[llvm] [OptBisect] Add function filtering support to opt-bisect (PR #222123)

[Nikita Popov via llvm-commits]

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@@ -86,15 +86,24 @@ static cl::list<std::string> OptDisablePasses(
     }),
     cl::desc("Optimization pass(es) to disable (comma-separated list)"));
 
+static cl::list<std::string> OptBisectFuncsList(
+    "opt-bisect-funcs", cl::value_desc("function names"), cl::CommaSeparated,
+    cl::cb<void, std::string>([](const std::string &FuncName) {
+      getOptBisector().setEnabledFunc(FuncName);
+    }),
+    cl::Hidden,
+    cl::desc("Only perform opt bisect for functions that are included in this "
+             "list and if empty, apply to all functions."));
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nikic wrote:

I'm confused, at least in that the option description does not seem to match the implementation?

If you do `-opt-bisect-funcs=foo` what is *supposed* to happen with the non-foo functions? Based on the description, I would have assumed that all optimizations would run as usual for those, as opt-bisect is not applied to them. But from reading your tests, it seems like the behavior is actually the opposite and *all* optimizations for functions not in the list are disabled?

https://github.com/llvm/llvm-project/pull/222123