[ext/standard] Specialize min()/max() for numeric arrays

[mehmetcansahin]

Summary

This specializes the array-form min() / max() path for numeric arrays.

The fast path compares homogeneous IS_LONG and IS_DOUBLE values directly. If the array is empty or the first value is not numeric, execution falls back to the existing zend_hash_minmax() path. If a mixed value is encountered after a numeric prefix, comparison switches back to the existing php_data_compare() semantics for the rest of the scan. NaN-sensitive double cases are handed to the generic comparison path to preserve existing ordering behavior.

For arrays that remain all-long or all-double, the result is returned directly with ZVAL_LONG() or ZVAL_DOUBLE(), avoiding generic comparison dispatch and zval copy/deref overhead on the hot path.

An UPGRADING entry was added under Performance Improvements.

Benchmark

Local CLI build:

• Debug Build => no
• --disable-all --enable-cli
• opcache/JIT disabled
• separate baseline, long-only, and current CLI binaries
• n=100000
• each sample runs 700 min()+max() iterations
• 5 samples per case
• table reports median seconds

Case	origin/master	long-only	current long+double	Result vs master
packed long	0.612s	0.174s	0.171s	3.58x faster
sparse long	0.492s	0.163s	0.162s	3.04x faster
packed double	0.796s	0.747s	0.164s	4.86x faster
sparse double	0.757s	0.699s	0.158s	4.80x faster
mixed long, late fallback	0.573s	0.172s	0.168s	3.41x faster
mixed double, late fallback	0.781s	0.743s	0.165s	4.74x faster
double with late NaN	0.818s	0.743s	0.163s	5.01x faster

Fallback / non-numeric cases:

Case	origin/master	current long+double
first string, then longs	1.540s	1.430s
strings only	2.818s	2.901s

Across repeated samples, integer-only arrays stay roughly 3x faster and float-only arrays are roughly 4.8x-5x faster. Generic fallback cases stay within noise to small overhead.

Testing

• git diff --check
• git diff --cached --check
• TEST_PHP_EXECUTABLE=/Users/mehmetcan/work/php/php-src/sapi/cli/php ./sapi/cli/php -n run-tests.php -n -q ext/standard/tests/array/min_max_array_fast_path.phpt

Result:

• 1 test passed
• 0 failed
• 0 warned

[LamentXU123]

You may need to add an entry to the UPGRADING file, Performance Improvements section.
https://github.com/php/php-src/blob/master/UPGRADING#L382