[utils] Add a script to update regclass numbers in MIR tests

[jayfoad]

No description provided.

[shiltian]

I'm not really familiar with our rules regarding implementing utils. Do we need it to be in Python for portability? Other than that, this looks good to me.

CC @nikic @tstellar

[s-barannikov]

There aren't so many MIR tests that contain this kind of comment (I counted only 40). Why don't just use update_mir_test_checks.py?

[jayfoad]

There aren't so many MIR tests that contain this kind of comment (I counted only 112 *.mir and 87 *.ll). Why don't just use update_mir_test_checks.py?

This is a different kind of update. It is not just updating CHECK lines, it is also updating the source lines, like (example from #142359):

-    INLINEASM &"; def $0", 1 /* sideeffect attdialect */, 1966090 /* regdef:VGPR_32 */, def $vgpr0
+    INLINEASM &"; def $0", 1 /* sideeffect attdialect */, 2228234 /* regdef:VGPR_32 */, def $vgpr0

[s-barannikov]

I agree with @arsenm here #142359 (comment)

While this script may be useful, it doesn't guarantee the tests don't rot over time. Unless we have an automated way to update them, that is.

[jayfoad]

I agree with @arsenm here #142359 (comment)

Me too, and I would happily remove this script when that suggestion is implemented.

[arsenm]

It's better than nothing

[llvm-ci]

LLVM Buildbot has detected a new failure on builder amdgpu-offload-ubuntu-22-cmake-build-only running on rocm-docker-ubu-22 while building llvm at step 2 "update-annotated-scripts".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/203/builds/17416

Here is the relevant piece of the build log for the reference

Step 2 (update-annotated-scripts) failure: update (failure)
git version 2.34.1
fatal: unable to access 'https://github.com/llvm/llvm-zorg.git/': Could not resolve host: github.com
fatal: unable to access 'https://github.com/llvm/llvm-zorg.git/': Could not resolve host: github.com