Re: tools/nolibc: fix missing strlen() definition and infinite loop with gcc-12
From: Alexey Dobriyan
Date: Sun Oct 09 2022 - 11:46:10 EST
Willy Tarreau wrote:
> +#if defined(__GNUC__) && (__GNUC__ >= 12)
> +__attribute__((optimize("no-tree-loop-distribute-patterns")))
> +#endif
> static __attribute__((unused))
> -size_t nolibc_strlen(const char *str
I'd suggest to use asm("") in the loop body. It worked in the past
to prevent folding division loop back into division instruction.
Or switch to
size_t f(const char *s)
{
const char *s0 = s;
while (*s++)
;
return s - s0 - 1;
}
which compiles to 1 branch, not 2.
But of course they could recognise this pattern too.