void ConnectedVNInfoEqClasses::Distribute(LiveInterval &LI, LiveInterval *LIV[],
MachineRegisterInfo &MRI) {
// Rewrite instructions.
for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg),
RE = MRI.reg_end(); RI != RE;) {
MachineOperand &MO = *RI;
MachineInstr *MI = RI->getParent();
++RI;
// DBG_VALUE instructions don't have slot indexes, so get the index of the
// instruction before them.
// Normally, DBG_VALUE instructions are removed before this function is
// called, but it is not a requirement.
SlotIndex Idx;
if (MI->isDebugValue())
Idx = LIS.getSlotIndexes()->getIndexBefore(MI);
else
Idx = LIS.getInstructionIndex(MI);
LiveQueryResult LRQ = LI.Query(Idx);
const VNInfo *VNI = MO.readsReg() ? LRQ.valueIn() : LRQ.valueDefined();
// In the case of an <undef> use that isn't tied to any def, VNI will be
// NULL. If the use is tied to a def, VNI will be the defined value.
if (!VNI)
continue;
if (unsigned EqClass = getEqClass(VNI))
MO.setReg(LIV[EqClass-1]->reg);
}
// Move runs to new intervals.
LiveInterval::iterator J = LI.begin(), E = LI.end();
while (J != E && EqClass[J->valno->id] == 0)
++J;
for (LiveInterval::iterator I = J; I != E; ++I) {
if (unsigned eq = EqClass[I->valno->id]) {
assert((LIV[eq-1]->empty() || LIV[eq-1]->expiredAt(I->start)) &&
"New intervals should be empty");
LIV[eq-1]->segments.push_back(*I);
} else
*J++ = *I;
}
// TODO: do not cheat anymore by simply cleaning all subranges
LI.clearSubRanges();
LI.segments.erase(J, E);
// Transfer VNInfos to their new owners and renumber them.
unsigned j = 0, e = LI.getNumValNums();
while (j != e && EqClass[j] == 0)
++j;
for (unsigned i = j; i != e; ++i) {
VNInfo *VNI = LI.getValNumInfo(i);
if (unsigned eq = EqClass[i]) {
VNI->id = LIV[eq-1]->getNumValNums();
LIV[eq-1]->valnos.push_back(VNI);
} else {
VNI->id = j;
LI.valnos[j++] = VNI;
}
}
LI.valnos.resize(j);
}
