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[Bug c/39375] asm with a "=X" output overwrites the output
- From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 16 Mar 2009 17:02:27 -0000
- Subject: [Bug c/39375] asm with a "=X" output overwrites the output
- References: <bug-39375-17395@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #5 from pinskia at gcc dot gnu dot org 2009-03-16 17:02 -------
(In reply to comment #4)
> Reopening because
> int params; __asm__ ("xxx" : "=X" (params));
> and
> int params[1]; __asm__ ("xxx" : "=X" (params[0]));
> still produce different output in a way that is undocumented.
How so? "=X" (params[0]) says it can be in memory which means params is
addressable. This is documented as "=X" really means "=rfm" (plus extra
constraints which don't correspond to r, f, or m).
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39375