[PATCH v12 14/31] string: Improve generic strrchr with memrchr and strlen

[Wilco Dijkstra]

Hi Adhemerval,

 STRRCHR (const char *s, int c)
 {
+  return __memrchr (s, c, strlen (s) + 1);
 }

LGTM

I did a quick check on AArch64 and the speedup vs the old generic version
on bench-strrchr is 9.9 times! It's ~15% slower overall than the assembler
strrchr.

While the benchmark is not perfect, it shows that if you have decent strlen
and memrchr then strlen+memchr gives a competitive strrchr.

Cheers,
Wilco