Stream: git-wasmtime

Topic: wasmtime / issue #6958 Use `Uimm64` for `UnaryImm::imm` i...

view this post on Zulip Wasmtime GitHub notifications bot (Sep 02 2023 at 21:51):

timjrd opened issue #6958:

Feature

Use Uimm64 for UnaryImm::imm instead of Imm64, since UnaryImm::imm is now always encoding an unsigned integer; following #6850 & #3059.

Benefit

Make it clear that UnaryImm::imm must be interpreted as an unsigned integer; or that it should be reinterpreted as a signed integer if necessary, taking into account the actual bit-length of the encoded value. For example, since #6850, the immediate of iconst.i32 -2 is encoded in UnaryImm::imm as 0xffff_fffe, and not -2, despite being stored in a signed 64-bit integer.

Implementation

Change the type, listen to the complaints of the compiler, and address tests breakage.

I would like to try to address this issue, if it's suitable for a compiler beginner with limited time resource.

Alternatives

Keep using Imm64 since the verifier is already rejecting incorrect encodings.

Last updated: Dec 06 2025 at 06:05 UTC