perf(allocator/vec2): resolve performance regression for extend by marking reserve as #[cold] and #[inline(never)]

[Dunqing]

I guess the performance regression reason is that the current implementation has more instructions than before. Here to use the lower of size_hint to reserve space, which is bloating the loop body. Also, the for loop is easier to optimize by the compiler. reserve inside extend is rarely taken, so mark it as #[cold] and #[inline(never)], which can reduce the instructions in while loop. We got a 3%-4% performance improvement in the minfier, but the transformer performance did not fully get back to before #10670.

Anyway, I think we can accept the less than 1% performance regression; this change can unblock us from pushing forward the Vec improvement; we will get it back in at the end of the stack! See #9856

[Dunqing]

• perf(allocator/vec2): align min amortized cap size with std #9857
• feat(allocator/vec2): align RawVec::reserve with standard library implementation #10701
• perf(allocator/vec2): replace self.reserve(1) calls with self.grow_one() for better efficiency #9856
• feat(allocator/vec2): add specialized grow_one method #9855
• perf(allocator/vec2): calling Bump::grow or Bump::shrink at the call site directly instead of calling realloc #10686
• perf(allocator/vec2): resolve performance regression for extend by marking reserve as #[cold] and #[inline(never)] #10675 👈 (View in Graphite)
• feat(allocator/vec2): introduce extend_desugared method as extend internal implementation #10670
• perf(transformer/refresh): use take/take_in instead of drain #10656
• perf(transformer): optimize inserting var/let statements #10654
• main

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #10675 will create unknown performance changes

_{Comparing 04-28-perf_allocator_vec2_resolve_performance_regression_for_extend (b4953b4) with main (6ce3bbb)}

Summary

🆕 36 new benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
🆕	codegen[checker.ts]	N/A	22.2 ms	N/A
🆕	codegen_sourcemap[checker.ts]	N/A	65.2 ms	N/A
🆕	formatter[antd.js]	N/A	715.8 ms	N/A
🆕	formatter[react.development.js]	N/A	8.1 ms	N/A
🆕	formatter[typescript.js]	N/A	1.1 s	N/A
🆕	isolated-declarations[vue-id.ts]	N/A	58.5 ms	N/A
🆕	lexer[RadixUIAdoptionSection.jsx]	N/A	21.5 µs	N/A
🆕	lexer[antd.js]	N/A	24.1 ms	N/A
🆕	lexer[cal.com.tsx]	N/A	5.8 ms	N/A
🆕	lexer[checker.ts]	N/A	14.4 ms	N/A
🆕	lexer[pdf.mjs]	N/A	3.9 ms	N/A
🆕	linter[RadixUIAdoptionSection.jsx]	N/A	2.7 ms	N/A
🆕	linter[cal.com.tsx]	N/A	1.2 s	N/A
🆕	linter[checker.ts]	N/A	3.1 s	N/A
🆕	mangler[antd.js]	N/A	16 ms	N/A
🆕	mangler[react.development.js]	N/A	294.5 µs	N/A
🆕	mangler[typescript.js]	N/A	39.6 ms	N/A
🆕	minifier[antd.js]	N/A	159.4 ms	N/A
🆕	minifier[react.development.js]	N/A	1.8 ms	N/A
🆕	minifier[typescript.js]	N/A	279.3 ms	N/A
...	...	...	...	...

ℹ️ Only the first 20 benchmarks are displayed. Go to the app to view all benchmarks.

[graphite-app]

Merge activity

• May 3, 9:02 AM EDT: Boshen added this pull request to the Graphite merge queue.
• May 3, 9:10 AM EDT: Merged by the Graphite merge queue.