[FFmpeg-devel] [PATCH] define _DARWIN_C_SOURCE for MAP_ANON

[Reimar Döffinger]

On Wed, Jul 21, 2010 at 11:37:27AM -0700, Alexander Strange wrote:
> sys_icache_invalidate doesn't do anything on x86.
> x86 (at least Intel and AMD) don't even have an icache in the first
> place,

That's nonsense.

> so they don't need to be flushe and I don't think could test
> code to flush one.

They have some special hacks to ensure D and I-cache are coherent.
Actually they have some even worse hacks, truly horrible things
in order to make self-modifying code continue to work (like the
debugger-defeating stuff where one instruction write to the one
directly following it).
However I do not know for sure if there are any corner-cases
where flushing may still be necessary.