#include "Spiller.h"
#include "VirtRegMap.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Support/Debug.h"
-#include <algorithm>
-#include <map>
-
using namespace llvm;
Spiller::~Spiller() {}
namespace {
-class TrivialSpiller : public Spiller {
-public:
- TrivialSpiller(MachineFunction *mf, LiveIntervals *lis, VirtRegMap *vrm) :
- mf(mf), lis(lis), vrm(vrm)
+/// Utility class for spillers.
+class SpillerBase : public Spiller {
+protected:
+
+ MachineFunction *mf;
+ LiveIntervals *lis;
+ LiveStacks *ls;
+ MachineFrameInfo *mfi;
+ MachineRegisterInfo *mri;
+ const TargetInstrInfo *tii;
+ VirtRegMap *vrm;
+
+ /// Construct a spiller base.
+ SpillerBase(MachineFunction *mf, LiveIntervals *lis, LiveStacks *ls,
+ VirtRegMap *vrm) :
+ mf(mf), lis(lis), ls(ls), vrm(vrm)
{
mfi = mf->getFrameInfo();
mri = &mf->getRegInfo();
tii = mf->getTarget().getInstrInfo();
}
- std::vector<LiveInterval*> spill(LiveInterval *li) {
+ /// Ensures there is space before the given machine instruction, returns the
+ /// instruction's new number.
+ unsigned makeSpaceBefore(MachineInstr *mi) {
+ if (!lis->hasGapBeforeInstr(lis->getInstructionIndex(mi))) {
+ lis->scaleNumbering(2);
+ ls->scaleNumbering(2);
+ }
+
+ unsigned miIdx = lis->getInstructionIndex(mi);
+
+ assert(lis->hasGapBeforeInstr(miIdx));
+
+ return miIdx;
+ }
+
+ /// Ensure there is space after the given machine instruction, returns the
+ /// instruction's new number.
+ unsigned makeSpaceAfter(MachineInstr *mi) {
+ if (!lis->hasGapAfterInstr(lis->getInstructionIndex(mi))) {
+ lis->scaleNumbering(2);
+ ls->scaleNumbering(2);
+ }
+
+ unsigned miIdx = lis->getInstructionIndex(mi);
+
+ assert(lis->hasGapAfterInstr(miIdx));
+
+ return miIdx;
+ }
+
+
+ /// Insert a store of the given vreg to the given stack slot immediately
+ /// after the given instruction. Returns the base index of the inserted
+ /// instruction. The caller is responsible for adding an appropriate
+ /// LiveInterval to the LiveIntervals analysis.
+ unsigned insertStoreFor(MachineInstr *mi, unsigned ss,
+ unsigned vreg,
+ const TargetRegisterClass *trc) {
+
+ MachineBasicBlock::iterator nextInstItr(mi);
+ ++nextInstItr;
+
+ unsigned miIdx = makeSpaceAfter(mi);
+
+ tii->storeRegToStackSlot(*mi->getParent(), nextInstItr, vreg,
+ true, ss, trc);
+ MachineBasicBlock::iterator storeInstItr(mi);
+ ++storeInstItr;
+ MachineInstr *storeInst = &*storeInstItr;
+ unsigned storeInstIdx = miIdx + LiveInterval::InstrSlots::NUM;
+
+ assert(lis->getInstructionFromIndex(storeInstIdx) == 0 &&
+ "Store inst index already in use.");
+
+ lis->InsertMachineInstrInMaps(storeInst, storeInstIdx);
+
+ return storeInstIdx;
+ }
+
+ void insertStoreOnInterval(LiveInterval *li,
+ MachineInstr *mi, unsigned ss,
+ unsigned vreg,
+ const TargetRegisterClass *trc) {
+
+ unsigned storeInstIdx = insertStoreFor(mi, ss, vreg, trc);
+ unsigned start = lis->getDefIndex(lis->getInstructionIndex(mi)),
+ end = lis->getUseIndex(storeInstIdx);
+
+ VNInfo *vni =
+ li->getNextValue(storeInstIdx, 0, true, lis->getVNInfoAllocator());
+ vni->kills.push_back(storeInstIdx);
+ LiveRange lr(start, end, vni);
+
+ li->addRange(lr);
+ }
+
+ /// Insert a load of the given veg from the given stack slot immediately
+ /// before the given instruction. Returns the base index of the inserted
+ /// instruction. The caller is responsible for adding an appropriate
+ /// LiveInterval to the LiveIntervals analysis.
