- // The live segment is ending inside EndMBB
- const MachineInstr *MI =
- LiveInts->getInstructionFromIndex(I->end.getPrevSlot());
- if (!MI) {
- report("Live segment doesn't end at a valid instruction", EndMBB);
- I->print(*OS);
- *OS << " in " << LI << '\n' << "Basic block starts at "
- << MBBStartIdx << '\n';
+ // No more checks for live-out segments.
+ if (I->end == LiveInts->getMBBEndIdx(EndMBB))
+ return;
+
+ // RegUnit intervals are allowed dead phis.
+ if (!TargetRegisterInfo::isVirtualRegister(LI.reg) && VNI->isPHIDef() &&
+ I->start == VNI->def && I->end == VNI->def.getDeadSlot())
+ return;
+
+ // The live segment is ending inside EndMBB
+ const MachineInstr *MI =
+ LiveInts->getInstructionFromIndex(I->end.getPrevSlot());
+ if (!MI) {
+ report("Live segment doesn't end at a valid instruction", EndMBB, LI);
+ *OS << *I << '\n';
+ return;
+ }
+
+ // The block slot must refer to a basic block boundary.
+ if (I->end.isBlock()) {
+ report("Live segment ends at B slot of an instruction", EndMBB, LI);
+ *OS << *I << '\n';
+ }
+
+ if (I->end.isDead()) {
+ // Segment ends on the dead slot.
+ // That means there must be a dead def.
+ if (!SlotIndex::isSameInstr(I->start, I->end)) {
+ report("Live segment ending at dead slot spans instructions", EndMBB, LI);
+ *OS << *I << '\n';
+ }
+ }
+
+ // A live segment can only end at an early-clobber slot if it is being
+ // redefined by an early-clobber def.
+ if (I->end.isEarlyClobber()) {
+ if (I+1 == LI.end() || (I+1)->start != I->end) {
+ report("Live segment ending at early clobber slot must be "
+ "redefined by an EC def in the same instruction", EndMBB, LI);
+ *OS << *I << '\n';
+ }
+ }
+
+ // The following checks only apply to virtual registers. Physreg liveness
+ // is too weird to check.
+ if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
+ // A live range can end with either a redefinition, a kill flag on a
+ // use, or a dead flag on a def.
+ bool hasRead = false;
+ bool hasDeadDef = false;
+ for (ConstMIBundleOperands MOI(MI); MOI.isValid(); ++MOI) {
+ if (!MOI->isReg() || MOI->getReg() != LI.reg)