Fix an inline asm pasto from 117667; was preventing

[oota-llvm.git] / lib / CodeGen / LiveInterval.cpp

diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index 2ed4d124972ebdcb5b61a1bc1eb2457d41280df6..3c18017f3fc3c442c50f86ba5844dcff94780952 100644 (file)
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -709,53 +709,51 @@ void LiveRange::print(raw_ostream &os) const {
 /// multiple LiveIntervals.
 
 void ConnectedVNInfoEqClasses::Connect(unsigned a, unsigned b) {
-  // Add new eq classes as needed.
-  for (unsigned i = eqClass_.size(), m = std::max(a, b); i <= m; ++i)
-    eqClass_.push_back(i);
-
-  unsigned eqa = eqClass_[a];
-  unsigned eqb = eqClass_[b];
-  if (eqa == eqb)
-    return;
-  if (eqa > eqb)
-    std::swap(eqa, eqb);
-  // Now, eqa < eqb. Switch all eqb members over to eqa.
-  for (unsigned i = eqb, e = eqClass_.size(); i != e; ++i)
-    if (eqClass_[i] == eqb)
-      eqClass_[i] = 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() {
-  // No values at all.
-  if (eqClass_.empty())
-    return 0;
-
-  // Common case: A single connected component.
-  if (eqClass_.back() == 0)
-    return 1;
-
-  // Renumber classes. We use the fact that eqClass_[i] == i for class leaders.
+  // Assign final class numbers.
+  // We use the fact that eqClass_[i] == i for class leaders.
+  // For others, eqClass_[i] points to an earlier value in the same class.
   unsigned count = 0;
   for (unsigned i = 0, e = eqClass_.size(); i != e; ++i) {
     unsigned q = eqClass_[i];
-    if (q == i)
-      eqClass_[i] = count++;
-    else
-      eqClass_[i] = eqClass_[q];
+    assert(q <= i && "Invariant broken");
+    eqClass_[i] = q == i ? count++ : eqClass_[q];
   }
 
   return count;
 }
 
 unsigned ConnectedVNInfoEqClasses::Classify(const LiveInterval *LI) {
-  // Determine connections.
+  // Create initial equivalence classes.
   eqClass_.clear();
+  eqClass_.reserve(LI->getNumValNums());
+  for (unsigned i = 0, e = LI->getNumValNums(); i != e; ++i)
+    eqClass_.push_back(i);
+
+  const VNInfo *used = 0, *unused = 0;
+
+  // Determine connections.
   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");
+    // Group all unused values into one class.
+    if (VNI->isUnused()) {
+      if (unused)
+        Connect(unused->id, VNI->id);
+      unused = VNI;
+      continue;
+    }
+    used = VNI;
     if (VNI->isPHIDef()) {
       const MachineBasicBlock *MBB = lis_.getMBBFromIndex(VNI->def);
       assert(MBB && "Phi-def has no defining MBB");
@@ -773,6 +771,11 @@ unsigned ConnectedVNInfoEqClasses::Classify(const LiveInterval *LI) {
         Connect(VNI->id, UVNI->id);
     }
   }
+
+  // Lump all the unused values in with the last used value.
+  if (used && unused)
+    Connect(used->id, unused->id);
+
   return Renumber();
 }
 
@@ -788,7 +791,7 @@ void ConnectedVNInfoEqClasses::Distribute(LiveInterval *LIV[]) {
     ++J;
   for (LiveInterval::iterator I = J; I != E; ++I) {
     if (unsigned eq = eqClass_[I->valno->id]) {
-      assert(LIV[eq]->empty() || LIV[eq]->expiredAt(I->start) &&
+      assert((LIV[eq]->empty() || LIV[eq]->expiredAt(I->start)) &&
              "New intervals should be empty");
       LIV[eq]->ranges.push_back(*I);
     } else