[PATCH] D116832: [UpdateLLCTestChecks] Allow replacing register names with variables

[David Greene via Phabricator via llvm-commits]

greened added a comment.

In D116832#3257235 <https://reviews.llvm.org/D116832#3257235>, @pengfei wrote:

> What I mainly wanted to demonstrate is there exists such a test generated for other purpose. For a scheduling patch, the unexpected changes of other use and def of %R1 <https://reviews.llvm.org/diffusion/L/> and %R2 <https://reviews.llvm.org/source/clang-tools-extra/> on an unrelated test are confusing.
>
>   ; CHECK-NEXT:    add %[[GPR_1:(%r[0-9]+)]], %[[GPR_2:(%r[0-9]+)]] <== These two lines won't be changed, that's fine.
>   ; CHECK-NEXT:    add %[[GPR_1:(%r[0-9]+)]], %[[GPR_3:(%r[0-9]+)]]
>   ; ... ...
>   ; CHECK-NEXT:    other_use_def %[[GPR_2]] <== These lines will be changed, that's bad.
>   ; CHECK-NEXT:    other_use_def %[[GPR_3]] <== Same here.

Ok, I gotcha.  I think maybe it would be useful to add (in a follow-on patch) the ability to not care about register dependencies at all, so not generate any FileCheck variables and use just pure regular expressions to scrub the register names.  That would give flexibility to allow testing different scenarios.

> So I'm not arguing don't use this tool for number sensitive patches. I'm arguing any test cases generated in this way may confuse future number sensitive patches.
> I agree filtering out unrelated code is a good idea. Then why we still need this patch if we have already filtered them?

Because we might still want to scrub names after filtering.


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