Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

`pass` test failures on 32-bit systems

Open
#8,366 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
cmake, python, wasm

Research direction

Reproduce the failure with the provided CMake, Ninja, and check.py commands, then inspect passes/O_fast-math.wast and passes/optimize-instructions-mvp.wast, focusing on their NaN CHECK lines. Done means both pass tests produce the expected NaN values on a 32-bit build.

Written by the indexing model from the issue text.

Description

When running

cmake -G Ninja -DCMAKE_CXX_FLAGS="-m32" -DCMAKE_C_FLAGS="-m32" -DCMAKE_BUILD_TYPE=Debug .
ninja
python3 check.py lit

I get test failures in passes/O_fast-math.wast and passes/optimize-instructions-mvp.wast. Both tests give the wrong NaN:

$ "filecheck" "/usr/local/google/home/stevenfont/code/binaryen/test/lit/passes/O_fast-math.wast"
# command output:
/usr/local/google/home/stevenfont/code/binaryen/test/lit/passes/O_fast-math.wast:41:17: error: CHECK-NEXT: expected string not found in input
 ;; CHECK-NEXT: (f32.const -nan:0x23017a)
                ^
<stdin>:19:1: note: scanning from here
  (f32.const -nan:0x63017a)
^

error: command failed with exit status: 1
Dominant language
WebAssembly
Stars
8.6k
Forks
885
Avg merge
2d 1h
Merged PRs (30d)
70

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from WebAssembly/binaryen

All issues in WebAssembly/binaryen

Similar issues

More Compilers issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.