y: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: balrogg at gmail dot com
GCC build triplet: x86_64-linux-gnu
GCC host triplet: x86_64-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39373
the array element.
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Summary: asm with a "=X" output overwrites the output
Product: gcc
Version: 4.3.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu
--- Comment #1 from balrogg at gmail dot com 2009-03-05 02:55 ---
(In reply to comment #0)
> Similarly for "=X" but not "=m" or "=r".
Rather, similarly for "=g".
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39375
--- Comment #2 from balrogg at gmail dot com 2009-03-05 07:32 ---
Yes! I haven't executed it but correct assembly seems to be emitted for x86.
Marking INVALID.
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balrogg at gmail dot com changed:
What|Removed |
--- Comment #3 from balrogg at gmail dot com 2009-03-06 10:34 ---
(In reply to comment #2)
> You need to use a "memory" clobber instead. "=X" (params[1]) says to GCC
> that the asm operand 0 should be stored to params[1], which it does
> (it allocate
--- Comment #4 from balrogg at gmail dot com 2009-03-16 16:53 ---
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.
--- Comment #18 from balrogg at gmail dot com 2010-05-15 03:23 ---
(In reply to comment #11)
> An example program that shows 3 different methods. Only one works (see
> comment)
> .c = 3, //Will not work
> {.c = 3}, //works
> {.c= 2}, //Does not work
For sake o
