[AMDGPU] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 310541
diff --git a/llvm/lib/Target/AMDGPU/GCNRegPressure.h b/llvm/lib/Target/AMDGPU/GCNRegPressure.h
index 5dfe440..32a199d 100644
--- a/llvm/lib/Target/AMDGPU/GCNRegPressure.h
+++ b/llvm/lib/Target/AMDGPU/GCNRegPressure.h
@@ -1,4 +1,4 @@
-//===---------------------- GCNRegPressure.h -*- C++ -*--------------------===//
+//===- GCNRegPressure.h -----------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -6,20 +6,26 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-/// \file
-//
-//===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_TARGET_AMDGPU_GCNREGPRESSURE_H
 #define LLVM_LIB_TARGET_AMDGPU_GCNREGPRESSURE_H
 
 #include "AMDGPUSubtarget.h"
-
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/SlotIndexes.h"
+#include "llvm/MC/LaneBitmask.h"
+#include "llvm/Support/Debug.h"
+#include <algorithm>
 #include <limits>
 
 namespace llvm {
 
+class MachineRegisterInfo;
+class raw_ostream;
+
 struct GCNRegPressure {
   enum RegKind {
     SGPR32,
@@ -68,7 +74,7 @@
     return !(*this == O);
   }
 
-  void print(raw_ostream &OS, const SISubtarget *ST=nullptr) const;
+  void print(raw_ostream &OS, const SISubtarget *ST = nullptr) const;
   void dump() const { print(dbgs()); }
 
 private:
@@ -89,7 +95,7 @@
 
 class GCNRPTracker {
 public:
-  typedef DenseMap<unsigned, LaneBitmask> LiveRegSet;
+  using LiveRegSet = DenseMap<unsigned, LaneBitmask>;
 
 protected:
   const LiveIntervals &LIS;
@@ -97,7 +103,9 @@
   GCNRegPressure CurPressure, MaxPressure;
   const MachineInstr *LastTrackedMI = nullptr;
   mutable const MachineRegisterInfo *MRI = nullptr;
+
   GCNRPTracker(const LiveIntervals &LIS_) : LIS(LIS_) {}
+
 public:
   // live regs for the current state
   const decltype(LiveRegs) &getLiveRegs() const { return LiveRegs; }
@@ -111,9 +119,11 @@
     MaxPressure.clear();
     return Res;
   }
+
   decltype(LiveRegs) moveLiveRegs() {
     return std::move(LiveRegs);
   }
+
   static void printLiveRegs(raw_ostream &OS, const LiveRegSet& LiveRegs,
                             const MachineRegisterInfo &MRI);
 };
@@ -121,6 +131,7 @@
 class GCNUpwardRPTracker : public GCNRPTracker {
 public:
   GCNUpwardRPTracker(const LiveIntervals &LIS_) : GCNRPTracker(LIS_) {}
+
   // reset tracker to the point just below MI
   // filling live regs upon this point using LIS
   void reset(const MachineInstr &MI, const LiveRegSet *LiveRegs = nullptr);
@@ -202,6 +213,6 @@
                   const LiveIntervals &LIS,
                   const MachineRegisterInfo &MRI);
 
-} // End namespace llvm
+} // end namespace llvm
 
 #endif // LLVM_LIB_TARGET_AMDGPU_GCNREGPRESSURE_H