[BOLT] Report flow conservation scores (#127954)

Add two additional profile quality stats for CG (call graph) and CFG
(control flow graph) flow conservations besides the CFG discontinuity
stats introduced in #109683. The two new stats quantify how different
"in-flow" is from "out-flow" in the following cases where they should be
equal. The smaller the reported stats, the better the flow conservations
are.

CG flow conservation: for each function that is not a program entry, the
number of times the function is called according to CG ("in-flow")
should be equal to the number of times the transition from an entry
basic block of the function to another basic block within the function
is recorded ("out-flow").

CFG flow conservation: for each basic block that is not a function entry
or exit, the number of times the transition into this basic block from
another basic block within the function is recorded ("in-flow") should
be equal to the number of times the transition from this basic block to
another basic block within the function is recorded ("out-flow").

Use `-v=1` for more detailed bucketed stats, and use `-v=2` to dump
functions / basic blocks with bad flow conservations.
8 files changed
tree: 2ca1cad34837c23d88cb061d947207fb80cb5edb
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-tidy
  30. .git-blame-ignore-revs
  31. .gitattributes
  32. .gitignore
  33. .mailmap
  34. CODE_OF_CONDUCT.md
  35. CONTRIBUTING.md
  36. LICENSE.TXT
  37. pyproject.toml
  38. README.md
  39. SECURITY.md
README.md

The LLVM Compiler Infrastructure

OpenSSF Scorecard OpenSSF Best Practices libc++

Welcome to the LLVM project!

This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.

C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

Consult the Getting Started with LLVM page for information on building and running LLVM.

For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting in touch

Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.

The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.