[llvm] [LTO] Introduce a helper function collectImportStatistics (NFC) (PR #106179)

[Jan Voung via llvm-commits]

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@@ -1217,21 +1225,19 @@ void llvm::ComputeCrossModuleImport(
     auto ModName = ModuleImports.first;
     auto &Exports = ExportLists[ModName];
     unsigned NumGVS = numGlobalVarSummaries(Index, Exports);
+    DenseMap<StringRef, ImportStatistics> Histogram =
+        collectImportStatistics(Index, ModuleImports.second);
     LLVM_DEBUG(dbgs() << "* Module " << ModName << " exports "
                       << Exports.size() - NumGVS << " functions and " << NumGVS
-                      << " vars. Imports from "
-                      << ModuleImports.second.getImportMap().size()
+                      << " vars. Imports from " << Histogram.size()
                       << " modules.\n");
-    for (const auto &Src : ModuleImports.second.getImportMap()) {
-      auto SrcModName = Src.first;
-      unsigned DefinedFS = 0;
-      unsigned NumGVSPerMod =
-          numGlobalVarSummaries(Index, Src.second, DefinedFS);
-      LLVM_DEBUG(dbgs() << " - " << DefinedFS << " function definitions and "
-                        << Src.second.size() - NumGVSPerMod - DefinedFS
+    for (const auto &[SrcModName, Summary] : Histogram) {
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jvoung wrote:

small nit -- update the local variable names from "Summary" too?

https://github.com/llvm/llvm-project/pull/106179