This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/49367] New: missed optimization with __restrict field
- From: "jason at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 10 Jun 2011 17:21:09 +0000
- Subject: [Bug tree-optimization/49367] New: missed optimization with __restrict field
- Auto-submitted: auto-generated
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49367
Summary: missed optimization with __restrict field
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: trivial
Priority: P3
Component: tree-optimization
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: jason@gcc.gnu.org
GCC fails to optimize away the call to g() in this C testcase. It should
recognize that since we've established that a1 is different from a2, their
pointer fields must also be disjoint. This is necessary to be able to improve
optimization of C++ container classes, which currently have worse performance
than raw restricted pointers.
typedef struct A
{
int *__restrict p;
} A;
void g();
void f (A* a1, A* a2)
{
if (a1 == a2)
return;
*a1->p = 0;
*a2->p = 1;
if (*a1->p != 0)
g();
}
int main()
{
A a,b;
f (&a,&b);
}