Avoid iterating with LiveIntervals::iterator.

That is a DenseMap iterator keyed by pointers, so the iteration order is
nondeterministic.

I would like to replace the DenseMap with an IndexedMap which doesn't
allow iteration.

llvm-svn: 158856

1 files changed, 11 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/CalcSpillWeights.cpp b/llvm/lib/CodeGen/CalcSpillWeights.cpp
index 3782a1d99ab..939af3f0ccc 100644
--- a/llvm/lib/CodeGen/CalcSpillWeights.cpp
+++ b/llvm/lib/CodeGen/CalcSpillWeights.cpp
@@ -39,18 +39,20 @@ void CalculateSpillWeights::getAnalysisUsage(AnalysisUsage &au) const {
   MachineFunctionPass::getAnalysisUsage(au);
 }
 
-bool CalculateSpillWeights::runOnMachineFunction(MachineFunction &fn) {
+bool CalculateSpillWeights::runOnMachineFunction(MachineFunction &MF) {
 
   DEBUG(dbgs() << "********** Compute Spill Weights **********\n"
                << "********** Function: "
-               << fn.getFunction()->getName() << '\n');
-
-  LiveIntervals &lis = getAnalysis<LiveIntervals>();
-  VirtRegAuxInfo vrai(fn, lis, getAnalysis<MachineLoopInfo>());
-  for (LiveIntervals::iterator I = lis.begin(), E = lis.end(); I != E; ++I) {
-    LiveInterval &li = *I->second;
-    if (TargetRegisterInfo::isVirtualRegister(li.reg))
-      vrai.CalculateWeightAndHint(li);
+               << MF.getFunction()->getName() << '\n');
+
+  LiveIntervals &LIS = getAnalysis<LiveIntervals>();
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+  VirtRegAuxInfo VRAI(MF, LIS, getAnalysis<MachineLoopInfo>());
+  for (unsigned i = 0, e = MRI.getNumVirtRegs(); i != e; ++i) {
+    unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
+    if (MRI.reg_nodbg_empty(Reg))
+      continue;
+    VRAI.CalculateWeightAndHint(LIS.getInterval(Reg));
   }
   return false;
 }