[tree-ssa] RFC: Never gimplify ASM_EXPRs

[Janis Johnson]

On Thu, Jun 05, 2003 at 06:23:07PM +0100, Andrew Haley wrote:
> Richard Henderson writes:
>  > On Thu, Jun 05, 2003 at 04:35:56PM +0100, Andrew Haley wrote:
>  > > Diego Novillo writes:
>  > >  > Is this an invalid use of __asm__ then?
>  > 
>  > I don't think so.
>  > 
>  > > I think so.  The asm is asking for a mem operand for something that it
>  > > never intends actually to access.
>  > 
>  > It DID access it.  With a prefetch instruction.
> 
> Not really; a prefetch instruction is more of a suggestion than an
> access, is it not?

Hardware that implements prefetch, rather than merely recognizing the
instructions, moves data into a cache line.  Data prefetch instructions
for several GCC targets are summarized in
http://gcc.gnu.org/projects/prefetch.html.

Janis