Stream: git-wasmtime

Topic: wasmtime / PR #11038 x64: Delete the `Imm` instruction va...

Wasmtime GitHub notifications bot (Jun 13 2025 at 17:49):

alexcrichton requested abrown for a review on PR #11038.

Wasmtime GitHub notifications bot (Jun 13 2025 at 17:49):

alexcrichton opened PR #11038 from alexcrichton:x64-no-imm to bytecodealliance:main:

This commit deletes the Imm instruction variant in ISLE in favor of preexisting instructions already added to the new assembler. This required rejiggering and refactoring the imm constructor in ISLE and refactoring the Inst::imm method as well.

One minor change in this PR is that the immediate u64::from(u32::MAX) was mistakenly classified previously as requiring movabsq but after this PR it's now classified as being able to use movl because the upper bits are zero'd with movl. This was an off-by-one mistake in the nonzero_u64_fits_in_u32 extractor that was deleted in this PR.

This change also documents the preexisting behavior of the imm constructor and the Inst::imm helper which is to zero the upper bits of the 64-bit immediate passed in to those functions if the desired size is less than 64-bits. This is something I would prefer to avoid because it means the logical value of the immediate is not being preserved which could be a way to possibly subtly introduce bugs in the future. For now though more widespread changes would be needed to fix this so they're omitted.

<!--
Please make sure you include the following information:

• If this work has been discussed elsewhere, please include a link to that
  conversation. If it was discussed in an issue, just mention "issue #...".

• Explain why this change is needed. If the details are in an issue already,
  this can be brief.

Our development process is documented in the Wasmtime book:
https://docs.wasmtime.dev/contributing-development-process.html

Please ensure all communication follows the code of conduct:
https://github.com/bytecodealliance/wasmtime/blob/main/CODE_OF_CONDUCT.md
-->

Wasmtime GitHub notifications bot (Jun 13 2025 at 17:49):

alexcrichton requested wasmtime-compiler-reviewers for a review on PR #11038.

Wasmtime GitHub notifications bot (Jun 13 2025 at 18:04):

alexcrichton updated PR #11038.

Wasmtime GitHub notifications bot (Jun 13 2025 at 18:24):

alexcrichton requested dicej for a review on PR #11038.

Wasmtime GitHub notifications bot (Jun 13 2025 at 18:24):

alexcrichton updated PR #11038.

Wasmtime GitHub notifications bot (Jun 13 2025 at 18:24):

alexcrichton requested wasmtime-core-reviewers for a review on PR #11038.

Wasmtime GitHub notifications bot (Jun 13 2025 at 20:46):

github-actions[bot] commented on PR #11038:

Subscribe to Label Action

cc @cfallin, @fitzgen

<details>
This issue or pull request has been labeled: "cranelift", "cranelift:area:x64", "isle"

Thus the following users have been cc'd because of the following labels:

• cfallin: isle
• fitzgen: isle

To subscribe or unsubscribe from this label, edit the <code>.github/subscribe-to-label.json</code> configuration file.

Learn more.
</details>

Wasmtime GitHub notifications bot (Jun 16 2025 at 17:17):

abrown submitted PR review.

Wasmtime GitHub notifications bot (Jun 16 2025 at 17:46):

abrown merged PR #11038.

Last updated: Dec 06 2025 at 06:05 UTC