[llvm] [ctx_prof] "Use" support for pre-thinlink. (PR #101338)

[Teresa Johnson via llvm-commits]

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@@ -1176,8 +1180,11 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
   // Enable contextual profiling instrumentation.
   const bool IsCtxProfGen = !IsPGOInstrGen && IsPreLink &&
                             PGOCtxProfLoweringPass::isContextualIRPGOEnabled();
+  const bool IsCtxProfUse = !UseCtxProfile.empty() && !PGOOpt &&
+                            Phase == ThinOrFullLTOPhase::ThinLTOPreLink;
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teresajohnson wrote:

Yes I think it means essentially not post link. But I'm wondering why you check IsPreLink for IsCtxProfGen above and the more restrictive check here.

https://github.com/llvm/llvm-project/pull/101338