Remove extraneous branch from push #241
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@bors-servo r+ Thanks! |
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mbrubeck
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Release notes: * Improve performance of `push` (servo#241).
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bors-servo
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Version 1.5.1 Release notes: * Improve performance of `push` (#241).
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pushdoes two branches on the "smallness" of thesmallvec: one before the reserve check and one after. LLVM doesn't seem to optimize the second branch away for the (very common) non-growing case. In addition, in the growing branch we know the memory will be on the heap, so no need to branch here.On my machine, this improves
bench_pushfrom approx 300ns to 263ns (+/- 5 on both).