Subzero: Clean up a few areas.

src/IceRegAlloc.cpp

 //===- subzero/src/IceRegAlloc.cpp - Linear-scan implementation -----------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the LinearScan class, which performs the
@@ skipping 476 matching lines @@
     std::vector<RegWeight> Weights(RegMask.size());
 
     // Remove registers from the Free[] list where an Unhandled
     // precolored range overlaps with the current range, and set those
     // registers to infinite weight so that they aren't candidates for
     // eviction.  Cur->rangeEndsBefore(Item) is an early exit check
     // that turns a guaranteed O(N^2) algorithm into expected linear
     // complexity.
     llvm::SmallBitVector PrecoloredUnhandledMask(RegMask.size());
     // Note: PrecoloredUnhandledMask is only used for dumping.
-    for (auto I = UnhandledPrecolored.rbegin(), E = UnhandledPrecolored.rend();
-         I != E; ++I) {
-      Variable *Item = *I;
+    for (Variable *Item : reverse_range(UnhandledPrecolored)) {
       assert(Item->hasReg());
       if (Cur->rangeEndsBefore(Item))
         break;
       if (Item->rangeOverlaps(Cur)) {
         int32_t ItemReg = Item->getRegNum(); // Note: not getRegNumTmp()
         Weights[ItemReg].setWeight(RegWeight::Inf);
         Free[ItemReg] = false;
         PrecoloredUnhandledMask[ItemReg] = true;
         // Disable AllowOverlap if the preferred register is one of
         // these precolored unhandled overlapping ranges.
@@ skipping 214 matching lines @@
   if (!Func->getContext()->isVerbose(IceV_LinearScan))
     return;
   Func->resetCurrentNode();
   Str << "**** Current regalloc state:\n";
   Str << "++++++ Handled:\n";
   for (const Variable *Item : Handled) {
     dumpLiveRange(Item, Func);
     Str << "\n";
   }
   Str << "++++++ Unhandled:\n";
-  for (auto I = Unhandled.rbegin(), E = Unhandled.rend(); I != E; ++I) {
-    dumpLiveRange(*I, Func);
+  for (const Variable *Item : reverse_range(Unhandled)) {
+    dumpLiveRange(Item, Func);
     Str << "\n";
   }
   Str << "++++++ Active:\n";
   for (const Variable *Item : Active) {
     dumpLiveRange(Item, Func);
     Str << "\n";
   }
   Str << "++++++ Inactive:\n";
   for (const Variable *Item : Inactive) {
     dumpLiveRange(Item, Func);
     Str << "\n";
   }
 }
 
 } // end of namespace Ice