Completed basic intra block split implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74114 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Lang Hames 2009-06-24 20:46:24 +00:00
parent 1c47c7db1e
commit 6bbc73d3fd

View File

@ -78,24 +78,21 @@ protected:
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 insertStoreAfter(MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
MachineBasicBlock::iterator nextInstItr(mi);
++nextInstItr;
MachineBasicBlock::iterator nextInstItr(next(mi));
unsigned miIdx = makeSpaceAfter(mi);
tii->storeRegToStackSlot(*mi->getParent(), nextInstItr, vreg,
true, ss, trc);
MachineBasicBlock::iterator storeInstItr(mi);
++storeInstItr;
MachineBasicBlock::iterator storeInstItr(next(mi));
MachineInstr *storeInst = &*storeInstItr;
unsigned storeInstIdx = miIdx + LiveInterval::InstrSlots::NUM;
@ -107,37 +104,81 @@ protected:
return storeInstIdx;
}
void insertStoreOnInterval(LiveInterval *li,
MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
/// Insert a store of the given vreg to the given stack slot immediately
/// before the given instructnion. Returns the base index of the inserted
/// Instruction.
unsigned insertStoreBefore(MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
unsigned miIdx = makeSpaceBefore(mi);
tii->storeRegToStackSlot(*mi->getParent(), mi, vreg, true, ss, trc);
MachineBasicBlock::iterator storeInstItr(prior(mi));
MachineInstr *storeInst = &*storeInstItr;
unsigned storeInstIdx = miIdx - LiveInterval::InstrSlots::NUM;
unsigned storeInstIdx = insertStoreFor(mi, ss, vreg, trc);
assert(lis->getInstructionFromIndex(storeInstIdx) == 0 &&
"Store inst index already in use.");
lis->InsertMachineInstrInMaps(storeInst, storeInstIdx);
return storeInstIdx;
}
void insertStoreAfterInstOnInterval(LiveInterval *li,
MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
unsigned storeInstIdx = insertStoreAfter(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);
DOUT << " Inserting store range: [" << start << ", " << end << ")\n";
LiveRange lr(start, end, vni);
li->addRange(lr);
}
/// Insert a load of the given veg from the given stack slot immediately
/// Insert a load of the given vreg from the given stack slot immediately
/// after the given instruction. Returns the base index of the inserted
/// instruction. The caller is responsibel for adding/removing an appropriate
/// range vreg's LiveInterval.
unsigned insertLoadAfter(MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
MachineBasicBlock::iterator nextInstItr(next(mi));
unsigned miIdx = makeSpaceAfter(mi);
tii->loadRegFromStackSlot(*mi->getParent(), nextInstItr, vreg, ss, trc);
MachineBasicBlock::iterator loadInstItr(next(mi));
MachineInstr *loadInst = &*loadInstItr;
unsigned loadInstIdx = miIdx + LiveInterval::InstrSlots::NUM;
assert(lis->getInstructionFromIndex(loadInstIdx) == 0 &&
"Store inst index already in use.");
lis->InsertMachineInstrInMaps(loadInst, loadInstIdx);
return loadInstIdx;
}
/// Insert a load of the given vreg 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 insertLoadBefore(MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
unsigned miIdx = makeSpaceBefore(mi);
tii->loadRegFromStackSlot(*mi->getParent(), useInstItr, vreg, ss, trc);
MachineBasicBlock::iterator loadInstItr(mi);
--loadInstItr;
tii->loadRegFromStackSlot(*mi->getParent(), mi, vreg, ss, trc);
MachineBasicBlock::iterator loadInstItr(prior(mi));
MachineInstr *loadInst = &*loadInstItr;
unsigned loadInstIdx = miIdx - LiveInterval::InstrSlots::NUM;
@ -149,18 +190,19 @@ protected:
return loadInstIdx;
}
void insertLoadOnInterval(LiveInterval *li,
MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
void insertLoadBeforeInstOnInterval(LiveInterval *li,
MachineInstr *mi, unsigned ss,
unsigned vreg,
const TargetRegisterClass *trc) {
unsigned loadInstIdx = insertLoadFor(mi, ss, vreg, trc);
unsigned loadInstIdx = insertLoadBefore(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));
DOUT << " Intserting load range: [" << start << ", " << end << ")\n";
LiveRange lr(start, end, vni);
li->addRange(lr);
@ -180,6 +222,8 @@ protected:
assert(!li->isStackSlot() &&
"Trying to spill a stack slot.");
DOUT << "Trivial spill everywhere of reg" << li->reg << "\n";
std::vector<LiveInterval*> added;
const TargetRegisterClass *trc = mri->getRegClass(li->reg);
@ -189,6 +233,9 @@ protected:
regItr = mri->reg_begin(li->reg); regItr != mri->reg_end();) {
MachineInstr *mi = &*regItr;
DOUT << " Processing " << *mi;
do {
++regItr;
} while (regItr != mri->reg_end() && (&*regItr == mi));
@ -227,11 +274,11 @@ protected:
assert(hasUse || hasDef);
if (hasUse) {
insertLoadOnInterval(newLI, mi, ss, newVReg, trc);
insertLoadBeforeInstOnInterval(newLI, mi, ss, newVReg, trc);
}
if (hasDef) {
insertStoreOnInterval(newLI, mi, ss, newVReg, trc);
insertStoreAfterInstOnInterval(newLI, mi, ss, newVReg, trc);
}
added.push_back(newLI);
@ -258,29 +305,53 @@ public:
std::vector<LiveInterval*> intraBlockSplit(LiveInterval *li, VNInfo *valno) {
std::vector<LiveInterval*> spillIntervals;
MachineBasicBlock::iterator storeInsertPoint;
if (!valno->isDefAccurate() && !valno->isPHIDef()) {
// Early out for values which have no well defined def point.
return spillIntervals;
}
// Ok.. we should be able to proceed...
const TargetRegisterClass *trc = mri->getRegClass(li->reg);
unsigned ss = vrm->assignVirt2StackSlot(li->reg);
vrm->grow();
vrm->assignVirt2StackSlot(li->reg, ss);
MachineInstr *mi = 0;
unsigned storeIdx = 0;
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)));
mi = lis->getInstructionFromIndex(valno->def);
storeIdx = insertStoreAfter(mi, ss, li->reg, trc) +
LiveInterval::InstrSlots::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;
}
// if we get here we have a PHI def.
mi = &lis->getMBBFromIndex(valno->def)->front();
storeIdx = insertStoreBefore(mi, ss, li->reg, trc) +
LiveInterval::InstrSlots::DEF;
}
MachineBasicBlock *defBlock = mi->getParent();
unsigned loadIdx = 0;
// Now we need to find the load...
MachineBasicBlock::iterator useItr(mi);
for (; !useItr->readsRegister(li->reg); ++useItr) {}
if (useItr != defBlock->end()) {
MachineInstr *loadInst = useItr;
loadIdx = insertLoadBefore(loadInst, ss, li->reg, trc) +
LiveInterval::InstrSlots::USE;
}
else {
MachineInstr *loadInst = &defBlock->back();
loadIdx = insertLoadAfter(loadInst, ss, li->reg, trc) +
LiveInterval::InstrSlots::USE;
}
li->removeRange(storeIdx, loadIdx, true);
return spillIntervals;
}