Re: [PATCH 2.4.31 7/9] gcc4: fix const function warnings

[Willy Tarreau <willy@w.ods.org>]

Hi Mikael,

Just out of curiosity, I understand why we can have a const on an inline
function to help the compiler optimize the code at compile time in cases
such as below :

> -static inline const unsigned char dehex(char c) {
> +static inline __attribute_const__ unsigned char dehex(char c) {
>  	if ((c>='0')&&(c<='9')) {
>  		return c-'0';
>  	}

But I don't see how it can be useful in asm code like below, since the
compiler cannot evaluate it at compile time :

> -static __inline__ __const__ __u32 ___arch__swab32(__u32 x)
> +static __inline__ __attribute_const__ __u32 ___arch__swab32(__u32 x)
>  {
>  #ifdef CONFIG_X86_BSWAP
>  	__asm__("bswap %0" : "=r" (x) : "0" (x));

Am I missing something, or could we simply remove the __const__ every
time the function only uses asm ?

Regards,
Willy