Fix broken equivalence class calculation. We could probably also use
EquvivalenceClasses.h except it looks like overkill when elements are continuous
integers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117631 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index 6fb60362..27a572c 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -709,15 +709,14 @@
/// multiple LiveIntervals.
void ConnectedVNInfoEqClasses::Connect(unsigned a, unsigned b) {
- unsigned eqa = eqClass_[a];
- unsigned eqb = eqClass_[b];
- if (eqa == eqb)
- return;
- // Make sure a and b are in the same class while maintaining eqClass_[i] <= i.
- if (eqa > eqb)
- eqClass_[a] = eqb;
- else
- eqClass_[b] = eqa;
+ while (eqClass_[a] != eqClass_[b]) {
+ if (eqClass_[a] > eqClass_[b])
+ std::swap(a, b);
+ unsigned t = eqClass_[b];
+ assert(t <= b && "Invariant broken");
+ eqClass_[b] = eqClass_[a];
+ b = t;
+ }
}
unsigned ConnectedVNInfoEqClasses::Renumber() {
@@ -745,8 +744,6 @@
for (LiveInterval::const_vni_iterator I = LI->vni_begin(), E = LI->vni_end();
I != E; ++I) {
const VNInfo *VNI = *I;
- if (VNI->id == eqClass_.size())
- eqClass_.push_back(VNI->id);
assert(!VNI->isUnused() && "Cannot handle unused values");
if (VNI->isPHIDef()) {
const MachineBasicBlock *MBB = lis_.getMBBFromIndex(VNI->def);