+ unsigned insertLoadFor(MachineInstr *mi, unsigned ss,
+ unsigned vreg,
+ const TargetRegisterClass *trc) {
+ MachineBasicBlock::iterator useInstItr(mi);
+
+ unsigned miIdx = makeSpaceBefore(mi);
+
+ tii->loadRegFromStackSlot(*mi->getParent(), useInstItr, vreg, ss, trc);
+ MachineBasicBlock::iterator loadInstItr(mi);
+ --loadInstItr;
+ MachineInstr *loadInst = &*loadInstItr;
+ unsigned loadInstIdx = miIdx - LiveInterval::InstrSlots::NUM;
+
+ assert(lis->getInstructionFromIndex(loadInstIdx) == 0 &&
+ "Load inst index already in use.");
+
+ lis->InsertMachineInstrInMaps(loadInst, loadInstIdx);
+
+ return loadInstIdx;
+ }
+
+ void insertLoadOnInterval(LiveInterval *li,
+ MachineInstr *mi, unsigned ss,
+ unsigned vreg,
+ const TargetRegisterClass *trc) {
+
+ unsigned loadInstIdx = insertLoadFor(mi, ss, vreg, trc);
+ unsigned start = lis->getDefIndex(loadInstIdx),
+ end = lis->getUseIndex(lis->getInstructionIndex(mi));
+
+ VNInfo *vni =
+ li->getNextValue(loadInstIdx, 0, true, lis->getVNInfoAllocator());
+ vni->kills.push_back(lis->getInstructionIndex(mi));
+ LiveRange lr(start, end, vni);
+
+ li->addRange(lr);
+ }
+
+
- DOUT << "Trivial spiller spilling " << *li << "\n";
+ /// Add spill ranges for every use/def of the live interval, inserting loads
+ /// immediately before each use, and stores after each def. No folding is
+ /// attempted.
+ std::vector<LiveInterval*> trivialSpillEverywhere(LiveInterval *li) {
+ DOUT << "Spilling everywhere " << *li << "\n";
assert(li->weight != HUGE_VALF &&
"Attempting to spill already spilled value.");
std::vector<LiveInterval*> added;
const TargetRegisterClass *trc = mri->getRegClass(li->reg);
- /*unsigned ss = mfi->CreateStackObject(trc->getSize(),
- trc->getAlignment());*/
unsigned ss = vrm->assignVirt2StackSlot(li->reg);
- MachineRegisterInfo::reg_iterator regItr = mri->reg_begin(li->reg);
-
- while (regItr != mri->reg_end()) {
+ for (MachineRegisterInfo::reg_iterator
+ regItr = mri->reg_begin(li->reg); regItr != mri->reg_end();) {
MachineInstr *mi = &*regItr;
-
+ do {
+ ++regItr;
+ } while (regItr != mri->reg_end() && (&*regItr == mi));
+
SmallVector<unsigned, 2> indices;
bool hasUse = false;
bool hasDef = false;
}
unsigned newVReg = mri->createVirtualRegister(trc);
- LiveInterval *newLI = &lis->getOrCreateInterval(newVReg);
- newLI->weight = HUGE_VALF;
-
vrm->grow();
vrm->assignVirt2StackSlot(newVReg, ss);
+ LiveInterval *newLI = &lis->getOrCreateInterval(newVReg);
+ newLI->weight = HUGE_VALF;
+
for (unsigned i = 0; i < indices.size(); ++i) {
mi->getOperand(indices[i]).setReg(newVReg);
}
}
- if (hasUse) {
- unsigned loadInstIdx = insertLoadFor(mi, ss, newVReg, trc);
- unsigned start = lis->getDefIndex(loadInstIdx),
- end = lis->getUseIndex(lis->getInstructionIndex(mi));
-
- VNInfo *vni =
- newLI->getNextValue(loadInstIdx, 0, lis->getVNInfoAllocator());
- vni->kills.push_back(lis->getInstructionIndex(mi));
- LiveRange lr(start, end, vni);
+ assert(hasUse || hasDef);
- newLI->addRange(lr);
- added.push_back(newLI);
+ if (hasUse) {
+ insertLoadOnInterval(newLI, mi, ss, newVReg, trc);
}
if (hasDef) {
- unsigned storeInstIdx = insertStoreFor(mi, ss, newVReg, trc);
- unsigned start = lis->getDefIndex(lis->getInstructionIndex(mi)),
- end = lis->getUseIndex(storeInstIdx);
-
- VNInfo *vni =
- newLI->getNextValue(storeInstIdx, 0, lis->getVNInfoAllocator());
- vni->kills.push_back(storeInstIdx);
- LiveRange lr(start, end, vni);
-
- newLI->addRange(lr);
- added.push_back(newLI);
