Replace TargetRegisterInfo::printReg with a PrintReg class that also works without a TRI instance.

Print virtual registers numbered from 0 instead of the arbitrary
FirstVirtualRegister. The first virtual register is printed as %vreg0.
TRI::NoRegister is printed as %noreg.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123107 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp
index 58ab0bf..109da42 100644
--- a/lib/CodeGen/RegAllocFast.cpp
+++ b/lib/CodeGen/RegAllocFast.cpp
@@ -262,8 +262,8 @@
     // instruction, not on the spill.
     bool SpillKill = LR.LastUse != MI;
     LR.Dirty = false;
-    DEBUG(dbgs() << "Spilling %reg" << LRI->first
-                 << " in " << TRI->getName(LR.PhysReg));
+    DEBUG(dbgs() << "Spilling " << PrintReg(LRI->first, TRI)
+                 << " in " << PrintReg(LR.PhysReg, TRI));
     const TargetRegisterClass *RC = MRI->getRegClass(LRI->first);
     int FI = getStackSpaceFor(LRI->first, RC);
     DEBUG(dbgs() << " to stack slot #" << FI << "\n");
@@ -461,8 +461,8 @@
 /// register must not be used for anything else when this is called.
 ///
 void RAFast::assignVirtToPhysReg(LiveRegEntry &LRE, unsigned PhysReg) {
-  DEBUG(dbgs() << "Assigning %reg" << LRE.first << " to "
-               << TRI->getName(PhysReg) << "\n");
+  DEBUG(dbgs() << "Assigning " << PrintReg(LRE.first, TRI) << " to "
+               << PrintReg(PhysReg, TRI) << "\n");
   PhysRegState[PhysReg] = LRE.first;
   assert(!LRE.second.PhysReg && "Already assigned a physreg");
   LRE.second.PhysReg = PhysReg;
@@ -506,8 +506,8 @@
       return assignVirtToPhysReg(LRE, PhysReg);
   }
 
-  DEBUG(dbgs() << "Allocating %reg" << VirtReg << " from " << RC->getName()
-               << "\n");
+  DEBUG(dbgs() << "Allocating " << PrintReg(VirtReg) << " from "
+               << RC->getName() << "\n");
 
   unsigned BestReg = 0, BestCost = spillImpossible;
   for (TargetRegisterClass::iterator I = AOB; I != AOE; ++I) {
@@ -587,8 +587,8 @@
     allocVirtReg(MI, *LRI, Hint);
     const TargetRegisterClass *RC = MRI->getRegClass(VirtReg);
     int FrameIndex = getStackSpaceFor(VirtReg, RC);
-    DEBUG(dbgs() << "Reloading %reg" << VirtReg << " into "
-                 << TRI->getName(LR.PhysReg) << "\n");
+    DEBUG(dbgs() << "Reloading " << PrintReg(VirtReg, TRI) << " into "
+                 << PrintReg(LR.PhysReg, TRI) << "\n");
     TII->loadRegFromStackSlot(*MBB, MI, LR.PhysReg, FrameIndex, RC, TRI);
     ++NumLoads;
   } else if (LR.Dirty) {
@@ -660,7 +660,7 @@
     if (MO.isEarlyClobber() || MI->isRegTiedToDefOperand(i) ||
         (MO.getSubReg() && MI->readsVirtualRegister(Reg))) {
       if (ThroughRegs.insert(Reg))
-        DEBUG(dbgs() << " %reg" << Reg);
+        DEBUG(dbgs() << ' ' << PrintReg(Reg));
     }
   }
 
@@ -764,7 +764,7 @@
             dbgs() << "*";
             break;
           default:
-            dbgs() << "=%reg" << PhysRegState[Reg];
+            dbgs() << '=' << PrintReg(PhysRegState[Reg]);
             if (LiveVirtRegs[PhysRegState[Reg]].Dirty)
               dbgs() << "*";
             assert(LiveVirtRegs[PhysRegState[Reg]].PhysReg == Reg &&