Subzero: Slight improvement to phi lowering.

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.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 89 matching lines @@
   // Unhandled set.
   for (Variable *Var : Vars) {
     // Explicitly don't consider zero-weight variables, which are
     // meant to be spill slots.
     if (Var->getWeight().isZero())
       continue;
     // Don't bother if the variable has a null live range, which means
     // it was never referenced.
     if (Var->getLiveRange().isEmpty())
       continue;
-    // Post phi lowering register allocation is only concerned with variables
-    // that are infinite-weight or pre-colored.
-    if (Kind == RAK_Phi && !Var->getWeight().isInf() && !Var->hasReg())
-      continue;
     Var->untrimLiveRange();
     Unhandled.push_back(Var);
     if (Var->hasReg()) {
       Var->setRegNumTmp(Var->getRegNum());
       Var->setLiveRangeInfiniteWeight();
       UnhandledPrecolored.push_back(Var);
     }
   }
 
   // Build the (ordered) list of FakeKill instruction numbers.
@@ skipping 727 matching lines @@
     Str << "\n";
   }
   Str << "++++++ Inactive:\n";
   for (const Variable *Item : Inactive) {
     dumpLiveRange(Item, Func);
     Str << "\n";
   }
 }
 
 } // end of namespace Ice