php-in-php: GcCollectCyclesStandaloneLlvm — quarantine visit/mark LLVM from GcCollectCyclesRuntime (#15852 phase 2)

[PurHur]

Category

php-in-php · runtime-shrink · php-compiler-strict (standalone AOT cycle scan)

Problem

GcCollectCyclesCollectRuntimeShrinkTest::testEmbedCollectCyclesImplIsThinPhpBridge fails on master: embed JIT routes gc_collect_cycles() through GcCollectCyclesJitHelper::collectCyclesEmbed (PHP visit via visitNativeRegistryObject), but lib/JIT/Builtin/GcCollectCyclesRuntime.php still contains ~500 LOC of standalone LLVM (phpc_gc_visit_object, mark/sweep/inbound) that the shrink test expects quarantined.

php-src reference

• php/php-src Zend/zend_gc.c

PHP implementation target

• New lib/JIT/Builtin/GcCollectCyclesStandaloneLlvm.php — standalone-only cycle scan LLVM
• GcCollectCyclesRuntime.php — embed PHP bridge only; net shrink of phpc_gc_visit_object string + LLVM bodies

Repro / verification

./script/docker-exec.sh -- bash -lc 'vendor/bin/phpunit test/unit/GcCollectCyclesCollectRuntimeShrinkTest.php'
make bootstrap-selfhost-vm-driver-execute-probe

Done when

• GcCollectCyclesCollectRuntimeShrinkTest green (no phpc_gc_visit_object in Runtime)
• GcCollectCyclesRuntimeStandaloneTest + VM gc_collect_cycles repro unchanged
• Net LLVM shrink documented in PR

Related

• Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 · php-in-php: GcCollectCyclesRuntime phase 2 — shrink collect/mark LLVM via GcCollectCyclesJitHelper PHP #15852 · php-in-php: GcCollectCyclesRuntime implementCollectCyclesImpl — route cycle scan LLVM through CycleCollector PHP (#13403 follow-up) #13882

[PurHur]

claim: PHP Runtime → PHP — starting this run (#17015 GcCollectCyclesStandaloneLlvm quarantine).

[PurHur]

Merged via #17016

Shrink: GcCollectCyclesRuntime.php 1742 → 1323 LOC (−419). Standalone visit/mark/sweep LLVM quarantined in GcCollectCyclesStandaloneLlvm.php (516 LOC). Embed path uses GcCollectCyclesJitHelper::collectCyclesEmbed PHP only.

Verification:

• GcCollectCyclesCollectRuntimeShrinkTest — OK (5 tests)
• GcCollectCyclesRuntimeStandaloneTest — OK (2 tests)
• VM gc_collect_cycles() two-node cycle → 2
• make bootstrap-selfhost-vm-driver-execute-probe — OK