------- Comment #29 from jakub at gcc dot gnu dot org 2007-12-11 11:13 -------
Actually, I was wrong, that insn 99 is inside of the if (__count == 1) { ...
return ...; }
So it is dbr that messes this up.
Simplified testcase (only for visual inspection of the generated code, someone
with access to pa could turn that into an executable testcase):
extern "C" void __assert (const char *, const char *, int);
template<typename S, typename T>
S foo1 (S s1, S s2, int i1, const int &i2, T t);
template<typename S, typename T>
S foo (S s1, S s2, int i1, const int &i2, T t)
{
if (i1 <= 0)
return s1;
if (i1 == 1)
{
while (s1 != s2 && !bool (t (*s1, i2)))
++s1;
return s1;
}
return foo1 (s1, s2, i1, i2, t);
}
template<typename T>
struct B
{
T *first;
T *last;
B (T *x, T *y) : first (x), last (y) { }
};
template<class T>
struct C
{
C () { }
typedef B<T> BT;
T *t;
BT *bt;
C (T *x, BT *y) : t (x), bt (y) { (t >= bt->first && t <= bt->last) ? (void)
0 : __assert ("f", "y", 203); }
C (const C &in) : t (in.t), bt (in.bt) { }
bool
operator!= (const C& in) const
{
(bt != __null && bt == in.bt) ? (void) 0 : __assert ("g", "y", 212);
(t >= bt->first && in.t >= bt->first) ? (void) 0 : __assert ("h", "y",
213);
return t != in.t;
}
C&
operator= (const C& in)
{
t = in.t;
bt = in.bt;
return *this;
}
};
template<class T>
struct D : public C<T>
{
typedef B<T> BT;
D (T *x, BT *y) : C<T> (x, y) { }
D (const D &in) : C<T> (in) { }
D () { this->t = __null; this->bt = __null; }
T&
operator* () const
{
(this->bt && this->t < this->bt->last) ? (void) 0 : __assert ("x", "y",
292);
return *(this->t);
}
D&
operator++ ()
{
(this->bt && this->t < this->bt->last) ? (void) 0 : __assert ("z", "y",
303);
this->t++;
return *this;
}
};
bool
pred (int i, int j)
{
return i == j;
}
int
main ()
{
int a[2] = { 0, 0 };
D<int>::BT ct (&a[0], &a[1]);
foo (D<int> (&a[0], &ct), D<int> (&a[1], &ct), 0, 1, pred);
return 0;
}
At -O2 this has:
comib,>= 0,%r24,L$0025
stw %r4,-72(%r30)
comib,= 1,%r24,L$0026
ldil LR'L$C0002,%r28
stw %r7,-52(%r30)
ldw 4(%r26),%r20
ldo -112(%r30),%r25
ldo -120(%r30),%r26
stw %r20,-116(%r30)
ldw 4(%r6),%r19
ldw 0(%r3),%r20
stw %r19,-108(%r30)
stw %r20,-120(%r30)
ldw 0(%r6),%r19
.CALL ARGW0=GR,ARGW1=GR,ARGW2=GR,ARGW3=GR
bl _Z4foo1I1DIiEPFbiiEET_S4_S4_iRKiT0_,%r2
stw %r19,-112(%r30)
where the undesirable ldil LR'L$C0002,%r28 is in the delay slot of the
conditional branch. %r28 should contain the original %r28 value passed to the
function.
--
jakub at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rsandifo at nildram dot co
| |dot uk
Component|rtl-optimization |tree-optimization
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32636
