Backing out previous check-in.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28219 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index fd7d5a6d760a14f6d59386c812cbfba9d9d1bbe8..90b8fe27143ccd43a2fa6d986755d67812ebe821 100644 (file)
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -406,15 +406,6 @@ static void RevertVectorIteratorsTo(RA::IntervalPtrs &V, unsigned Point) {
   }
 }
 
-static bool isZeroLengthInterval(LiveInterval *li) {
-  for (LiveInterval::Ranges::const_iterator
-         i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i)
-    if (i->end - i->start > LiveIntervals::InstrSlots::NUM)
-      return false;
-  return true;
-}
-
-
 /// assignRegOrStackSlotAtInterval - assign a register if one is available, or
 /// spill.
 void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
@@ -565,16 +556,10 @@ void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
   DEBUG(std::cerr << "\t\tregister with min weight: "
         << mri_->getName(minReg) << " (" << minWeight << ")\n");
 
-  // If the live interval legnth is essentially zero, i.e. in every live range
-  // the use follows def immediately, it doesn't make sense to spill it and
-  // hope it will be easier to allocate for this li.
-  if (isZeroLengthInterval(cur))
-    DEBUG(std::cerr << "\t\tavoid spilling zero length live interval: "
-          << *cur << '\n';);
   // if the current has the minimum weight, we need to spill it and
   // add any added intervals back to unhandled, and restart
   // linearscan.
-  else if (cur->weight <= minWeight) {
+  if (cur->weight <= minWeight) {
     DEBUG(std::cerr << "\t\t\tspilling(c): " << *cur << '\n';);
     int slot = vrm_->assignVirt2StackSlot(cur->reg);
     std::vector<LiveInterval*> added =