[llvm] [GlobalISel] Add a GISelValueTracker printing pass (PR #139687)

[Matt Arsenault via llvm-commits]

================
@@ -875,20 +875,50 @@ unsigned GISelValueTracking::computeNumSignBits(Register R, unsigned Depth) {
   return computeNumSignBits(R, DemandedElts, Depth);
 }
 
-void GISelValueTrackingAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+void GISelValueTrackingAnalysisLegacy::getAnalysisUsage(
+    AnalysisUsage &AU) const {
   AU.setPreservesAll();
   MachineFunctionPass::getAnalysisUsage(AU);
 }
 
-bool GISelValueTrackingAnalysis::runOnMachineFunction(MachineFunction &MF) {
+bool GISelValueTrackingAnalysisLegacy::runOnMachineFunction(
+    MachineFunction &MF) {
   return false;
 }
 
-GISelValueTracking &GISelValueTrackingAnalysis::get(MachineFunction &MF) {
+GISelValueTracking &GISelValueTrackingAnalysisLegacy::get(MachineFunction &MF) {
   if (!Info) {
     unsigned MaxDepth =
         MF.getTarget().getOptLevel() == CodeGenOptLevel::None ? 2 : 6;
     Info = std::make_unique<GISelValueTracking>(MF, MaxDepth);
   }
   return *Info;
 }
+
+AnalysisKey GISelValueTrackingAnalysis::Key;
+
+GISelValueTracking
+GISelValueTrackingAnalysis::run(MachineFunction &MF,
+                                MachineFunctionAnalysisManager &MFAM) {
+  return Result(MF);
+}
+
+PreservedAnalyses
+GISelValueTrackingPrinterPass::run(MachineFunction &MF,
+                                   MachineFunctionAnalysisManager &MFAM) {
+  auto &VTA = MFAM.getResult<GISelValueTrackingAnalysis>(MF);
+  OS << "name: " << MF.getName() << "\n";
+  for (MachineBasicBlock &BB : MF) {
+    for (MachineInstr &MI : BB) {
+      for (MachineOperand &MO : MI.defs()) {
+        if (!MO.isReg() || MO.getReg().isPhysical())
+          continue;
+        KnownBits Known = VTA.getKnownBits(MO.getReg());
+        unsigned SignedBits = VTA.computeNumSignBits(MO.getReg());
+        OS << "KnownBits:" << Known << " SignBits:" << SignedBits << " for "
+           << MO << "\n";
----------------
arsenm wrote:

```suggestion
           << MO << '\n';
```

https://github.com/llvm/llvm-project/pull/139687