------- Comment #5 from rguenth at gcc dot gnu dot org 2006-08-08 09:09 -------
Confirmed. The problem is probably latent on mainline. check_header is being
miscompiled, -O -fno-loop-optimize2 -fno-loop-optimize -fno-branch-count-reg
is enough to trigger the bug (i.e. no loop bug).
extern void abort(void);
struct input_ty
{
unsigned char *buffer_position;
unsigned char *buffer_end;
};
int input_getc_complicated (struct input_ty *x) { return 0; }
int
check_header (struct input_ty *deeper)
{
unsigned len;
for (len = 0; len < 6; len++)
if (((deeper)->buffer_position < (deeper)->buffer_end
? *((deeper)->buffer_position)++
: input_getc_complicated((deeper))) < 0)
return 0;
return 1;
}
struct input_ty s;
unsigned char b[6];
int
main (void)
{
s.buffer_position = b;
s.buffer_end = b + sizeof b;
if (!check_header(&s))
return 1;
if (s.buffer_position != s.buffer_end)
abort();
return 0;
}
it looks like ifcvt messes up in pass 3 and puts the post-inc in the cond-exec
block.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Component|middle-end |rtl-optimization
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2006-08-08 09:09:48
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28636
