MIR Printer: Use a module slot tracker to print global address operands. NFC.

This commit adopts the 'ModuleSlotTracker' class, which was surfaced in r240842,
to print the global address operands. This change ensures that the slot tracker
won't have to be recreated every time a global address operand is printed,
making the MIR printing more efficient.

llvm-svn: 241645
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index e02f54a..4a66365 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -19,6 +19,7 @@
 #include "llvm/CodeGen/MIRYamlMapping.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/ModuleSlotTracker.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/YAMLTraits.h"
@@ -41,7 +42,7 @@
   void print(const MachineFunction &MF);
 
   void convert(yaml::MachineFunction &MF, const MachineRegisterInfo &RegInfo);
-  void convert(const Module &M, yaml::MachineBasicBlock &YamlMBB,
+  void convert(ModuleSlotTracker &MST, yaml::MachineBasicBlock &YamlMBB,
                const MachineBasicBlock &MBB);
 
 private:
@@ -51,14 +52,14 @@
 /// This class prints out the machine instructions using the MIR serialization
 /// format.
 class MIPrinter {
-  const Module &M;
   raw_ostream &OS;
+  ModuleSlotTracker &MST;
   const DenseMap<const uint32_t *, unsigned> &RegisterMaskIds;
 
 public:
-  MIPrinter(const Module &M, raw_ostream &OS,
+  MIPrinter(raw_ostream &OS, ModuleSlotTracker &MST,
             const DenseMap<const uint32_t *, unsigned> &RegisterMaskIds)
-      : M(M), OS(OS), RegisterMaskIds(RegisterMaskIds) {}
+      : OS(OS), MST(MST), RegisterMaskIds(RegisterMaskIds) {}
 
   void print(const MachineInstr &MI);
   void printMBBReference(const MachineBasicBlock &MBB);
@@ -95,7 +96,7 @@
   convert(YamlMF, MF.getRegInfo());
 
   int I = 0;
-  const auto &M = *MF.getFunction()->getParent();
+  ModuleSlotTracker MST(MF.getFunction()->getParent());
   for (const auto &MBB : MF) {
     // TODO: Allow printing of non sequentially numbered MBBs.
     // This is currently needed as the basic block references get their index
@@ -105,7 +106,7 @@
            "Can't print MBBs that aren't sequentially numbered");
     (void)I;
     yaml::MachineBasicBlock YamlMBB;
-    convert(M, YamlMBB, MBB);
+    convert(MST, YamlMBB, MBB);
     YamlMF.BasicBlocks.push_back(YamlMBB);
   }
   yaml::Output Out(OS);
@@ -119,7 +120,8 @@
   MF.TracksSubRegLiveness = RegInfo.subRegLivenessEnabled();
 }
 
-void MIRPrinter::convert(const Module &M, yaml::MachineBasicBlock &YamlMBB,
+void MIRPrinter::convert(ModuleSlotTracker &MST,
+                         yaml::MachineBasicBlock &YamlMBB,
                          const MachineBasicBlock &MBB) {
   assert(MBB.getNumber() >= 0 && "Invalid MBB number");
   YamlMBB.ID = (unsigned)MBB.getNumber();
@@ -134,7 +136,7 @@
   for (const auto *SuccMBB : MBB.successors()) {
     std::string Str;
     raw_string_ostream StrOS(Str);
-    MIPrinter(M, StrOS, RegisterMaskIds).printMBBReference(*SuccMBB);
+    MIPrinter(StrOS, MST, RegisterMaskIds).printMBBReference(*SuccMBB);
     YamlMBB.Successors.push_back(StrOS.str());
   }
 
@@ -143,7 +145,7 @@
   std::string Str;
   for (const auto &MI : MBB) {
     raw_string_ostream StrOS(Str);
-    MIPrinter(M, StrOS, RegisterMaskIds).print(MI);
+    MIPrinter(StrOS, MST, RegisterMaskIds).print(MI);
     YamlMBB.Instructions.push_back(StrOS.str());
     Str.clear();
   }
@@ -226,10 +228,7 @@
     printMBBReference(*Op.getMBB());
     break;
   case MachineOperand::MO_GlobalAddress:
-    // FIXME: Make this faster - print as operand will create a slot tracker to
-    // print unnamed values for the whole module every time it's called, which
-    // is inefficient.
-    Op.getGlobal()->printAsOperand(OS, /*PrintType=*/false, &M);
+    Op.getGlobal()->printAsOperand(OS, /*PrintType=*/false, MST);
     // TODO: Print offset and target flags.
     break;
   case MachineOperand::MO_RegisterMask: {