------- Comment #12 from rguenth at gcc dot gnu dot org 2007-07-07 17:04
-------
So the problem is that we detect
PHI node __i$D47460$SharedInfo_92 copy-of chain: __i$D47460$SharedInfo_92 ->
__i$D47460$SharedInfo_40 -> SR.1030_31 -> SR.1030_31 [COPY]
but later replace with __i$D47460$SharedInfo_40 instead of SR.1030_31.
So the problem seems to be we sort of have
struct Foo {
int x;
};
void use(int);
void foo(struct Foo *p, int q)
{
int a = p->x;
int b, c, d;
if (a)
c_1 = p->x;
else
{
c_3 = a;
}
# c_4 = PHI <c_1, c_3>
use (c);
}
where copyprop figures that c_1 and a are the same load and so does
figure that c_4 is a copy of a and c_1 and c_3. But there is no
code that figures the proper ssa_name loaded into as of a dominance
relationship. (Of course the above testcase doesn't fail... but you
get the idea what happens.)
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |dnovillo at gcc dot gnu dot
| |org
Target Milestone|4.3.0 |---
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32636
