Re: Definition of BUG on x86

[Ingo Molnar <mingo@elte.hu>]

* Petr Tesarik <ptesarik@suse.cz> wrote:

> So, the only method I could invent was using gas macros. It 
> works but is quite ugly, because it relies on the actual 
> assembler instruction which is generated by the compiler. Now, 
> AFAIK gcc has always translated "for(;;)" into a jump to self, 
> and that with any conceivable compiler options, but I don't 
> know anything about Intel cc.

> +static inline __noreturn void discarded_jmp(void)
> +{
> +	asm volatile(".macro jmp target\n"
> +		     "\t.purgem jmp\n"
> +		     ".endm\n");
> +	for (;;) ;
> +}

hm, that's very fragile.

Why not just:

 static inline __noreturn void x86_u2d(void)
 {
	asm volatile("u2d\n");
 }

If GCC emits a bogus warning about _that_, then it's a bug in 
the compiler that should be fixed.

	Ingo