Fix PR8612 in the standard spiller, take two.
The live range of a register defined by an early clobber starts at the use slot,
not the def slot.
Except when it is an early clobber tied to a use operand. Then it starts at the
def slot like a standard def.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119305 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index aa2f965..9b42012 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -1136,11 +1136,14 @@
rewriteImplicitOps(li, MI, NewVReg, vrm);
// Reuse NewVReg for other reads.
+ bool HasEarlyClobber = false;
for (unsigned j = 0, e = Ops.size(); j != e; ++j) {
MachineOperand &mopj = MI->getOperand(Ops[j]);
mopj.setReg(NewVReg);
if (mopj.isImplicit())
rewriteImplicitOps(li, MI, NewVReg, vrm);
+ if (mopj.isEarlyClobber())
+ HasEarlyClobber = true;
}
if (CreatedNewVReg) {
@@ -1199,7 +1202,11 @@
}
}
if (HasDef) {
- LiveRange LR(index.getDefIndex(), index.getStoreIndex(),
+ // An early clobber starts at the use slot, except for an early clobber
+ // tied to a use operand (yes, that is a thing).
+ LiveRange LR(HasEarlyClobber && !HasUse ?
+ index.getUseIndex() : index.getDefIndex(),
+ index.getStoreIndex(),
nI.getNextValue(SlotIndex(), 0, VNInfoAllocator));
DEBUG(dbgs() << " +" << LR);
nI.addRange(LR);