Support ldelem.u8, ldelem.u opcode aliases

[brianrourkeboll]

Description

Fixes #18066.

Followup to #17067, etc.

• Support ldelem.u8, ldelem.u opcode aliases.

Checklist

• Test cases added.
• Release notes entry updated.

[github-actions]

❗ Release notes required

---

✅ Found changes and release notes in following paths:

Change path	Release notes path	Description
src/Compiler	docs/release-notes/.FSharp.Compiler.Service/9.0.200.md

[T-Gro]

This matches the translations which we have elsewhere. I would prefer if we made ldelem.u8 work (as an alias to the same bytecode which ldelem.i8 uses), but I cannot asses where else this could resurface.
It is supported in the ASCII representation of IL as well as the mapping in the compiler codebase:

fsharp/src/Compiler/AbstractIL/ilascii.fs

Lines 93 to 96 in 7526d75

	[ "ldelem"; "i4" ], I_ldelem DT_I4
	[ "ldelem"; "i8" ], I_ldelem DT_I8
	[ "ldelem"; "u8" ], I_ldelem DT_I8
	[ "ldelem"; "u1" ], I_ldelem DT_U1

https://en.wikipedia.org/wiki/List_of_CIL_instructions

We also do support this aliasing for stelem, just missing for ldelem:

fsharp/src/Compiler/AbstractIL/ilwrite.fs

Lines 2018 to 2023 in 7526d75

	| DT_I2 | DT_U2 -> i_stelem_i2
	| DT_I4 | DT_U4 -> i_stelem_i4
	| DT_I8 | DT_U8 -> i_stelem_i8
	| DT_R4 -> i_stelem_r4
	| DT_R8 -> i_stelem_r8
	| DT_REF -> i_stelem_ref

Maybe that's a better way to fix it?
(so that future contributors emitting I_ldelem DT_U8 will not experience the same problem?)

[brianrourkeboll]

Maybe that's a better way to fix it?
(so that future contributors emitting I_ldelem DT_U8 will not experience the same problem?)

Good idea.

[psfinaki]

Thanks for the quick fix!

[T-Gro]

/backport to release/dev17.12

[github-actions]

Started backporting to release/dev17.12: https://github.com/dotnet/fsharp/actions/runs/12118597396

[github-actions]

@T-Gro backporting to release/dev17.12 failed, the patch most likely resulted in conflicts:

$ git am --3way --empty=keep --ignore-whitespace --keep-non-patch changes.patch

Applying: Emit `ldelem.i8`, `ldelem.i`, etc.
Applying: Update release notes
Using index info to reconstruct a base tree...
A	docs/release-notes/.FSharp.Compiler.Service/9.0.200.md
Falling back to patching base and 3-way merge...
CONFLICT (modify/delete): docs/release-notes/.FSharp.Compiler.Service/9.0.200.md deleted in HEAD and modified in Update release notes. Version Update release notes of docs/release-notes/.FSharp.Compiler.Service/9.0.200.md left in tree.
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config advice.mergeConflict false"
Patch failed at 0002 Update release notes
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[github-actions]

@T-Gro an error occurred while backporting to release/dev17.12, please check the run log for details!

Error: git am failed, most likely due to a merge conflict.