0 for use by the reload but ended up reuse r1
- /// t3 <- assigned r1 for use by the reload but ended up reuse r0
- /// t1 <- desires r1
- /// sees r1 is taken by t2, tries t2's reload register r0
- /// sees r0 is taken by t3, tries t3's reload register r1
- /// sees r1 is taken by t2, tries t2's reload register r0 ...
- unsigned GetRegForReload(unsigned PhysReg, MachineInstr *MI,
- AvailableSpills &Spills,
- std::vector<MachineInstr*> &MaybeDeadStores,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM) {
- SmallSet<unsigned, 8> Rejected;
- return GetRegForReload(PhysReg, MI, Spills, MaybeDeadStores, Rejected,
- RegKills, KillOps, VRM);
- }
};
-
- // ************************************************************************ //
-
- /// LocalSpiller - This spiller does a simple pass over the machine basic
- /// block to attempt to keep spills in registers as much as possible for
- /// blocks that have low register pressure (the vreg may be spilled due to
- /// register pressure in other blocks).
- class VISIBILITY_HIDDEN LocalSpiller : public Spiller {
- MachineRegisterInfo *RegInfo;
- const TargetRegisterInfo *TRI;
- const TargetInstrInfo *TII;
- BitVector AllocatableRegs;
- DenseMap<MachineInstr*, unsigned> DistanceMap;
- public:
- bool runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM,
- LiveIntervals* LI);
- private:
- void TransferDeadness(MachineBasicBlock *MBB, unsigned CurDist,
- unsigned Reg, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps);
- bool OptimizeByUnfold(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- std::vector<MachineInstr*> &MaybeDeadStores,
- AvailableSpills &Spills, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
+ /// Create and return a spiller that will insert spill code directly instead
+ /// of deferring though VirtRegMap.
+ Spiller *createInlineSpiller(MachineFunctionPass &pass,
+ MachineFunction &mf,
+ VirtRegMap &vrm);
- bool OptimizeByUnfold2(unsigned VirtReg, int SS,
- MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- std::vector<MachineInstr*> &MaybeDeadStores,
- AvailableSpills &Spills, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
-
- bool CommuteToFoldReload(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- unsigned VirtReg, unsigned SrcReg, int SS,
- AvailableSpills &Spills,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- const TargetRegisterInfo *TRI,
- VirtRegMap &VRM);
-
- void SpillRegToStackSlot(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- int Idx, unsigned PhysReg, int StackSlot,
- const TargetRegisterClass *RC,
- bool isAvailable, MachineInstr *&LastStore,
- AvailableSpills &Spills,
- SmallSet<MachineInstr*, 4> &ReMatDefs,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
-
- void RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
- LiveIntervals *LIs, AvailableSpills &Spills,
- BitVector &RegKills, std::vector<MachineOperand*> &KillOps);
- };
}
#endif
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