because it's much slower on M1 https://github.com/ruby/erb/pull/29.
It'd be too complicated to switch the implementation based on known
optimized platforms / versions.
Besides, short strings are the most common usages of this method and
SIMD doesn't really help that case. All in all, I can't justify the
existence of this code.
https://github.com/ruby/erb/commit/30691c8995
(https://github.com/ruby/erb/pull/29)
Typically, strpbrk(3) is optimized pretty well with SIMD instructions.
Just using it makes this as fast as a SIMD-based implementation for the
no-escape case.
Not utilizing this for escaped cases because memory allocation would be
a more significant bottleneck for many strings anyway. Also, there'll be
some overhead in calling a C function (strpbrk) many times because we're
not using SIMD instructions directly. So using strpbrk all the time
might not necessarily be faster.
Takashi Kokubun