[llvm-profgen] Support COFF binary for llvm-profgen

Beginners
1

Hi all,
As we know llvm-profgen is able to generate pgo profile data file with perf-script containing LBR records collected by Linux perf tool. Previously, only Linux perf tool can generate perf script, so llvm-profgen only supports ELF binary.
Recently, Intel Vtune/SEP has supported collecting LBR on Windows and generating perf-script file which is same format as Linux perf script. See link. I’m planning to make llvm-profgen support COFF format so that we can do Sampling based PGO on Windows.

2

Hi @HaohaiWen! This sounds fantastic if this gives us a path to collecting LBR and using that in compilations on Windows, something that has been lacking.

Hopefully if this works out, it could be the base for BOLT/COFF as well.

I am not someone that can review this, but I will be cheering it on :slight_smile:

3

This is the patch: [llvm-profgen] Support COFF binary by HaohaiWen · Pull Request #83972 · llvm/llvm-project · GitHub
Suggestions are welcome :slight_smile: