Make dense maps keyed on physical registers smallerusing
MRegisterInfo::getNumRegs() instead of
MRegisterInfo::FirstVirtualRegister.

Also use MRegisterInfo::is{Physical,Virtual}Register where
appropriate.

llvm-svn: 11477
diff --git a/llvm/lib/Target/X86/Printer.cpp b/llvm/lib/Target/X86/Printer.cpp
index f591612..31ac00f 100644
--- a/llvm/lib/Target/X86/Printer.cpp
+++ b/llvm/lib/Target/X86/Printer.cpp
@@ -399,7 +399,7 @@
     }
     // FALLTHROUGH
   case MachineOperand::MO_MachineRegister:
-    if (MO.getReg() < MRegisterInfo::FirstVirtualRegister)
+    if (MRegisterInfo::isPhysicalRegister(MO.getReg()))
       // Bug Workaround: See note in Printer::doInitialization about %.
       O << "%" << RI.get(MO.getReg()).Name;
     else