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

[mehmetcansahin]

Summary

This specializes the array-form min() / max() path for arrays whose first value is IS_LONG.

The fast path compares IS_LONG values directly. If the array is empty or the first value is not IS_LONG, execution falls back to the existing zend_hash_minmax() path. If a non-IS_LONG value is encountered after a long prefix, comparison switches back to the existing php_data_compare() semantics for the rest of the scan.

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

Float fast paths were intentionally not added: local benchmarks showed no meaningful win, and adding extra type dispatch would increase complexity for little benefit.

Benchmark

Local CLI build:

• Debug Build => no
• --disable-all --enable-cli
• opcache/JIT disabled
• separate baseline and patched CLI binaries
• n=10000
• each case processes roughly 20M elements total
• 6 alternating baseline/current batches
• each batch reports median of 7 runs
• table shows the median across batches

Case	Baseline	Patched	Result
min() packed long desc	73.673 ms	25.309 ms	3.02x faster
max() packed long asc	73.826 ms	25.165 ms	2.94x faster
min() hash long	74.676 ms	25.659 ms	3.02x faster
min() mixed long-prefix	74.130 ms	24.826 ms	2.94x faster
min() mixed non-long first	74.254 ms	75.981 ms	+2.3% overhead
min() floats	108.886 ms	109.369 ms	+0.4% overhead
min() strings	470.430 ms	452.911 ms	within noise

Across the repeated batches, long-array and long-prefix mixed cases were roughly 3x faster. First-non-long, float, and string fallback cases stayed within noise to small overhead.

Testing

• ./sapi/cli/php run-tests.php -q ext/standard/tests/array/min_max_array_long_fast_path.phpt ext/standard/tests/array/min.phpt ext/standard/tests/array/max.phpt ext/standard/tests/array/min_basic.phpt ext/standard/tests/array/max_basic.phpt ext/standard/tests/array/min_basiclong_64bit.phpt ext/standard/tests/array/max_basiclong_64bit.phpt ext/standard/tests/array/min_int_float_optimisation.phpt ext/standard/tests/array/max_int_float_optimisation.phpt
• ./sapi/cli/php run-tests.php -q ext/standard/tests/array

Full array test result:

• 858 tests
• 846 passed
• 12 skipped
• 0 failed
• 0 warned

Differential behavior hash against baseline:

2d53aa26b0e8da297a97d311a9cb71c86f195b53b25295541ccc06f4996b9303