math/big: pool temporary variables to reduce allocations of Int.ModInverse by allocz · Pull Request #79708 · golang/go

allocz · 2026-05-27T23:32:58Z

Before the changes, Int.ModInverse was doing several allocations for
temporary variables, this PR added pooling for those, effectively
reducing the total amount of allocations as the benchmarks below show.

goos: linux
goarch: amd64
pkg: math/big
cpu: Intel(R) Core(TM) i5-1031`0U CPU @ 1.70GHz
│ /tmp/before │ /tmp/after │
│ sec/op │ sec/op vs base │
ModInverse-8 815.9n ± 7% 450.6n ± 6% -44.78% (p=0.000 n=10)

         │ /tmp/before  │              /tmp/after               │
         │     B/op     │     B/op      vs base                 │

ModInverse-8 1.055Ki ± 0% 0.000Ki ± 0% -100.00% (p=0.000 n=10)

         │ /tmp/before │             /tmp/after             │
         │  allocs/op  │ allocs/op  vs base                 │

ModInverse-8 11.00 ± 0% 0.00 ± 0% -100.00% (p=0.000 n=10)

As we can see, ModInverse is faster now.

This merge request Closes #79707

…tions

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gopherbot · 2026-05-27T23:51:47Z

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recycling

gopherbot · 2026-05-28T18:21:51Z

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math/big: Int.ModInverse: pool temporary allocations to reduce alloca…

c5ff0e5

…tions

math/big.Int.ModInverse: use defer to recycle pool pointers

ae66eba

hbrooks mentioned this pull request May 28, 2026

math/big: Int.ModInverse: pool temporary allocations to reduce allocations ellipsis-dev-test/go#2

Open

allocz changed the title ~~math/big: Int.ModInverse: pool temporary allocations to reduce allocations~~ math/big: pool temporary variables to reduce allocations of Int.ModInverse May 28, 2026

math/big: reduce indirection and document the purpose of the Int

a0031fa

recycling

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