issue-link js-issue-link" data-error-text="Failed to load title" data-id="632097716" data-permission-text="Title is private" data-url="https://github.com/JuliaLang/julia/issues/36169" data-hovercard-type="pull_request" data-hovercard-url="/JuliaLang/julia/pull/36169/hovercard" href="https://github.com/JuliaLang/julia/pull/36169">#36169. Rather than re-implementing the iteration analysis as done there, this uses the new stmtinfo infrastrcture to propagate all the analysis done during inference all the way to inlining. As a result, it applies not only to splats of singletons, but also to splats of any other short iterable that inference can analyze. E.g.: ``` f(x) = (x...,) @code_typed f(1=>2) @benchmark f(1=>2) ``` Before: ``` julia> @code_typed f(1=>2) CodeInfo( 1 ─ %1 = Core._apply_iterate(Base.iterate, Core.tuple, x)::Tuple{Int64,Int64} └── return %1 ) => Tuple{Int64,Int64} julia> @benchmark f(1=>2) BenchmarkTools.Trial: memory estimate: 96 bytes allocs estimate: 3 -------------- minimum time: 242.659 ns (0.00% GC) median time: 246.904 ns (0.00% GC) mean time: 255.390 ns (1.08% GC) maximum time: 4.415 μs (93.94% GC) -------------- samples: 10000 evals/sample: 405 ``` After: ``` julia> @code_typed f(1=>2) CodeInfo( 1 ─ %1 = Base.getfield(x, 1)::Int64 │ %2 = Base.getfield(x, 2)::Int64 │ %3 = Core.tuple(%1, %2)::Tuple{Int64,Int64} └── return %3 ) => Tuple{Int64,Int64} julia> @benchmark f(1=>2) BenchmarkTools.Trial: memory estimate: 0 bytes allocs estimate: 0 -------------- minimum time: 1.701 ns (0.00% GC) median time: 1.925 ns (0.00% GC) mean time: 1.904 ns (0.00% GC) maximum time: 6.941 ns (0.00% GC) -------------- samples: 10000 evals/sample: 1000 ``` I also implemented the TODO, I had left in #36169 to inline the iterate calls themselves, which gives another 3x improvement over the solution in that PR: ``` julia> @code_typed f(1) CodeInfo( 1 ─ %1 = Core.tuple(x)::Tuple{Int64} └── return %1 ) => Tuple{Int64} julia> @benchmark f(1) BenchmarkTools.Trial: memory estimate: 0 bytes allocs estimate: 0 -------------- minimum time: 1.696 ns (0.00% GC) median time: 1.699 ns (0.00% GC) mean time: 1.702 ns (0.00% GC) maximum time: 5.389 ns (0.00% GC) -------------- samples: 10000 evals/sample: 1000 ``` Fixes #36087 Fixes #29114

Commits

Commits on Jul 17, 2020

Propagate iteration info to optimizer