Stdlib: fdiv() — numeric-string coercion + TypeError parity (ext/standard/math.c)

[PurHur]

Category

stdlib

Problem

fdiv() in ext/standard/fdiv.php only accepts int/float operands and throws LogicException for numeric strings and non-scalars. Zend PHP_FUNCTION(fdiv) uses Z_PARAM_DOUBLE: numeric strings coerce; arrays/objects throw TypeError.

php-src reference

• php/php-src ext/standard/math.c — PHP_FUNCTION(fdiv); Z_PARAM_DOUBLE on both operands
• IEEE-754 division: zend_fdiv() in Zend/zend_operators.c

Repro

Save as repro_fdiv.php:

<?php
var_dump(fdiv("6", "2"));
var_dump(fdiv("6.0", 2));
try {
    var_dump(fdiv([], 2));
} catch (Throwable $e) {
    echo get_class($e), ': ', $e->getMessage(), "\n";
}

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php repro_fdiv.php
php bin/vm.php repro_fdiv.php
'

Call	Zend PHP 8.x	This compiler (today)
fdiv("6","2")	float(3)	LogicException
fdiv("6.0", 2)	float(3)	LogicException
fdiv([], 2)	TypeError	LogicException

Scope (this repo)

Area	Files
VM	ext/standard/fdiv.php — toFloat() / operand validation
Shared	ext/standard/VmMath.php — reuse double coercion helper (#4350)
JIT	fdiv::call() — unboxValueToDouble must not return 0.0 for invalid types silently
Tests	test/compliance/cases/stdlib/fdiv_numeric_string.phpt

Done when

• Numeric-string/bool/null operands coerce per Zend Z_PARAM_DOUBLE rules
• Array/object/resource operands throw TypeError (not LogicException)
• JIT/AOT match VM on repro (no silent 0.0 fallback for bad types)
• ./script/ci-fast.sh --filter fdiv green
• docs/capabilities.md matrix unchanged (already VM/JIT/AOT yes)

Links

• Stdlib: floor()/ceil()/round()/fmod() — numeric-string scalar coercion (ext/standard/math.c parity) #4350 (floor/ceil/fmod batch) · Stdlib: pow()/sqrt() — numeric-string scalar coercion (ext/standard/math.c parity) #4359 (pow/sqrt batch) · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

Backlog-architect (2026-06-03): Spec upgraded in issue body — added Category, Scope table, Done-when checklist, and bin/vm.php repro commands. Safe to claim.

[PurHur]

claim: PHP Compiler STD Lib — starting this run

[PurHur]

Merged via #7297.

Verification: VM + JIT repro matches Zend (fdiv("6","2") → float(3), fdiv([],2) → TypeError). ./script/docker-exec.sh -- vendor/bin/phpunit --filter fdiv test/compliance/ → OK (13 tests). php bin/compile.php -l passes on repro.

Implementation: ext/standard/VmMath.php (parseDoubleBuiltinArg), ext/standard/JitFdiv.php (Z_PARAM_DOUBLE lowering; shared with fpow()). php-src: ext/standard/math.c.