1799014 - f64x2.max produces incorrect result when 0 compared with -0

Status: RESOLVED FIXED

(Core :: JavaScript: WebAssembly, defect)

Description

[Yury Delendik (:yury)]

The script case below outputs 0,0,0,0,0,0,0,128,0,0,0,0,0,0,0,128:

const wasm = wasmTextToBinary(`(module
  (memory (export "memory") 1 1)
  (func (export "f64x2.max") (param v128 v128) (result v128) (f64x2.max (local.get 0) (local.get 1)))
  (func (export "f")
      i32.const 0
      v128.const f64x2 0.0 0.0
      v128.const f64x2 -0.0 -0.0
      call 0
      v128.store)
)`);
const mod = new WebAssembly.Module(wasm);
const ins = new WebAssembly.Instance(mod);

ins.exports.f();
const mem = ins.exports.memory.buffer;
console.log(new Uint8Array(mem, 0, 16));

Expected all 0

Comment 1

[Yury Delendik (:yury)]

Affects only AVX lowering: works as expected with --no-avx

Comment 2

[Yury Delendik (:yury)]

Attachment: Bug 1799014 - Fix f64x2./f32x4.max for AVX cpus. r?rhunt

Addresses wrong refactoring/optimization of the
minMaxFloat32x4AVX and minMaxFloat64x2AVX functions.

Testing of this case is covered by spec tests.
(Also to be addressed in bug 1797194)

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a2a4b5166fd5
Fix f64x2./f32x4.max for AVX cpus. r=rhunt

Comment 4

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/a2a4b5166fd5