[llvm] [WPD]: Enable speculative devirtualizatoin. (PR #159048)

[Teresa Johnson via llvm-commits]

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@@ -790,11 +812,22 @@ struct DevirtIndex {
 PreservedAnalyses WholeProgramDevirtPass::run(Module &M,
                                               ModuleAnalysisManager &MAM) {
   if (UseCommandLine) {
-    if (!DevirtModule::runForTesting(M, MAM))
+    if (!DevirtModule::runForTesting(M, MAM, ClDevirtualizeSpeculatively))
       return PreservedAnalyses::all();
     return PreservedAnalyses::none();
   }
-  if (!DevirtModule(M, MAM, ExportSummary, ImportSummary).run())
+
+  std::optional<ModuleSummaryIndex> Index;
+  if (!ExportSummary && !ImportSummary && DevirtSpeculatively) {
+    // Build the ExportSummary from the module.
+    assert(!ExportSummary &&
+           "ExportSummary is expected to be empty in non-LTO mode");
+    ProfileSummaryInfo PSI(M);
+    Index.emplace(buildModuleSummaryIndex(M, nullptr, &PSI));
+    ExportSummary = Index.has_value() ? &Index.value() : nullptr;
+  }
+  if (!DevirtModule(M, MAM, ExportSummary, ImportSummary, DevirtSpeculatively)
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teresajohnson wrote:

I don't think DevirtSpeculatively is set by this PR, as mentioned above.

https://github.com/llvm/llvm-project/pull/159048