Stream: git-wasmtime

Topic: wasmtime / issue #2735 Support PLT entries in `cranelift-...

Wasmtime GitHub notifications bot (Oct 01 2021 at 21:25):

akirilov-arm labeled issue #2735:

Feature

JIT for arm64

Benefit

x86 works and it would be nice to be able to use it on M1 mac as well

Implementation

it currently panics here: https://github.com/bytecodealliance/wasmtime/blob/5fecdfa49150e3304c1b949aab73bd4a0a02dbac/cranelift/jit/src/backend.rs#L183-L195 I'm unsure what needs to change/ whats blocking it

Alternatives

only make JIT available on x86

Wasmtime GitHub notifications bot (Oct 01 2021 at 21:31):

akirilov-arm labeled issue #2735:

Feature

JIT for arm64

Benefit

x86 works and it would be nice to be able to use it on M1 mac as well

Implementation

it currently panics here: https://github.com/bytecodealliance/wasmtime/blob/5fecdfa49150e3304c1b949aab73bd4a0a02dbac/cranelift/jit/src/backend.rs#L183-L195 I'm unsure what needs to change/ whats blocking it

Alternatives

only make JIT available on x86

Wasmtime GitHub notifications bot (Oct 01 2021 at 21:38):

akirilov-arm commented on issue #2735:

Issue #2907 is related to this.

Wasmtime GitHub notifications bot (Feb 28 2025 at 19:24):

Somfic commented on issue #2735:

hi, are there any updates on this? i’m running into

PLT is currently only supported on x86_64

with use_colocated_libcalls and is_pic flags in my isa set to false

Wasmtime GitHub notifications bot (Feb 28 2025 at 19:45):

cfallin commented on issue #2735:

@Somfic no, this issue hasn't been worked on. PRs welcome if you're interested in tackling it!

Wasmtime GitHub notifications bot (Feb 28 2025 at 19:49):

Somfic commented on issue #2735:

@Somfic no, this issue hasn't been worked on. PRs welcome if you're interested in tackling it!

@cfallin I wish I had the technical knowledge to contribute.

As mentioned earlier in this issue thread, setting is_pic to false should disable PLT entries for aarch64, but it doesn't? Is this a bug or intented behaviour?

Wasmtime GitHub notifications bot (Feb 28 2025 at 19:54):

cfallin commented on issue #2735:

cc @bjorn3 -- I don't know the PLT functionality well enough to say, sorry.

Wasmtime GitHub notifications bot (Mar 05 2025 at 19:45):

bjorn3 commented on issue #2735:

It is used for the hot code swapping functionality of cranelift-jit that I introduced for cg_clif. I've removed hot code swapping support in https://github.com/rust-lang/rustc_codegen_cranelift/commit/5d03df9431833ad992c1507fedc7daee3e232443. I might reintroduce it at some point, but will likely do so by replacing cranelift-jit usage entirely. Because of this and the fact that it reduces portability of cranelift-jit I did propose removing the hot code swapping support from cranelift-jit.

Wasmtime GitHub notifications bot (Mar 06 2025 at 16:09):

bjorn3 commented on issue #2735:

With https://github.com/bytecodealliance/wasmtime/pull/10345 cranelift-jit should work if you set is_pic=false in your TargetIsa. In a future PR I plan to enforce is_pic=false and remove all the PIC handling code that doesn't work on non-x86_64 targets.

Wasmtime GitHub notifications bot (Mar 06 2025 at 16:16):

bjorn3 edited a comment on issue #2735:

With https://github.com/bytecodealliance/wasmtime/pull/10345 cranelift-jit should work if you set is_pic=false in your TargetIsa. In a future PR I plan to enforce is_pic=false and remove all the PIC handling code that doesn't work on non-x86_64 targets. I've already created a branch remove_cranelift_jit_pic_handling for that.

Wasmtime GitHub notifications bot (Mar 20 2025 at 19:25):

abrown closed issue #2735:

Feature

JIT for arm64

Benefit

x86 works and it would be nice to be able to use it on M1 mac as well

Implementation

it currently panics here: https://github.com/bytecodealliance/wasmtime/blob/5fecdfa49150e3304c1b949aab73bd4a0a02dbac/cranelift/jit/src/backend.rs#L183-L195 I'm unsure what needs to change/ whats blocking it

Alternatives

only make JIT available on x86

Last updated: Apr 18 2025 at 18:04 UTC