[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:

Just use the IsPreLink flag like you did above for IsCtxProfGen? What happens for regular LTO, which is the other case where IsPreLink could be true? If not supported there then consider adding an assert.

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