1803043 - Implement remaining instructions for wasm-gc via Ion

Status: RESOLVED FIXED

(Core :: JavaScript: WebAssembly, enhancement)

Description

[Julian Seward [:jseward]]

Bug 1797933 implemented various wasm-gc struct insns via Ion, and bug 1799856
implements various array insns. This bug is for implementation of all
remaining un-implemented insns, which are believed to be:

  br_on_cast           br_on_cast_fail
  extern.internalize   extern.externalize
  ref.eq               ref.test
  struct.new_default

Comment 1

[Julian Seward [:jseward]]

Attachment: Bug 1803043 - Implement remaining instructions for wasm-gc via Ion. r=rhunt.

This patch implements the following instructions for wasm-gc via Ion:

• struct.new_default (mistakenly omitted from bug 1797933)

• br_on_cast, br_on_cast_fail

• extern.internalize, extern.externalize

• ref.eq, ref.test

These are all pretty straightforwardly derived from their baseline
equivalents. Changes:

• many test cases: remove the guard || wasmCompileMode().includes("ion")

• tests/wasm/gc/br-on-cast{,-fail}.js: add another test that seems necessary
  given the Ion implementation of these

• class MTest: remove a trivial constructor-wrapper for the case trueBranch
  being null, since that makes it impossible to create another wrapper for the
  case falseBranch being null (they would have the same signature). Fix up
  the (very few) use points accordingly.

• new routines FunctionCompiler::refTest, ::brOnCastCommon, to generate MIR
  for those insns.

• new routines EmitStructNewDefault, EmitRefTest, EmitBrOnCastCommon,
  EmitExternInternalize, EmitExternExternalize.

• for the existing implementation of ref.eq, change the expected argument
  type from RefType::extern_() to RefType::eq(). This makes it consistent
  with the baseline implementation; without that some test cases are
  incorrectly rejected by validation.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d83f51f4f606
Implement remaining instructions for wasm-gc via Ion.  r=rhunt.

Comment 3

[Sandor Molnar]

https://hg.mozilla.org/mozilla-central/rev/d83f51f4f606