[llvm] [MCA] New option to report scheduling information: -scheduling-info (PR #126703)

[Julien Villette via llvm-commits]

jvillette38 wrote:

> There's a few things going on here. I can see value in some of the extra info alongside the instruction like bypass latency/resources/LLVM OpcodeName, but this could be added to the existing `-instruction-info` view if there's agreement this is useful?
> 
> For the reference, why not just make the CHECK lines in a test like `llvm/test/tools/llvm-mca/AArch64/Neoverse/V1-basic-instructions.s` be the reference? It would have to be XFAIL'ed until the model matched the reference, but any difference would be obvious looking at the diff after running the update script.

Thanks for the review.
I can add this information in InstructionInfoView:
```
[3]: Bypass Latency
[4]: Throughput
[5]: Resources
[6]: LLVM OpcodeName
[7]: Instruction
[8]: Comment if any
```

I can let reverse throughput instead of throughput (it was easier to compare with documentation). The goal was to have an easy way to compare llvm scheduling information with documentation/llvm-exegesis and be able to fix llvm target description with  LLVM opcode name.

Note: If I do these changes in InstructionInfoView, it will modify all tests that use this view.
Are you agree with that?

My point was to extract scheduling information from documentation or llvm-exegesis to get a reference and then fix easily llvm scheduling information in target description (I have done that by using Software Optimization Guide). l should use llvm-exegesis in second time.
So It is possible to use comments with scheduling information from documentation/llvm-exegesis during update of target description (scripts help to check differences) and then we can remove them when pushing updates.

https://github.com/llvm/llvm-project/pull/126703