Re: [PATCH 7/8] i386: bitops: Kill needless usage of __asm__ __volatile__

From: Jeremy Fitzhardinge
Date: Mon Jul 23 2007 - 14:29:52 EST


Satyam Sharma wrote:
> The (3) as I had originally written / meant was that multiple
> instructions in a volatile asm would not get _individually_
> interspersed with the rest of the code i.e. be emitted out
> _consecutively_. I don't think we need any such guarantees for
> the non-atomic variants of those operations, so it's good to
> let the compiler have a free hand with what it wants to do,
> and optimize/combine multiple bitops as necessary / possible,
> which was the original intention.
>

No, a single asm statement is always emitted in one piece. Gcc doesn't
parse the string other than to do %-substitution to insert arguments, so
it has no way to meaningfully split it up.

J
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