From df9c1d840da66dea9b5aaf0a0ff3a61e82d4980b Mon Sep 17 00:00:00 2001
From: Jakob Nybo Nissen <jakobnybonissen@gmail.com>
Date: Thu, 6 Jun 2024 13:51:04 +0200
Subject: [PATCH] Make findall slightly faster

Take fast path not in every iteration, but just once, outside the loop.
---
 base/strings/search.jl | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/base/strings/search.jl b/base/strings/search.jl
index 2d697eb8c11585..94bb6ef8da797a 100644
--- a/base/strings/search.jl
+++ b/base/strings/search.jl
@@ -237,7 +237,14 @@ function findall(
     pred::Fix2{<:Union{typeof(isequal),typeof(==)},<:AbstractChar},
     s::Union{String, SubString{String}},
 )
-    collect(FwCharPosIter(s, pred.x))
+    iter = FwCharPosIter(s, pred.x)
+    return if is_standalone_byte(iter.last_char_byte)
+        findall(==(iter.last_char_byte), codeunits(s))
+    else
+        # It is slightly wasteful that every iteration will check is_standalone_byte
+        # again, but this should only be minor overhead in the non-fast path.
+        collect(iter)
+    end
 end
 
 """