Stream: git-wasmtime

Topic: wasmtime / PR #14956 cranelift: aarch64: pass args after ...

view this post on Zulip Wasmtime GitHub notifications bot (Oct 23 2026 at 03:15):

pujitha24 opened PR #14956 from pujitha24:auto/issue-14945 to bytecodealliance:main:

Issue: https://github.com/bytecodealliance/wasmtime/issues/14945

On aarch64, an i128 argument that doesn't fit in the remaining integer registers goes on the stack, but the next-register counter wasn't advanced. A following i64 was then assigned to x7. AAPCS64 C.13 (and clang/gcc, including on Darwin) pass it on the stack. This sets the counter to 8 in that case, for system_v and apple_aarch64 arguments only.

Cranelift-to-Cranelift calls were self-consistent, so this only affects signatures shared with C/Rust code. Wasmtime doesn't pass i128 across calls.

Testing: new cases in isa/aarch64/call.clif (previously compiled to mov x0, x7, now a stack load). The aarch64 and runtests filetest directories pass.

Disclosure: I used an AI tool (Claude) to help prepare this change.

This PR was written in part with the assistance of generative AI.

Fixes #14945

view this post on Zulip Wasmtime GitHub notifications bot (Oct 23 2026 at 03:15):

pujitha24 removed the review request for wasmtime-compiler-reviewers from PR #14956.

view this post on Zulip Wasmtime GitHub notifications bot (Oct 23 2026 at 03:15):

pujitha24 requested cfallin for a review on PR #14956.

view this post on Zulip Wasmtime GitHub notifications bot (Oct 23 2026 at 03:15):

pujitha24 requested wasmtime-compiler-reviewers for a review on PR #14956.

view this post on Zulip Wasmtime GitHub notifications bot (Oct 23 2026 at 05:49):

github-actions[bot] added the label cranelift on PR #14956.

view this post on Zulip Wasmtime GitHub notifications bot (Oct 23 2026 at 05:49):

github-actions[bot] added the label cranelift:area:aarch64 on PR #14956.

view this post on Zulip Wasmtime GitHub notifications bot (Oct 23 2026 at 19:10):

:thumbs_up: cfallin submitted PR review:

Thanks for this fix!

view this post on Zulip Wasmtime GitHub notifications bot (Oct 23 2026 at 19:10):

cfallin added PR #14956 cranelift: aarch64: pass args after a stack-passed i128 on the stack to the merge queue.

view this post on Zulip Wasmtime GitHub notifications bot (Oct 24 2026 at 02:52):

:check: cfallin merged PR #14956.

view this post on Zulip Wasmtime GitHub notifications bot (Oct 24 2026 at 02:52):

cfallin removed PR #14956 cranelift: aarch64: pass args after a stack-passed i128 on the stack from the merge queue.

Last updated: Oct 31 2026 at 23:03 UTC