Benchmarks

#[builder] generates code that is easily optimizable by the compiler. This has been tested by the benchmarks below. The benchmarks compare regular positional function call syntax and builder syntax for functions annotated with #[builder].

In many cases rustc generates the same assembly code for the builder syntax as it would for a regular function call. Even when the generated assembly differs, the performance differences are negligible.

TIP

Don't take these microbenchmarks for granted. Do your own performance measurements in your application in real conditions. Feel free to open an issue if you find performance problems in bon.

Wallclock statistics

Benchmark	Description	Assembly output	Run time
`args_3`	3 args of primitive types	Equal	regular: `6.6536ns` builder: `6.6494ns`
`args_5`	5 args of primitive types	Equal	regular: `7.9592ns` builder: `7.9731ns`
`args_10`	10 args of primitive types	Ordering diff	regular: `18.082ns` builder: `18.217ns`
`args_10_structs`	10 args of primitive types and structs	Equal	regular: `9.2492ns` builder: `9.2325ns`
`args_10_alloc`	10 args of primitive and heap-allocated types	Instructions diff	regular: `86.090ns` builder: `86.790ns`
`args_20`	20 args of primitive types	Ordering diff	regular: `36.121ns` builder: `36.298ns`

High-precision statistics

Benchmark	Instructions count	L1 accesses	L2 accesses	RAM accesses
`args_3`	regular: `108` builder: `108`	regular: `138` builder: `138`	regular: `2` builder: `2`	regular: `4` builder: `4`
`args_5`	regular: `126` builder: `126`	regular: `161` builder: `161`	regular: `2` builder: `2`	regular: `10` builder: `10`
`args_10`	regular: `281` builder: `281`	regular: `381` builder: `380`	regular: `2` builder: `2`	regular: `19` builder: `20`
`args_10_structs`	regular: `75` builder: `75`	regular: `106` builder: `106`	regular: `4` builder: `4`	regular: `12` builder: `12`
`args_10_alloc`	regular: `2028` builder: `2027`	regular: `2824` builder: `2824`	regular: `3` builder: `2`	regular: `36` builder: `36`
`args_20`	regular: `556` builder: `556`	regular: `767` builder: `767`	regular: `4` builder: `4`	regular: `36` builder: `36`

Conditions

The code was compiled with opt-level = 3 and debug = 0.

Hardware

The benchmarks were run on a dedicated root server AX51-NVMe on Hetzner.

OS: Ubuntu 22.04.4 (Linux 5.15.0-76-generic)
CPU: AMD Ryzen 7 3700X 8-Core Processor (x86_64)
RAM: 62.8 GiB

References

The source code of the benchmarks is available here.

Benchmarks ​

Wallclock statistics ​

High-precision statistics ​

Conditions ​

Hardware ​