[llvm] [ctx_prof] CtxProfAnalysis: populate module data (PR #102930)

[Snehasish Kumar via llvm-commits]

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@@ -81,7 +83,56 @@ CtxProfAnalysis::Result CtxProfAnalysis::run(Module &M,
                              toString(MaybeCtx.takeError()));
     return {};
   }
-  return Result(std::move(*MaybeCtx));
+
+  PGOContextualProfile Result;
+
+  for (const auto &F : M) {
+    if (F.isDeclaration())
+      continue;
+    auto GUID = AssignUniqueIDPass::getGUID(F);
+    assert(GUID && "guid not found for defined function");
+    const auto &Entry = F.begin();
+    uint32_t MaxCounters = 0; // we expect at least a counter.
+    for (const auto &I : *Entry)
+      if (auto *C = dyn_cast<InstrProfIncrementInst>(&I)) {
+        MaxCounters =
+            static_cast<uint32_t>(C->getNumCounters()->getZExtValue());
+        break;
+      }
+    if (!MaxCounters)
+      continue;
+    uint32_t MaxCallsites = 0;
+    for (const auto &BB : F)
+      for (const auto &I : BB)
+        if (auto *C = dyn_cast<InstrProfCallsite>(&I)) {
+          MaxCallsites =
+              static_cast<uint32_t>(C->getNumCounters()->getZExtValue());
+          break;
+        }
+    auto [It, Ins] = Result.FuncInfo.insert(
+        {GUID, PGOContextualProfile::FunctionInfo(F.getName())});
+    (void)Ins;
+    assert(Ins);
+    It->second.NextCallsiteIndex = MaxCallsites;
+    It->second.NextCounterIndex = MaxCounters;
+  }
+  // If we made it this far, the Result is valid - which we mark by setting
+  // .Profiles.
+  // Trim first the roots that aren't in this module.
+  DenseSet<GlobalValue::GUID> ProfiledGUIDs;
+  for (auto &[RootGuid, Tree] : llvm::make_early_inc_range(*MaybeCtx))
----------------
snehasish wrote:

Do you need to check MaybeCtx before deref? 

Also Tree is unused so maybe just `for auto&[RootGuid, Unused]`?

https://github.com/llvm/llvm-project/pull/102930