Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM

Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp
index fbf81c2..44d0233 100644
--- a/llvm/lib/CodeGen/RegAllocFast.cpp
+++ b/llvm/lib/CodeGen/RegAllocFast.cpp
@@ -455,7 +455,7 @@
   if (MO.isUndef())
     return;
 
-  unsigned PhysReg = MO.getReg();
+  Register PhysReg = MO.getReg();
   assert(Register::isPhysicalRegister(PhysReg) && "Bad usePhysReg operand");
 
   markRegUsedInInstr(PhysReg);
@@ -645,7 +645,7 @@
   unsigned C = 0;
   for (const MachineInstr &MI : MRI->def_instructions(VirtReg)) {
     if (isCoalescable(MI)) {
-      unsigned Reg = MI.getOperand(1).getReg();
+      Register Reg = MI.getOperand(1).getReg();
       Reg = traceCopyChain(Reg);
       if (Reg != 0)
         return Reg;
@@ -750,7 +750,7 @@
 
 void RegAllocFast::allocVirtRegUndef(MachineOperand &MO) {
   assert(MO.isUndef() && "expected undef use");
-  unsigned VirtReg = MO.getReg();
+  Register VirtReg = MO.getReg();
   assert(Register::isVirtualRegister(VirtReg) && "Expected virtreg");
 
   LiveRegMap::const_iterator LRI = findLiveVirtReg(VirtReg);
@@ -889,7 +889,7 @@
   SmallSet<unsigned, 8> ThroughRegs;
   for (const MachineOperand &MO : MI.operands()) {
     if (!MO.isReg()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Register::isVirtualRegister(Reg))
       continue;
     if (MO.isEarlyClobber() || (MO.isUse() && MO.isTied()) ||
@@ -904,7 +904,7 @@
   LLVM_DEBUG(dbgs() << "\nChecking for physdef collisions.\n");
   for (const MachineOperand &MO : MI.operands()) {
     if (!MO.isReg() || !MO.isDef()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Reg || !Register::isPhysicalRegister(Reg))
       continue;
     markRegUsedInInstr(Reg);
@@ -919,7 +919,7 @@
   for (unsigned I = 0, E = MI.getNumOperands(); I != E; ++I) {
     MachineOperand &MO = MI.getOperand(I);
     if (!MO.isReg()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Register::isVirtualRegister(Reg))
       continue;
     if (MO.isUse()) {
@@ -945,7 +945,7 @@
   for (unsigned I = 0, E = MI.getNumOperands(); I != E; ++I) {
     const MachineOperand &MO = MI.getOperand(I);
     if (!MO.isReg()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Register::isVirtualRegister(Reg))
       continue;
     if (!MO.isEarlyClobber())
@@ -960,7 +960,7 @@
   UsedInInstr.clear();
   for (const MachineOperand &MO : MI.operands()) {
     if (!MO.isReg() || (MO.isDef() && !MO.isEarlyClobber())) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Reg || !Register::isPhysicalRegister(Reg))
       continue;
     LLVM_DEBUG(dbgs() << "\tSetting " << printReg(Reg, TRI)
@@ -1043,7 +1043,7 @@
       continue;
     }
     if (!MO.isReg()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Reg) continue;
     if (Register::isVirtualRegister(Reg)) {
       VirtOpEnd = i+1;
@@ -1094,7 +1094,7 @@
   for (unsigned I = 0; I != VirtOpEnd; ++I) {
     MachineOperand &MO = MI.getOperand(I);
     if (!MO.isReg()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Register::isVirtualRegister(Reg))
       continue;
     if (MO.isUse()) {
@@ -1123,7 +1123,7 @@
     for (MachineOperand &MO : MI.uses()) {
       if (!MO.isReg() || !MO.isUse())
         continue;
-      unsigned Reg = MO.getReg();
+      Register Reg = MO.getReg();
       if (!Register::isVirtualRegister(Reg))
         continue;
 
@@ -1138,7 +1138,7 @@
   if (hasEarlyClobbers) {
     for (const MachineOperand &MO : MI.operands()) {
       if (!MO.isReg()) continue;
-      unsigned Reg = MO.getReg();
+      Register Reg = MO.getReg();
       if (!Reg || !Register::isPhysicalRegister(Reg))
         continue;
       // Look for physreg defs and tied uses.
@@ -1166,7 +1166,7 @@
     const MachineOperand &MO = MI.getOperand(I);
     if (!MO.isReg() || !MO.isDef() || !MO.getReg() || MO.isEarlyClobber())
       continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
 
     if (!Reg || !Register::isPhysicalRegister(Reg) || !MRI->isAllocatable(Reg))
       continue;
@@ -1179,7 +1179,7 @@
     const MachineOperand &MO = MI.getOperand(I);
     if (!MO.isReg() || !MO.isDef() || !MO.getReg() || MO.isEarlyClobber())
       continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
 
     // We have already dealt with phys regs in the previous scan.
     if (Register::isPhysicalRegister(Reg))
@@ -1214,7 +1214,7 @@
   // mostly constants and frame indices.
   if (!MO.isReg())
     return;
-  unsigned Reg = MO.getReg();
+  Register Reg = MO.getReg();
   if (!Register::isVirtualRegister(Reg))
     return;