-/// ComputeUltimateVN - Assuming we are going to join two live intervals,
-/// compute what the resultant value numbers for each value in the input two
-/// ranges will be. This is complicated by copies between the two which can
-/// and will commonly cause multiple value numbers to be merged into one.
-///
-/// VN is the value number that we're trying to resolve. InstDefiningValue
-/// keeps track of the new InstDefiningValue assignment for the result
-/// LiveInterval. ThisFromOther/OtherFromThis are sets that keep track of
-/// whether a value in this or other is a copy from the opposite set.
-/// ThisValNoAssignments/OtherValNoAssignments keep track of value #'s that have
-/// already been assigned.
-///
-/// ThisFromOther[x] - If x is defined as a copy from the other interval, this
-/// contains the value number the copy is from.
-///
-static unsigned ComputeUltimateVN(VNInfo *VNI,
- SmallVector<VNInfo*, 16> &NewVNInfo,
- DenseMap<VNInfo*, VNInfo*> &ThisFromOther,
- DenseMap<VNInfo*, VNInfo*> &OtherFromThis,
- SmallVector<int, 16> &ThisValNoAssignments,
- SmallVector<int, 16> &OtherValNoAssignments) {
- unsigned VN = VNI->id;
-
- // If the VN has already been computed, just return it.
- if (ThisValNoAssignments[VN] >= 0)
- return ThisValNoAssignments[VN];
-// assert(ThisValNoAssignments[VN] != -2 && "Cyclic case?");
-
- // If this val is not a copy from the other val, then it must be a new value
- // number in the destination.
- DenseMap<VNInfo*, VNInfo*>::iterator I = ThisFromOther.find(VNI);
- if (I == ThisFromOther.end()) {
- NewVNInfo.push_back(VNI);
- return ThisValNoAssignments[VN] = NewVNInfo.size()-1;
- }
- VNInfo *OtherValNo = I->second;
-
- // Otherwise, this *is* a copy from the RHS. If the other side has already
- // been computed, return it.
- if (OtherValNoAssignments[OtherValNo->id] >= 0)
- return ThisValNoAssignments[VN] = OtherValNoAssignments[OtherValNo->id];
-
- // Mark this value number as currently being computed, then ask what the
- // ultimate value # of the other value is.
- ThisValNoAssignments[VN] = -2;
- unsigned UltimateVN =
- ComputeUltimateVN(OtherValNo, NewVNInfo, OtherFromThis, ThisFromOther,
- OtherValNoAssignments, ThisValNoAssignments);
- return ThisValNoAssignments[VN] = UltimateVN;
-}
-
-void StrongPHIElimination::mergeLiveIntervals(unsigned primary,
- unsigned secondary,
- unsigned secondaryVN) {