[llvm] [llvm-profgen] Improve sample profile density (PR #92144)

[via llvm-commits]

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@@ -76,13 +76,16 @@ static cl::opt<int, true> CSProfMaxContextDepth(
     cl::location(llvm::sampleprof::CSProfileGenerator::MaxContextDepth));
 
 static cl::opt<double> HotFunctionDensityThreshold(
-    "hot-function-density-threshold", llvm::cl::init(1000),
-    llvm::cl::desc(
-        "specify density threshold for hot functions (default: 1000)"),
+    "hot-function-density-threshold", llvm::cl::init(20),
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WenleiHe wrote:

The switch name is also no longer accurate, since we are no longer selecting the top N functions. Perhaps `profile-density-threshold` is good enough. 

https://github.com/llvm/llvm-project/pull/92144