Stdlib/JIT: array_udiff/array_uintersect/array_*_u* — native JIT lowering still throws (VM interpreter fallback only)

[PurHur]

Category

stdlib

Problem

User-comparator array builtins registered in #5644 work on VM, and bin/jit.php can produce correct output today via interpreter fallback. However each handler's call() method still throws LogicException('… is VM-only in this compiler build') — e.g. ext/standard/array_udiff.php, array_uintersect.php, array_diff_ukey.php, …

Native JIT lowering is required for self-host/AOT performance and to match other array builtins (usort, array_map closure JIT). Without it, compiled hot paths pay full interpreter dispatch per call.

php-src reference

• php/php-src ext/standard/array.c — array_udiff, array_uintersect, array_diff_uassoc, …
• Pattern: existing lib/JIT/UsortCallbackPolicy.php, ext/standard/uksort_.php closure JIT (Stdlib: usort() / uksort() — JIT Closure and callable comparators (ext/standard/array.c parity) #3597)

Repro

<?php
$a = [1, 2, 3];
$b = [2, 3, 4];
print_r(array_udiff($a, $b, fn ($x, $y) => $x <=> $y));

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php repro.php
php bin/jit.php repro.php
# Inspect: ext/standard/array_udiff.php call() still throws if invoked directly from JIT compile path
grep -n "VM-only" ext/standard/array_udiff.php
'

Builtin	call() today	VM	JIT (2026-06-17)
array_udiff	throws LogicException	OK	OK via fallback
array_uintersect	throws	OK	fallback
array_diff_ukey	throws	OK	fallback

Scope

Path	Work
ext/standard/array_udiff.php, array_uintersect.php, array_diff_u*.php, array_intersect_u*.php	Implement call() using shared JitArrayUserComparator helper
lib/JIT/	New helper modeled on VmArrayUserSetOps + closure/string callback policies
docs/stdlib-jit-audit.md	Regenerate after lowering
Tests	test/compliance/cases/stdlib/array_udiff_jit.phpt — assert native JIT (no interpreter-only marker)

PHP-in-PHP: comparator loop in PHP compiled through normal pipeline; no new runtime/*.c.

Done when

• array_udiff / array_uintersect / array_diff_ukey (minimum batch) implement call() without throwing
• JIT execute compliance green; AOT fixture optional v1
• ./script/ci-fast.sh --filter array_udiff_jit green
• script/audit-stdlib-jit.php no longer lists these as missing/deferred

Links

• Stdlib: array_udiff/array_uintersect/array_diff_u* — user-comparator builtins missing (ext/standard/array.c) #5644 VM registration (closed) · Stdlib: usort() / uksort() — JIT Closure and callable comparators (ext/standard/array.c parity) #3597 usort JIT · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

claim: cursor-agent-lane-c — starting this run

[PurHur]

Merged via #10283.

Fix: array_udiff(), array_uintersect(), and array_diff_ukey() implement native JIT call() via new lib/JIT/JitArrayUserSetOps.php (closure comparator path). No more LogicException('… is VM-only') on the compile path.

Verification:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
grep -n "VM-only" ext/standard/array_udiff.php ext/standard/array_uintersect.php ext/standard/array_diff_ukey.php || echo "no VM-only throws"
vendor/bin/phpunit --filter array_udiff_jit'

→ no VM-only throws, OK (2 tests, 2 assertions) (VM + JIT).

Remaining follow-up (separate issues): other array_*_u* builtins, compile-time strcmp/strcasecmp string callbacks for JIT.