Stream: git-wasmtime

Topic: wasmtime / issue #13988 Memory.atomic.wait instructions f...

Wasmtime GitHub notifications bot (Jul 25 2026 at 20:23):

alexcrichton opened issue #13988:

This test:

(module
  (memory (export "shared") 1 1 shared)

  (func (export "eq32") (result i32)
    (i32.atomic.store (i32.const 0) (i32.const 1))
    (memory.atomic.wait32 (i32.const 0) (i32.const 1) (i64.const 0)))

  (func (export "ne32") (result i32)
    (i32.atomic.store (i32.const 0) (i32.const 1))
    (memory.atomic.wait32 (i32.const 0) (i32.const 0x01000000) (i64.const 0)))

  (func (export "eq64") (result i32)
    (i64.atomic.store (i32.const 8) (i64.const 1))
    (memory.atomic.wait64 (i32.const 8) (i64.const 1) (i64.const 0)))

  (func (export "ne64") (result i32)
    (i64.atomic.store (i32.const 8) (i64.const 1))
    (memory.atomic.wait64 (i32.const 8) (i64.const 0x0100000000000000) (i64.const 0)))
)

(assert_return (invoke "eq32") (i32.const 2))
(assert_return (invoke "ne32") (i32.const 1))
(assert_return (invoke "eq64") (i32.const 2))
(assert_return (invoke "ne64") (i32.const 1))

passes on little-endian hosts:

$ cargo run wast atomic_wait_endianness.wast
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.15s
     Running `/home/alex/code/wasmtime2/target/debug/wasmtime wast atomic_wait_endianness.wast`

and fails on big-endian hosts:

$ cargo run --target s390x-unknown-linux-gnu wast atomic_wait_endianness.wast
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.20s
     Running `qemu-s390x -L /usr/s390x-linux-gnu -E LD_LIBRARY_PATH=/usr/s390x-linux-gnu/lib -E WASMTIME_TEST_NO_HOG_MEMORY=1 /home/alex/code/wasmtime2/target/s390x-unknown-linux-gnu/debug/wasmtime wast atomic_wait_endianness.wast`
Error: failed to run script file 'atomic_wait_endianness.wast'

Caused by:
    0: failed directive on atomic_wait_endianness.wast:21
    1: result 0 didn't match
    2: expected                  2 / 0x0000000000000002
actual                    1 / 0x0000000000000001

Wasmtime GitHub notifications bot (Jul 25 2026 at 20:23):

alexcrichton added the bug label to Issue #13988.

Wasmtime GitHub notifications bot (Jul 25 2026 at 20:23):

alexcrichton added the wasm-proposal:threads label to Issue #13988.

Last updated: Jul 29 2026 at 05:03 UTC