Compile the following with the C and C++ front-end and you will get different
assembly, the C front-
end does not do NVR at all while the C++ front-end will change the a decl to be
the return_decl before
so we the vectorizer cannot do the vectorization because it does not hanndle
RETURN_DECLs at all.
struct A
{
int x[4];
};
struct A foo()
{
struct A a;
for (int i=0; i<4; ++i)
a.x[i] = 0;
return a;
}
--
Summary: tree vectorizer does not understand RETURN_DECL
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: pinskia at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18546