Slow type-checking

[ilya-klyuchnikov]

Elixir and Erlang/OTP versions

Erlang/OTP 28 [erts-16.3] [source] [64-bit] [smp:10:10] [ds:10:10:10] [async-threads:1] [jit] [dtrace]

Elixir 1.20.0-rc.2 (0df45fd) (compiled with Erlang/OTP 28)

Operating system

MacOS

Current behavior

defmodule DT do
    @abc [:a, :b]
    defguard g1(t) when tuple_size(t) == 7
    defguard g2(t, i) when elem(t, i) in @abc

    def main() do 
        foo({:a, :a, :a,
                {:a, :a, :a, {:c, :c, :c, :a, :a, :a, :c}, {:c, :c, :c, :c, :a, :a, :a}, :c, :c},
                {:a, :a, :a, {:c, :c, :c, :c, :a, :a, :a}, {:c, :c, :c, :a, :a, :a, :c}, :c, :c},
                :c, :c})
    end

    def foo(t) when g1(t) and g2(t, 0) and g2(t, 1) and g2(t, 2), do: {bar(elem(t, 3)), bar(elem(t, 4))}
    def foo(t) when g1(t) and g2(t, 1) and g2(t, 2) and g2(t, 3), do: {bar(elem(t, 4)), bar(elem(t, 5))}
    def foo(t) when g1(t) and g2(t, 2) and g2(t, 3) and g2(t, 4), do: {bar(elem(t, 5)), bar(elem(t, 6))}
    def foo(t) when g1(t) and g2(t, 3) and g2(t, 4) and g2(t, 5), do: {bar(elem(t, 6)), bar(elem(t, 0))}
    def foo(t) when g1(t) and g2(t, 4) and g2(t, 5) and g2(t, 6), do: {bar(elem(t, 0)), bar(elem(t, 1))}
    def foo(t) when g1(t) and g2(t, 5) and g2(t, 6) and g2(t, 0), do: {bar(elem(t, 1)), bar(elem(t, 2))}
    def foo(t) when g1(t) and g2(t, 6) and g2(t, 0) and g2(t, 1), do: {bar(elem(t, 2)), bar(elem(t, 3))}

    def bar(t) when g1(t) and g2(t, 0) and g2(t, 1) and g2(t, 2), do: {baz(elem(t, 3)), baz(elem(t, 4))}
    def bar(t) when g1(t) and g2(t, 1) and g2(t, 2) and g2(t, 3), do: {baz(elem(t, 4)), baz(elem(t, 5))}
    def bar(t) when g1(t) and g2(t, 2) and g2(t, 3) and g2(t, 4), do: {baz(elem(t, 5)), baz(elem(t, 6))}
    def bar(t) when g1(t) and g2(t, 3) and g2(t, 4) and g2(t, 5), do: {baz(elem(t, 6)), baz(elem(t, 0))}
    def bar(t) when g1(t) and g2(t, 4) and g2(t, 5) and g2(t, 6), do: {baz(elem(t, 0)), baz(elem(t, 1))}
    def bar(t) when g1(t) and g2(t, 5) and g2(t, 6) and g2(t, 0), do: {baz(elem(t, 1)), baz(elem(t, 2))}
    def bar(t) when g1(t) and g2(t, 6) and g2(t, 0) and g2(t, 1), do: {baz(elem(t, 2)), baz(elem(t, 3))}

    def baz(t) when g1(t) and elem(t, 0) in @abc and elem(t, 1) in @abc and elem(t, 2) in @abc, do: 0
    def baz(t) when g1(t) and elem(t, 1) in @abc and elem(t, 2) in @abc and elem(t, 3) in @abc, do: 1
    def baz(t) when g1(t) and elem(t, 2) in @abc and elem(t, 3) in @abc and elem(t, 4) in @abc, do: 2
    def baz(t) when g1(t) and elem(t, 3) in @abc and elem(t, 4) in @abc and elem(t, 5) in @abc, do: 3
    def baz(t) when g1(t) and elem(t, 4) in @abc and elem(t, 5) in @abc and elem(t, 6) in @abc, do: 4
    def baz(t) when g1(t) and elem(t, 5) in @abc and elem(t, 6) in @abc and elem(t, 0) in @abc, do: 5
    def baz(t) when g1(t) and elem(t, 6) in @abc and elem(t, 0) in @abc and elem(t, 1) in @abc, do: 6
end

compiling this single module takes more than 3min on my machine

Expected behavior

Compilation takes reasonable time (< 1sec)

[josevalim]

Thank you, I will take a look!