Stream: git-wasmtime

Topic: wasmtime / PR #3906 Fix uextend on x64 for non-i32-source...

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2022 at 18:15):

cfallin opened PR #3906 from uextend-sextend-fix to main:

In #3849, I moved uextend over to ISLE in the x64 backend. Unfortunately, the lowering patterns had a bug in the i32-to-i64 special case (when we know the generating instruction zeroes the upper 32 bits): it wasn't actually special casing for an i32 source! This meant that e.g. zero extends of the results of i8 adds did not work properly.

This PR fixes the bug and updates the runtest for extends significantly to cover the narrow-value cases.

No security impact to Wasm as Wasm does not use narrow integer types.

Thanks @bjorn3 for reporting!

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2022 at 18:15):

cfallin requested fitzgen for a review on PR #3906.

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2022 at 18:31):

bjorn3 submitted PR review.

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2022 at 18:49):

fitzgen submitted PR review.

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2022 at 19:11):

cfallin merged PR #3906.

Last updated: Dec 23 2024 at 12:05 UTC