[llvm] [MemProf] Prune unneeded non-cold contexts (PR #124823)

[Snehasish Kumar via llvm-commits]

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@@ -51,6 +51,13 @@ cl::opt<bool> MemProfReportHintedSizes(
     "memprof-report-hinted-sizes", cl::init(false), cl::Hidden,
     cl::desc("Report total allocation sizes of hinted allocations"));
 
+// This is useful if we have enabled reporting of hinted sizes, and want to get
+// information from the indexing step for all contexts (especially for testing),
+// or have specified a value less than 100% for -memprof-cloning-cold-threshold.
+cl::opt<bool> MemProfKeepAllNotColdContexts(
+    "memprof-keep-all-not-cold-contexts", cl::init(false), cl::Hidden,
+    cl::desc("Disable pruning of non-cold contexts unneeded for cold cloning"));
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snehasish wrote:

nit: The current description is a bit hard to parse how about "Keep all non-cold contexts (increases cloning overheads)" instead of the current description. 

Also should the default be `true` (existing behaviour) since internal users set `-memprof-cloning-cold-threshold` to less than 100?

https://github.com/llvm/llvm-project/pull/124823