llvm-project

172f6ddf - [memprof] Add Version2 of the indexed MemProf format (#89100)

[memprof] Add Version2 of the indexed MemProf format (#89100) This patch adds Version2 of the indexed MemProf format. The new format comes with a hash table from CallStackId to actual call stacks llvm::SmallVector<FrameId>. The rest of the format refers to call stacks with CallStackId. This "values + references" model effectively deduplicates call stacks. Without this patch, a large indexed memprof file of mine shrinks from 4.4GB to 1.6GB, a 64% reduction. This patch does not make Version2 generally available yet as I am planning to make a few more changes to the format.