Stream: git-wasmtime

Topic: wasmtime / issue #15057 Cranelift: Can't distinguish betw...

Wasmtime GitHub notifications bot (Oct 29 2026 at 11:17):

bjorn3 opened issue #15057:

.clif Test Case

use std::arch::aarch64::uint64x1_t;
pub fn lane(_a: u8, b: uint64x1_t) -> uint64x1_t {
    b
}

Steps to Reproduce

• Compile with cg_clif

Expected Results

b is passed in a vector register.

Actual Results

b is passed in an integer register as I64.by(1) returns i64 as type rather than a i64x1 vector type.

Versions and Environment

Cranelift version or commit: 0.137

Operating system: Linux

Architecture: arm64

Extra Info

Originally reported at https://github.com/rust-lang/rustc_codegen_cranelift/issues/1718

Wasmtime GitHub notifications bot (Oct 29 2026 at 11:17):

bjorn3 added the bug label to Issue #15057.

Wasmtime GitHub notifications bot (Oct 29 2026 at 11:17):

bjorn3 added the cranelift label to Issue #15057.

Wasmtime GitHub notifications bot (Oct 29 2026 at 11:17):

bjorn3 edited issue #15057:

.clif Test Case

use std::arch::aarch64::uint64x1_t;
#[unsafe(no_mangle)]
fn lane(_a: u8, b: uint64x1_t) -> uint64x1_t {
    b
}

Steps to Reproduce

• Compile with cg_clif

Expected Results

b is passed in a vector register.

Actual Results

b is passed in an integer register as I64.by(1) returns i64 as type rather than a i64x1 vector type.

Versions and Environment

Cranelift version or commit: 0.137

Operating system: Linux

Architecture: arm64

Extra Info

Originally reported at https://github.com/rust-lang/rustc_codegen_cranelift/issues/1718

Wasmtime GitHub notifications bot (Oct 29 2026 at 11:22):

bjorn3 edited issue #15057:

.clif Test Case

use std::arch::aarch64::uint64x1_t;
#[unsafe(no_mangle)]
extern "C" fn lane(_a: u8, b: uint64x1_t) -> uint64x1_t {
    b
}

Steps to Reproduce

• Compile with cg_clif

Expected Results

b is passed in a vector register.

Actual Results

b is passed in an integer register as I64.by(1) returns i64 as type rather than a i64x1 vector type.

Versions and Environment

Cranelift version or commit: 0.137

Operating system: Linux

Architecture: arm64

Extra Info

Originally reported at https://github.com/rust-lang/rustc_codegen_cranelift/issues/1718

Last updated: Oct 31 2026 at 23:03 UTC