+ insertStoreOnInterval(newLI, mi, ss, newVReg, trc);
}
- regItr = mri->reg_begin(li->reg);
+ added.push_back(newLI);
}
-
return added;
}
+};
-private:
-
- MachineFunction *mf;
- LiveIntervals *lis;
- MachineFrameInfo *mfi;
- MachineRegisterInfo *mri;
- const TargetInstrInfo *tii;
- VirtRegMap *vrm;
-
-
-
- void makeRoomForInsertBefore(MachineInstr *mi) {
- if (!lis->hasGapBeforeInstr(lis->getInstructionIndex(mi))) {
- lis->computeNumbering();
- }
-
- assert(lis->hasGapBeforeInstr(lis->getInstructionIndex(mi)));
- }
-
- unsigned insertStoreFor(MachineInstr *mi, unsigned ss,
- unsigned newVReg,
- const TargetRegisterClass *trc) {
- MachineBasicBlock::iterator nextInstItr(mi);
- ++nextInstItr;
-
- makeRoomForInsertBefore(&*nextInstItr);
-
- unsigned miIdx = lis->getInstructionIndex(mi);
- tii->storeRegToStackSlot(*mi->getParent(), nextInstItr, newVReg,
- true, ss, trc);
- MachineBasicBlock::iterator storeInstItr(mi);
- ++storeInstItr;
- MachineInstr *storeInst = &*storeInstItr;
- unsigned storeInstIdx = miIdx + LiveIntervals::InstrSlots::NUM;
+/// Spills any live range using the spill-everywhere method with no attempt at
+/// folding.
+class TrivialSpiller : public SpillerBase {
+public:
- assert(lis->getInstructionFromIndex(storeInstIdx) == 0 &&
- "Store inst index already in use.");
-
- lis->InsertMachineInstrInMaps(storeInst, storeInstIdx);
+ TrivialSpiller(MachineFunction *mf, LiveIntervals *lis, LiveStacks *ls,
+ VirtRegMap *vrm) :
+ SpillerBase(mf, lis, ls, vrm) {}
- return storeInstIdx;
+ std::vector<LiveInterval*> spill(LiveInterval *li) {
+ return trivialSpillEverywhere(li);
}
- unsigned insertLoadFor(MachineInstr *mi, unsigned ss,
- unsigned newVReg,
- const TargetRegisterClass *trc) {
- MachineBasicBlock::iterator useInstItr(mi);
-
- makeRoomForInsertBefore(mi);
-
- unsigned miIdx = lis->getInstructionIndex(mi);
-
- tii->loadRegFromStackSlot(*mi->getParent(), useInstItr, newVReg, ss, trc);
- MachineBasicBlock::iterator loadInstItr(mi);
- --loadInstItr;
- MachineInstr *loadInst = &*loadInstItr;
- unsigned loadInstIdx = miIdx - LiveIntervals::InstrSlots::NUM;
-
- assert(lis->getInstructionFromIndex(loadInstIdx) == 0 &&
- "Load inst index already in use.");
+ std::vector<LiveInterval*> intraBlockSplit(LiveInterval *li, VNInfo *valno) {
+ std::vector<LiveInterval*> spillIntervals;
+ MachineBasicBlock::iterator storeInsertPoint;
+
+ if (valno->isDefAccurate()) {
+ // If we have an accurate def we can just grab an iterator to the instr
+ // after the def.
+ storeInsertPoint =
+ next(MachineBasicBlock::iterator(lis->getInstructionFromIndex(valno->def)));
+ } else {
+ // If the def info isn't accurate we check if this is a PHI def.
+ // If it is then def holds the index of the defining Basic Block, and we
+ // can use that to get an insertion point.
+ if (valno->isPHIDef()) {
+
+ } else {
+ // We have no usable def info. We can't split this value sensibly.
+ // FIXME: Need sensible feedback for "failure to split", an empty
+ // set of spill intervals could be reasonably returned from a
+ // split where both the store and load are folded.
+ return spillIntervals;
+ }
+ }
- lis->InsertMachineInstrInMaps(loadInst, loadInstIdx);
+
- return loadInstIdx;
+ return spillIntervals;
}
};
}
-
llvm::Spiller* llvm::createSpiller(MachineFunction *mf, LiveIntervals *lis,
- VirtRegMap *vrm) {
- return new TrivialSpiller(mf, lis, vrm);
+ LiveStacks *ls, VirtRegMap *vrm) {
+ return new TrivialSpiller(mf, lis, ls, vrm);
}
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