perf(allocator): Allocator::alloc_concat_strs_array check for 0 length earlier

[overlookmotel]

Allocator::alloc_concat_strs_array bails out early if total_len is 0. Move this check from alloc_concat_strs_array_with_total_len_in into alloc_concat_strs_array itself. That function is inlined into callers so compiler can likely prove that total_len cannot be 0, and remove the check entirely when any of the strings passes in are static (e.g. allocator.alloc_concat_strs_array(["_", name]).

[overlookmotel]

• fix(allocator): move allocation tracking into Bump #21342
• refactor(allocator): route all Bump creation through Bump::new_impl function #21341
• fix(allocator): StringBuilder use Allocator::alloc_layout #21340
• perf(formatter): use Allocator::alloc_concat_strs_array instead of StringBuilder::from_strs_array_in #21339
• perf(allocator): StringBuilder::from_strs_array_in check for 0 length earlier #21338
• perf(allocator): Allocator::alloc_concat_strs_array check for 0 length earlier #21337 👈 (View in Graphite)
• fix(allocator): fix allocation counting in Allocator::alloc_concat_strs_array #21336
• perf(allocator): mark Allocator::alloc_layout as #[inline(always)] #21335
• main

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[codspeed-hq]

Merging this PR will not alter performance

✅ 48 untouched benchmarks
⏩ 3 skipped benchmarks¹

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_{Comparing om/04-12-perf_allocator_allocator_alloc_concat_strs_array_check_for_0_length_earlier (c2422bb) with main (6dd061c)²}

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (7a08a6f) during the generation of this report, so 6dd061c was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[Copilot]

Pull request overview

Moves the total_len == 0 early-return in Allocator::alloc_concat_strs_array so the check is visible to inlined callers, improving the compiler’s ability to constant-fold/eliminate the branch in common cases (e.g. concatenations with known non-empty static fragments).

Changes:

• Add if total_len == 0 { return "" } directly in alloc_concat_strs_array.
• Remove the redundant total_len == 0 check from the internal helper alloc_concat_strs_array_with_total_len_in.

[graphite-app]

Merge activity

• Apr 12, 3:02 PM UTC: overlookmotel added this pull request to the Graphite merge queue.
• Apr 12, 3:12 PM UTC: Merged by the Graphite merge queue.