add special case for findlast on tuples of length >= 32, fixes #45117 (…

…#45254)
JuliaLang · May 10, 2022 · c69a202 · c69a202
1 parent 0ba4e71
commit c69a202
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Showing 2 changed files with 14 additions and 1 deletion.
diff --git a/base/tuple.jl b/base/tuple.jl
@@ -419,10 +419,17 @@ function _findfirst_loop(f::Function, t)
 end
 findfirst(f::Function, t::Tuple) = length(t) < 32 ? _findfirst_rec(f, 1, t) : _findfirst_loop(f, t)
 
-function findlast(f::Function, x::Tuple)
+findlast(f::Function, t::Tuple) = length(t) < 32 ? _findlast_rec(f, t) : _findlast_loop(f, t)
+function _findlast_rec(f::Function, x::Tuple)
     r = findfirst(f, reverse(x))
     return isnothing(r) ? r : length(x) - r + 1
 end
+function _findlast_loop(f::Function, t)
+    for i in reverse(1:length(t))
+        f(t[i]) && return i
+    end
+    return nothing
+end
 
 ## filter ##
 

diff --git a/test/tuple.jl b/test/tuple.jl
@@ -600,6 +600,12 @@ end
     @test Base.return_types() do
         findlast(==(0), (1.0,2,3f0))
     end == Any[Nothing]
+
+    @testset "long tuples" begin
+        longtuple = ntuple(i -> i in (15,17) ? 1 : 0, 40)
+        @test findfirst(isequal(1), longtuple) == 15
+        @test findlast(isequal(1), longtuple) == 17
+    end
 end
 
 @testset "properties" begin