------- Comment #23 from rguenther at suse dot de 2010-09-15 13:56 -------
Subject: Re: [4.5/4.6 Regression] GCC 4.5.[01]
breaks our ffi on Linux64. ABI break?
On Wed, 15 Sep 2010, mh+gcc at glandium dot org wrote:
> ------- Comment #22 from mh+gcc at glandium dot org 2010-09-15 13:52 -------
> (In reply to comment #21)
> > For the original code? Then your reduced testcase is different from the
> > original problem.
>
> It doesn't work for the reduced testcase here, with gcc 4.5.1
It does fix the PTA problem (thus makes it work at -O1). Still
fails at -O2 for some reason (but can't reproduce that on
the tip of the branch, only with the 4.5.1 release). Alias-correct
testcase:
#include <stdint.h>
extern void abort (void);
char *s1 = "foo";
char *s2 = "bar";
char **ss1 = &s1;
typedef union jsval_layout
{
uint64_t asBits;
char **ptr;
} jsval_layout;
int main()
{
jsval_layout l, m;
l.ptr = ss1;
m.asBits = l.asBits;
char ** data = m.ptr;
*data = s2;
if (s1 != s2)
abort ();
return 0;
}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45623
